Increased theophylline metabolism in the menstrual phase of healthy women☆,☆☆,★
Section snippets
Subjects
Seven healthy, ovulatory Japanese women aged 30 to 44 years (mean age, 34.9 years) were investigated. No subject had asthma, and none of them had received theophylline previously. They recorded their basal body temperature during the 1-month study. All subjects gave their informed consent to participate in this study.
Sampling
Blood samples were collected after 30 minutes of bed rest and before breakfast on the day of onset or day 2 of menses, day 10, and day 20 or 25. These sampling times corresponded
Menstrual cycle
All subjects showed a biphasic pattern of basal body temperature and an increase in progesterone level in the luteal phase, indicating that they were in the ovulatory cycle. A normal pattern of change was seen in the estrogen and progesterone levels for all subjects (Table I).
Values are expressed asPhase Estradiol (pg/ml) Progesterone (ng/ml) Follicular 80.7 ± 44.2 0.26 ± 0.14 Luteal 154.4 ± 123.1 13.17 ± 5.23 Menstrual 22.8 ± 12.6 0.46 ± 0.24
Discussion
In our previous study of a woman with asthma, theophylline clearance was higher, and the half-life was shorter in the premenstrual and menstrual phases.1 In this study of healthy nonasthmatic women, theophylline clearance was significantly higher in the menstrual phase than in the follicular phase, and the half-life was shorter in the menstrual phase than in the follicular phase. These results are compatible with those in our previous report.
Diet and activity are significant factors for
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Cited by (0)
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From aThe Third Department of Internal Medicine and bHealth Science Center of Tottori University Faculty of Medicine, Yonago, Japan.
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Reprint requests: Keiko Nagata, MD, The Third Department of Internal Medicine, Tottori University Faculty of Medicine, 36-1 Nishi-Machi Yonago, 683, Japan.
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