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

Abstract

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.

Influence of chronic dosing on theophylline clearance.

“…Concentrationdependence of theophylline clearance has been suggested as a result of disproportionate increases in plasma concentration in adults (Butcher et al, 1982;Jenne et al, 1972;Marlin et al, 1980) and children (Sarrazin et al, 1980;Weinberger & Ginchansky, 1977). Moreover, the formation of several theophylline metabolites has been shown to be saturable (Tang-Liu et al, 1982).…”

Graphene layer modified glassy carbon electrode for the determination of norepinephrine and theophylline in pharmaceutical formulations

“…6 TP poisoning is a serious issue which causes tachycardia, arrhythmias, metabolic acidosis, seizures, hypokalemia, and death. [7][8][9] It is a competitive inhibitor of the enzyme phosphodiesterase, which is responsible for the conversion of 3 0 ,5 0 -cyclic adenosine monophosphate (c-AMP) to 5 0 -adenosine monophosphate (AMP). 10 c-AMP plays an important role in mediating the cardiac effects of catecholamines.…”

Pharmacokinetics of a single evening dose of slow release theophylline in patients with chronic lung disease [letter]

“…However, the theophylline dose requires individualizing for each patient because of variable theophylline clearance due to the interaction of factors such as severe airways obstruction, left and right heart failure, hepatic disease and smoking (Piafsky et al, 1977a, b;Powell et al, 1977;Powell et al, 1978;Vicuna et al, 1979) and also because some patients may demonstrate dose-dependent kinetics (Marlin et al, 1980). Many patients with airways obstruction have symptoms predominantly during the night and early morning (Turner-Warwick, 1977).…”

“…Slow release theophylline preparations administered twice daily may be safely used for control of airways obstruction in patients with chronic lung disease (Marlin et al, 1980). However, the theophylline dose requires individualizing for each patient because of variable theophylline clearance due to the interaction of factors such as severe airways obstruction, left and right heart failure, hepatic disease and smoking (Piafsky et al, 1977a, b;Powell et al, 1977;Powell et al, 1978;Vicuna et al, 1979) and also because some patients may demonstrate dose-dependent kinetics (Marlin et al, 1980).…”