Abstract
The effects of separate 5 day pretreatments of propranolol 120 mg day‐1 and 720 mg day‐1 on theophylline clearance and metabolism at steady‐ state were determined in seven healthy males. Propranolol 120 mg day‐1 decreased theophylline plasma clearance (CL) by 30%. Clearance of theophylline to each metabolite was reduced by this treatment, clearances to the two demethylated products by 42‐43% and clearance to the 8‐hydroxylation product by 27%. Propranolol 720 mg day‐1 decreased theophylline CL by 52%. Again, clearance of theophylline to each metabolite was reduced by this treatment, clearances to the two demethylation products by 73‐77% and clearance to the 8‐hydroxylation product by 44%. These data are consistent with a dose‐dependent and selective inhibitory effect of propranolol on the separate forms of cytochrome P‐450 involved in theophylline demethylation and 8‐ hydroxylation. 1985 The British Pharmacological Society
| Original language | English |
|---|---|
| Pages (from-to) | 219-223 |
| Number of pages | 5 |
| Journal | British Journal of Clinical Pharmacology |
| Volume | 20 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Sept 1985 |
| Externally published | Yes |