The document discusses adrenergic drugs, which act on the adrenergic nervous system to produce effects similar to the sympathetic nervous system. It defines adrenergic receptors and classifies adrenergic drugs according to their mode of action, receptor selectivity, and chemical nature. Key adrenergic drugs discussed include adrenaline, noradrenaline, clonidine, and their mechanisms of action, pharmacological effects, indications, and adverse effects.
This document discusses various factors that can modify drug action, including genetic and non-genetic factors. Body size, age, sex, species, race, and genetics can impact drug pharmacokinetics and dosing requirements. Route of administration, environmental factors, psychological states, concurrent diseases, and drug interactions can also influence drug effects both quantitatively and qualitatively. Tolerance can develop with repeated drug use due to changes in disposition or receptor sensitivity. These modifying factors are important to consider for safe and effective use of medications.
Drugs used in myasthenia gravis and galucomaAshviniGovande
This document provides information about myasthenia gravis (MG) and drugs used to treat it, as well as information about glaucoma and drugs used to treat glaucoma.
MG is an autoimmune disorder causing muscle weakness due to antibodies blocking acetylcholine receptors at the neuromuscular junction. Drugs used to treat MG include acetylcholinesterase inhibitors like pyridostigmine to increase acetylcholine levels, immunosuppressants to reduce antibody production, and thymectomy to remove the thymus gland source of antibodies.
Glaucoma involves increased fluid pressure in the eye damaging the optic nerve. The most common type is primary open-angle glaucoma. Drugs
NON STEROIDAL ANTI INFLAMMTORY DRUGS ( NSAID'S)Suvarta Maru
NSAIDs are a heterogeneous group of drugs that have analgesic, antipyretic, and anti-inflammatory properties. They work by inhibiting the enzyme cyclooxygenase (COX) and the synthesis of prostaglandins. NSAIDs can be classified as non-selective COX inhibitors, preferential COX-2 inhibitors, or selective COX-2 inhibitors. Common NSAIDs like aspirin, ibuprofen, and naproxen are available over the counter, while others require a prescription. Celecoxib is a selective COX-2 inhibitor used to treat pain and inflammation.
Pharmacodynamics is the study of how drugs act on the body and their mechanisms of action. It involves drug-receptor interactions and explains the relation between drug effects. Pharmacodynamics provides a basis for rational drug use and design. Drugs can act through stimulation, depression, irritation, replacement or cytotoxic effects on cells. Their main targets are receptors, ion channels, enzymes, and transporter proteins. Understanding drug-receptor interactions is important for explaining drug effects and determining their potency and efficacy. Drug interactions can enhance or reduce the effects of drugs and should be considered when administering multiple medications.
This document summarizes different types of adrenergic receptor antagonists or β-blockers. It describes:
1) Nonselective β-blockers that block both β1 and β2 receptors like propranolol, and cardioselective β1 blockers like metoprolol.
2) β-blockers with intrinsic sympathomimetic activity like pindolol that can minimize metabolic side effects.
3) Dual α and β-blockers like labetalol and carvedilol that are used to treat hypertension and heart failure.
This document discusses the autonomic nervous system and cholinergic transmission. It describes how drugs can have parasympathomimetic or parasympatholytic effects by stimulating or opposing muscarinic receptors. There are three main types of muscarinic receptors (M1, M2, M3) located throughout the body. Drugs that stimulate muscarinic receptors can be direct acting parasympathomimetics or indirect acting via inhibiting acetylcholinesterase. Common cholinergic drugs and their effects/indications are also outlined.
Nonsteroidal anti inflammatory drugs (NSAIDS)abdul waheed
NSAIDs work by inhibiting the cyclooxygenase (COX) enzymes, which prevents the formation of prostaglandins. Aspirin is a nonselective COX inhibitor that irreversibly acetylates both COX-1 and COX-2. It has analgesic, antipyretic and anti-inflammatory effects. Common adverse effects include gastrointestinal irritation and bleeding. Aspirin is metabolized to salicylic acid and excreted by the kidneys. It is used to treat fever, pain, and inflammatory conditions like rheumatoid arthritis, but carries risks in children and those with asthma or prior gastrointestinal issues.
The document discusses adrenergic drugs, which act on the adrenergic nervous system to produce effects similar to the sympathetic nervous system. It defines adrenergic receptors and classifies adrenergic drugs according to their mode of action, receptor selectivity, and chemical nature. Key adrenergic drugs discussed include adrenaline, noradrenaline, clonidine, and their mechanisms of action, pharmacological effects, indications, and adverse effects.
This document discusses various factors that can modify drug action, including genetic and non-genetic factors. Body size, age, sex, species, race, and genetics can impact drug pharmacokinetics and dosing requirements. Route of administration, environmental factors, psychological states, concurrent diseases, and drug interactions can also influence drug effects both quantitatively and qualitatively. Tolerance can develop with repeated drug use due to changes in disposition or receptor sensitivity. These modifying factors are important to consider for safe and effective use of medications.
Drugs used in myasthenia gravis and galucomaAshviniGovande
This document provides information about myasthenia gravis (MG) and drugs used to treat it, as well as information about glaucoma and drugs used to treat glaucoma.
MG is an autoimmune disorder causing muscle weakness due to antibodies blocking acetylcholine receptors at the neuromuscular junction. Drugs used to treat MG include acetylcholinesterase inhibitors like pyridostigmine to increase acetylcholine levels, immunosuppressants to reduce antibody production, and thymectomy to remove the thymus gland source of antibodies.
Glaucoma involves increased fluid pressure in the eye damaging the optic nerve. The most common type is primary open-angle glaucoma. Drugs
NON STEROIDAL ANTI INFLAMMTORY DRUGS ( NSAID'S)Suvarta Maru
NSAIDs are a heterogeneous group of drugs that have analgesic, antipyretic, and anti-inflammatory properties. They work by inhibiting the enzyme cyclooxygenase (COX) and the synthesis of prostaglandins. NSAIDs can be classified as non-selective COX inhibitors, preferential COX-2 inhibitors, or selective COX-2 inhibitors. Common NSAIDs like aspirin, ibuprofen, and naproxen are available over the counter, while others require a prescription. Celecoxib is a selective COX-2 inhibitor used to treat pain and inflammation.
