Liver damage from low-dose oral contraceptives.

OBJECTIVE

To study whether the decrease in the content of oestrogen and gestagen in modern low-dose oral contraceptives (OC) has yielded a lower incidence of adverse liver reactions, and to describe the biochemical pattern of the adverse liver reactions from low-dose OC.

DESIGN

We surveyed all liver reactions from OC reported to SADRAC (Swedish Adverse Drug Reactions Advisory Committee) from 1966 to 1989.

MAIN OUTCOME MEASURE

Incidence of reported adverse liver reactions (number of reported adverse reactions/OC sales in defined daily dose [DDD]).

RESULTS

There was a sharp decline in the number of reports during the studied period, suggesting changes in reporting habits. However, there was also a significantly lower incidence of reports for medium-compared to high-oestrogen dose OC, and a further decrease, albeit non-significant, in incidence with low-oestrogen dose OC. Furthermore, in three comparisons of pairs of OC that differed only in the gestagen dose, there was a strong trend towards a higher reporting rate with higher gestagen dose. Cholestatic and hepatocellular liver enzyme patterns were equally frequent in patients with adverse reactions from low-dose oestrogen OC. There was no report of liver tumours related to use of low-oestrogen dose OC.

CONCLUSION

There seems to be a decrease in the incidence of adverse liver reactions related to lower contents of both oestrogen and gestagens in OC of the combined-preparation type.