Classification of Emetics (Emetic Drugs – Drugs that cause vomiting)

Classification Of Emetics is as follows :-

Emetics: Emetics are drugs which induce vomiting.
Vomiting is controlled by two centres in the medulla.
They are 1.Vomiting Centre   2.Chemoreceptor Trigger Zone (CTZ)

Classification:

Emetics are classified into following groups
1. Centrally Acting Emetics: These drugs directly stimulate the chemoreceptor trigger zone or vomiting centre e.g. AMORPHINE.
2. Reflexly Acting Emetics: These drugs stimulate the vomiting centre by irritating gastric and duodenal mucosa which stimulate afferent fibres of the vagus nerve e.g. IPECACUANHA, TAR TAR Emetic.
3. Locally Acting: These are ALUM,COPPER SULPHATE,ZINC SULPHATE,SODIUM CHLORIDE(one tablespoon dissolved in a glass of warm water)
Many drugs given to patients for treatment of various diseases cause vomiting as their adverse effects e.g.
cardiac glycosides (DIGITALIS),
dopamine agonists(LEVODOPA, BROMOCRIPTINE),
narcotic analgesics(MORPHINE,PETHIDINE),
antimitotic drugs(MUSTINE),
non-narcotic analgesics(ASPIRIN,PHENYLBUTAZONE,INDOMETHACIN),
Veratum alkaloids and amino-phyline.
Note: Cardiac glycosides produce vomiting by dual action i.e. centrally through stimulation of CTZ and reflexly through irritation of gastric mucosa