Drug addiction is common disorder its tolerance is also a main difficulty including antibiotic and anti physcotic tolerance topic includes basics concepts related to tolerance and its mechanism
4. “Tolerance is actually requirement of high dose of
prescribed drug in order to produce a
therapeutic response or action after it is being used
repeatedly.”
Drug Tolerance
6. Tolerance developed when an organism or species is inherited to
show low response or less sensitive to a specific agent or drug.
Example:
Negros or black people are less sensitive to mydriatic drugs
Natural/ Innate Tolerance
7. Tolerance developed in a person with repeated and constant
dose of drug although the person was initially responsive to the
particular dose of drug.
Example: Development of tolerance with drugs
use for CNS depression
Acquired Tolerance
8. Tachyphylaxis
The spontaneous decline in drug action with repeated
administration of agonist or repeated application of drug on same
dose. Drug is administered continuously after short interval of time
and clinical effects diminish
Example
Acute tolerance of cocaine and alcohol develop as if we administer
same dose it will not provide similar effect with the dose as
previous so we have to increase the dose to get the effects.
9. The tolerance against a specific drug develops through constant
use of alternative drug with similar pharmacological action.
Cross Tolerance
Example Morphine× Barbiturates and Ethanol × Nicotine
10. Functional tolerance develop if reactivity of site of action or
receptor of drug reduces. During Functional tolerance number of
receptor requires for drug action reduces or drug efficiency to bind
the receptor reduces as a result receptor become less responsive to
the drugs.
Example
Functional tolerance or lorazepam and alcohol has been observe
after long term exposure to rats and Mice
Pharmacodynamic Tolerance
Functional Tolerance
11. Change in process that may lead to reduction of drug reaching to site
of action,via any of pharmacokinetic parameter changes (ADME
chnages) this may be develop by increasing drug 1st pass metabolism
by increasing liver enzyme or somehow by enzyme activators that
result in excessive 1st pass metabolism as a results drugs can’t
absorb or distribute towards their site of action.
Pharmacodynamic Tolerance
Dispositional tolerance
MetabolicTolerance
13. Types of Drug Dependence
Physical Dependence
Psychological Dependence
14. Physical Dependence
When a person stops using a drug, their body goes through
withdrawal.Withdrawal symptoms are the group of
physical and mental symptoms that can range from
mild (for e.g. if the drug is caffeine) to life threatening (such
as opioids including heroin and prescription pain relievers
or alcohol)
15. Physical Dependence types currently recognized and
their clinical features:
Morphine (Restlessness, rubbing the face and body, irritability, yawning,
salivation, apprehension, nausea, vomiting, abdominal cramps, tremors,
diarrhea and in later stages elevated blood pressure, raised blood sugar)
Tobacco (Physcomotor , sleep and ECG change)
Ethanol (Abstinence syndrome)
Barbiturate/sedative type (barbiturates, meprobamate)anxiety,
insomnia, anorexia, nausea , vomiting, muscle twitching , delirium and
convulsions.
17. Psychological Dependence/addiction
New Defination
Substance use disorder (SUD) is a complicated
psychological illness in which a person impulsively
consumes substances such as alcohol, tobacco, and
illegal drugs despite being aware of the harmful
consequences.
18. Substances are divided into seven categories
based on their behavioral and psychological
effects
Nicotine
Alcohol
Cannabis
Opioids
Stimulants
Hallucinogens