The progestin-only pills and the levonorgestrel-releasing IUD: two progestin-only contraceptives.

Abstract

The author reviewed available study findings in the literature to evaluate the merits, disadvantages, and unsettled issues of progestin-only contraceptive pills (POPs) and the newly developed levonorgestrel-releasing (LNG) IUD. The mechanism of POP action and the brands marketed are first considered, followed by discussion of safety considerations, efficacy and compliance, side effects, clinical acceptability, continuation patterns, the advantages of using POPs, current use, and issues to be addressed. The author then discusses the LNG IUD in sections on its mode of action, studies used for evaluation, safety considerations, clinical performance, noncontraceptive effects, and use perspectives and issues to be addressed. The benefits of POPs outweigh their risks, especially for lactating and/or postpartum women, with available information suggesting that POPs are at least as safe as, if not safer than, combined oral contraceptives (COCs). The incidence of nonmenstrual systemic side effects in POP users, such as headaches, nausea, vomiting, and dizziness, tend to be milder, and their incidence may have been overreported in previous studies. However, for POPs to be as effective as COCs, strict compliance is required. Moreover, compared to COCs, POPs are more likely to cause menstrual disturbances in the first few months of use.