Drugs Acting on Autonomic Nervous System (P. Chemistry

If you are a D.Pharm student looking for complete notes on drugs acting on the autonomic nervous system, you have landed on the right page. This master guide covers every drug in the Chapter 6 syllabus — from sympathomimetics to anticholinergics — with IUPAC names, mechanisms of action, uses, side effects, and brand names, exactly as required for your D.Pharm first year pharmaceutical chemistry examination.

This page is your complete index. Each section links to a detailed post covering that drug category in full. Bookmark this page and use it as your Chapter 6 revision hub.

What is the Autonomic Nervous System?

The autonomic nervous system (ANS) controls all the involuntary functions of the body — heart rate, blood pressure, digestion, breathing, sweating, and glandular secretions. Unlike voluntary muscles which we consciously control, the ANS works automatically, 24 hours a day, keeping the body in balance.

The ANS has two divisions that work in opposite directions:

Sympathetic nervous system activates the body during stress or danger — increases heart rate, raises blood pressure, dilates bronchi, and diverts blood to muscles. This is the “fight or flight” response triggered by norepinephrine and epinephrine.

Parasympathetic nervous system returns the body to rest after a stressor — slows the heart, stimulates digestion, constricts the pupils, and increases secretions. This is the “rest and digest” response controlled by acetylcholine.

Drugs acting on the ANS either mimic or block these two neurotransmitter systems. Understanding which receptor a drug targets tells you exactly what it will do in the body — and what side effects to expect.

Why This Chapter is Important for D.Pharm Exams

Chapter 6 is one of the highest-scoring chapters in D.Pharm first year pharmaceutical chemistry. Questions from this chapter appear every year in university examinations in multiple formats:

IUPAC names and chemical structures of starred compounds
Mechanism of action of individual drug classes
Differences between drug categories (e.g., direct vs indirect sympathomimetics)
Uses, side effects, and brand names
Short notes on specific drugs
Long answer questions on drug classes like beta blockers, anticholinergics

Every drug in this chapter follows the same pattern in exam questions — IUPAC name, chemical structure, classification, mechanism, uses, stability, formulations, and brand names. Our detailed posts cover all of these systematically.

Complete Drug List — Chapter 6 Syllabus

Sympathomimetic Agents (Adrenergic Agonists)

Direct Acting: Nor-epinephrine, Phenylephrine, Terbutaline, Naphazoline, Epinephrine, Dopamine, Salbutamol, Tetrahydrozoline

Indirect Acting: Hydroxyamphetamine, Pseudoephedrine

Mixed Acting: Ephedrine, Metaraminol

Adrenergic Antagonists (Sympatholytic Agents)

Alpha Adrenergic Blockers: Tolazoline, Phentolamine, Phenoxybenzamine, Prazosin

Beta Adrenergic Blockers: Propranolol, Atenolol, Carvedilol

Cholinergic Drugs (Parasympathomimetics)

Direct Acting: Acetylcholine, Carbachol, Pilocarpine

Cholinesterase Inhibitors (Indirect Acting): Neostigmine, Edrophonium chloride, Tacrine hydrochloride, Echothiophate iodide

Cholinergic Blocking Agents (Anticholinergics)

Natural: Atropine sulphate, Ipratropium bromide

Synthetic: Tropicamide, Cyclopentolate hydrochloride, Clidinium bromide, Dicyclomine hydrochloride

