This document discusses adrenal receptor antagonists or adrenergic receptor blockers. It describes their classification based on receptor selectivity, including alpha and beta receptor subtypes. It covers topics like mechanisms of action, pharmacokinetics, effects, uses and adverse effects of various alpha and beta blocking drugs. Key drugs discussed include prazosin, doxazosin, propranolol, metoprolol, atenolol and others. It provides a detailed overview of these important cardiovascular drug classes.
These are the drugs which antagonize the receptor action of adrenaline and related drugs.
These drugs act by blocking a and/or ß-adrenergic receptors.
α-blockers
PRAZOSIN is a competitive antagonist effective in the management of hypertension. Similar drugs with longer half-lives (e.g. doxazosin, terazosin).
β-blockers
Heart - Decrease heart rate, force of contraction and cardiac output.
Blood Pressure - Decrease in blood pressure (blockage).
Respiratory System – bronchoconstriction.
Eye – Beta-blocking agents reduce intraocular pressure, especially in glaucoma. The mechanism usually reported is decreased aqueous humor production.
Metabolic - Increase LDL and decrease HDL.
Uterus - Relaxation of uterus.
Local anaesthetic - Propranolol has some local anaesthetic action
These are the drugs which antagonize the receptor action of adrenaline and related drugs.
These drugs act by blocking a and/or ß-adrenergic receptors.
α-blockers
PRAZOSIN is a competitive antagonist effective in the management of hypertension. Similar drugs with longer half-lives (e.g. doxazosin, terazosin).
β-blockers
Heart - Decrease heart rate, force of contraction and cardiac output.
Blood Pressure - Decrease in blood pressure (blockage).
Respiratory System – bronchoconstriction.
Eye – Beta-blocking agents reduce intraocular pressure, especially in glaucoma. The mechanism usually reported is decreased aqueous humor production.
Metabolic - Increase LDL and decrease HDL.
Uterus - Relaxation of uterus.
Local anaesthetic - Propranolol has some local anaesthetic action
Dr. Jibachha Sah,M.V.Sc( Veterinary pharmacology, TU,Nepal),posted lecturer notes on AUTONOMIC AND SYSTEMIC PHARMACOLOGY for B.V.Sc & A.H. 6 th semester veterinary students of College of veterinary science,Nepal Polytechnique Institute, Bharatpur, Bhojard, Chitwan, Nepal.I hope this lecture notes may be beneficial for other Nepalese veterinary students. Please send your comment and suggestion .Email:jibachhashah@gmail.com,moble,00977-9845024121
Dr. Jibachha Sah,M.V.Sc( Veterinary pharmacology, TU,Nepal),posted lecturer notes on AUTONOMIC AND SYSTEMIC PHARMACOLOGY for B.V.Sc & A.H. 6 th semester veterinary students of College of veterinary science,Nepal Polytechnique Institute, Bharatpur, Bhojard, Chitwan, Nepal.I hope this lecture notes may be beneficial for other Nepalese veterinary students. Please send your comment and suggestion .Email:jibachhashah@gmail.com,moble,00977-9845024121
This presentation was delivered over two days to second year pharmacy students enrolled in a course in pharmacology & toxicology. This lecture is designed to accompany Goodman & Gilman's (12e) chapter 11.
About pharmacological classification of sympathetic nervus system both sympathomimetics and sympatholytics drug and all about his pharmacokinetics and pharmacodynamics action on body
Advances in current medication and new therapeutic approaches in epilepsySelf-employed researcher
Epilepsy is one of the most complicated neurological disorders associated with a brain disorder in which, after an initial
physiological insult, the networks of neurons regroup and communicate abnormally that can be defined as the neuronal hyper -
synchronizayion. The affected part of brain defines the patient’s abnormality behavior. Unlike the younger patients, who can
become seizure free after the age of 16-18, older patients are hardly able to overcome the seizures, especially once the type of
seizure developed to generalize tonic-clonic phase. Globally, epilepsy is considered as a disease which is originated from the
disorder of electrical function of the brain and estimated to effect approximately 50 million people worldwide.
