Flutamide — a plain guide for patients

Flutamide is an oral antiandrogen drug most often used in prostate cancer care. It blocks testosterone signals that fuel some prostate tumors. You may also see it used off-label for severe androgen-driven conditions like hirsutism, but that carries special risks for women who could become pregnant.

How flutamide works and when it's used

Flutamide stops androgens (male hormones) from activating their receptor on target cells. In prostate cancer this slows tumor growth if the cancer depends on those signals. Doctors sometimes give flutamide alongside medical or surgical castration (combined androgen blockade) to add extra antiandrogen effect.

Typical adult dose has been 250 mg taken by mouth three times daily. That schedule aims to keep active levels steady. Never change dose or stop taking flutamide without checking with your prescriber — suddenly stopping cancer drugs or hormone therapies can cause problems.

Side effects, safety and monitoring

The most serious risk with flutamide is liver injury. Before starting, most clinicians check liver tests (AST/ALT) and repeat them during treatment. Watch for jaundice (yellow skin or eyes), dark urine, persistent nausea, belly pain or extreme tiredness — those are red flags. If you notice them, stop the drug and get medical help right away.

Common side effects include hot flashes, decreased libido, erectile problems, breast tenderness or enlargement (gynecomastia), and mild gastrointestinal upset. Some people report fatigue or weight changes. Because flutamide affects hormones, it must never be used during pregnancy — it can harm a male fetus. Women of childbearing potential should use reliable contraception while taking it.

Flutamide is processed by the liver. Tell your doctor about other medicines you take, especially those that stress the liver or change liver enzyme activity (for example certain antibiotics, antifungals, or herbal supplements). Avoid heavy alcohol use while on flutamide to lower liver risk.

Expect to wait several weeks to see benefit for hormone-driven symptoms. In cancer care, doctors follow PSA (prostate-specific antigen) and imaging as needed to judge treatment effect. Labs and clinical checks are part of safe use.

If you have pre-existing liver disease, active hepatitis, or unexplained liver test abnormalities, your doctor may choose a different treatment. The same goes if you have severe heart disease or other conditions that make side effects risky.

Buying flutamide online? Use only licensed pharmacies and a valid prescription. Counterfeit or poor-quality drugs can be dangerous, especially with a medicine that affects the liver and hormones.

Questions for your clinician: "Do I need baseline liver tests?" "What symptoms require stopping the drug?" "How will we monitor effectiveness?" Keep a list of side effects and share any new symptoms promptly.

Flutamide can be a useful tool when used carefully and monitored. If you’re starting it, get clear instructions on dose, warning signs, and follow-up tests so you know what to expect and when to call for help.