Lack of effect of smoking on the metabolism and pharmacokinetics of quinidine in patients.

14 hospitalized patients (5 smokers, 9 non-smokers) with a diagnosis of acute myocardial infarction or chest pain unrelated to myocardial infarction, aged 52 to 73 years. Excluded: patients with congestive heart failure, liver disease, or history of exposure to cimetidine or any known enzyme-inducing drug.

Oral quinidine (sulphate or gluconate) administered at various schedules (200 mg every 6 h, 330 mg every 8 h, 300 mg every 6 h, or 300 mg every 8 h) for a minimum of 3 days to achieve steady state in smoking patients.

Non-smoking patients receiving similar oral quinidine therapy at steady state.

Oral clearance of quinidine and urinary recovery of unchanged quinidine and its major metabolites (3S-3-hydroxyquinidine, 2'-oxoquinidinone, quinidine-N-oxide) over a dosing interval at steady state.surrogate