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DESCRIPTION

Clomiphene citrate tablets USP is an orally administered, non steroidal, ovulatory stimulant designated chemically as 2[p-(2- chloro-1,2-diphenylvinyl) phenoxy]] trieth lamine citrate (1:1). It has the molecular formula of C26H28ClNO•C6H8O7 and a molecular weight of 598.09.

Clomiphene citrate is a white to pale yellow, essentially odorless, crystalline powder. It is freely soluble in methanol, soluble in ethanol; slightly soluble in acetone, water, and chloroform; and insoluble in ether. Clomiphene citrate tablets USP is a mixture of two geometric isomers [cis (zuclomiphene) and trans (enclomiphene)] containing between 30% and 50% of the cis-isomer.

Each white scored tablet contains 50 mg clomiphene citrate USP. The tablet also contains the following Inactive Ingredients: corn starch, lactose, magnesium stearate, pregelatinized corn starch, and sucrose



CLINICAL PHARMACOLOGY

Action

Clomiphene citrate tablets USP is a drug of considerable pharmacologic and proper management of the patient, clomiphene citrate tablets USP potency. With careful selection has been demonstrated to be a useful therapy for the anovulatory patient desiring pregnancy.

Clomiphene citrate is capable of interacting with estrogen-receptor-containing tissues, including the hypothalamus, pituitary, ovary, endometrium. vagina, and cervix it may compete with estrogen for estrogen-receptor-binding sites and may delay replenishment of intracellular estrogen receptors. Clomiphene crtrate initiates a series of endocrine events culminating in a preovulatory gonadotropin surge and subsequent follicular rupture. The first endocrine event in response to a course of clomiphene therapy, is an increase in the release of pituitary gonadotropins. This initiates steroidogenesis and folliculogenesis resulting in growth of the ovarian follicle and an increase in the circulating level of estradiol. Following ovulation, plasma progesterone and estradiol rise and fall as they would in a normal ovulatory cycle.

Available data suggest that both the estrogenic and antiestrogenic properties of clomiphene may participate in the initiation of ovulation. The two clomiphene isomers have been found to have mixed estrogenic and antrestrogenic effects, which may vary from one species to another. Some data suggest that zuclomiphene has greater estrogenic activity then enclomrphene.

Clomiphene citrate has no apparent progestational, androgenic , or antrandrogenic effects and does not appear to interfere with pituitary-adrenal or pituitary-thyroid function.

Although there is no evidence of a carryover effect of clomiphene citrate tablets USP, spontaneous ovulatory menses have been noted in some patients after clomiphene citrate tablets USP therapy.

Pharmacokinetics

Based on early studies with 14 C-labeled clomiphene citrate, the drug was shown to be readily absorbed orally in humans and excreted principally in the feces. Cumulative urinary and fecal excretion of the 14C averaged about 50% of the oral dose and 37% of an intravenous dose after 5 days. Mean urinary excretion was approximately 8% with fecal excretion of about 42 %.

Some 14C label was still present in the feces 6 weeks after administration Subsequent single-dose studies in normal volunteers showed that zuclomiphene (CIS) has a longer half-life than enclomiphene (trans). Detectable levels of zuclomiphene persisted for longer than a month in these subjects. This may be suggestive of stereo-specific enterohepatic recycling or sequestering of the zuclomiphene. Thus, it is possible that some active drug may remain in the body during early pregnancy in women who conceive in the menstrual cycle during clomiphene citrate tablets USP therapy


SIDE EFFECTS

Clinical Events

Trial Adverse: Clomiphene citrate Tablets USP at recommended dosages, is generally well tolerated. Adverse reactions usually have been mild and transient and most have disappeared promptly after treatment has been discontinued.

The following adverse events have been reported in fewer than 1% of patients in clinical trails: Acute abdomen, appetite increase, constipation, dermatitis or rash, depression, diarrhea, dizziness, fatigue, hair loss/dry hair, increased urinary frequency/volume, insomnia, light-headedness, nervous tension, vaginal dryness, vertigo, weight gain/loss.

Patients on prolonged clomiphene citrate tablets USP therapy may show elevated serum levels of desmoschol. This is most likely due to a direct interference with cholesterols synthesis. However, the serum sterols in patients receiving the recommended dose of clomiphene citrate tablets USP are not significantly altered. Ovarian cancer has been infrequently reported in patients who have received fertility drugs. Infertility is a primary risk factor for ovarian cancer; however, epidemiology data suggest that prolonged use of clomiphene citrate tablets USP may increase the risk of a borderline or invasive ovarian tumor.

Dermatologic: Acne, allergic reaction, erythema, erythema multiforme, erythema nodosum, hypertrichosis, pruritus.

Central Nervous System: Migraine headache, paresthesia, seizure, stroke, syncope.

Psychiatric: Anxiety irritability, mood changes, psychosis.

Visual Disorders: Abnormal accommodation, cataract, eye pain, macular edema, optic neuritis, photopsia, posterior vitreous detachment, retinal hemorrhage, retinal thrombosis, retinal vascular spasm, temporary loss of vision.

Cardiovascular: Arrhythmia, chest pain, edema, hypertension, palpitation, phlebitis, pulmonary embolism, shortness of breath, tachycardia, thrombophlebitis.

Musculoskeletal: Arthralgia, back pain, myalgia.

Hepatic: Transaminases increased, hepatitis.

Neoplasms: Liver (hepatic hemangiosarcoma, liver cell adenoma, hepatocellular carcinoma); breast (fibrocystic disease, breast carcinoma); endometrium (endometrial carcinoma); nervous system (astrocytoma, pituitary tumor, prolactinoma, neurofibromatosis, glioblastoma multiforme, brain abcess); ovary (luteoma of pregnancy, dermoid cyst of the ovary, ovarian carcinoma); trophoblastic (hydatiform mole, choriocarcinoma); miscellaneous (melanoma, myeloma, perianal cysts, renal cell carcinoma, Hodgkin’s lymphoma, tongue carcinoma, bladder carcinoma); and neoplasms of offspring (neuroectodermal tumor, thyroid tumor, hepatoblastoma, lymphocytic leukemia).

Genitourinary: Endometriosis, ovarian cyst (ovarian enlargement or cysts could, as such, be complicated by adnexal torsion), ovarian hemorrhage, tubal pregnancy, uterine hemorrhage Body as a Whole: Fever, tinnitus, weakness.

Other: Leukocytosis, th roid disorder.

Fetal/Neoastal Anomalies


DRUG INTERACTIONS

Drug interactions with clomiphene citrate tablets USP have not been documented.