Pharmacoresistance, drug interactions, drug tolerability, and various adverse effects are among the common problems
associated with the treatments of epilepsy with antiepileptic drugs (AEDs). Although, approximately 70% of the patient's
exhibit seizures that can be controlled with most AEDs, the remaining 30% of the patients fail to respond to treatment with
AEDs. Thus, looking for alternatives such as traditional treatment methods like utilizing medicinal plants, ketogenic diet, and
the Atkins diet as well as self-physical therapy like relaxation and yoga, are all positive options that can be considered as
a replacement and supportive therapy methods for the medications which are used in seizure control of epilepsy. Medicinal
plants are more commonly used by folk for making infusions administered as herbal teas for the pain relief and maintaining
good health. Investigating the active components of a plant extract, isolating and identifying their structure and
pharmacological effects, and finally utilizing them as a new agent from nature with fewer side effects and high economic value
is a widely interesting topic in the field of ethnopharmacology. In addition to AEDs, which are currently used, the suggested
alternative therapies are also able minimize the seizures of epilepsy but the surgical intervention still remains as the last option
in the treatment of epilepsy.
Phytochemical Profile and in vitro and in vivo Anticonvulsant and Antioxidant...Self-employed researcher
This study presents the phytochemical profile and in vitro and in
vivo anticonvulsant and antioxidant activities of Epilobium hirsutum, which
has been traditionally used in the treatment of epilepsy by local people of
Turkey. In vitro studies revealed that the extract contained a pronounced
amount of phenolics (206.3±0.9 mg Gallic acid Eq/g extract) and exhibited
significant levels of antioxidant (FRAP; 6226 µmol Fe2+/g extract, ORAC;
6593 µmol Trolox Eq/g extract, DPPH; IC50:33.8 ug/mL and metal chelation;
IC50:114 ug/mL) and anticonvulsant (AChE; IC50:71.2 ug/mL, BChE; IC50:92.5
ug/mL, GABA-T; IC50:94.7 ug/mL) activities. In vivo studies shown that the
the extract exhibited high anticonvulsant activities. In addition, the extracts
regulated the behavior, locomotion, and mental activities of the mice tested.
Biochemical evaluation of the brain tissue revealed that the extract inhibited
the production of MDA and stimulated the increase of antioxidant enzyme
levels, which suggest the possible antioxidative role of the extract that worked
as neuroprotective agents by scarfing the free radicals produced through PTZ
seizure inducer and attenuate convulsions. Moreover the extract regulated
serum biochemical parameters, total antioxidants, total oxidant, and ischemia modified albumin levels. Chromatographic studies were revealed that gallic
acid principally might be the major contributor of anticonvulsant and
antioxidant activities with the additive contributions of fatty acids and mineral
compounds. Findings obtained from this study partially justified the traditional
use of Epilobium hirsutum in the treatment of epilepsy and suggest potential
use of the extract as an industrial or pharmaceutical agent.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
5. General effects of α blockers
Blood vessels
• α1-blockade→reduces peripheral resistance
Fall in BP
Postural hypotension
• α2-blockade in brain ↑se vasomotor tone.
• Block pressor action of adrenaline, fall in BP due
toβ2.
action- “vasomotor reversal of Dale”
• Actions of selective α-agonists supressed.
6. Heart
• Reflex tachycardia due to:-
fall in mean arterial pressure
Blockade of presynaptic α2 receptors- ↑ NA release.
Nose: nasal stuffiness
Eye: miosis
GIT: intestinal motility ↑se
Kidney: Hypotension
↓se GFR
NA+ & H2O reabsorption
7. Urinary bladder
• α1A blockade- ↓se tone of smooth muscle in trigone,
sphincter & prostrate.
• Improved urine flow, used in BPH.
Reproductive system
• Contraction of vas deferens result in ejaculation
through α receptors.
• Blockade results in impotence.
8. Alpha-Blocking Drugs
A. Classification
–based on: selective affinity for alpha
receptors, reversibility
1. Irreversible, long-acting alpha
blockers
2. Reversible, short-acting alpha
blockers
3. a1-selective blockers
4. a2-selective blockers
9. Classification
1. Irreversible alpha blockers :
Phenoxybenzamine
–slightly a 1 -selective, long-acting
2. Reversible alpha blockers:
Phentolamine (nonselective), tolazoline
(slightly a 2 -selective)
3. a 1 blockers: Prazosin, Doxazosin,
Terazosin
4. a 2 blockers: Yohimbine
used primarily in researches
10. Pharmacokinetics
• All active orally as well as
parenterally
• Phenoxybenzamine: short t1/2 but long
duration-48 hr (covalent bond)
• Phentolamine, tolazoline: parenteral,
duration 20-40 min by parenteral
route
• Prazosin: oral, duration 8-10 hr
11. Irreversible non-selective α- blockers
Phenoxybenzamine
• Cyclizes spontaneously to highly reactive
ethyleniminium intermediate.
