The nervous system is a highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes that impact the body, then works in tandem with the endocrine system to respond to such events.

1. Classification of Drugs
Acts on Nervous System
Mr. Abhay Rajpoot

2. Drugs acting on Nervous system
Drugs acting on Nervous system is classified into:
A.Drug acting on Autonomous Nervous system.
B.Drug acting on central and peripheral nervous
system.

3. Drug acting on Autonomous
Nervous system.
• It is classified into:
1.Cholinergic Drugs.
2.Anticholinergics drugs.
3.Drugs acting on autonomic Ganglia.
4.Adrenergic Drugs [sympathomimetics].
5.Adrenergic Receptor Antagonists/
Antiadrenergics.

4. Drug acting on central and
peripheral nervous system.
• It is classified into:
1)Skeletal muscle relaxants.
2)Local Anesthetics.
3)General Anesthetics.
4)Drug used in Pre-anaesthetic medication.
5)Sedatives & Hypnotics.
6)Anti-epileptic Drugs
7)Anti-parkinsonian Drugs.
8)Anti-psychotic Drugs.
9)Anti-anxiety Drugs.
10)Anti-depressants.
11)Anti-manic [mood stabilising ] Drugs.

5. contd
12) Psychotomimetic drugs [Hallucinogens].
13) Opioids.
14) CNS Stimulants.
15) Cerebroactive Drugs.

6. Drugs Acting on Autonomic
Nervous Systems.

7. Cholinergic Drugs
• It is classified into:
1] Directly Acting (Receptor Antagonists)
a) Choline esters
➢Acetylcholine.
➢Methacholine.
➢Carbachol.
➢Bethanechol.
b) Alkaloids
➢Arecholine.
➢Pilocarpine.
➢Muscarine.

8. contd
2] Indirectly Acting [Anticholinisterases /Cholinisterase
inhibitors]
It is classified into:
a) Reversible:
1] Carbamates.
Neostigmine.
Physostigmine.
Pyridostigmine.
Revastigmine.
Distigmine.
Galantamine.
Edrophonium.
Donepezil.
2] Acredine.
Tacrine.

9. contd
• B) Irreversible
1] Carbamates
o Carbaryl.
oPropoxur.
2]Organophosphates:
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Therapeutically used
Dyflos[DFP]
Echothiophate.
Insecticides.
Parathion.
Malathion.
Diazinon
Toxic Nerve Gases
Tabun.
Sarin.
Soman.

10. Anticholinergic Drugs
• It is classified into;
1. NaturalAlkaloids.
- Atropine. [Hyoscyamine]
- Hyoscine [Scopolamine]
2. Semi synthetic Derivatives.
- Homatropine.
- Atropine Methonitrate.
- Hyoscine butyl bromide.
- Ipratropium bromide.
- Tiotropium bromide.

11. contd
3. Synthetic Compounds.
a) Mydriatics
-
-
Cyclopentolate.
Tropicamide.
b) Antisecretary Antispasmodics.
❑ Tertiary Amines.
Dicyclomine.
Oxybutynin.
Flavoxate.
Pirenzepine.
Tolterodine.
•
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•
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• Telenzepine. [used as urinary bladder relaxants]
❑ Quaternary compounds.
•
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Propantheline.
Glycopyrolate.
Oxyphenonium.
Clidinium.
Isopropamide.
Pipenzolate methylbromide

12. contd
c) Antiparkinsonian
- Benzhexol [ Trihexiphenidyl]
- Biperiden.
- Benztropine.
- Procyclidine.
- Cycrimine.
- Ethopropazine.

