To the Editor.
—Dr Grossman and colleagues1 mention the practical problems associated with the administration of sublingual nifedipine. As an alternative method to cutting the capsule and squeezing its contents into the patient's mouth, nurses and physicians may frequently attempt to withdraw the liquid contents of the capsule using a needle and syringe. We investigated the accuracy and precision of this method of administration.The preparation of 10-mg doses of nifedipine was simulated by requesting 20 pharmacy staff to withdraw the total contents of a liquid-filled nifedipine capsule (Adalat, 10 mg, Bayer, Auckland, New Zealand) by puncturing the gelatin shell and withdrawing the contents into a preweighed 1-mL needle and syringe. The 10-mg capsules contain 0.34 mL of liquid nifedipine, which has a density of 1.135 gm/L (written communication, data on file, Bayer, Auckland, New Zealand). After removal of the dose, each syringe and needle was reweighed, and the amount of nifedipine
Woods DJ, Fowler S. Nifedipine for Hypertensive Emergencies. JAMA. 1997;277(10):790. doi:10.1001/jama.1997.03540340024020