This integrated analysis evaluates nonmenstrual adverse events, blood pressure, and
body weight changes during the use of the single-rod
etonogestrel-containing
contraceptive implant,
Implanon; these aspects are compared for
Implanon and
Norplant, the six-
capsule implant containing
levonorgestrel. Overall, 47% of
Implanon users had
drug-related adverse events, whereas in the comparative studies the figure for those using
Implanon (61%) was slightly lower than that for
Norplant users (69%). In all
Implanon studies, 12 of 1716 women (0.7%) were affected by serious adverse events that were considered
drug related. In comparative studies three of the 689
Implanon users (0.4%) and one of 689
Norplant users (0.1%) had such experiences. The most frequently reported
drug-related adverse events were
acne,
breast pain,
headache and
weight gain. The adverse events that most often caused discontinuation of
Implanon were
weight gain and
acne. The development or aggravation of
acne was a frequent adverse event (in 18.5% of
Implanon and 22.3% of
Norplant users in the comparative studies) but individual studies indicated that there were also many subjects whose
acne improved during implant use. There were gradual increases in
body weight over time but these may be only partly attributable to implant use and partly attributable to normal increases over time.