Depo-Provera in adolescents: effects of early second injection or prior oral contraception

Abstract

Purpose: To examine the effects of an early second injection or prior use of oral contraceptive pills (OCP) on side effects of Depo-Provera during the early months of use in adolescents.

Methods: Thirty-six girls, gynecologic age 4.2 +/- 0.3 years, and body mass index (BMI) 23.2 +/- 0.8, received the currently recommended injection of 150 mg every three months. Twenty-seven girls (gynecologic age 3.9 +/- 0.5 years, BMI 24.0 +/- 0.8) received the second injection six weeks after the first injection. Fifteen girls (gynecologic age 5.0 +/- 0.5, BMI 25.4 +/- 1.3) switched directly from an OCP to Depo-Provera. The patients were periodically assessed by their care providers.

Results: Early administration of the second injection of Depo-Provera did not alter the bleeding episodes, onset of bleeding, or total days of bleeding (14.3 +/- 3.7 vs. 17.1 +/- 4.0, p = 0.62) during the three months interval following injection, compared with the standard second injection interval. Moreover, an excessive BMI gain (BMI increase 0.99 +/- 0.22 vs. 0.40 +/- 0.14, p = 0.03) was observed in these girls. Girls who switched directly from OCP showed no difference in the rate of BMI gain when compared to those not previously on OCP (BMI increase 0.38 +/- 0.3). Bleeding duration of these girls, however, was markedly reduced; the total number of days of bleeding was 5.7 +/- 1.9 (p = 0.0003) during the first three month interval, and 5.7 +/- 2.3 (p = 0.019) during the three month period following the second injection. This reduction did not persist beyond the first six months.

Conclusions: Early second Depo-Provera injection does not alter the experience of menstrual abnormalities, and predisposes to greater weight gain; OCP use prior to Depo-Provera results in a decrease in the duration of bleeding with no change in the weight gain rate.

PIP: The capability of an early second injection or prior use of oral contraceptives (OCs) to improve satisfaction and long-term continuation of Depo-Provera in adolescents was investigated in a clinical trial involving 78 females 12-20 years of age (average, 15.9 years) recruited from a hospital-based adolescent health clinic. 36 subjects received injection of 150 mg of Depo-Provera every three months (Group 1), 27 received the second injection after only six weeks (Group 2), and 15 switched directly from OCs to the standard Depo-Provera regimen (Group 3). There was no difference between Groups 1 and 2 in terms of duration or frequency of menstrual bleeding; however, prior OC users experienced a significant reduction in the duration and intensity of bleeding in the first six months of Depo-Provera use (when estrogen was still present in the women's systems). Overall, 64% of study subjects reported less dysmenorrhea while on Depo-Provera. A slightly greater change in body mass index was observed among girls in Group 2 than in Groups 1 and 3; moreover, 70% of those in the early injection group reported increased appetite and weight gain compared to 39% of those on the standard schedule. The most commonly reported side effects included initial pain and soreness at the injection site (27%), decreased libido (56%), mood changes (31%), depression (26%), frequent headache (25%), fatigue (24%), and increase in acne (15%); there were no significant differences by group. 17 adolescents (22%) discontinued Depo-Provera, generally after two injections and due to bleeding irregularities or weight gain. 87% of adolescents who were prior OC users, 52% of those on the regular schedule, and 39% of those who received an early injection stated they were very satisfied with Depo-Provera. These findings indicate that early second Depo-Provera injection offers no advantages; use of OCs immediately prior to Depo-Provera should be further investigated, however, given its potential to minimize bleeding problems.