Pharmacodynamics is the study of how drugs act on the body and their mechanisms of action. It involves drug-receptor interactions and explains the relation between drug effects. Pharmacodynamics provides a basis for rational drug use and design. Drugs can act through stimulation, depression, irritation, replacement or cytotoxic effects on cells. Their main targets are receptors, ion channels, enzymes, and transporter proteins. Understanding drug-receptor interactions is important for explaining drug effects and determining their potency and efficacy. Drug interactions can enhance or reduce the effects of drugs and should be considered when administering multiple medications.
This document summarizes different types of adrenergic receptor antagonists or β-blockers. It describes:
1) Nonselective β-blockers that block both β1 and β2 receptors like propranolol, and cardioselective β1 blockers like metoprolol.
2) β-blockers with intrinsic sympathomimetic activity like pindolol that can minimize metabolic side effects.
3) Dual α and β-blockers like labetalol and carvedilol that are used to treat hypertension and heart failure.
This document discusses the autonomic nervous system and cholinergic transmission. It describes how drugs can have parasympathomimetic or parasympatholytic effects by stimulating or opposing muscarinic receptors. There are three main types of muscarinic receptors (M1, M2, M3) located throughout the body. Drugs that stimulate muscarinic receptors can be direct acting parasympathomimetics or indirect acting via inhibiting acetylcholinesterase. Common cholinergic drugs and their effects/indications are also outlined.
Nonsteroidal anti inflammatory drugs (NSAIDS)abdul waheed
NSAIDs work by inhibiting the cyclooxygenase (COX) enzymes, which prevents the formation of prostaglandins. Aspirin is a nonselective COX inhibitor that irreversibly acetylates both COX-1 and COX-2. It has analgesic, antipyretic and anti-inflammatory effects. Common adverse effects include gastrointestinal irritation and bleeding. Aspirin is metabolized to salicylic acid and excreted by the kidneys. It is used to treat fever, pain, and inflammatory conditions like rheumatoid arthritis, but carries risks in children and those with asthma or prior gastrointestinal issues.
Drug Antagonism
The effect of one drug blocked (or inhibited) due to another drug is said to be antagonism. In other word, an interaction between two or more drugs that have opposite effects on the body. Drug antagonism may block or reduce effectiveness of one or more of the drugs.
e.g., atropine blocks the action of acetylcholine
Types of antagonism
1. Pharmacological antagonism: Competitive and Non-Competitive
2. Physiological antagonism
3. Chemical antagonism
Competitive Antagonism
If both the agonist and the antagonist compete for the same receptor in a reversible manner, they are said to be “competitive.” The antagonist drug interacts with the receptor and blocks it. Therefore it does not produce pharmacological action. The extent of antagonism depends on number of receptors occupied by the both drugs (agonist and antagonist), their affinity for receptors and their concentration. The increase in concentration of either one of these drugs can displace the other from receptor binding sites. Drugs interact with their receptors by weak bonds i.e. ionic bond or Hydrogen bond or Vander wal force. Hence duration of action of drug is short. Both agonist and antagonist have chemical resemblance (structural similarity).
First-pass metabolism refers to the process where a drug administered orally is absorbed through the gastrointestinal tract and transported to the liver via the portal vein, where it is metabolized before reaching systemic circulation. As a result, only a small proportion of the active drug reaches the intended target tissue. Notable drugs like morphine, propranolol, and lidocaine experience significant first-pass metabolism through the liver. Administering drugs via routes other than oral can bypass first-pass metabolism and increase bioavailability.
This document discusses adrenergic antagonists, which are drugs that block adrenergic receptors to inhibit the functions of epinephrine, norepinephrine, and dopamine. It classifies them as alpha or beta blockers and provides examples of each. Key drugs discussed include tolazoline, phentolamine, phenoxybenzamine, prazosin, dihydroergotamine, methysergide, propranolol, metoprolol, atenolol, betaxolol, esmolol, metaprolol, and carvedilol. Their structures, mechanisms of action, and clinical uses for conditions like hypertension and cardiac issues are summarized. The synthesis of tolazoline and
This document discusses sulfonamides, including their history, mechanisms of action, classifications, uses, and adverse effects. It specifically focuses on cotrimoxazole and sulfadoxine + pyrimethamine combinations. Cotrimoxazole is a fixed dose combination of sulfamethoxazole and trimethoprim that is bactericidal and has a wide spectrum of action. It is used for urinary tract, respiratory, and intestinal infections. Sulfadoxine + pyrimethamine is also a fixed dose combination that acts synergistically through sequential blockade of protozoal folic acid synthesis, making it effective against chloroquine resistant malaria and toxoplasmosis. Both combinations can cause hypersensitivity reactions and
Adrenergic blocking agents, also known as adrenergic antagonists, block alpha and/or beta receptor sites and have the opposite effect of adrenergic agents. They are classified based on the type of adrenergic receptor they block, including alpha1, alpha2, beta1, beta2, and beta3 receptors. Common uses include treatment of hypertension, heart failure, and benign prostatic hyperplasia. Side effects may include hypotension, tachycardia, and bronchospasm.
Centrally acting muscle relaxants work in the central nervous system to reduce muscle tone without affecting consciousness. They selectively depress polysynaptic reflexes in the spinal cord and brain that are involved in regulating muscle tone. They also depress pathways in the brainstem that maintain wakefulness, but to a lesser degree. Common classes of centrally acting muscle relaxants include mephenesin congeners, benzodiazepines, GABA mimetics, and central α2 agonists. Examples are carisoprodol, diazepam, baclofen, and tizanidine. These drugs are used to treat muscle spasms, spasticity, and pain conditions involving muscle spasms.
