Interaction of slow-channel calcium blocking drugs with sodium restriction, diuretics and angiotensin converting enzyme inhibitors.
The interactions of nifedipine with sodium restriction, diuretics and enalapril were studied using a 2 x 2 factorial design. Nifedipine lowered blood pressure to a greater extent than sodium restriction or hydrochlorothiazide. With both of these therapies there was a negative interactive term, which indicated that their combination had no greater effect than the use of nifedipine alone. Enalapril and nifedipine lowered blood pressure by 10 +/- 2/8 +/- 1 and 11 +/- 3/8 +/- 1 mmHg, respectively. The combination lowered blood pressure by 32 +/- 3/24 +/- 2 mmHg. The reasons for these negative and positive interactions are not clear, but may relate to interactions that regulate the availability of calcium for initiation of contraction in smooth muscle cells of the arterioles.
Morgan
T
T
Department of Physiology, University of Melbourne, Victoria, Australia.
Anderson
A
A
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage*; D001794:Blood Pressure; D004039:Diet, Sodium-Restricted; D004232:Diuretics / Q000008:administration & dosage*; D004347:Drug Interactions; D004357:Drug Synergism; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D009543:Nifedipine / Q000008:administration & dosage*
D000806:Angiotensin-Converting Enzyme Inhibitors; D004232:Diuretics; D009543:Nifedipine