13. Drugs acting on Autonomic Ganglia
• It is classified into :
1.Ganglionic stimulants.
2.Ganglion blocking agents.

14. Ganglionic stimulants.
• It is classified into;
a) Non selective/Muscarinic antagonists-
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-
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Acetylcholine.
Carbachol, Pilocarpine.
Anticholinesterases, MCN343-A.
b) Selective nicotinic antagonists-
I. Alkaloids
-
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Nicotine [low dose].
Lobeline.
II. Synthetic Compounds-
- Dimethyl phenyl piperazinium.
- Iodide [DMPP]
- Tetramethyl ammonium [TMA]

15. Ganglion blocking agents
a) Persistent depolarising blockers-
-
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Nicotine [high dose].
Anticholinesterases [high doses].
b) Competittive blockers.
1. Monosulfonium Compound – Trimethaphan.
2. Secondary teriary amines – Mecamylamine,
Pempidine.
3. Quaternary ammonium compounds-
pentolinium, Hexamethonium.

16. Adrenergic Drugs [Sympathomimetics]
• It is classified into :
1. Based on biochemicalbasis.
a). Catacholamines.
I. Natural : Adrenaline, Noradrenaline, Dopamine.
II.Synthetic: Isoprenaline, Dobutamine.
b) Non catacholamines- Ephedrine, Amphetamine,
Mephentermine, phenylephrine.

17. Based on Mechanism of action
a) Directly acting – Adrenaline, Noradrenaline,
Isoprenaline, phenylephrine, salbutamol,
Methoxamine, Xylometazoline.
b) Indirectly acting – Tyramine.
c) Acting by both Mechanisms - Ephedrine,
Amphetamine, Mephentermine.

18. 3. Based on spectrum activity
a) α antagonists [Alpha]
I. α 1 selective- phenylephrine.
II. α 2 selective – clonidine [catapres]
b) β antagonist [Beta]
I. Non selective – Isoprenaline
II. β1 selective Dobutamine.
III.β2 selective – Terbutaline, Salbutamol.
c)α antagonists & β antagonist -Adrenaline,
Noradrenaline.
d)Dopamine agonists- Dopamine [D1& D2]
Fenoldopam [D1]

19. 4. Clinical therapeutic classification
1) Pressor Agents: Dopamine, Noradrenaline, Methoxamine,
Mephentermine, phenylephrine, Ephedrine.
2) Cardiac stimulants: Adrenaline, Dobutamine, Isoprenaline.
3) CNS stimulants: Amphetamine, Dexamphetamine,
Methamphetamine.
4) Bronchodilators: Adrenaline, Isoprenalne, salbutamol
[Albuterol], salmetrol , formoterol, Fenoterol, Terbutaline,
orciprenaline, isoetherine
5) Nasal Decongestants: Naphazoline, Xylometazoline,
Oxymetazoline, phenylephrine, pseudoephedrine, Tuamino
heptane sulfate.
6) Uterine relaxants & Vasodilators: Ritodrine, Isoxsuprine,
salbutamol, terbutaline.
7) Anorectics [Appetite Supressants] : Fenfluramine,
Dexfenfluramine, Sibuteramine.

20. 5. Adrenergic Receptor Antagonists/
Antiadrenergics
1. α Adrenergic blocking agents.
a. Non equilibrium type – Phenoxybenzamine.
b. Equilibrium type – (Competitive)
I. Non selective-
2. Ergots alkaloids and derivatives-
Ergotamine.,Ergotoxine, Dihydroergotamine (DHE),
Dihydroergotoxine.
3. Imidazolines- Tolazoline, Phentolamine.
4. Others – Ketansarin, Chlorpromazine.
I. α1 selective- Prazocine, Doxazosin, Terazosin,
Tamsulosin.
II. α2 selective-Yohimbine.

21. 2. β Adrenergic blocking agents.
a) Non Selective.
I. Without intrinsic sympathomimetic activity –
Propranolol, Sotalol, Timolol.
II. With intrinsic sympathomimetic activity –
Pindolol.
a) Cardioselective (β1) – Atenolol, Acebutolol,
Metoprolol, Bisoprolol, Celiprolol, Esmolol,
Betaxolol, Nebivolol.
b) Selctive (β2) –
1. α&β Adrenergic blockers- Labetalol,
Carvedilol.

