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Inhibition of Theophylline Elimination by Diltiazem Therapy
Author(s) -
Nafziger Anne N.,
May John J.,
Bertino Joseph S.
Publication year - 1987
Publication title -
the journal of clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.92
H-Index - 116
eISSN - 1552-4604
pISSN - 0091-2700
DOI - 10.1002/j.1552-4604.1987.tb05580.x
Subject(s) - diltiazem , theophylline , aminophylline , pharmacokinetics , volume of distribution , medicine , drug interaction , pharmacology , oral administration , bronchodilator , anesthesia , asthma , calcium
To investigate the effects of diltiazem on theophylline pharmacokinetics, nine healthy male subjects (four smokers and five nonsmokers) received intravenous aminophylline (6 mg/kg) prior to and following 10 days of oral diltiazem therapy. Theophylline half‐life increased significantly whereas total body clearance showed a significant decrease following diltiazem. Volume of distribution was unchanged. The small group of smokers had a significantly greater increase in theophylline half‐life than the nonsmokers. Inhibition of metabolism of theophylline by diltiazem likely explains the significant changes in theophylline pharmacokinetics. A clinically important drug interaction may occur with theophylline when diltiazem therapy is given concurrently.