## **Core Concept**
Clomiphene citrate is a selective estrogen receptor modulator (SERM) used primarily for inducing ovulation in women with anovulatory disorders. It acts by binding to estrogen receptors in the hypothalamus, leading to an increase in gonadotropin-releasing hormone (GnRH) and subsequently luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion. However, its use can be associated with several side effects due to its estrogenic and anti-estrogenic effects on various tissues.

## **Why the Correct Answer is Right**
The correct answer, **D. Visual disturbances**, is the side effect because of which the use of clomiphene should be immediately stopped. Visual disturbances, including blurred vision, double vision (diplopia), and flashes of light (scintillating scotomas), can be indicative of a serious condition. These symptoms may suggest the development of a condition known as clomiphene-induced retinopathy or other ocular complications. Given the potential for irreversible visual impairment, any visual disturbances necessitate the immediate discontinuation of clomiphene.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While gastrointestinal side effects like nausea and vomiting are common with clomiphene, they are generally not severe enough to warrant immediate cessation of therapy.
- **Option B:** Hot flashes are a very common side effect of clomiphene due to its anti-estrogenic effects on the hypothalamus but do not typically require immediate discontinuation of the drug.
- **Option C:** Breast tenderness or gynecomastia can occur in men taking clomiphene for conditions like oligospermia. While uncomfortable, these side effects usually do not necessitate immediate stopping of the medication.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that any patient on clomiphene who reports visual disturbances should have an immediate ophthalmologic evaluation. Early detection and management of ocular side effects can prevent long-term visual impairment. This vigilance is crucial for the safe use of clomiphene.

## **Correct Answer:** D. Visual disturbances