Mirdametinib: what it treats, how to take it, side effects
Last updated September 7, 2026.
**Mirdametinib (Gomekli) is a prescription MEK inhibitor used to treat certain nerve tumors in neurofibromatosis type 1.** It blocks growth signals that help these tumors grow. It can damage your eyes, so keep scheduled eye exams and report vision changes immediately.
What does it treat?
You may receive mirdametinib for neurofibromatosis type 1 (NF1) with plexiform neurofibromas that cause symptoms and cannot be completely removed surgically. These nerve tumors can cause pain or limit movement. It is approved for adults and children ages 2 and older.
How do you take it?
The labeled dose is 2 mg per square meter of body surface area twice daily, about 12 hours apart, for 21 days followed by 7 days off. Your prescriber calculates your dose from your height and weight; at a body surface area of at least 1.5 square meters, the dose is 4 mg twice daily, the maximum of 8 mg daily. Take it with or without food. Capsules come in 1 mg and 2 mg strengths and must stay whole; 1 mg tablets for oral suspension can be swallowed whole or dispersed in water as instructed. Skip missed doses; never replace a vomited dose. Hold treatment and seek urgent advice for severe vision changes, peeling rash, or symptoms of heart failure.
Side effects to know
- Common: You may develop rash, diarrhea, nausea, vomiting, fatigue, or muscle and joint pain.
- Serious: Serious effects include retinal damage, weakened heart pumping, and severe skin reactions. Stop taking it and get urgent help for vision loss, chest pain, new breathlessness, or peeling skin.
Who should not take it?
Discuss heart, eye, kidney, or liver disease and medication allergies before starting. Have your pharmacist review every medicine and supplement. Mirdametinib can harm a pregnancy; discuss pregnancy plans before treatment and report pregnancy immediately. Do not breastfeed during treatment or for 1 week afterward. The label gives no alcohol limit; ask your prescriber before drinking.
When is it an emergency?
For any suspected overdose, call Poison Control at 1-800-222-1222 immediately, even without symptoms. Specific overdose signs are not established. Call 911 for collapse or breathing trouble, including throat swelling from a possible allergic reaction. Sudden vision loss or severe chest pain needs emergency evaluation.
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Common questions
What is the maximum dose?
The maximum is 4 mg twice daily. That totals 8 mg on treatment days. Your prescribed dose may be lower, and you take no doses during the scheduled 7 days off.
Can I drink alcohol?
The FDA label does not set an alcohol limit. That does not establish that drinking is safe for you. Ask your prescriber to review your symptoms, liver health, and other medicines before drinking.
What if I could become pregnant?
Have a pregnancy test before starting. Use effective birth control during treatment and for 6 weeks afterward if you can become pregnant. If you are male with a partner who can become pregnant, use effective contraception during treatment and for 3 months afterward.
Do I need to take it with food?
You can take it with or without food. Keep doses about 12 hours apart. If you vomit afterward, wait until your next scheduled dose.
What are overdose symptoms?
A specific overdose symptom pattern is not established. Do not wait for symptoms: call Poison Control at 1-800-222-1222. Call 911 for collapse or breathing trouble.
Does it interact with other medicines?
Clinical drug interaction studies have not been conducted. Give your pharmacist a complete medication and supplement list. Check before adding, stopping, or changing any product.