22. Drugs Acting on Central &
Peripheral Nervous Systems.

23. Skeletal muscle relaxants
1. Peripherally Acting muscle relaxants:
2. Centrally Acting muscle relaxants:

24. Peripherally Acting muscle relaxants
• Neuromuscular blocking agents:
1. Competitive antagonists (Non depolarizing
blockers)
➢Long acting – d-Tubocucurarine, Pancuronium,
Doxicurium, Pipecuronium.
➢Intermediate acting – Vecuronium, Atracurium,
Cisatracurium, Rocuronium, Rapacuronium.
➢Short acting – Mevacurium.
2. Depolarizing blockers – Succinylcholine (Sch),
Decamethonion (C-10).
• Agents acting directly on skeletal muscle –
Dantrolene, Quinine.

25. Centrally Acting muscle relaxants
a) Central α2 agonist – Tizanidine.
b) Mephenesin group – Mephenesin,
Carisoprodol, Methocarabamol,
Chlorozoxazone, Chloromezanone.
c) GABA derivatives: Baclofen.
d) Benzodiazepines: Diazepam and others.

26. Local Anesthetics
1. Injectable Anesthetics:
2. Surface Anesthetics:
3. Miscellaneous Agents with local action:

27. Injectable Anesthetics
1) Low potency, short duration: Procaine,
Choroprocaine.
2) Intermediate potency, & duration:
Lignocaine (Lidocaine), Prilocaine.
3) High potency, long duration: Tetracaine,
Bupivacaine, Ropivacaine, Dibucaine
(Cinchocaine).

28. Surface Anesthetics
a) Insoluble: Benzocaine, Oxethazaine,
Butylamino – benzoate (Butamben)
b) Soluble: Cocaine, Lignocaine, Tetracaine,
Binoxinate,
[ Eutectic mixture: Lignocaine (Lidocaine) +
Prilocaine. (Applicable on intact skin
directly)]

29. Miscellaneous Agents with local action
• Phenol.
• Chlorpromazine.
• Clove oil.

30. General Anesthetics
• Inhalational Anesthetics:
1.Gases: Nitrous oxide, cyclopropane (no longer
used),
2.Volatile liquids
a)Non halogenated – Ether.
b)Halogenated – Halothane, Sevoflurane,
Isoflurane, Enflurane, Desflurane, Ethyl
chloride, Chloroform (no longer used)
•

31. Intravenous non volatile anesthetics:
a) Inducing agents: (Short acting)- Thiopentone
sodium, Methohexitone sodium, Propofol,
etomidate.
b) Slow acting drugs:
i. Benzodiazepines – Diazepam, Lorazepam,
Midazolam.
ii. Steroids – Althesin, Pregendone
iii. Dissociative Anasthetic – Ketamin
(Phencyclidine derivatives)
iv. Opioid analgia – Fentanyl.

32. 1. Neurolept Analgesia:
(Fentanyl + short acting neuroleptic droperidol)
2. Neurolept Anesthesia:
65% N2O + 35% O2 Inhalation + Fentanyl +
Droperidol.

33. Drugs used in pre-anesthetic medication
1) Opioids: Morphine, Pethidine.
2) Sedative: Anxiolytic Drugs – Diazepam,
Lorazepam.
3) Neuroleptics: Haloperidol, Chlorpromazine,
Triflupromazine.
4) Anticholinergics: Atropine, Hyoscine.
5) H2 Blockers: Ranitidine, Famotidine.
6) Antiemetics: Metoclopramide, Domperidone,
Ondansetron.

34. Sedatives & Hypnotics
1. Barbiturates:
a) Ultra short acting: Thiopentone,
Methohexitone, Hexobarbitone.
b) Short acting: Secobabitone, Butobarbitone,
Pentobarbitone.
c) Long acting: Phenobarbitone,
Mephobarbitone.