Quick Reference: All Chapter 6 Drugs at a Glance

Drug	Class	IUPAC Name	Key Use	Brand Name
Norepinephrine	Direct sympathomimetic (α1, α2, β1)	4-[(1R)-2-amino-1-hydroxyethyl]benzene-1,2-diol	Septic shock vasopressor	Levophed
Phenylephrine	Direct sympathomimetic (α1)	(R)-3-[-1-hydroxy-2-(methylamino)ethyl]phenol	Nasal decongestant	Nostril
Epinephrine	Direct sympathomimetic (all α and β)	4-[(1R)-1-hydroxy-2-(methylamino)ethyl]benzene-1,2-diol	Anaphylaxis	EpiPen
Dopamine	Direct sympathomimetic (D1, β1, α1)	4-(2-aminoethyl)benzene-1,2-diol	Shock, heart failure	Intropin
Salbutamol	Direct sympathomimetic (β2)	(RS)-4-[2-(tert-Butylamino)-1-hydroxyethyl]-2-(hydroxymethyl)phenol	Asthma	Ventolin
Terbutaline	Direct sympathomimetic (β2)	(RS)-5-[2-(tert-Butylamino)-1-hydroxyethyl]benzene-1,3-diol	Asthma, preterm labor	Brethine
Naphazoline	Direct sympathomimetic (α1, α2)	2-(naphthalen-1-ylmethyl)-4,5-dihydro-1H-imidazole	Eye redness, nasal congestion	Naphcon-A
Tetrahydrozoline	Direct sympathomimetic (α)	(RS)-2-(1,2,3,4-tetrahydronaphthalen-1-yl)-4,5-dihydro-1H-imidazole	Eye redness	Visine
Hydroxyamphetamine	Indirect sympathomimetic	Hydroxyamphetamine hydrobromide	Mydriasis (eye exam)	Paremyd
Pseudoephedrine	Indirect sympathomimetic	(S,S)-2-methylamino-1-phenylpropan-1-ol	Nasal decongestant	Sudafed
Ephedrine	Mixed sympathomimetic	benzenemethanol α-[1-(methylamino)ethyl]-sulfate	Anaesthesia hypotension	Akovaz
Metaraminol	Mixed sympathomimetic (α dominant)	(1R,2S)-3-[-2-amino-1-hydroxy-propyl]phenol	Anaesthesia hypotension	Aramine
Tolazoline	Alpha blocker (non-selective)	2-Benzyl-4,5-dihydro-1H-imidazole	Pulmonary hypertension	Priscoline
Phentolamine	Alpha blocker (non-selective)	3-[(4,5-Dihydro-1H-imidazol-2-ylmethyl)(4-methylphenyl)amino]phenol	Pheochromocytoma	Regitine
Phenoxybenzamine	Alpha blocker (irreversible)	N-(2-chloroethyl)-N-(1-methyl-2-phenoxyethyl)benzylamine	Pheochromocytoma preop	Dibenzyline
Prazosin	Alpha-1 blocker (selective)	4-(4-Amino-6,7-dimethoxy-2-quinazolinyl)-1-piperazinylmethanone	Hypertension, BPH	Minipress
Propranolol	Beta blocker (non-selective)	1-(1-isopropylamino)-3-(1-naphthoxy)-2-propanol	Hypertension, migraine, arrhythmia	Inderal
Atenolol	Beta blocker (β1 selective)	[4-[2-hydroxy-3-isopropyl-aminopropoxy]-phenyl-acetamide]	Hypertension, angina	Tenormin
Carvedilol	Beta + alpha-1 blocker	(2RS)-1-(9H-carbazol-4-yloxy)-3-[[2-(2-methoxyphenoxy)ethyl]amino]propan-2-ol	Heart failure, hypertension	Coreg
Acetylcholine	Direct cholinergic	2-Acetoxy-N,N,N-trimethylethanaminium	Ophthalmic miosis	Miochol-E
Carbachol	Direct cholinergic (resistant to AChE)	2-[(Aminocarbonyl)oxy]-N,N,N-trimethylethanaminium chloride	Glaucoma, ophthalmic miosis	Miostat
Pilocarpine	Direct cholinergic (muscarinic agonist)	(3S,4R)-3-Ethyl-4-((1-methyl-1H-imidazol-5-yl)methyl)dihydrofuran-2(3H)-one	Glaucoma, dry mouth	Salagen
Neostigmine	ChEI (reversible, no BBB)	3-{[(Dimethylamino)carbonyl]oxy}-N,N,N-trimethylbenzenaminium	Myasthenia gravis, NMB reversal	Prostigmin
Edrophonium	ChEI (ultra-short)	N-ethyl-3-hydroxy-N,N-dimethylbenzenaminium chloride	Diagnosis of myasthenia gravis	Tensilon
Tacrine	ChEI (central, crosses BBB)	1,2,3,4-Tetrahydroacridin-9-amine hydrochloride	Alzheimer’s disease	Cognex
Echothiophate	ChEI (irreversible, organophosphate)	2-(Diethoxyphosphorylsulfanyl)ethyl-N,N,N-trimethylazanium iodide	Glaucoma	Phospholine Iodide
Atropine sulphate	Anticholinergic (natural)	Hyoscyamine Sulfate	Bradycardia, organophosphate poisoning	Isopto Atropine
Ipratropium bromide	Anticholinergic (quaternary)	[8-methyl-8-(1-methylethyl)-8-azoniabicyclo[3.2.1]oct-3-yl] 3-hydroxy-2-phenylpropanoate	COPD bronchodilator	Atrovent
Tropicamide	Synthetic anticholinergic	Benzeneacetamide, N-ethyl-α-(hydroxymethyl)-N-(4-pyridinylmethyl)-	Mydriasis for eye exam	Mydriacyl
Cyclopentolate	Synthetic anticholinergic	(RS)-2-(dimethylamino)ethyl (1-hydroxycyclopentyl)(phenyl)acetate	Cycloplegic refraction	Cyclogyl
Clidinium bromide	Synthetic anticholinergic (GI)	3-[(2-hydroxy-2,2-diphenylacetyl)oxy]-1-methyl-1-azabicyclo[2.2.2]octan-1-ium bromide	IBS, peptic ulcer	Librax
Dicyclomine HCl	Synthetic anticholinergic + antispasmodic	2-(diethylamino)ethyl 1-cyclohexylcyclohexanecarboxylate	IBS antispasmodic	Bentyl

Detailed Posts — Chapter 6 Complete Series

Each post below covers one drug category in full detail with mechanisms, side effects, contraindications, drug interactions, clinical pearls, and FAQs. Click on each to study that section.