Impotence, constipation, difficulty in micturition, dry mouth, blurred vision, nausea, bloating, abdominal pain, vomiting, diarrhoea, colic. Psychosis, depression, skin rashes, dizziness, fatigue, muscle weakness, headache, cholestatic jaundice, elevated liver enzymes, thrombocytopenia, agranulocytosis, ventricular tachycardia and fibrillation, heart failure, hypotension, conduction disturbances.

Enhanced antimuscarinic effects with other antimuscarinic drugs. Potentiates negative chronotropic and inotropic effects of b-blockers and verapamil. Potentiates inhibitory effect on the conduction system produced by digitalis. Potentiates QT interval prolongation produced by TCAs and amiodarone.

Avoid other Class I antiarrhythmics and other cardiac depressants including b-blockers except in life-threatening arrhythmias. Risk of worsening of arrhythmias, precipitation of new arrhythmias and ventricular fibrillation when used with other anti-arrhythmics. Reduced efficacy when co-admin with phenytoin.