[Liver function tests during administration of triphasic contraceptives containing Norgestimate]

To evaluate serum levels of liver enzymes and bilirubin before and after six cycles of use of a triphasic oral contraceptive containing 35 micrograms of ethinylestradiol and 180/215/250 micrograms of norgestimate (Pramino, Janssen-Cilag).

A prospective, open-label, non-comparative, multicentric phase IV study.

Department of Obstetrics and Gynaecology, 1st Medical Faculty, Charles University, Prague.

Before the start and after six cycles of Pramino use, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GMT), and bilirubin were determined in women. As the analyses were performed in different laboratories, the evaluation involved: 1. Subgroups of women examined in laboratories with the same reference range; 2. A group of women examined in laboratories with the upper reference range within the mean +/- SD interval; 3. Percentage variations of the measured values from a concrete upper reference limit.

When evaluating subgroups of women from laboratories with the same standards, significant decreases in AST and bilirubin were seen in some subgroups, a rise in GMT in one subgroup; the other changes were non-significant. When assessing the entire group and percentage variations from standard, a mild rise in GMT was again seen; however, the values remain deep within the normal range. Values above the upper reference limit at the start of the study either do not change significantly throughout the study, or they normalize spontaneously.

No clinically significant changes in liver function tests occurred in users of a triphasic oral contraceptive containing norgestimate along with 35 micrograms EE over a period of six cycles of use. The results, as judged by their dynamics, suggest liver function tests are not a useful tool for routine monitoring a healthy combined oral contraceptive user.