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Dynamic and biochemical responses to single and repeated doses of clonidine during dynamic physical activity
Author(s) -
Lowenthal David T,
Affrime Melton B,
Rosenthal Leslie,
Gould Anne B,
Borruso John,
Falkner Bonita
Publication year - 1982
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1038/clpt.1982.121
Subject(s) - hypoaldosteronism , heart rate , plasma renin activity , blood pressure , endocrinology , clonidine , medicine , rate pressure product , aldosterone , placebo , chemistry , renin–angiotensin system , alternative medicine , pathology
Beta‐adrenoceptor blockade increases serum K, which may be related to renin inhibition, hypoaldosteronism, and exercise‐induced skeletal muscle release of serum K. We report on the dynamic and biochemical response to Clonidine (C) after single (S) 0.2‐mg and repeated (R) 0.1‐mg bid doses of C to six normal subjects at rest, 2 hr after dosing and immediately before dynamic physical activity (DPA) on a treadmill, and at peak activity and 2 hr after DPA. Blood pressure (BP), heart rate (HR), plasma renin concentration (PRC), aldosterone (ALD), serum K, epinephrine (E), and norepinephrine (NE) were measured in standing subjects before and 2 hr after placebo or C (S or R), at peak DPA, and 2 hr after exercise. K, BP, and HR were also determined during all stages of DPA. Results show a parallel rise in K at peak over rest after C (S or R) and after placebo. NE, E, and PRC decreased after 1 wk of C (P < 0.01), but the fall of ALD was only slight. The fall in NE at rest suggested a relationship to the decrease in systolic BP and rate pressure product after 1 wk on C. With DPA there is a normal yet smaller increase in systolic BP and also a smaller rise in HR with S‐ and R‐dose C. There is no adverse rise in K in C‐treated subjects during DPA. Clinical Pharmacology and Therapeutics (1982) 32, 18–24; doi: 10.1038/clpt.1982.121