ABSTRACT
Encountering women of reproductive age with significant medical problems, for which they are taking prescribed medications, is becoming increasingly common. Discussions in the pre-conception period will prevent such non-compliance in early pregnancy of important medications, such as antiepileptics or immunosuppressants. Pregnancy is associated with a reduction in gastric motility and an increase in gastric pH, but studies have demonstrated that pregnancy has no measurable affect on drug bioavailability via the mechanisms. There are many enzymes involved and their activity is modified by pregnancy. Pregnancy causes an increase in renal blood flow and glomerular filtration rate of more than 50 percent, which can have a significant effect on drugs that are predominantly excreted by the kidneys. Prescribing during pregnancy requires careful consideration of the risks and benefits, in discussion with the woman herself. In general, use of the lowest number of drugs and the lowest effective dose are recommended, remembering the effects of pregnancy on plasma levels of a drug.
