Anti-cholinergic Drugs Lecture Notes

Vocabulary terms and definitions covering the classification, mechanisms, symptoms, and clinical uses of anti-cholinergic drugs based on medical lecture notes.

Anticholinergic drugs

Drugs that block acetylcholine receptors, specifically muscarinic receptors (also known as antimuscarinic drugs).

Ganglionic blockers

Drugs that block $N_N$ receptors (Nicotinic neuronal) present on both sympathetic and parasympathetic ganglia.

Non-depolarising muscle relaxants

Drugs that block $N_M$ receptors (Nicotinic muscular) present on skeletal muscle; examples include Tubocurare, Atracurium, and Vecuronium.

Atropa belladonna

A plant from which the natural antimuscarinic drug Atropine is obtained, historically used by women to produce mydriasis (dilated pupils) and reduce sweating.

Hyoscine (scopolamine)

A natural antimuscarinic drug obtained from the Hyoscyamus niger plant that crosses the blood-brain barrier more effectively than atropine.

ATAQA

A mnemonic for other classes of drugs possessing anticholinergic effects: Antihistaminics, Tricyclic antidepressants (Imipramine), Antipsychotics (Chlorpromazine), Quinine, and Amantadine.

DUMBBELSS

A mnemonic for symptoms caused by Acetylcholine muscarinic receptor stimulation (increased body secretions): Diarrhea, Urination, Miosis, Bradycardia, Bronchoconstriction, Excitation, Lacrimation, Sweating, and Salivation.

Cycloplegia

Paralysis of the ciliary muscles of the eye, leading to a loss of accommodation and blurred vision for near objects.

Physostigmine

The antidote for atropine poisoning; it is a tertiary amine that crosses the blood-brain barrier to reverse CNS effects.

Narcoanalysis

An interrogation technique using Hyoscine, also known as 'truth serum,' to decrease memory or cognition and produce sedation.

Drug-induced parkinsonism

Condition caused by drugs blocking $D_2$ receptors in the basal ganglia; treated with anticholinergics like Benzhexol or Benztropine rather than Levodopa.

Motion sickness

Condition treated by blocking the vestibular nerve with antimuscarinic (Hyoscine) or first-generation antihistaminic (Diphenhydramine, Promethazine) drugs.

Glycopyrrolate

A quaternary amine antimuscarinic drug that does not cross the BBB; used during surgery to reduce bronchial secretions and risk of aspiration.

Tropicamide

The shortest-acting cycloplegic mydriatic ($3-6$ hours), used specifically for refractive error testing and fundoscopy.

Overactive bladder

A condition where detrusor muscles contract unnecessarily; treated with Vasico-Selective anticholinergics like Oxybutynin, Tolterodine, or Solifenacin.

Pirenzepine

A specific $M_1$ receptor blocker used to decrease hydrochloric acid production in the treatment of peptic ulcers.

Dicyclomine

An antispasmodic tertiary amine used in the treatment of abdominal colicky pain by relaxing intestinal muscles.

Trimethaphan

A ganglionic blocker used during arterial surgeries, such as for aortic dissection, to block both sympathetic and parasympathetic activity.

Mecamylamine

A ganglionic blocker used for the treatment of nicotinic poisoning and off-label for smoking cessation.