Anticholinergic drugs work by blocking the effects of the neurotransmitter acetylcholine at muscarinic receptors in the central and peripheral nervous systems. The main anticholinergic drugs discussed are atropine, glycopyrrolate, and scopolamine. Atropine is a naturally occurring tertiary amine that can cross the blood-brain barrier and exert central effects. Glycopyrrolate is a synthetic quaternary ammonium compound that does not cross the blood-brain barrier and lacks central effects. Scopolamine is similar to atropine but is more potent and lipid soluble, allowing it to more easily cross the blood-brain barrier and exert greater central antimuscarinic effects than atrop
Plasma half-life refers to the time it takes for a drug's concentration in the blood to reduce to half its original level. Steady state concentration occurs when the rate of drug administration equals the rate of elimination, which generally takes around five half-lives. Steady state is important when interpreting drug concentrations over time or assessing clinical response. Therapeutic drug monitoring measures drug levels and is useful when the relationship between concentration and response/toxicity is established and the therapeutic range is narrow.
Epilepsy is characterized by recurrent seizures and is treated using anticonvulsant drugs like phenytoin, carbamazepine, valproic acid, phenobarbital, and benzodiazepines. Phenytoin works by blocking sodium channels in neurons to inhibit neuronal firing and seizures. Carbamazepine has a similar mechanism of action and indication as phenytoin. Valproic acid enhances GABA levels to reduce seizures. Choice of anticonvulsant depends on seizure type, with carbamazepine, phenytoin, and valproic acid used for partial seizures and valproic acid and diazepam used for absence seizures.
This document discusses nonsteroidal anti-inflammatory drugs (NSAIDs), including their classification, mechanisms of action, examples of different drug classes, and pharmacological effects. It focuses on aspirin as the prototype NSAID, describing its absorption, metabolism, uses, adverse effects, and interactions. Selective COX-2 inhibitors like celecoxib and rofecoxib are also introduced as NSAIDs with reduced gastric irritation.
Cephalosporins are a group of antibiotics derived from the fungus Cephalosporium. The first cephalosporin was discovered in 1948. They have a bicyclic molecular structure containing a beta-lactam ring. Cephalosporins are classified into generations based on their spectrum of activity, with later generations having broader spectra. They work by inhibiting bacterial cell wall synthesis. Common indications include UTIs, respiratory infections, and surgical prophylaxis. Side effects include allergic reactions and nephrotoxicity. Resistance can develop through beta-lactamase production or alterations in penicillin-binding proteins. Cephalosporins are commonly used oral and parenteral antibiotics with broad spectrums
This document summarizes key information about aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs). It discusses aspirin's mechanism of action as an irreversible inhibitor of cyclooxygenase, leading to reduced prostaglandin production and its analgesic, antipyretic and anti-inflammatory effects. It also outlines aspirin's effects on platelets and potential interactions, as well as its therapeutic uses including cardiovascular applications. The document details aspirin's absorption, distribution, metabolism and excretion, along with its adverse effects and drug interactions.
Anticholinergic drugs work by blocking the actions of acetylcholine in the parasympathetic nervous system. They are competitive antagonists that bind to muscarinic receptors, reversibly blocking acetylcholine transmission. Atropine is a prototypical anticholinergic derived from deadly nightshade. It causes dilation of the pupils, increased heart rate, decreased secretions, and relaxed smooth muscles. Anticholinergics are used to treat Parkinson's disease, motion sickness, asthma, peptic ulcers, overactive bladder, and other conditions. Side effects include dry mouth, blurred vision, constipation, urinary retention, and excitement or delirium in overdose.
Barbiturates are CNS depressants that were historically used as sedatives and hypnotics. They are synthesized from urea and malonic acid. Barbiturates work by enhancing the effects of the neurotransmitter GABA, causing neuronal hyperpolarization. They can cause sedation, hypnosis, narcosis, general anesthesia, and even death depending on dosage. Barbiturates are classified based on their duration of action and chemical structure. While formerly widely used, barbiturates have been replaced by safer alternatives due to risks of overdose, tolerance, and drug interactions.
Individuals vary in their response to drugs due to several factors:
1. Body size influences drug concentration - larger individuals may require higher doses and smaller individuals like children require adjusted doses based on age and weight.
2. Age also impacts drug metabolism - children and elderly metabolize and excrete drugs differently than adults.
3. Other factors like sex, diet, alcohol use, genetics, disease states, and psychological factors can increase or decrease a drug's effects between patients. Doses often need adjusting based on these individual characteristics to achieve the desired therapeutic response without toxicity.
Levodopa is the immediate precursor to dopamine and can cross the blood-brain barrier to be converted into dopamine in the brain. It is used to treat Parkinson's disease by stimulating dopamine receptors, especially D2 receptors. When taken with a peripheral decarboxylase inhibitor like carbidopa, less levodopa is broken down peripherally, increasing the amount that reaches the brain. Common side effects include nausea, dyskinesias, psychiatric issues, and fluctuations in response. Long term use can lead to diminished effectiveness and problematic side effects.
This document provides an overview of opioids including their pharmacology, mechanisms of action, classifications, and clinical uses. It discusses how opioids bind to receptors in the central and peripheral nervous systems to produce analgesic and other effects. Opioids are classified based on their receptor activities and include pure agonists, partial agonists, mixed agonist-antagonists, and pure antagonists. The document reviews the central and peripheral effects of opioids as well as their indications, contraindications, and interactions. It also discusses opioid tolerance, dependence, overdose, and withdrawal.
This document discusses drug interactions, which occur when two drugs are administered together and one modifies the effects of the other. It describes several types of interactions, including drug-drug, drug-food, and drug-environment. Interactions can be quantitative, increasing or decreasing a drug's effects, or qualitative, producing abnormal or new responses. The mechanisms of interactions include pharmaceutical, pharmacokinetic, and pharmacodynamic effects. It is important for doctors to consider potential interactions when prescribing multiple medications to a patient.
Drug interactions occur when one drug alters the activity of another drug. There are several types of interactions including drug-drug, drug-food, and drug-laboratory tests. Interactions can be pharmacokinetic, affecting absorption, distribution, metabolism, or excretion of a drug. They can also be pharmacodynamic, altering a drug's effects. Factors like multiple medications, diseases, smoking, and food can influence interactions. It is important for healthcare providers to consider a patient's full drug history to avoid potential adverse reactions from interactions.
