First year clinical experience with six levonorgestrel rods as subdermal contraception

Contraception. 1979 Aug;20(2):167-75. doi: 10.1016/0010-7824(79)90089-1.

Abstract

Previous clinical experience with six levonorgestrel subdermal capsules showed a very good contraceptive effectiveness and continuation rate, but with a high proportion of bleeding disturbances, particularly of increased bleeding. It was hypothesized that bleeding could be reduced by higher plasma levels of the steroid, using subdermal rods instead of capsules, as rods have been shown to have a release rate 3 or 4 times that of the capsules. Fifty volunteers were enrolled in a study of the clinical performance of 6 subdermal levonorgestrel rods. Results were compared with a previous experience with 100 volunteers who wore 6 levonorgestrel capsules for a year in the same clinic. Requirement for volunteers to enter the study were the same for capsules and rods. The proportion of women wearing 6 subdermal rods who had increased bleeding was about one half as for the women using 6 levonorgestrel capsules. On the other hand, women using rods had about twice the incidence of amenhorrea, and about four times more hypomenorrhea (4 days or less of bleeding in a 90-day period). There were no pregnancies among the rod users and the discontinuation rate for medical reasons was not higher than for capsule users in the same clinic.

PIP: Because subdermal implants of levonorgestrel (NG) were shown in previous trials to be effective contraceptives but bleeding irregularities limited acceptability, it was hypothesized that bleeding could be reduced by higher plasma levels of the steroid, which was accomplished by using subdermal rods instead of capsules, since rods have been shown to have a release rate 3 or 4 times that of capsules. 50 volunteers were recruited and enrolled in the study of clinical performance of 6 subdermal NG rods. Results were compared with a previous experience with 100 volunteers who wore 6 NG capsules for 1 year in the same clinic. The proportion of women wearing 6 subdermal rods who had increased bleeding (the main bleeding complaint with the NG capsules) was about 1/2 as for the NG capsule study. However, women using rods had 2 times the incidence of amenorrhea, and 4 times more hypomenorrhea (4 days or less of bleeding in a 90-day period). No pregnancies were recorded among rod users, and discontinuation for medical reasons was no higher than for capsule users in the same clinic. Rod removal was laborious and difficult compared with capsule removal.

MeSH terms

  • Adolescent
  • Adult
  • Amenorrhea / etiology
  • Capsules
  • Contraceptive Agents*
  • Dosage Forms
  • Female
  • Hematocrit
  • Humans
  • Hydrocortisone / blood
  • Norgestrel / administration & dosage*
  • Norgestrel / adverse effects
  • Norgestrel / blood
  • Uterine Hemorrhage / etiology

Substances

  • Capsules
  • Contraceptive Agents
  • Dosage Forms
  • Norgestrel
  • Hydrocortisone