Trametinib (Oral)

As an antineoplastic, trametinib is a prescription medication used to treat skin cancer (melanoma) that can't be surgically removed or that has spread to other parts of the body.


Trametinib helps treat skin cancer (melanoma) in patients with BRAF V600E or V600K mutations. It's only used in NSCLC patients that have the BRAF V600E mutation. Before prescribing this medication, your doctor will use a test to determine whether you have those mutations. As an antineoplastic drug, trametinib is used in combination with another medication called dabrafenib (Tafinlar)--or by itself. It works by blocking the action of an abnormal protein that tells cancer cells to replicate. This medication helps stop the spread of cancer cells.

As with any medication, there are known risks of side effects. You and your doctor must weigh the risks against the good the medication can do--in this case, preventing your cancer from spreading. Also known by its brand name, Mekinist, trametinib belongs to the group of medications called antineoplastic kinase inhibitors. This medication is available in tablet form and is only available by prescription from a licensed healthcare professional.

Conditions Treated

Type of Medicine

  • Kinase inhibitor
  • Antineoplastic drug

Side Effects

Using certain medications comes with the understanding that there's a risk of certain side effects. Some of these side effects may not occur, but if they do, seek medical attention immediately. Call your doctor if the following more common side effects occur:

  • Bleeding from the rectum or bloody stools
  • Rapid weight gain
  • Tightness in the chest
  • Extreme fatigue
  • Bleeding gums
  • Faintness
  • Dry, cracked, or scaly skin
  • Blemishes on the skin
  • Shortness of breath
  • Irregular breathing
  • Tingling in the hands and feet
  • Irritation, crusting, blistering, itching, or reddening of the skin
  • Decreased urine output
  • Swelling or bloating of the hands, face, feet, arms, or lower legs
  • Bloody nose
  • Rash
  • Pounding in the ears
  • Irregular heartbeat
  • Unusual weight loss or gain
  • Diarrhea
  • Blurred vision
  • Lightheadedness, dizziness, or fainting
  • Dilated neck veins
  • Chest pain or discomfort
  • Unusual weakness or tiredness
  • Fast, slow, pounding, or irregular heartbeat
  • Dizziness
  • Nervousness
  • Pain, swelling, or redness of the skin
  • Headache
  • Pimples
  • Troubled breathing
  • Scaling of the skin on the feet and hands
  • Ulcerations on the skin

Less common side effects include:

The following are rare side effects of this medication:

  • Seeing floating spots before the eyes, or a curtain or veil across part of your vision
  • Change in vision
  • Seeing sparks of light or flashing

Some side effects that may occur do not require medical attention, as they tend to go away during the course of treatment as your body gets used to the medication. Your doctor can help you figure out ways to prevent or reduce some of these side effects. Talk to your doctor if you experience these side effects and they become troublesome.

  • Abdominal or stomach pain
  • Itching, burning, and pain in hairy areas (accompanied by pus at the root of the hair)
  • Canker sores
  • Change in taste
  • Dark-colored urine
  • Dry eyes
  • Dry mouth
  • Dry skin
  • Pain, itching, swelling, redness, tenderness, or warmth on the skin
  • Loosening of the fingernails
  • Loss of taste
  • Muscle cramps or spasms
  • Muscle stiffness or pain
  • Soreness or redness around the fingernails
  • Ulcers, sores, or white spots on the tongue or lips, or inside the mouth
  • Inflammation or swelling of the mouth
  • Thirst

You may experience side effects not listed here. If you experience side effects other than the ones listed here, contact your healthcare provider.


Your dosage of trametinib will vary, as it varies from patient to patient. Read the directions that come with the medication and follow your doctor's instructions carefully. The following information is the average dose of trametinib. Do not change your dose if it's different than this information unless your doctor tells you to. Your dosage will be based on the strength of the medication.

To treat melanoma, adults should take two milligrams once per day. Children must have their dosage determined by a doctor.

Take trametinib at least an hour before or two hours after a meal.

If you miss a dose of trametinib, take it as soon as you remember--unless it's near the time for your next dose. In that case, skip the missed dose and resume your normal dosing schedule. Never double up on doses to make up for a missed dose. If your missed dose is within less than 12 hours of your next normal dose, skip the missed dose and take your next normal dose at the regular time.


Certain medications and medical conditions can cause interactions to occur, which could mean an increased risk of side effects. You and your doctor must determine whether the medication is worth the risk. Consider the following before taking trametinib.

Trametinib, as with any medication, may interact with certain other medications. Some include:

  • Idealisib (Zydelig)
  • Isavuconazonium (Cresemba)

It can also interact with certain foods, or with alcohol or tobacco. Talk to your doctor about taking this medication with alcohol, food, or tobacco. Medical problems that can affect the use of this medication include:

  • Bleeding problems
  • Blood clots
  • Diabetes, or a history of diabetes
  • Vision or eye problems
  • Heart disease (heart failure, cardiomyopathy, etc.)
  • Hyperglycemia (high blood sugar)
  • Hypertension (high blood pressure)
  • Lung disease or other breathing problems
  • Stomach or bowel problems (perforation, colitis, etc.)
  • Dehydration
  • Hypotension (low blood pressure)
  • Kidney failure

Those with kidney failure and stomach or bowel problems should use trametinib with caution, as they can cause any side effects you experience to become worse.


