Hepatic and renal impairment, heart disease, recent acute MI, arrhythmias, significant bradycardia (<50 beats/min), severe respiratory disease, epilepsy (and conditions at risk of epilepsy, e.g. alcohol withdrawal or brain damage), Parkinson's disease, acute angle glaucoma, prostatic hypertrophy, hypothyroidism, hyperthyroidism, myasthenia gravis, phaeochromocytoma. Patients at risk of stroke and QT interval prolongation. Avoid abrupt withdrawal. Ability to drive a car or operate machinery may be impaired.