Drug Antagonism
The effect of one drug blocked (or inhibited) due to another drug is said to be antagonism. In other word, an interaction between two or more drugs that have opposite effects on the body. Drug antagonism may block or reduce effectiveness of one or more of the drugs.
e.g., atropine blocks the action of acetylcholine
Types of antagonism
1. Pharmacological antagonism: Competitive and Non-Competitive
2. Physiological antagonism
3. Chemical antagonism
Competitive Antagonism
If both the agonist and the antagonist compete for the same receptor in a reversible manner, they are said to be “competitive.” The antagonist drug interacts with the receptor and blocks it. Therefore it does not produce pharmacological action. The extent of antagonism depends on number of receptors occupied by the both drugs (agonist and antagonist), their affinity for receptors and their concentration. The increase in concentration of either one of these drugs can displace the other from receptor binding sites. Drugs interact with their receptors by weak bonds i.e. ionic bond or Hydrogen bond or Vander wal force. Hence duration of action of drug is short. Both agonist and antagonist have chemical resemblance (structural similarity).
First-pass metabolism refers to the process where a drug administered orally is absorbed through the gastrointestinal tract and transported to the liver via the portal vein, where it is metabolized before reaching systemic circulation. As a result, only a small proportion of the active drug reaches the intended target tissue. Notable drugs like morphine, propranolol, and lidocaine experience significant first-pass metabolism through the liver. Administering drugs via routes other than oral can bypass first-pass metabolism and increase bioavailability.
This document discusses adrenergic antagonists, which are drugs that block adrenergic receptors to inhibit the functions of epinephrine, norepinephrine, and dopamine. It classifies them as alpha or beta blockers and provides examples of each. Key drugs discussed include tolazoline, phentolamine, phenoxybenzamine, prazosin, dihydroergotamine, methysergide, propranolol, metoprolol, atenolol, betaxolol, esmolol, metaprolol, and carvedilol. Their structures, mechanisms of action, and clinical uses for conditions like hypertension and cardiac issues are summarized. The synthesis of tolazoline and
This document discusses sulfonamides, including their history, mechanisms of action, classifications, uses, and adverse effects. It specifically focuses on cotrimoxazole and sulfadoxine + pyrimethamine combinations. Cotrimoxazole is a fixed dose combination of sulfamethoxazole and trimethoprim that is bactericidal and has a wide spectrum of action. It is used for urinary tract, respiratory, and intestinal infections. Sulfadoxine + pyrimethamine is also a fixed dose combination that acts synergistically through sequential blockade of protozoal folic acid synthesis, making it effective against chloroquine resistant malaria and toxoplasmosis. Both combinations can cause hypersensitivity reactions and
Adrenergic blocking agents, also known as adrenergic antagonists, block alpha and/or beta receptor sites and have the opposite effect of adrenergic agents. They are classified based on the type of adrenergic receptor they block, including alpha1, alpha2, beta1, beta2, and beta3 receptors. Common uses include treatment of hypertension, heart failure, and benign prostatic hyperplasia. Side effects may include hypotension, tachycardia, and bronchospasm.
Centrally acting muscle relaxants work in the central nervous system to reduce muscle tone without affecting consciousness. They selectively depress polysynaptic reflexes in the spinal cord and brain that are involved in regulating muscle tone. They also depress pathways in the brainstem that maintain wakefulness, but to a lesser degree. Common classes of centrally acting muscle relaxants include mephenesin congeners, benzodiazepines, GABA mimetics, and central α2 agonists. Examples are carisoprodol, diazepam, baclofen, and tizanidine. These drugs are used to treat muscle spasms, spasticity, and pain conditions involving muscle spasms.
Anticholinergic drugs work by blocking the effects of the neurotransmitter acetylcholine at muscarinic receptors in the central and peripheral nervous systems. The main anticholinergic drugs discussed are atropine, glycopyrrolate, and scopolamine. Atropine is a naturally occurring tertiary amine that can cross the blood-brain barrier and exert central effects. Glycopyrrolate is a synthetic quaternary ammonium compound that does not cross the blood-brain barrier and lacks central effects. Scopolamine is similar to atropine but is more potent and lipid soluble, allowing it to more easily cross the blood-brain barrier and exert greater central antimuscarinic effects than atrop
Plasma half-life refers to the time it takes for a drug's concentration in the blood to reduce to half its original level. Steady state concentration occurs when the rate of drug administration equals the rate of elimination, which generally takes around five half-lives. Steady state is important when interpreting drug concentrations over time or assessing clinical response. Therapeutic drug monitoring measures drug levels and is useful when the relationship between concentration and response/toxicity is established and the therapeutic range is narrow.
Epilepsy is characterized by recurrent seizures and is treated using anticonvulsant drugs like phenytoin, carbamazepine, valproic acid, phenobarbital, and benzodiazepines. Phenytoin works by blocking sodium channels in neurons to inhibit neuronal firing and seizures. Carbamazepine has a similar mechanism of action and indication as phenytoin. Valproic acid enhances GABA levels to reduce seizures. Choice of anticonvulsant depends on seizure type, with carbamazepine, phenytoin, and valproic acid used for partial seizures and valproic acid and diazepam used for absence seizures.
This document discusses nonsteroidal anti-inflammatory drugs (NSAIDs), including their classification, mechanisms of action, examples of different drug classes, and pharmacological effects. It focuses on aspirin as the prototype NSAID, describing its absorption, metabolism, uses, adverse effects, and interactions. Selective COX-2 inhibitors like celecoxib and rofecoxib are also introduced as NSAIDs with reduced gastric irritation.
