Pseudotumor Cerebri and Implanon: Is Rapid Weight Gain the Trigger?

The relationship between pseudotumor cerebri and contraceptive drugs is controversial. Its association with Implanon, an implantable single-rod contraceptive containing etonogestrel (a progestogen) has not been reported but is the subject of many medico-legal cases. The authors present two case reports of patients using Implanon and who subsequently developed pseudotumor cerebri. Rapid weight gain rather than direct hormonal influence is probably the trigger. Headaches, visual obscurations, and rapid weight gain in patients using Implanon should alert one to the probable diagnosis of pseudotumor cerebri.