Dexetimide

Oral
Drug-induced extrapyramidal symptoms

Mild to moderate: reduce initial dose; severe: avoid use.

Mild to moderate: reduce initial dose; severe: avoid use.

Prostatic hyperplasia, paralytic ileus, pylori stenosis, close-angle glaucoma, and myasthenia gravis (except in decreasing muscarinic side-effects of anticholinesterases).

Child and elderly, pregnancy and lactation, Down's syndrome, gastroesophageal reflux disease, diarrhoea, ulcerative colitis, acute MI, hypertension, hyperthyroidism, cardiac insufficiency and surgery; pyrexia. Patients with arteriosclerosis or history of drug idiosyncrasy may produce severe mental disturbances, excitement, nausea and vomiting; starting with small initial doses with gradual increase may be necessary. Increases in dosage and treatment withdrawal should be gradual.

Dryness of the mouth, difficulty in swallowing and talking; thirst and reduced bronchial secretions. Mydriasis with cycloplegia and photophobia. Flushing, dryness of the skin, transient bradycardia followed by tachycardia with palpitations and arrhythmias; difficulty in micturition. Reduction in tone and motility of GI tract leading to constipation. Drowsiness; slight transient hypotension following parenteral administration.

Overdosage symptoms usually occur within 4 hr. Common symptoms are abdominal pain, nausea, vomiting, lethargy, drowsiness, headache, nystagmus, tinnitus and ataxia. Rarely, moderate or severe symptoms include GI bleed, hypotension, hypothermia, metabolic acidosis, seizures, impaired renal function, coma, adult respiratory distress syndrome and transient episodes of apnea. Treatment is symptomatic, and there is no specific antidote. Drink water to minimize GI upset if <50 mg/kg dexibuprofen consumed. Activated charcoal should be admin in more severe overdose. Empty the stomach by emesis if within 60 min of ingestion. Gastric lavage to be attempted only if a potentially life-threatening amount of the drug have been consumed and within 60 min of ingestion. Forced diuresis, haemodialysis or haemoperfusion are unlikely to be helpful.

Effects enhanced by the concomitant admin of other drugs with antimuscarinic properties eg, amantadine, antihistamines, phenothiazine antipsychotics, and tricyclic antidepressants. Effects also enhanced by MAOIs. Dexetimide may affect the absorption of other drugs. Antimuscarinics and parasympathomimetics may counteract each others effects.

Description: Dexetimide is a tertiary antimuscarinic having similar actions with benzhexol (trihexyphenidyl). It has been used to alleviate drug-induced extrapyramidal syndrome. Like other antimuscarinics, it is of no value against tardive dyskinesia.

Antiparkinsonian Drugs