Echinacea (E purpurea root) reduced the oral clearance of substrates of CYP1A2 but not the oral clearance of substrates of CYP2C9 and CYP2D6. Echinacea selectively modulates the catalytic activity of CYP3A at hepatic and intestinal sites. The type of drug interaction observed between echinacea and other CYP3A substrates will be dependent on the relative extraction of drugs at hepatic and intestinal sites. Caution should be used when echinacea is coadministered with drugs dependent on CYP3A or CYP1A2 for their elimination.

The physiological changes of pregnancy may predispose females to develop sleepdisordered breathing (SDB) or protect against it. Studies evaluating outcomes of SDB symptoms in pregnancy are scarce. The goal of this study was to evaluate the prevalence of SDB symptoms in pregnancy and their relationship with pregnancy and neonatal outcomes.A cross-sectional survey of randomly selected immediate postpartum females was performed using the multivariable apnoea prediction index. Record review, including demographics and medical history, was performed. Main outcome measures included pregnancy and neonatal outcomes.1,000 subjects were recruited. Mean¡SD age was 29.1¡6.1 yrs. Factors used in the regression analysis included age, body mass index, diabetes, chronic hypertension, multifetal gestations, smoking and renal disease. Snoring was present in 35.1% of subjects. Symptoms of SDB were associated with a higher likelihood of pregnancy-induced hypertension and pre-eclampsia (adjusted OR 2.3, 95% CI 1.4-4.0), gestational diabetes (adjusted OR 2.1, 95% CI 1.3-3.4) and unplanned Caesarean deliveries (adjusted OR 2.1, 95% CI 1.4-3.2) after multivariable regression analysis. Gasping may have been associated with a higher likelihood of preterm delivery, after adjusting for age and multifetal pregnancies (adjusted OR 1.8, 95% CI 1.1-3.2) but this association appeared to be mediated by pre-eclampsia.Symptoms of SDB are common in pregnancy and associated with a higher likelihood of gestational hypertensive disorders, gestational diabetes and unplanned Caesarean deliveries.

St John's wort causes an induction of ethinyl estradiol-norethindrone metabolism consistent with increased CYP3A activity. Women taking oral contraceptive pills should be counseled to expect breakthrough bleeding and should consider adding a barrier method of contraception when consuming St Johns wort.