35. 2. Benzodiazepines (BZD)
a)Hypnotics – Diazepam, Flurazepam, Nitrazepam,
Flunitrazepam, Temazepam, Triazolam, Midazolam.
b)Anti-anxiety drugs – Diazepam, Lorazepam,
Alprazolam, Chlordiazepoxide, Oxazepam.
c)Anticonvalscents – Diazepam, Clonazepam,
Clobazam.
3.Newer non BZD Hypnotics – Zalepion, Zopiclone,
Zopidem.
4.Miscellaneous – (no longer used) – chloral hydrate,
Meprobamate, Paraldehyde, Glutethimide.

36. Anti – Epileptic Drugs.
1) Barbiturates – Phenobarbitone.
2) Deoxybarbiturates – Primidone.
3) Hydantoin Derivatives – Phenytoin, Phosphenytoin, Ethotoin,
Methotoin.
4) Iminostilbene – Carbamazapine, Oxy carbamazepine.
5) Succinimide – Ethosuximide.
6) Aliphatic Carboxylic acid – Valporic acid (Sodium valproate).
7) Phenyltriazines – Lamotrigine.
8) Benzodiazepine – Anticonvalscent Drugs (not true
entiepileptics) Diazepam, Clonazepam, Clobazam.
9) Newer Drugs –
a) GABA transminase inhibitors – Vigabatrin.
b) GABA reuptake inhibitors – Tiagabine.
c) Others – Levetiracetam, Topiramate, Zonisamide.

37. Anti-parkinsonian Drugs.
1) Drugs enhancing dopaminergic activity
a) Precursors of Dopamine – Levodopa (L-
dopa)
b) Dopaminergic agonist – Bromocriptine,
Lisuride, Pergolide, Pirbedil, Ropinirole,
Apomorphine.
c) Drugs releasing dopamine (Dopamine
fascilitator) amantadine.
d) Drugs inhibiting dopamine metabolism.
•
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MAO – B inhibitor – Selegiline.
COMT inhibitor – Entacapone,

38. e) Peripheral decarboxylase inhibitors –
Carbidopa, Benserzide.
2) Drugs reducing cholinergic activity:
a)Central anti-cholinergics:
b)Anti-histaminics: Orphenadrine,
Promethazine.

39. Anti-psychotic Drugs
1) Phenothiazines:
a) Aliphatic side chain: Chlorpromazine,
Triflupromazine.
b) Piperidine side chain: Thioridazine,
Pericyazine.
c) Piperazine side chain: Trifluoperazine,
fluphenazine, prochlorperazine.
2) Butyrophenones: Haloperidol, Droperidol,
Penfluridol.
3) Thioxanthanes: Thithixane, flupenthixol,
Zuclopenthixol.

40. 4) Indolic Derivatives: Molindone, Oxypertin.
5) Substituted Benzamide: Sulpiride.
6)Other Heterocyclic:Pimozide, Loxapine,
Reserpine.
7)Atypical Neuroleptics: Clozapine,
Olanzapine, Quetiapine, Zotepine, Risperidone,
Amisulpride, Sertindole.

41. Anti-Anxiety Drugs
• Antianxiety Drugs: (Anxiolytics/Minor
tranquilizers)
1)Benzodiazepines – Diazepam, Oxazepam,
Lorazepam, Alprazolam,
Chordiazepoxide.
2)Non-Sedative Azapirones: Buspirone,
Ispapirone, Gepirone.
3)Sedative Antihistaminic: Hydroxizine.
4)ꞵ Blockers – Propanol.

42. Antidepressants
1)Reversible inhibitors of MAO – A (RIMAS) –
Moclobemide, Clorgyline.
2)Non – selective MAO inhibitors – Phenelzine,
Isocarboxazid.
3) Tri-cyclic Antidepressants (TCA’s)
a)Na+ 5-HT Reuptake inhibitors – imipramine,
Amitriptyline, Trimipramine, Clomipramine,
Lofepramine, Doxepin, Dothiepin.
b)Predominantly NA Reuptake inhibitors –
Desipramine, Amoxapine, Nortriptyline.

