Abdomen, Pelvis, and Perineun

Physicians taking care of patients in the reproductive age need to know the efficacy, safety, and side effects of contraceptive methods.

As the physician, one must help the patient make the appropriate decision based on likelihood of compliance and access to follow up.

Birth Control Pills
Tab 2
Tab 3

Estrogen and progestin(the generic name for any synthetic progesterone compound) molecules inhibit GnRH pulses, which then decreases FSH and LH secretion, inhibiting development of ovarian follicles and ovulation. The estrogen component in the oral contraceptive pill primarily suppresses FSH secretion and the progesterone component suppresses LH secretion, thereby preventing follicular recruitment and ovulation, respectively.

As a group, antibiotics have been implicated in decreasing the efficacy of oral contraceptives. Fortunately, this has been proven in very few, and these are listed in (Table 5-11).

Table 5-11. Drugs that May Reduce Combined Hormonal Contraceptive Efficacy

Interacting Drug	Evidence
Antituberculous
Rifampin	Established; reduced efficacy if <50 μg EE pill is used
Antifungals
Griseofulvin	Strongly suspected
Anticonvulsants and sedatives
Phenytoin, mephenytoin, phenobarbital, primidone, carbamazepine, ethosuximide, topiramate, oxcarbazepine	Strongly suspected; reduced efficacy if <50 μg EE pill is used; trials lacking
Antibiotics
Tetracycline, doxycycline Penicillins Ciprofloxacin Ofloxacin	Two small studies find no association No association documented No effect on efficacy of a 30 μg EE + desogestrel pill No effect on efficacy of a 30 μg EE + levonorgestrel pill
Antiretrovirals	Variable effects; see manufacturer or othera

aUniversity of California at San Francisco (UCSF): HIV Insite, 2011.

EE = ethinyl estradiol.

From the Centers for Disease Control and Prevention, 2010b; Wallach, 2000.

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Family Planning and Contraception