Research on pharmacokinetics during pregnancy.

The pharmacokinetics of some drugs important for treatment in pregnancy were studied in several groups, women in stage III of pregnancy, women in labour and non-pregnant women as a control group. The half-life of elimination of the drugs is one of the most important parameters in pharmacokinetics. The following drugs were used: noramidopyrine methane sulphonate sodium, aminophenyzone, pethidine, methaqualone, ampicillin, cephalothin, chlorsulfamethin, and indocyanine green. The results show that all drugs except cephalothin had a prolonged half-life during labour. In contrast to this the half-life of most of the drugs is diminished in pregnancy. The extent and direction of the changes depend on the pathway of elimination and on the rate of biotransformation of the drug.