Over the past 2 decades, nifedipine in the form of capsules has become widely popular in the treatment of hypertensive emergencies. Unlike other agents, such as sodium nitroprusside, nicardipine hydrochloride, diazoxide, and nitroglycerin— which require intravenous administration and monitoring of blood pressure— nifedipine can be given orally, and close monitoring is said not to be necessary. Although administration of nifedipine capsules has been reported to be expedient and safe, it has not been approved by the Food and Drug Administration for labeling for treatment of hypertensive emergencies or of any other form of hypertension because of lack of outcome data. A review of the literature revealed reports of serious adverse effects such as cerebrovascular ischemia, stroke, numerous instances of severe hypotension, acute myocardial infarction, conduction disturbances, fetal distress, and death. Sublingual absorption of nifedipine has been found to be poor; most of the drug is absorbed by the intestinal mucosa. Given the seriousness of the reported adverse events and the lack of any clinical documentation attesting to a benefit, the use of nifedipine capsules for hypertensive emergencies and pseudoemergencies should be abandoned.
Grossman E, Messerli FH, Grodzicki T, Kowey P. Should a Moratorium Be Placed on Sublingual Nifedipine Capsules Given for Hypertensive Emergencies and Pseudoemergencies?. JAMA. 1996;276(16):1328-1331. doi:10.1001/jama.1996.03540160050032