Tell your doctor if you're allergic to trametinib or the ingredients in the medication. Your pharmacist can give you a list of ingredients. Talk to your doctor about all of the medications you're allergic to and all of the medications you're currently taking. This includes prescription and OTC drugs, as well as nutritional supplements, vitamins, and herbal products. Keeping a list of your current medications on you at all times in case of an emergency is recommended. You can easily reference this list when you visit the doctors or the pharmacy.

Tell your doctor if you're pregnant or if you plan on getting pregnant. Try to avoid getting pregnant while taking this medication. Using birth control is recommended. Continue using it for up to four months after you take your final dose of trametinib. Your doctor can help you determine the best birth control methods for you. If you do get pregnant while taking trametinib, contact your doctor right away as this medication can harm your baby. This medication can make certain forms of birth control less effective, such as birth control pills, patches or injections.

Do not breastfeed your baby while taking this medication for at least four months after you take your final dose. Trametinib can also cause fertility problems, meaning it can affect your ability to have children, despite whether you're a man or a woman.

Tell your doctor if you've ever had breathing problems or lung disease; heart, kidney, eye, or liver disease; stomach problems; colitis (inflammation of the colon); diabetes; high blood pressure; bleeding problems or blood clots; or any other medical conditions.

It's vital to keep your regular doctor's appointment while taking this medication so that your doctor can closely monitor you and check your progress. This way it's easier to see whether the medication is working for you and to determine whether you should continue taking it. Urine and blood tests may be required to check for unexpected effects of the medication.

Trametinib can increase your risk of developing cutaneous squamous cell carcinoma (cuSCC) or other cancers of the skin. Talk to your doctor if you begin seeing changes to your skin, such as a new wart, a skin sore or reddish bump that won't heal, or a change in the color or size of a mole. Your doctor may want to check your skin for new skin lesions before you begin using trametinib, during your course of treatment, and for up to six months after you take your last dose. Your doctor may need to check your skin on a regular basis while using this medication.

Trametinib can cause bleeding problems so it's important to let your doctor know if you develop any of the following symptoms while taking this medication: headache, coughing up blood, prolonged bleeding from cuts, bleeding gums, increased vaginal bleeding or menstrual flow, dark brown or red urine, dizziness, difficulty swallowing or breathing, or red or black, tarry stools.

This medication can cause severe diarrhea, but you should not try to treat it yourself. Instead, contact your healthcare provider, especially if your diarrhea goes from mild to worse.

Your doctor may also need to check your blood pressure regularly while you're taking trametinib. Your doctor will closely monitor your heart function with an electrocardiograph (ECG), also called an EKG every two to three months while you're taking this medication. You might also need to have your eyes checked regularly while on trametinib.

Trametinib can pass into bodily fluids, such as vomit, urine, and feces. Anyone caring for you or your loved one should wear rubber gloves while cleaning up the patient's bodily fluids, as well as when changing diapers, or handling dirty laundry or trash. Be sure to wash your hands before putting gloves on and after taking them off. Also, washing the patient's soiled linens and clothing separately from other laundry is recommended.


Keep this medication out of sight and reach of children, and throw out any unused medication. Store trametinib in the refrigerator, but do not put it in the freezer. Keep it in its original bottle away from excess moisture and light. Do not put your medication tablets in other containers, like weekly pillboxes, as they are easier for children to open and typically do not come with a locking mechanism. Make sure to remove the desiccant (small packet included with the medication used to absorb moisture) from your medication bottle. To protect young children from accidental poisoning, keep your medication in a safe location.

Ask your doctor about safe ways to dispose of your unused medication. Ask your doctor or pharmacist about a community medicine take-back program in your area. Do not throw your medication in the trashcan and do not flush it down the toilet. Do not share your medication with anyone else and do not take anyone else's medication.

If you need to refill your prescription, ask your pharmacist or your doctor any questions you have about the process.


While trametinib is a greatly beneficial drug, it can also cause drug interactions if patients fail to let their doctors know about every medication they're taking. Designed to treat melanoma and non-small-cell lung cancer (NSCLC), this medication is used in combination with dabrafenib (Tafinlar) to treat cancer that is inoperable, or has spread to other parts of the body. It's typically only used in melanoma patients with certain mutations and NSCLC patients with one of the same mutations. Certain conditions and medications can cause your condition to worsen or cause an increased risk of side effects.

When taken correctly--that is, on time and without any missed doses--trametinib can help prevent the spread of certain skin cancers. Whether the patient suffers from melanoma or NSCLC, this medication can help improve the overall quality of life.

Last Reviewed:
December 22, 2017
Last Updated:
April 05, 2018
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