Cephalosporins are a group of antibiotics derived from the fungus Cephalosporium. The first cephalosporin was discovered in 1948. They have a bicyclic molecular structure containing a beta-lactam ring. Cephalosporins are classified into generations based on their spectrum of activity, with later generations having broader spectra. They work by inhibiting bacterial cell wall synthesis. Common indications include UTIs, respiratory infections, and surgical prophylaxis. Side effects include allergic reactions and nephrotoxicity. Resistance can develop through beta-lactamase production or alterations in penicillin-binding proteins. Cephalosporins are commonly used oral and parenteral antibiotics with broad spectrums
This document summarizes key information about aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs). It discusses aspirin's mechanism of action as an irreversible inhibitor of cyclooxygenase, leading to reduced prostaglandin production and its analgesic, antipyretic and anti-inflammatory effects. It also outlines aspirin's effects on platelets and potential interactions, as well as its therapeutic uses including cardiovascular applications. The document details aspirin's absorption, distribution, metabolism and excretion, along with its adverse effects and drug interactions.
Anticholinergic drugs work by blocking the actions of acetylcholine in the parasympathetic nervous system. They are competitive antagonists that bind to muscarinic receptors, reversibly blocking acetylcholine transmission. Atropine is a prototypical anticholinergic derived from deadly nightshade. It causes dilation of the pupils, increased heart rate, decreased secretions, and relaxed smooth muscles. Anticholinergics are used to treat Parkinson's disease, motion sickness, asthma, peptic ulcers, overactive bladder, and other conditions. Side effects include dry mouth, blurred vision, constipation, urinary retention, and excitement or delirium in overdose.
Barbiturates are CNS depressants that were historically used as sedatives and hypnotics. They are synthesized from urea and malonic acid. Barbiturates work by enhancing the effects of the neurotransmitter GABA, causing neuronal hyperpolarization. They can cause sedation, hypnosis, narcosis, general anesthesia, and even death depending on dosage. Barbiturates are classified based on their duration of action and chemical structure. While formerly widely used, barbiturates have been replaced by safer alternatives due to risks of overdose, tolerance, and drug interactions.
Individuals vary in their response to drugs due to several factors:
1. Body size influences drug concentration - larger individuals may require higher doses and smaller individuals like children require adjusted doses based on age and weight.
2. Age also impacts drug metabolism - children and elderly metabolize and excrete drugs differently than adults.
3. Other factors like sex, diet, alcohol use, genetics, disease states, and psychological factors can increase or decrease a drug's effects between patients. Doses often need adjusting based on these individual characteristics to achieve the desired therapeutic response without toxicity.
Levodopa is the immediate precursor to dopamine and can cross the blood-brain barrier to be converted into dopamine in the brain. It is used to treat Parkinson's disease by stimulating dopamine receptors, especially D2 receptors. When taken with a peripheral decarboxylase inhibitor like carbidopa, less levodopa is broken down peripherally, increasing the amount that reaches the brain. Common side effects include nausea, dyskinesias, psychiatric issues, and fluctuations in response. Long term use can lead to diminished effectiveness and problematic side effects.
This document provides an overview of opioids including their pharmacology, mechanisms of action, classifications, and clinical uses. It discusses how opioids bind to receptors in the central and peripheral nervous systems to produce analgesic and other effects. Opioids are classified based on their receptor activities and include pure agonists, partial agonists, mixed agonist-antagonists, and pure antagonists. The document reviews the central and peripheral effects of opioids as well as their indications, contraindications, and interactions. It also discusses opioid tolerance, dependence, overdose, and withdrawal.
This document discusses drug interactions, which occur when two drugs are administered together and one modifies the effects of the other. It describes several types of interactions, including drug-drug, drug-food, and drug-environment. Interactions can be quantitative, increasing or decreasing a drug's effects, or qualitative, producing abnormal or new responses. The mechanisms of interactions include pharmaceutical, pharmacokinetic, and pharmacodynamic effects. It is important for doctors to consider potential interactions when prescribing multiple medications to a patient.
Drug interactions occur when one drug alters the activity of another drug. There are several types of interactions including drug-drug, drug-food, and drug-laboratory tests. Interactions can be pharmacokinetic, affecting absorption, distribution, metabolism, or excretion of a drug. They can also be pharmacodynamic, altering a drug's effects. Factors like multiple medications, diseases, smoking, and food can influence interactions. It is important for healthcare providers to consider a patient's full drug history to avoid potential adverse reactions from interactions.
The document discusses factors that influence the dosage of drugs, noting that dosage cannot be fixed rigidly and must account for factors like age, health, weight, administration route, and drug interactions. It provides details on how factors like age, sex, weight, time of administration, disease states, and metabolic disturbances can impact a drug's effects and required dosage. The goal of considering these influencing factors is to determine the optimal dosage for each individual to achieve the desired therapeutic effects while avoiding toxicity.
The document discusses various concepts related to pharmacology including dose-response relationships, drug potency and efficacy, therapeutic index, and factors that can influence drug response. It describes the graded and quantal types of dose-response curves and defines potency as the amount of drug required to produce a desired response. Therapeutic index is defined as the ratio of lethal to effective doses. The document also discusses how drug responses can be increased or decreased through summation, synergism, potentiation, and antagonism. Multiple factors are described that can affect drug response including route of administration, presence of other drugs, accumulation, and patient-related factors.
This document discusses adverse drug reactions and drug interactions. It begins by defining adverse drug reactions as unwanted effects caused by normal drug doses. Reactions are classified as Type A, which are common and dose-related, or Type B, which are unpredictable and idiosyncratic. Drug interactions can occur through pharmaceutical, pharmacodynamic, or pharmacokinetic mechanisms. While some interactions are useful to increase effects or minimize side effects, others can be harmful and even severe, causing issues like hypertensive crisis or hemorrhage. Identifying the culprit drug can be difficult, requiring a careful history, provocation testing, or stopping all medications one by one. Caution is important as multiple drug use commonly occurs.
The document discusses drug interactions, which occur when two or more drugs react when administered together or in quick succession. There are three types of interactions: drug-drug, drug-food/beverage, and drug-condition. Drug-drug interactions can cause unexpected side effects or make activities like driving dangerous. Interactions are caused by changes to a drug's absorption, distribution, metabolism, or excretion in the body. They can also be due to drugs affecting each other at target sites. Many drug combinations are used deliberately in medicine to produce beneficial effects, but unintended interactions can sometimes lead to serious health issues.
