Effect of the ethinylestradiol/levonorgestrel combined oral contraceptive on the activity of cytochrome P4503A in obese women.
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Edelman A, Munar M, Elman MR, Koop D, Cherala G
Effect of the ethinylestradiol/levonorgestrel combined oral contraceptive on the activity of cytochrome P4503A in obese women.
Br J Clin Pharmacol. 2012 Sep;74(3):510-4. doi: 10.1111/j.1365-2125.2012.04209.x.
- PubMed ID
- 22299599 [ View in PubMed]
- Abstract
AIM(S): While it is known that CYP3A4/5 activity is decreased with combined oral contraceptive (COC) use and obesity suppresses CYP expression, the combined effects of obesity and COC use on CYP3A4/5 activity are unclear. Therefore, our aim was to examine the effect of COC usage on CYP3A4/5 activity in obese women. METHODS: Thirty-four, obese (body mass index, BMI > 30 kg m(-2)) women of reproductive age (18-35 years old) were placed on a COC pill containing 20 microg ethinylestradiol/100 microg levonorgestrel for 21 days starting at the onset of menses. A midazolam pharmacokinetic study was conducted prior to initiation and after 21 days of COC treatment. Serial blood samples were collected and plasma concentrations of midazolam were measured using liquid chromatography tandem mass spectrometry. Pharmacokinetic parameters were estimated using a non-compartmental method. RESULTS: Midazolam clearance, a surrogate measure of CYP3A4/5 activity, was significantly decreased upon COC use (63.3 l h(-1) vs. 53.9 l h(-1), P < 0.05). A median decrease of 5.6 l h(-1) (95% CI -4.1, 13.3 l h(-1)) was observed. However, the magnitude of change was similar to that reported in women with normal BMI. CONCLUSIONS: Although we hypothesized that obesity might amplify the impact on CYP3A4/5 activity in COC users, we found that this was not the case. This finding is reassuring regarding potential additional drug-drug interactions in obese COC users as CYP3A4/5 is a major enzyme in the metabolism of many marketed drugs.
DrugBank Data that Cites this Article
- Drug Enzymes
Drug Enzyme Kind Organism Pharmacological Action Actions Levonorgestrel Cytochrome P450 3A4 Protein Humans UnknownSubstrateDetails Levonorgestrel Cytochrome P450 3A5 Protein Humans UnknownSubstrateDetails