Parenteral contraceptive drugs: depot progestins
Rabe, T.; Runnebaum, B.
Wiener Medizinische Wochenschrift 137(20-21): 474-479
1987
ISSN/ISBN: 0043-5341 PMID: 2967589 Document Number: 286289
Depot progestins as injectables, implants, or vaginal rings are suitable for contraception in those females for whom risk factors such as cardiovascular risk exclude the use of estrogen-progestin mixtures. The mode of action, indications, contraindications, advantages, and disadvantages of the various methods using depot progestins are discussed. Injectables contain either medroxyprogesterone acetate or norethisterone enanthate; both steroids are released slowly over a finite time interval (2-4 months). The major effect is a change in cervical mucus. Side effects include disturbances in the menstrual cycle (e.g., breakthrough bleeding) as well as amenorrhea after frequent use (up to 50% of all cases). The subdermal implants (Norplant 2 or 5) release levonorgestrel out of a depot over a period of at least 5 years. Steroid plasma levels are lower than in those patients using a progestin-only pill. Side effects of implants include disturbances of the menstrual cycle as above. In patients who desire to conceive or suffer from undesirable side effects, the implants can be removed at any time. The progestin-releasing vaginal rings are in a stage of controlled clinical trials. The advantages depend on the easy mode of administration (implant or removal). Side effects also include breakthrough bleeding. (author's modified)