Summary General Pharmacology Notes for Quick Learning for Students and Professionals

General Pharmacology Notes for Quick Learning for Students and
Professionals

This compilation of pharmacology notes is designed as a rapid
reference and revision tool for pharmacy students, medical
students, and healthcare professionals. Covering all major drug
classes across body systems, these notes provide simplified yet
clinically relevant summaries of mechanisms of action, therapeutic
uses, adverse effects, contraindications, and key counseling points.

The format emphasizes high-yield, easy-to-retain information
suitable for academic study, exam preparation, and day-to-day
clinical application. From foundational pharmacokinetic principles to
system-based therapies and special topics such as toxicology,
herbal medicine, and pharmacovigilance, this guide offers a
comprehensive overview of general pharmacology in a practical,
accessible manner.

Whether you are revising for an exam or reinforcing core
pharmacological knowledge, this resource serves as an efficient and
structured companion for quick learning and confident application.



CHOLINERGIC AGONISTS (PARASYMPATHOMIMETICS)



1. Drug Class Name

Cholinergic Agonists
(Also called Parasympathomimetics)



2. Subclasses

A. Direct-acting Cholinergic Agonists

 Act directly on muscarinic and/or nicotinic receptors.

B. Indirect-acting Cholinergic Agonists (Anticholinesterases)

 Inhibit acetylcholinesterase → ↑ ACh levels at synapses.



3. Prototypes & Common Examples

,Subclass Drugs

Direct-acting Acetylcholine, Bethanechol, Carbachol, Pilocarpine, Methacholine

Indirect-acting Neostigmine, Physostigmine, Pyridostigmine, Edrophonium,
(Reversible) Donepezil, Rivastigmine

Indirect-acting
Organophosphates: Echothiophate, Malathion, Parathion
(Irreversible)



4. Mechanism of Action (MOA)

Type MOA

Mimic ACh by binding to muscarinic/nicotinic receptors and
Direct
activating them.

Indire Inhibit acetylcholinesterase → ↑ ACh at muscarinic and
ct nicotinic synapses.



5. Pharmacologic Effects

 Eye: Miosis, ↑ aqueous humor outflow (↓ IOP)

 Heart: ↓ HR, ↓ conduction velocity (via M2 receptors)

 Lungs: Bronchoconstriction, ↑ secretions

 GIT: ↑ motility, ↑ secretions

 Bladder: Detrusor contraction → urination

 Exocrine glands: ↑ salivation, lacrimation, sweating



6. Therapeutic Uses / Indications

Drug Use

Bethanechol Urinary retention, neurogenic bladder

Pilocarpine Glaucoma, xerostomia

Carbachol Glaucoma (miotic)

Methacholine Bronchial hyperreactivity test

, Myasthenia gravis, post-op ileus, urinary
Neostigmine
retention

Edrophonium Diagnosis of myasthenia gravis (Tensilon test)

Physostigmine Atropine poisoning

Donepezil,
Alzheimer's disease
Rivastigmine

Organophosphate No therapeutic use (toxic) – used as
s insecticides/nerve gas



7. Adverse Effects

Mnemonic: “DUMBBELSS”

 Diarrhea

 Urination

 Miosis

 Bradycardia

 Bronchoconstriction

 Emesis

 Lacrimation

 Salivation

 Sweating

Additional:

 Muscle cramps

 Hypotension

 Seizures (CNS penetration e.g., physostigmine)



8. Contraindications

 Asthma / COPD

 Bradycardia / Hypotension

,  Peptic ulcer

 Hyperthyroidism (risk of AFib)

 Urinary or intestinal obstruction



9. Drug Interactions

 Antagonism with anticholinergics (e.g., atropine)

 Synergistic bradycardia with beta-blockers

 Organophosphate toxicity potentiated by succinylcholine (depolarizing
NM blocker)



10. Pharmacokinetics

CNS
Drug Half-Life
Penetration

Physostigmine Crosses BBB ~15–40 min

Neostigmine No ~1–2 h

Edrophonium No ~5–10 min

Organophosph Yes (lipid Irreversible, long-
ates soluble) acting



11. Monitoring Parameters

 HR and BP

 Respiratory rate (esp. in MG or COPD)

 Muscle strength (in MG)

 Pupil size (for glaucoma)

 Salivation, bowel activity



12. Mnemonics

 DUMBBELSS = Cholinergic side effects