Syncope in a 65-year-old woman after nitrate ingestion

A 65-year-old woman with angina pectoris presented with syncope after sublingual ingestion of isosorbide dinitrate (5 mg). Her response to a postural challenge test, without medication, was normal. In a postural challenge test after administration of isosorbide dinitrate (5 mg), blood pressure decreased from 120/67 to 65/35 mmHg, followed by syncope with a sudden decrease in pulse rate from 85 to 60 beats/min. No evidence of myocardial infarction was detected. Elderly patients for whom nitrate has been prescribed should be warned of the occurrence of hypotension, leading to unconsciousness.