Overall, 14.5% of patients taking<unk>  experience luminous phenomena (by patients described as sensations of enhanced brightness in a fully maintained visual field). This is probably due to blockage of Ih ion channels in the retina, which are very similar to cardiac If. These symptoms are mild, transient, and fully reversible. In clinical studies, about 1% of all patients had to discontinue the drug because of these sensations, which occurred on average 40 days after the drug was started. In a large clinical trial, bradycardia (unusually slow heart rate) occurred in 2% and 5% of patients taking<unk>  at doses of 7.5 and 10 mg respectively (compared to 4.3% in those taking atenolol). 2.6–4.8% reported headaches. Other common adverse drug reactions (1–10% of patients) include first-degree AV block, ventricular extrasystoles, dizziness and/or blurred vision.
Ivabradine
Lofexidine
Setiptiline
Maprotiline
Verapamil
Nortilidine
Veratridine
Procainamide