Impaired theophylline clearance in patients with cor pulmonale.

Vicuna, N; McNay, J. L.; Ludden, T. M.; Schwertner, Harvey A.

doi:10.1111/j.1365-2125.1979.tb00893.x

Cited by 54 publications

(7 citation statements)

References 10 publications

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“…While age-dependent changes in splanchnic blood flow (Sherlock, Bearn, Billing & Patterson, 1950) and small bowel surface area (Warren, Papperman & Montgomery, 1978) have been observed suggesting that drug absorption might be altered in the elderly this aspect of kinetics has been little examined (Crooks, O'Malley & Stevenson, 1976 (Powell et al, 1978) or cor pulmonale (Vicuna, McNay, Ludden & Schwertner, 1979). Patients on medication considered to affect drug metabolism were excluded.…”

Section: Introductionmentioning

confidence: 99%

Theophylline kinetics in relation to age: the importance of smoking.

Cusack¹,

Kelly²,

Lavan³

et al. 1980

Brit J Clinical Pharma

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1 Single dose studies of theophylline kinetics were compared in groups of young and elderly smokers and non-smokers to assess the effect of age on theophylline absorption and the effect of smoking on drug metabolising enzyme activity in old age. 2 The rate and extent of absorption was not affected by age. Distribution and elimination kinetics were similar in young and elderly non-smokers. 3 In young subjects the elimination half-life of theophylline was shorter and clearance was significantly greater in smokers than in non-smokers. 4 In the elderly mean elimination half-life was significantly shorter in smokers and their plasma clearance was 40% higher than in non-smokers. The statistical difference for clearance was at the 7% level of significance. 5 These data indicate that ageing per se does not affect theophylline elimination and also that induction of theophylline metabolism due to smoking occurs in old age. Smoking is a variable that should be taken account of when assessing drug metabolism in elderly patients.

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Section: Introductionmentioning

confidence: 99%

Theophylline kinetics in relation to age: the importance of smoking.

Cusack¹,

Kelly²,

Lavan³

et al. 1980

Brit J Clinical Pharma

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“…The profiles of the patients in the clinical monitoring survey indicate numerous factors which might interact to influence theophylline clearance. Hepatic disease, left and right heart failure and severe airways obstruction all reduce theophylline clearance (Zwillich, Sutton, Neff, Cohen, Matthay&Weinberger, 1975;Weinberger, Matthay, Ginchansky, Chidsey & Petty, 1976;Jenne, Chick, Miller & Strickland, 1977;Jusko, Koup, Vance, Schentag & Kuritzky, 1977;Piafsky, Sitar, Rangno & Ogilvie, 1977a & Mangione, Imhoff, Lee, Shum & Jusko, 1978;Powell, Vozeh, Hopewell, Costello, Sheiner & Riegelman, 1978;Vicuna, McNay, Ludden & Schwertner, 1979). The patients were receiving numerous drugs and various quantities of alcohol which might interfere with hepatic enzyme activity and theophylline clearance.…”

Section: Discussionmentioning

confidence: 99%

Serum level monitoring of a new slow release theophylline formulation in patients with chronic lung disease.

Marlin¹,

Butcher²,

Klumpp³

et al. 1980

Brit J Clinical Pharma

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1 Serum theophylline levels were performed in 26 patients with chronic lung disease receiving rapid release theophylline (125 mg 6 hourly) and 28 patients receiving slow release theophylline (250 mg 12 hourly) under steady state conditions. 2 For rapid release theophylline the mean + s.d. serum theophylline levels at 0 and 2 h were 41.0 + 21.7 and 52.3 + 20.9 mol P1-respectively and for slow release theophylline at 0, 4 and 6 h 43.7 + 25.5, 50.9 + 23.0 and 51.7 + 26.4 pmol I1 respectively. 3 Serum theophylline monitoring with slow release theophylline was performed in 70 patients with chronic lung disease. The initial dose was 250 mg administered 12 hourly. 4 The mean + s.d. steady state serum theophylline level achieved was 76.0 + 18.8 jimol -1 and the mean + s.d. dose to produce this level was 9.4 + 2.3 mg kg-' day-'. There was no correlation between dosage and serum theophylline level. 5 Sixty percent of patients required a dosage change for stabilization (375 to 1000 mg/day). Seventeen patients reported unwanted effects (nausea or tremor), which either settled quickly or resolved with dosage reduction. 6 Serum theophylline levels were obtained at different dosages in 44 patients and 18 patients demonstrated dose-dependent kinetics. 7 An initial dose of 500 mg/day is recommended and dosage increments should not exceed 125 mg/day with monitoring by serum theophylline levels.

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“…The elimination of theophylline is significantly influenced by the interaction of various factors commonly present in these patients, e.g. severe airways obstruction, right and left heart failure, liver disease, smoking habits (Piafsky et al, 1977a, b;Powell et al, 1977Powell et al, , 1978Vicuna et al, 1979). Dosedependent pharmacokinetics for theophylline have been descibed in both adults and children (Jenne et al, 1972;Nicholson & Chick, 1973;Caldwell et al, 1977;Weinherger & Ginchansky, 1977;Fixley et al, 1977;Lesko, 1979;Marlin et al, 1980).…”

Section: Dose-dependent Pharmacokinetics With Single Daily Dose Slow mentioning

confidence: 99%