Drug interactions can occur when two or more drugs are taken together and interact through various mechanisms. This can intensify or reduce a drug's effects, produce new reactions, or increase toxicity. Key interaction types include pharmacokinetic changes affecting absorption, distribution, metabolism or excretion of one or both drugs. Foods like grapefruit can also interact through similar mechanisms like inhibiting drug metabolism. Close monitoring is needed when multiple drugs or foods that may interact are used together.
Before prescribing any pharmaceutical medicine, the physician should consider certain factors that can modify the effect of the drug. The same dose of a drug can produce different degrees of response in different patients and even in the same patient under different situations. The Important factors modify the effect of a drug are subdivided into two groups: patient related factors and drug related factors.
• Patient related factors: age, gender, body weight, presence of food, drug allergy, genetic variation, environmental state, pathological state, psychological state, etc.
• Drug related factors: physical state of a drug, route of drug administration, time of drug administration, drug cumulation, drug combination, drug tolerance, drug dependence, etc.
This document defines drug interactions and describes the main types including drug-drug, drug-food, drug-disease, and drug-laboratory test interactions. It explains that interactions occur via changes to a drug's pharmacokinetics or pharmacodynamics. The major mechanisms of drug-drug interactions are pharmaceutical interactions when drugs are mixed, and pharmacokinetic interactions which influence absorption, distribution, metabolism, or excretion of a drug. Pharmacodynamic interactions can be direct, acting on the same site, or indirect through other body systems. Factors that increase risk of interactions and strategies to reduce interactions are also outlined.
Modern Pharmacognosy BIO DRUG AND BIO DRUG-FOOD INTERACTIONSssuser22bccd
This document discusses different types of drug interactions including pharmaceutical, pharmacokinetic, and pharmacodynamic interactions. Pharmacokinetic interactions can occur through various absorption, distribution, metabolism, and excretion mechanisms. Direct pharmacodynamic interactions can result in antagonism, addition/summation, or synergism/potentiation effects. Food and alcohol can also influence drug interactions by affecting absorption or metabolism. Reducing risk involves identifying risk factors, considering alternative therapies, and monitoring for interactions.
Modern Pharmacognocy bio drug drug and bio food interactionNaveenVenkatesan8
This document discusses different types of drug interactions including pharmaceutical, pharmacokinetic, and pharmacodynamic interactions. Pharmacokinetic interactions can occur through various absorption, distribution, metabolism, and excretion mechanisms. Direct pharmacodynamic interactions can result in antagonism, addition/summation, or synergism/potentiation effects. Food and alcohol can also influence drug interactions by affecting absorption or metabolism. Reducing risk requires identifying risk factors, considering alternative therapies, and monitoring for interactions.
Modern Pharmacognocy drug drug and drug food interactionNaveenVenkatesan8
This document discusses different types of drug interactions including pharmaceutical, pharmacokinetic, and pharmacodynamic interactions. Pharmacokinetic interactions can occur through various absorption, distribution, metabolism, and excretion mechanisms. Direct pharmacodynamic interactions can result in antagonism, addition/summation, or synergism/potentiation effects. Food and alcohol can also influence drug interactions by affecting absorption or metabolism. Reducing risk requires identifying risk factors, considering alternative therapies, and monitoring for interactions.
This document discusses drug interactions, which occur when the pharmacological activity of one drug is altered by another substance like another drug, food, or disease. It describes the main types of interactions as drug-drug, drug-food, drug-chemical, drug-test, and drug-disease. Interactions can be undesirable or beneficial. The three main mechanisms are pharmaceutical, pharmacokinetic, and pharmacodynamic. Pharmacokinetic interactions alter absorption, distribution, metabolism, or excretion of a drug. Pharmacodynamic interactions involve drugs with similar, opposing, additive, antagonistic, or synergistic effects. Managing interactions requires identifying risks, reviewing drug history, monitoring therapy, and educating patients.
Factors modifying drug action by SandipSandip Maity
This document discusses various factors that can modify drug action in the human body. It identifies physiological factors like age, sex, pregnancy and food; pathological factors like liver and kidney disease; genetic factors; and environmental factors like route of administration and disease conditions as influencing drug response. It also covers drug interactions, noting that some drug combinations can produce synergistic or additive effects while others result in antagonism where the drugs oppose each other's actions. Understanding these modifying factors is important for choosing the appropriate drug and dose for each individual patient.
This document discusses drug-drug interactions, including their definition, types, mechanisms, and consequences. It defines a drug-drug interaction as occurring when one drug affects the pharmacological activity of another drug taken at the same time. The main types of interactions are due to drugs interacting at the absorption, distribution, metabolism, and excretion levels. Mechanisms include pharmaceutical, pharmacokinetic, and pharmacodynamic effects. Consequences range from decreasing or increasing drug effects to serious adverse reactions like organ damage. Factors that increase interaction risk and ways to reduce risk are also outlined.
Posology is the science of determining safe and effective drug doses based on factors like age, sex, body weight, presence of disease, and route of administration. Key factors include age affecting drug metabolism and sensitivity in infants and elderly; sex impacting drug effects during menstruation, pregnancy, and lactation; and body weight influencing average dose calculations. Drug interactions via additive, synergistic, or antagonistic effects must also be considered when determining appropriate posology. Posology aims to establish dosing guidelines while accounting for individual patient variability.
Pharmacogenomics: A new age drug technologyMahek Sharan
the pharmacogenomics require the pharmacology and genomic together to improve the drug responses and the new age drug potential according to individual need
Factors that can modify a drug's effect include body size, age, sex, genetics, route of administration, environmental factors, psychological state, other diseases, other drugs taken simultaneously, drug accumulation over time, and the development of tolerance. These factors can change the amount of drug in the bloodstream and tissues (quantitative factors) or change the type of response produced (qualitative factors). Accounting for these modifying factors helps ensure patients receive appropriate and effective drug dosages.
