Trametinib

Trametinib comes as tablets (0.5 mg and 2 mg).

• Dose: The usual dose is 2 mg once a day. Your dose may be changed depending on any side effects you may have. It's important to make sure you're taking the correct dose every time. Before every dose, check that what you're taking matches what you've been prescribed.
• Timing of your dose: Take trametinib once a day. If you're also taking dabrafenib, take your dose at the same time either with your morning or evening dose of dabrafenib.
• Food: Take trametinib tablets on an empty stomach. Don't eat for 2 hours before and 1 hour aftewards.
• Swallow the tablets whole with a glass of water: Don't crush, break or chew them.
• Missed dose: If you forget your dose, take it as soon as you remember that day unless it's 12 hours or less until your next dose is due. If that's the case, skip the forgotten dose and take your next dose at the usual time. Don't take 2 doses at once to make up for a missed dose.

Here are some things to know when you're taking trametinib. Other things may be important as well, so ask your healthcare provider what you should know about.

• Tests and monitoring: Trametinib can cause an increase in blood pressure so your blood pressure will be checked every few weeks while you're receiving treatment. It usually settles down when treatment is stopped. While you're taking trametinib, you'll also need regular blood tests to monitor for side effects and to check whether the treatment is working. Blood tests are very important during the first few months of treatment. Over time, these tests are needed less often.
• Pregnancy: Trametinib can harm an unborn baby. You should not become pregnant while you're taking trametinib and for 16 weeks after stopping treatment. Discuss with your healthcare provider which types of contraception are suitable for you and your partner. If you and your partner are planning a pregnancy, talk to your healthcare provider.
• Increased risk of infections:  Trametinib, when given with chemotherapy medicines, weakens your body’s immune (defence) system, so you're more likely to pick up infections. It's important to avoid anyone who has chickenpox or shingles.
• Vaccines: Some vaccines shouldn't be taken if you are on trametinib. Always check with your healthcare provider or pharmacist first. The annual flu vaccine is safe.
• Taking other medicines: Trametinib may interact with a few medicines and herbal supplements, so check with your healthcare provider or pharmacist before starting trametinib or  any new medicines. This includes those you may buy over the counter.
• Storing your trametinib tablets: Keep trametinib tablets in the fridge. Once opened, the bottle can be stored at room temperature for up to 30 days. Do not store the tablets in the bathroom or near a sink, or on a windowsill or in the car. Light, heat, and dampness will affect the medicine. There is a desiccant (moisture absorber) in the bottle to protect the capsules from moisture. Keep the desiccant in the bottle during use and keep the capsules in their original container.

Like all medicines, trametinib can cause side effects, although not everyone gets them. You may experience side effects at any time during your treatment or even months after treatment has finished. Most of the side effects of trametinib are likely to improve after you stop having treatment, but some may last longer.

To monitor your side effects, you'll need monitoring and blood tests to check your heart, liver, kidneys and blood before you start treatment and regularly while you're receiving treatment.

Note: This is not a full list of side effects and side effects can vary for different people. If you don't know whether your symptoms are side effects of the medicine, contact your healthcare team straight away.

Common side effects

Tell your healthcare provider if they're not getting better or are getting worse.

• Feeling very tired and weak (fatigue).
• Diarrhoea (runny poo) or nausea (feeling sick).
• Headache.
• Abdominal pain.
• Muscle and joint pain.
• Constipation.
• Skin rash, itching, dryness.
• Stuffy, blocked nose or sore throat.
• Unusual bleeding or bruising.
• Dry mouth.

Tell your healthcare provider immediately or phone Healthline free on 0800 611 116 if these occur

• Signs of a fever or temperature such as chills, sweats, shivers or shakes. If your temperature is 38C or higher stop taking dabrafenib (and trametinib) and contact your healthcare provider.
• Signs of lung problems such as cough, wheeze, fever (high temperature) or problems breathing.  
• Problems with your eyes such as blurring or loss of vision, eye pain or redness or sensitivity to light.
• Signs of kidney problems such as blood in your urine (pee) or peeing less often than usual.
• Signs of heart problems such as shortness of breath, dizziness, changes to your heartbeat (palpitations) or swollen feet and ankles.

Phone 111 for an ambulance or go to your nearest accident and emergency (A&E) clinic if these occur

• Signs of an allergic reaction such as itchy skin, and rash, swollen lips or tongue, problems breathing, like a tight chest or shortness of breath.
• Signs of heart problems such as chest pain, pressure, heaviness, tightness or squeezing across the chest, difficulty breathing.
• Temperature of 38C or higher if not getting better, despite stopping trametinib (and dabrafenib).