Systemic side effects associated with the ophthalmic administration of timolol

Since the introduction of ophthalmic timolol solution in 1978 there have been numerous reports of systemic toxicity associated with its use. The majority of the systemic side effects reported are the same as those associated with oral timolol. Several cases of respiratory distress have been described generally in patients with underlying restrictive airway disease. Cardiovascular effects range from effects on resting pulse rate to the development of overt bradycardia and heart failure. Central nervous system effects reported include fatigue, confusion, depression, and hallucinations. A variety of other systemic effects have also been described. Caution should be used when ophthalmic timolol is administered to elderly patients or those patients with contraindications to systemic beta-blockers.