43. 4)Selective Nor adrenaline Reuptake inhibitors
(SSRI’s):
Fluoxetine, Fluvoxamine, Paroxetine, Sertraline,
Citalporam.
5) Atypical antidepressants (Novel compounds)
a)Selective noradrenaline Reuptake inhibitor
(SNRI) – Reboxetine.
b)Others – Trazodone, Nafazodone, Mianserin,
Mirtazapine, Venlapazine, Tianeptine,
Amineptine, Bupropion, Milancipram.

44. Anti-manic (Mood stabilizing Drugs)
1) Lithium.
2) Lithium Alternatives – Carbamazepine,
Sodium valproate, lamotrigine, Gabapentin,
Atypical antipsychotics like olanzapine,
others.

45. Psychotomimetics (Hallucinogens)
1) Cannabinoids – Tetrahydrocannabinol
(Cannabies indica derieved – Bhang, Charas,
Ganja)
2) Indole amines – Lysergic acid Dimethyl
amide, Psilocybin, Harmine, Bufotenin.
3) Phenyl amine – Mescaline, Di-methoxy
amphetamine.
4) Arylcyclohexyl amines – Phencyclidine.

46. Opioids
1) Natural Opium Alkaloids -
2) Semisynthetic opiates –
3) Synthetic opioids – Pethidine (Meperidine),
Methadone, Fentanyl, Tramadol,
Levorphanol, Dextropropoxyphene,
Ethoheptazine.

47. contd
• Based on mode of action on receptors, opioids
are classified as:
1)Pure Agonists – Morphine, Fentanyl.
2)Partial μ Agonists – Buprenorphine, Propiram.
3)Agonists – Antagonists
1.Used as Analgesic (k Acting ) – Pentazocine,
Nalbyphine, Butorphanol.
2.Not used as Analgesics – Nalorphine.
4) Pure competitive Antagonists – Naloxone,
Naltrexone, Nalmefene.

48. CNS Stimulants
1) Respiratory stimulants (Analeptics):
Doxapram, Prethcamide.
2) Convulsants: Picrotoxin, Pentylenetetrazol
(PTZ), Strycnine, Bicuculline.
3) Psycho-motor stimulants: Amphetamines,
Methylphenidate, Pemoline, Cocaine,
Caffeine.
4) Other drug causing reflex CNS
Stimulation: Lobeline, Nicotine, Veratrum,
Ammonia.

49. Cerebroactive Drugs (for Dementia, Alzheimer's disease)
1) Cognition Enhancer – Piracetam.
2) Cholinergic Activators – Tacrine,
Rivastigmine, Donepezil, Galantamine.
3) Metabolic Enhancers – Dihydroergotoxine
( Codergocrine), Nicergoline, Piribedil.
4) Vasoactive cerebral protector – Pyritinol
(Pyrithioxine) Ginkgo, Biloba.
5) Newer approaches for Alzheimer’s disease –
Antioxidants, Glutamate, antagonists,
Neurotropic factors, etc.

50. References
1. Govind S. Mittal, Pharmacology at a Glance – Classification of
Drugs and Drug of Choice, Paras medical publication books, 4th
Edition 2016, Pg no. 01 – 12
2. Dr. P.K. Panwar, Essentials of pharmacology for nurses, AITBS
pub. 2017, India, Pg no. 90 – 117.
3. Dr. Suresh k sharma, Textbook of pharmacology, pathology &
genetics for nurses, Jaypee pub. 2016 India Pg no 256 – 360.
4. Tara v. Shanbhag, Smita shenoy, Pharmacology preparation
manual for undergraduate, Elsevier pub. 2014. Pg no. 164 – 233.
5. Marilyn Herbert – Ashton, Nancy Clarkson, Pharmacology,
Jones & Barllet pub 2010 India, Pg no 101 – 180.
6. Govind s. mittal, Pharmacology at a glance, Paras medical book
pub. 2009 India 1 – 12.
7. Madhuri Inamdar, Pharmacology in nursing, Vora medical pub.
2006 India 1stedition, Pg no 120 – 152.

51. Thanks