This document discusses posology, which is the science of determining safe and effective drug doses. It explains that the dose is usually expressed as a range, with a minimum dose to produce the intended effect and a maximum tolerated dose. Many factors affect the appropriate dose for a given patient, including age, sex, pregnancy status, body weight, disease severity, route of administration, and genetic differences. Close monitoring of these factors is needed to determine a safe individualized dosage.
Drug interactions can occur when two or more drugs are taken together and one drug modifies the effects of another. The modification can be quantitative, changing the intensity of the effect, or qualitative, producing an abnormal or new type of response. Drug interactions are caused by pharmaceutical, pharmacokinetic, and pharmacodynamic mechanisms. Pharmacokinetic interactions involve effects on absorption, distribution, metabolism and excretion of the drugs. Pharmacodynamic interactions occur when drugs directly interact at receptor sites. While some interactions are deliberately employed for treatment, others can increase risks and require vigilance, especially in vulnerable populations taking multiple medications.
Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
How to Make a Field Mandatory in Odoo 17Celine George
In Odoo, making a field required can be done through both Python code and XML views. When you set the required attribute to True in Python code, it makes the field required across all views where it's used. Conversely, when you set the required attribute in XML views, it makes the field required only in the context of that particular view.
Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
"Learn about all the ways Walmart supports nonprofit organizations.
You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
The webinar may also give some examples on how nonprofits can best leverage Walmart Business+.
The event will cover the following::
Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
Temple of Asclepius in Thrace. Excavation resultsKrassimira Luka
The temple and the sanctuary around were dedicated to Asklepios Zmidrenus. This name has been known since 1875 when an inscription dedicated to him was discovered in Rome. The inscription is dated in 227 AD and was left by soldiers originating from the city of Philippopolis (modern Plovdiv).
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) CurriculumMJDuyan
(𝐓𝐋𝐄 𝟏𝟎𝟎) (𝐋𝐞𝐬𝐬𝐨𝐧 𝟏)-𝐏𝐫𝐞𝐥𝐢𝐦𝐬
𝐃𝐢𝐬𝐜𝐮𝐬𝐬 𝐭𝐡𝐞 𝐄𝐏𝐏 𝐂𝐮𝐫𝐫𝐢𝐜𝐮𝐥𝐮𝐦 𝐢𝐧 𝐭𝐡𝐞 𝐏𝐡𝐢𝐥𝐢𝐩𝐩𝐢𝐧𝐞𝐬:
- Understand the goals and objectives of the Edukasyong Pantahanan at Pangkabuhayan (EPP) curriculum, recognizing its importance in fostering practical life skills and values among students. Students will also be able to identify the key components and subjects covered, such as agriculture, home economics, industrial arts, and information and communication technology.
𝐄𝐱𝐩𝐥𝐚𝐢𝐧 𝐭𝐡𝐞 𝐍𝐚𝐭𝐮𝐫𝐞 𝐚𝐧𝐝 𝐒𝐜𝐨𝐩𝐞 𝐨𝐟 𝐚𝐧 𝐄𝐧𝐭𝐫𝐞𝐩𝐫𝐞𝐧𝐞𝐮𝐫:
-Define entrepreneurship, distinguishing it from general business activities by emphasizing its focus on innovation, risk-taking, and value creation. Students will describe the characteristics and traits of successful entrepreneurs, including their roles and responsibilities, and discuss the broader economic and social impacts of entrepreneurial activities on both local and global scales.
2. FACTORS MODIFYING DRUG
RESPONSE
• variations in response to same dose of a drug
between different patients
• in the same patient on different occasions
•The dose of drug is generally expressed in the range,
which gives therapeutic effect in majority of patients.
• The dose range is usually based on the average
requirements of an adult and is not strictly applicable
under all circumstances
3. • IMPORTANT FACTORS MODIFYING DRUG
ACTION ARE:
• • BODY WEIGHT
• • AGE
• • SEX
• • ROUTE OF DRUG ADMINISTRATION
• • TIME OF DRUG ADMINISTRATION
• • GENETIC FACTORS
• • METABOLIC DISTURBANCES
• • PATHOLOGICAL CONDITIONS
• • TOLERANCE
• • TACHYPHYLAXIS
• • CUMMULATION
• • DRUG INTERACTIONS
4. BODY WEIGHT :
• average dose of a drug is mentioned in terms of mg/Kg body
weight. However, the dose mentioned may not be applicable
to all cases.
• in cases of edema weight of patient increases due to the
accumulation of ECF
• in malnutrition metabolizing capacity of drug is reduced
• these factors should be kept in mind while calculating the
dose of drug.
5. AGE:
Pharmacokinetics of many drugs change with age.
- Newborn: liver and renal function less developed
– Elderly: hepatic and renal functions decline
– Glomerular filtration rate: low in infants
– Blood brain barrier: more permeable in infants & may cause
accumulation
6. SEX:
• Females: smaller body size, require doses that are on lower
side of the range.
• Consideration given to menstruation, pregnancy and
lactation.
• Drugs given during pregnancy may affect the fetus.
• Physiological changes during pregnancy alter drug
disposition.
• drugs like methyldopa and blockers interfere with sexual
function in males but not in females.
7. • Gynecomastia produced by drugs like Digitalis, Cimetidine,
and Metoclopramide occurs in males not in females
ROUTE OF DRUG ADMINISTRATION:
• governs the speed and intensity of drug response.
• In general, intravenous dose of drug is usually smaller than
oral, and time of onset of action is quick with intravenous
route.
• A drug may have entirely different uses through different
routes. For example Magnesium sulfate given orally
produce purgation, applied locally on inflamed area
decreases the swelling while intravenously it produces
CNS depression and hypotension.
8. GENETIC FACTORS:
• The dose of a drug to produce same effects may vary 4–6
folds among different individuals. This is mainly due to the
differing rates of drug metabolism as the amount of
microsomal enzymes is genetically controlled.
• There are some specific genetic defects that lead to variation
in drug response. Example;
• Hemolysis by Primaquine and Sulfonamides in persons with
G.6.P.D. deficiency.
• Slow metabolism of Isoniazid in slow acetylators.
