OC practice guidelines: minimizing side effects.

Abstract

The side effects of oral contraceptives (OCs) can be minimized by appropriate OC selection. Side effects or perceived side effects that manifest themselves physically--e.g., weight gain, breakthrough bleeding (BTB), nausea, headache, breast tenderness, mood swings, acne, and hirsutism--are the most common causes of premature discontinuation of oral contraception. The relative androgenicity of the progestin component of combination OCs has become an important differential in selecting OC formulations. Several studies have indicated that preparations with less androgenic potential can minimize some of the "physical" side effects and adverse metabolic effects traditionally associated with oral contraception. Acne and hirsutism, common pre-existing conditions that are clearly related to the androgenicity of the progestin component, can be eliminated or improved by use of OCs with low androgenic activity. Many women perceive that OCs cause weight gain; although weight gain is to some extent androgen related, most studies comparing low-androgenic OCs with medium- or high-androgenic preparations have found little or no change in weight regardless of formulation. BTB, which usually subsides within a few months, is related to the dose, potency, and ratio of the estrogen and progestin in the OC formulation. Low-estrogen-dose OCs (< or = 35 micrograms ethinyl estradiol [EE]) containing less androgenic progestins are associated with bleeding patterns as acceptable as older low-estrogen-dose formulations. The same analysis found that smoking cigarettes promotes BTB in women who use OCs. There is no convincing evidence that the use of one progestin or another is less likely to cause or exacerbate headache; however, changing preparations sometimes reduces the incidence. Women with persistent headaches during the pill-free interval may benefit from a longer cycle of OC treatment. Nausea and breast tenderness are primarily estrogen-related effects; if a women experiences persistent nausea, switching to an OC formulation containing 20 micrograms EE may be appropriate as long as the patient is cautioned that BTB is more likely. Mood changes are a common, highly subjective complaint whose relationship to OC use is hard to assess. Concerns about the potentially deleterious effects of combination OCs on lipid/lipoprotein and carbohydrate metabolism have been substantially diminished by new epidemiologic findings relative to cardiovascular disease as well as by the development of low-androgenic progestins. Formulations containing these progestins lower LDL cholesterol and increase HDL cholesterol; they do not affect carbohydrate metabolism as much as older, more androgenic formulations.