Glyceryl trinitrate ointment in angina pectoris.
Skin absorption of glyceryl trinitrate (GTN) has been recognized for a long time. The effect of GTN and a placebo ointment in prevention of chest pain has been assessed and compared by studying the exercise capacity in 17 patients with angina pectoris. The placebo cream was ineffective but the GTN ointment was found to have beneficial effect in relief of pain in 16 cases. This was established by the patients' capacity to exercise on a bicycle ergometer without chest pain. The beneficial effect was sustained for up to 3 hr in 12 patients. This preparation appears to act as a long-acting nitrate and may be valuable for patients in whom beta-blocking agents are ineffective or contra-indicated, and surgery is not feasible.