9. • Example; • Hemolysis by Primaquine and
Sulfonamides in persons with G.6.P.D. deficiency.
• Slow metabolism of Isoniazid in slow acetylators.
10. TIME OF ADMINISTRATION:
There is delayed drug absorption when drug is given orally after meals,
which slows down the effects of drug. Under certain circumstances
drugs must be given before meals.
• To prevent mixing of drug with food Anthelminthics.
• To get immediate effect: Drugs used for prevention of motion sickness.
• To prevent formation of insoluble complexes: Tetracycline's.
• To prevent specific side effects, for example to prevent hypoglycemia
insulin and sulfonylureas are given before meals
11. METABOLIC DISTURBANCES:
Changes in water and electrolyte balance body temperature and
acid base balance may modify the effects of drug.
• For example aspirin reduces body temperature only in presence
of fever and have no effect on body temperature when it is
normal.
• Iron is well absorbed in states of iron deficiency.
12. PATHOLOGICAL CONDITIONS
several diseases influence drug disposition and action.
• Hepatic, renal and cardiovascular diseases have important
influence on drug clearance and drug actions.
• Drugs must be carefully used in presence of diseases of these
organs.
DRUG INTERACTIONS:
13. Drug interaction:
• Drugs may modify the response to each other by pharmacokinetic or
pharmacodynamics interaction between them.
• Drug interaction does not necessarily mean that their concurrent use
is contraindicated; many drugs can be used beneficially and some
with dose adjustment.
• Drug combinations can produce:
14. » Additive effect.
» Synergism.
» Potentiation.
» Antagonism.
ADDITIVE EFFECT OR SUMMATION
When total pharmacological effect produced by concomitant use of
two or more drugs is equal to the sum of their individual effects, it is
called “Additive effect.”
1 + 1 = 2.
Example: Combination of ephedrine and Theophylline in the
treatment of asthma. The individual side effects of an additive pair
may be different, and may not add up. The combination is better
tolerated than higher dose of one component.
15. SYNERGISM
• When total pharmacological effect produced by
concomitant use of two or more drugs is higher than the
sum of their individual effects, it is called “Synergism”.
• 1 + 1 = > 2.
• Example: • Codeine + Aspirin > Analgesia.
• Sulfonamide + Trimethoprim > Antibacterial effect.
16. POTENTIATION
• Enhancement of effect of one agent by another; so that the
combined effect is more than the sum of their individual effects is
called “Potentiation.”
• In case of potentiation one agent has no effect when given alone
but increases the effects of other co-administered drug.
• 0 + 1 = > 2.
• Example: • Levodopa + Carbidopa => Parkinsonism.
• Ampicillin + Clavulanic acid = > Antibacterial effect.
17. ANTAGONISM
• The phenomenon of opposing effects when two or more drugs are
given together is called “Antagonism.”
There are three types of antagonism
• Chemical antagonism.
• Physiological antagonism.
• Pharmacological antagonism.
CHEMICAL ANTAGONISM
• In this type of antagonism two or more drugs react chemically to form
inactive product, it occurs without involvement of drug receptors.
Examples: Acids react with Alkalis, Heparin and Protamine sulfate.
18. PHARMACOLOGICAL ANTAGONISM
• When two drugs produce opposite effects on same
physiological function by acting on same receptors it is called
“Pharmacological antagonism.” PHARMACOLOGICAL
ANTAGONISM
• Competitive antagonist
• Non competitive antagonism Equilibrium (reversible). Non
equilibrium (irreversible).
19. COMPETITIVE EQUILIBRIUM
ANTAGONISM
• agonist and antagonist compete for same receptor site. • Drug
receptor binding is weak & non-covalent.
• The extent to which the antagonist opposes the action of agonist is
dependent upon the number of receptors occupied by agonist and
antagonist.
• The antagonism is surmountable i.e. the antagonism can be reversed
by increasing the concentration of agonist at receptor site, for example
atropine and acetylcholine on muscarinic receptors.
• Maximal response of agonist is achieved by increasing the
concentration of agonist at receptor site.
20. COMPETITIVE NON-EQUILIBRIUM
ANTAGONISM
• agonist and antagonist compete with one another for
same receptor site.
• Antagonist binds with receptor by covalent bond.
• Example: Epinephrine and Phenoxybenzamine on
receptors.
21. NON COMPETITIVE ANTAGONISM
• Agonist and antagonist bind at different sites on the same
receptors.
• The antagonist inactivates the receptor so that effective
complex with agonist cannot be formed irrespective of the
concentration of agonist.
• Example: Acetylcholine and Decamethonium on nicotinic
receptors
22. TOLERANCE
• Reduction in the response due to continued use or repeated
administration of drug is called TOLERANCE
CROSS TOLERANCE: • It is the development of tolerance to
pharmacologically related drugs, e.g. alcoholic need relatively large
doses of barbiturates, as they are tolerant to this class of drugs.
• Closer the drugs are, more complete is the cross-tolerance between
them; e.g. there is partial tolerance between morphine and barbiturates
but complete cross tolerance between morphine and pethidine.
23. MECHANISM OF TOLERANCE:
• Reduction in response may be due to the changes in
absorption, distribution, metabolism and excretion leading to
the decreased effective concentration of drug at the site of
action, e.g. barbiturates on repeated administration enhance
their own metabolism due to enzyme induction, this is called
DISPOSITIONAL OR PHARMACOKINETIC
TOLERANCE.
• Reduction in response may be due to the reduced
responsiveness of target tissues due to down regulation of
receptors; this called FUNCTIONAL OR
PHARMACODYNAMIC TOLERANCE.
24. TACHYPHYLAXIS
• Rapid reduction in responsiveness due to repeated
administration of drug at frequent intervals is called
TACHYPHYLAXIS.
• It is also known as ACUTE TOLERANCE.
• This is usually seen with indirectly acting drugs, e.g.
ephedrine, tyramine, and amphetamine act by releasing
catecholamine in the body, synthesis of which does not match
release and stores deplete rapidly.
• Slow dissociation of drug from receptors is another
mechanism responsible for the development of Tachyphylaxis.