To the Editor.—
The case reports and excellent review of quinidine photosensitivity do not address prevention of this problem.1 I have prescribed β-carotene to three patients with quinidine photodermatitis. The dose was 30 mg three times a day to 60 mg three times a day orally titrated to the point of yellowing of the palms and soles. All three patients have been able to tolerate intense sun exposure without recurrence of the photodermatitis despite continued quinidine therapy. The drug was prescribed because of the report that β-carotene was effective in alleviating polymorphous light eruption in 32% of 19 patients so treated.2 Despite the advent of new antiarrhythmic agents such as β-blockers and calcium channel blockers, quinidine may not infrequently be the drug of choice in certain troublesome and, at times, life-threatening cardiac arrhythmias. Obviously, this clinical observation should have the scrutiny of a well-controlled, double-blind therapeutic trial before