CLOMIPHENE CITRATE

CLOMIPHENE CITRATE
(kloe'mi-feen)
Clomid, Milophene, Serophene
Classifications: hormone; ovulation stimulant; antiestrogenic;
Therapeutic:ovulation stimulant
Pregnancy Category: X

Availability

50 mg tablets

Action

Oral nonsteroidal selective estrogen receptor modulator (SERM). Induces ovulation in selected infrequently ovulating or anovulatory women. Clomiphene blocks the normal negative feedback of circulating estradiol on the hypothalamus, preventing estrogen from lowering the output of gonadotropin releasing hormone (GnRH). It acts by binding to hypothalamic estrogen receptors, decreasing their numbers, and thereby inhibiting receptor replenishment.

Therapeutic Effect

Inhibition of receptor replenishment results in a false hypoestrogenic state which stimulates pituitary release of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and gonadotropins, leading to ovarian stimulation.

Uses

Infertility in appropriately selected women desiring pregnancy whose partners are fertile and potent.

Unlabeled Uses

Male infertility, menstrual abnormalities, gynecomastia, fibrocystic breast disease, regulation of cycles in patients using rhythm method of contraception, endometrial hyperplasia, persistent lactation.

Contraindications

Neoplastic lesions, ovarian cyst; hepatic disease or dysfunction; abnormal uterine bleeding; endometriosis; primary ovarian failure; men with testicular failure; untreated thyroid disease; visual abnormalities; major depression or psychosis; thrombophlebitis; pregnancy (category X); lactation.

Cautious Use

Polycystic ovarian enlargement, pelvic discomfort, sensitivity to pituitary gonadotropins.

Route & Dosage

Infertility
Adult: PO First course: 50 mg/d for 5 d; start on 5th day of cycle following start of spontaneous or induced bleeding (with progestin) or at any time in the patient who has had no recent uterine bleeding Second course if ovulation: Repeat first course until conception or for 3 cycles Second course if no ovulation: 100 mg/d for 5 d as above (max: 100 mg/d)

Administration

Oral

Pretreatment with estrogen is indicated for the patient who has been hypoestrogenic for a long time. Estrogen therapy is stopped immediately before clomiphene therapy begins.
Each course of therapy should start on or about the 5th cycle day once ovulation has been established.
Store at 15°–30° C (59°–86° F) in tightly capped, light-resistant container.

Adverse Effects (≥1%)

Body as a Whole: Vasomotor flushes, breast discomfort, abdominal pain, heavy menses, exacerbation of endometriosis; mental depression, headache, fatigue, insomnia, dizziness, vertigo. GI: Nausea, vomiting, increased appetite with weight gain, constipation, bloating. Endocrine: Spontaneous abortion, multiple ovulations, ovarian failure, ovarian hyperstimulation syndrome, enlarged ovaries with multiple follicular cysts. Special Senses: Transient blurring, diplopia, scotomas, photophobia, floaters, prolonged after-images. Urogenital: Urinary frequency, polyuria.

Diagnostic Test Interference

Clomiphene may increase BSP retention; plasma transcortin, thyroxine and sex hormone binding globulin levels. Also increases follicle-stimulating and luteinizing hormone secretion in most patients.

Interactions

Drug: No clinically significant drug interactions established. Herbal: Black cohosh may antagonize infertility treatments.

Pharmacokinetics

Absorption: Readily absorbed from GI tract. Metabolism: In liver. Elimination: Primarily in feces in 5 d; the remainder is excreted slowly from enterohepatic pool or is stored in body fat for later release. Half-Life: 5 d.

Nursing Implications

Assessment & Drug Effects

Monitor for abnormal bleeding. If it occurs, full diagnostic measures are crucial. Report it immediately.
Monitor for visual disturbances. Their occurrence indicates the need for a complete ophthalmologic evaluation. Drug will be stopped until symptoms subside.
If clomiphene is continued more than 1 y, patient should have an ophthalmologic examination at regular intervals.
Pelvic pain indicates the need for immediate pelvic examination for diagnostic purposes.

Patient & Family Education

Take the medicine at same time every day to maintain drug levels and prevent forgetting a dose.
Missed dose: Take drug as soon as possible. If not remembered until time for next dose, double the dose, then resume regular dosing schedule. If more than one dose is missed, check with physician.
Incidence of multiple births during clomiphene use is reportedly increased to 6 times normal and appears to increase with dose increases.
Patient who is going to respond usually ovulates 4–10 d after last day of treatment.
Report these symptoms: hot flushes resembling those associated with menopause; nausea, vomiting, headache. Appropriate drug therapy may be prescribed. Symptoms disappear after clomiphene is discontinued.
Report promptly yellowing of eyes, light-colored stools, yellow, itchy skin, and fever symptomatic of jaundice.
Stop taking clomiphene if pregnancy is suspected. Contact physician for a confirmatory examination.
Because of the possibility of light-headedness, dizziness, and visual disturbances, do not perform hazardous tasks requiring skill and coordination in an environment with variable lighting.
Report promptly excessive weight gain, signs of edema, bloating, decreased urinary output.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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