Clomifene

Clomifene (INN) or clomiphene (USAN) (trademarked as Androxal, Clomid and Omifin, citrate salt Serophene) is a selective estrogen receptor modulator (SERM) of the triphenylethylene group that has become the most widely prescribed drug for ovulation induction to reverse anovulation or oligoovulation.

It is on the WHO Model List of Essential Medicines, the most important medications needed in a basic health system.

Medical uses

Clomifene is useful in those who are infertile due to anovulation or oligoovulation. Evidence is lacking for the use of clomifene in those who are infertile without a known reason. In such cases, studies have observed a clinical pregnancy rate 5.6% per cycle with clomifene treatment vs. 1.3%–4.2% per cycle without treatment.

Clomifene has also been used with other assisted reproductive technology to increase success rates of these other modalities.

Clomifene can be initiated at a dose of 50 mg daily for 5 days, starting on cycle day 3, 4, or 5 (where cycle day 1 is the first day of the menstrual period), thus being taken on cycle days 3-7, 4-8 or 5-9. During a clomifene-induced cycle, there should be frequent intercourse (every other day) the week before and including the estimated day of ovulation, (cycle days 9-18). If LH surge detection tests are used, these tests should be started 3 to 4 days after the last clomifene tablet is taken (that is, if taking clomifene on cycle days 4-8, LH surge tests should be started on cycle day 11) and continue until ovulation is indicated (that is, the test becomes positive.) or through cycle day 18. If there is no spontaneous surge, there may be an artificial triggering of oocyte release if there is an ovarian follicle of over 20 mm in size, such as by an intramuscular injection of 10,000 units of hCG. However, routinely using oocyte release triggering with hCG appears to decrease pregnancy chances compared to frequent monitoring with LH tests.