• Binds covalently to α-receptors- irreversible or non-
equilibrium competitive block.
• Blockade is slow onset & longer duration (3-4 days).
• Also inhibits reuptake of NE.
• Shifts blood from pulmonary to systemic circuit.
• Shift fluid from extravascular to vascular compartment-
relaxation of postcapillary vessels.
12. Reversible alpha blockers
Yohimbine
• Natural alkaloid from Pausinystalia yohimbe.
• No established clinical role.
Idazoxan
• Has membrane stabilizing action.
Ergot alkaloids
• Ergotamine & Dihydroergotamine
• Competitive α-receptor blockers.
• Principal use is migraine.
13.
14. Reversible, selective α1- blockers
Prazosin
• Highly selective α1-blocker , α1: α2 selectivity 1000:1
• Fall in BP with only mild tachycardia.
• Dilates arterioles more than veins
• Postural hypotension occurs as 1st dose effect,
minimized by starting with low doses at bed time.
• Also inhibits PDE- ↑se cAMP in smooth muscle.
PK
• Effective orally, BA- 60%.
• Highly bound to plasma proteins (α1 acid
glycoprotein).
15. • Metabolized in liver, 1o excreted in bile.
• t1/2 – 2-3hrs, effect lasts for 6-8hrs.
Uses
• Primarily as antihypertensive.
• LVF not controlled by diuretics & digitalis.
• Raynaud’s disease
• BPH
• Scorpion sting
16. PK
• Preferred ROA- i.v.
• Lipid soluble penetrates brain.
• Mainly excreted through urine in 24 hrs.
• Accumulates in adipose tissue on ch. Administration.
Dose
20-60 mg/d oral
1mg/kg/1hr slow i.v infusion.
Uses
Pheochromocytoma, occasionally 2oshock, PVD.
17. Reversible non-selective α-blockers
Tolazoline
• Block is modest & short lasting.
• Direct vasodilator & stimulates the heart.
• Also blocks 5-HT receptors, histamine like gastric
secretagouge & Ach like motor action on intestine.
SE
• N, V, cramps, diarrhoea, nervousness, chills
• Tachycardia, Exacerbation of MI, peptic ulcer.
Use
• PVD
• Pulmonary HT of newborn.
18. • Cause reflex tachycardia (due to decreased
MAP)
• Tachycardia may be exaggerated because a 2
receptors are also blocked.
• e.g. phenoxybenzamine, phentolamine,
tolazoline
Effects of Alpha Blockers
1. Nonselective alpha blockers (cont)
19. Clinical Uses
1. Nonselective alpha-blockers
Presurgery of pheochromocytoma: phenoxybenzamine
During surgery: phentolamine (sometimes)
Carcinoid tumor: phenoxybenzamine (5-HT blocking)
Mastocytosis: phenoxybenzamine (H1 antihistamine)
Accidental local infiltration of alpha agonist:
phentolamine
Overdose of sympathomimetics (amphetamine,
cocaine, phenylpropranolamine)
Raynaud’ s phenomenon, erectile dysfunction
(phentolamine)
20. 2. Selective a 1 blockers
• The same effects as nonselective alpha
blockers
• But cause much less tachycardia than
nonselective blocker
• e.g. Prazosin, Doxazosin, Terazosin
Effects of Alpha Blockers
21. Clinical Uses
2. Selective a 1 -blockers
Prazosin and others
Essential Hypertension
Urinary hesitancy
Prevention of urinary retention in
benign prostatic hyperplasia (BPH)
22. Terazosin &Doxazosin
• Long acting( t1/212 & 18hr) congener of prazosin.
• Used in HTN & BPH as single daily dose.
Tamsulosin & Silodosin
• Uroselective α1A blocker
• α1A –bladder base, prostrate. α1B- blood vessels.
• Don't cause significant changes in BP & HR.
• t1/2- 6-9hr, MR cap(0.2-0.4 mg) can be taken OD.
• Efficacious in Rx of BPH.
• SE: retrograde ejaculation, dizziness,, floppy iris syd.
• Silodosin weaker(4-8mg/d) but longer acting.
