clomiphene

Action and Spectrum

Clomiphene citrate is a selective estrogen receptor modulator used as a fertility drug to stimulate ovulation. It blocks estrogen receptors in the hypothalamus tricking the brain into thinking low estrogen levels. This leads to increased GnRH release, FSH and LH stimulation, and ovulation. 

Drug Interaction

Adverse Reaction

Frequency defined 

>10% 

Vasomotor flushing (10%) 

Ovarian enlargement (14%) 

1-10% 

Blurred vision (1.5%) 

Abdominal discomfort (6%) 

Nausea/vomiting (2%) 

Breast discomfort (2%) 

Black Box Warning

Blackbox warning: 

None 

Contraindication / Caution

Contraindication/caution: 

It is contraindicated with liver disease, ovarian cysts, hormone-dependent tumors, abnormal uterine bleeding, primary ovarian failure, and untreated thyroid or adrenal dysfunction. 

Pregnancy / Lactation

Pregnancy/lactation: 

Pregnancy warnings:     

US FDA pregnancy category: Not assigned.  

Lactation:  

Excreted into human milk is unknown  

Pregnancy Categories:        

• Category A: Satisfactory and well-controlled studies show no risk to the fetus in the first trimester or the later trimester        
• Category B: No evidence shown of risk to the fetus found in animal reproduction studies, and there are not enough studies on pregnant women        
• Category C: Adverse effects on the fetus found with evidence in animal reproduction studies and no adequate evidence for a result in humans must take care of potential risks in pregnant women        
• Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits        
• Category X: Drugs listed in this category outweigh risks over benefits. Hence these categories of drugs need to be avoided by pregnant women        
• Category N: There is no data available for the drug under this category      

Pharmacology

Pharmacology: 

Pharmacodynamics: 

Clomiphene acts by binding to estrogen receptors in hypothalamus leading to an inhibition of negative feedback by estrogen. This results in an increase in the release of gonadotropin-releasing hormone (GnRH). 

Increased GnRH stimulates the anterior pituitary gland to release more follicle-stimulating hormone and luteinizing hormone. 

Elevated levels of FSH and LH stimulate the growth and maturation of ovarian follicles which can lead to ovulation. 

Pharmacokinetics: 

Absorption 

It is well absorbed 

Distribution 

Highly bound to plasma proteins. 

Metabolism 

Metabolized by hydroxylation and desmethylation. 

Elimination 

Elimination half-life is 5 to 7 days. 

Adminstartion

Patient Information Leaflet

Patient Information Leaflet   

Generic Name: clomiphene 

Why do we use clomiphene? 

Clomiphene induces ovulation in women with infertility like anovulatory infertility, polycystic ovary syndrome (PCOS), unexplained infertility, and assisted reproductive technologies (ART). It works by blocking estrogen receptors in the hypothalamus by tricking brain into thinking low estrogen levels and releasing gonadotropin. Clomiphene is commonly used in these cases to increase the chances of ovulation and conception.