Safety and efficacy of a single-rod etonogestrel implant (Implanon): results from 11 international clinical trials.
OBJECTIVE
To present efficacy, safety, and bleeding profile results from the clinical trials that supported the U.S. Food and Drug Administration filing for the approval of a single-rod etonogestrel (ENG) contraceptive implant (Implanon).


METHODS
Integrated analysis of 11 international clinical trials.


METHODS
Contraceptive clinics in U.S., Chile, Asia, and Europe.


METHODS
A total of 942 healthy women, aged 18 to 40 years.


METHODS
Insertion of an ENG implant. Most women were enrolled in studies lasting either 2 or 3 years.


METHODS
Efficacy was measured by the cumulative Pearl Index in women <or=35 years old. Safety was primarily assessed by incidence of adverse events. Bleeding profiles were analyzed via reference period analyses.


RESULTS
No pregnancies were reported while the ENG implants were in place. Six pregnancies occurred during the first 14 days after ENG implant removal. Including these six pregnancies, the cumulative Pearl Index was 0.38 (year 1 and 2 Pearl Indexes were 0.27 and 0.30, respectively). Common drug-related adverse events were headache, weight gain, acne, breast tenderness, emotional lability, and abdominal pain. Bleeding pattern changes were observed, but no one pattern predominated.


CONCLUSIONS
The ENG implant is an efficacious and safe method of contraception which does not require patients' consistent action.
Darney
Philip
P
Bixby Center for Global Reproductive Health, San Francisco General Hospital, University of California, San Francisco, California 94941, USA. darneyp@obgyn.ucsf.edu
Patel
Ashlesha
A
Rosen
Kimberly
K
Shapiro
Lena S
LS
Kaunitz
Andrew M
AM
D000293:Adolescent; D000328:Adult; D002986:Clinical Trials as Topic; D003271:Contraceptive Agents, Female / Q000008:administration & dosage*; D017135:Desogestrel / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D006801:Humans; D011247:Pregnancy; D013997:Time Factors; D014592:Uterine Hemorrhage / Q000209:etiology
D003271:Contraceptive Agents, Female; C044815:etonogestrel; D017135:Desogestrel