23. Phentolamine
• More potent α-blocker than tolazoline.
• Other actions are less marked.
• Duration of action is shorter (min).
• Equally blocks α1 & α2 receptors- NA release ↑sed.
Uses
• ∆sis & intraop.management of pheochromocytoma. 5mg
i.v- B.P falls by 25(D)or35(S)mmHg.
• HTN due to clonidine withdrawl, cheese reaction.
• Dermal necrosis due to extravasated i.v NA/DA. Given
S.C as local infiltration.
24. Bunazosin & Alfuzosin
• Orally effective α1 blockers similar to prazosin.
• Alfuzosin t1/2 4hrs (2.5mgTDS or 10mg SR OD).
• CI in hepatic impairment, metabolized in liver.
• Bunazosin slightly longer t1/2.
• Primarily used in BPH.
25. F Adverse effects of Alpha blockers
Orthostatic hypotension (venodilatation)
Reflex tachycardia (nonselective >
selective)
First dose hypotension (take before going
to bed)
Nausea/vomiting
Caution in patients with coronary artery
disease (CAD or CHD): angina
26. Side effects of α-blockers
• Palpitation
• Postural hypotension
• Nasal blockade
• Diarrhea
• Fluid retention
• Inhibition of ejaculation & impotence.
27. Receptor Type a1 a2
Selective Agonist Phenylephrine
Oxymetazoline
Clonidine
Clenbuterol
Selective Antagonist Doxazosin
Prazosin
Yohimbine
Idazoxan
Agonist Potency
Order
A=NA>>ISO A=NA>>ISO
Second Messengers
and Effectors
PLC activation via
Gp/q causes inc.
[Ca2+]i
dec. cAMP via Gi/o
causes dec. [Ca2+]i
Physiological Effect Smooth muscle
contraction
Inhibition of
transmitter release
Hypotension,
anaesthesia,
Vasoconstriction
28. Beta-Blocking Drugs
A. Classification and Mechanisms
All are competitive antagonists
Propranolol is prototype
Classification is based on
Beta subtypes selectivity
Partial agonist activity
Lipid solubility
Local anesthetic action
29. 3. Propranolol is contraindicated in
one of the following diseases:
a) Hypertension
b) Tachycardia
c) Hyperthyroidism
d) Angina pectoris
e) Bronchial asthma
30. 4. Propranolol produces its
antihypertensive action by:
a) Vasodilatation
b) Ganglionic blockade
c) Decreased cardiac output
d) A diuretic action
e) Blockade of 1 receptors
31. Classification and Mechanisms
1. Receptor selectivity
– b 1 -selective: metoprolol, atenolol
– b 2 -selective: butoxamine (research
only)
– Nonselective: propranolol
–Combined beta- and alpha-
blocking: labetalol
32. A. Classification and Mechanisms
Partial agonist activity
–Intrinsic sympathomimetic
activity, ISA
–eg, pindolol, acebutolol
–may be useful in patients
with asthma
33. Classification and Mechanisms
3. Local anesthetic activity
(membrane-stabilizing activity):
–disadvantage when used topically
in the eye
–timolol: no this activity
4. Lipid solubility
–responsible for CNS adverse
effects: propranolol
34. Pharmacokinetics of
Beta blockers
• For systemic effects, developed for
chronic oral use
• Esmolol: short-acting--only used
parenterally
• Nadolol: longest-acting
• Atenolol, acebutolol are less lipid-
soluble
35. Effects and Clinical Uses
• Predict from beta blockade
–decreased HR, force of contraction
–decreased A-V conduction
–slow firing rate of SA node
• Cardiovascular and ophthalmic
applications are extremly important
41. Receptor
Type
b1 b2 b3 b4
Selective
Agonist
Dobutamine
xamoterol
Salbutamol
salmeterol
BRL 37344 none
Selective
Antagonists
Atenolol
metoprolol
Butoxamine SR59230A Bupranolol
Agonist
Potency
Order
ISO>A=NA ISO>A>>NA ISO=NA>A
Second
Messengers
and Effectors
Inc cAMP via
Gs
Inc cAMP via
Gs
Inc cAMP via
Gs
Inc cAMP via
Gs
Physiological
Effect
Inc heart rate
and force
Vasodilatation
and broncho-
dilation
Lipolysis and
thermogenesis
Inc heart rate
and force