Why is this medication prescribed?

Cobimetinib is prescribed for the treatment of a specific type of skin cancer called melanoma that has a certain genetic mutation. It is used in combination with another medication called vemurafenib, which targets the same mutation. Together, cobimetinib and vemurafenib work to inhibit the growth and spread of melanoma cells.

How should this medicine be used?

Here’s how cobimetinib is typically used:

• Combination Therapy: Cobimetinib is not used alone but is prescribed in combination with vemurafenib. This combination is specifically for melanoma patients whose tumors have a mutation in the BRAF gene (BRAF V600 mutation).
• Dosage: The dosage of cobimetinib can vary depending on factors such as your overall health, other medications you may be taking, and how well you tolerate the treatment. It is usually taken orally once daily for 21 days, followed by a 7-day break (21-day cycle). This cycle may be repeated as directed by your healthcare provider.
• Administration: Cobimetinib is available in tablet form. It should be taken at approximately the same time each day, with or without food, as directed by your healthcare provider.
• Monitoring: Your healthcare provider will monitor your condition closely during treatment with cobimetinib. This may include regular blood tests to check for any changes in your blood cell counts, liver function, and other parameters.
• Duration of Treatment: The duration of treatment with cobimetinib and vemurafenib will be determined by your healthcare provider based on how well you respond to the medication and any side effects you experience.
• Follow Healthcare Provider’s Instructions: It’s crucial to follow your healthcare provider’s instructions precisely regarding the dosage, timing, and duration of cobimetinib treatment to maximize its effectiveness and minimize potential side effects.

As with any medication, it’s important to discuss with your healthcare provider or pharmacist if you have any questions or concerns about cobimetinib, its use, potential side effects, or interactions with other medications. They can provide personalized guidance based on your specific health needs and circumstances.

Other uses for this medicine

Outside of its primary use in melanoma, cobimetinib is not widely used for other medical conditions. Its effectiveness is linked to its specific action against the BRAF V600 mutation in melanoma cells. Clinical trials and research are ongoing to explore potential uses in other types of cancers or conditions, but currently, melanoma treatment remains its main application.

What special precautions should I follow?

Special Precautions for Cobimetinib:

• Heart Problems: Cobimetinib can cause heart-related problems, such as abnormal heartbeats (arrhythmias) and heart muscle problems (cardiomyopathy). Inform your healthcare provider if you have a history of heart disease or any other heart-related issues before starting treatment.
• Liver Function: Cobimetinib can affect liver function, leading to elevated liver enzyme levels. Regular monitoring of liver function tests is essential during treatment. Inform your healthcare provider if you have a history of liver disease or if you notice symptoms such as yellowing of the skin or eyes (jaundice), abdominal pain, or dark urine.
• Eye Problems: Some patients may experience visual disturbances or eye problems while taking cobimetinib. Inform your healthcare provider if you experience any changes in vision, such as blurred vision or flashes of light.
• Bleeding: Cobimetinib may increase the risk of bleeding, including serious or fatal bleeding. Inform your healthcare provider if you have a history of bleeding disorders or are taking medications that affect blood clotting.
• Skin Reactions: Skin toxicity, including rash, photosensitivity reactions (increased sensitivity to sunlight), and severe skin reactions, can occur with cobimetinib. Use sunscreen and protective clothing when outdoors, and inform your healthcare provider if you develop any skin changes.
• Pregnancy and Breastfeeding: Cobimetinib can cause harm to an unborn baby if used during pregnancy. It is essential to use effective contraception during treatment and for a period after discontinuation. It is not known whether cobimetinib passes into breast milk, so breastfeeding is not recommended during treatment.
• Drug Interactions: Cobimetinib can interact with other medications, including over-the-counter drugs, supplements, and herbal products. Inform your healthcare provider about all medications you are taking to avoid potential interactions.
• Follow-up: Attend all scheduled appointments with your healthcare provider for monitoring and evaluation during treatment with cobimetinib. This includes regular blood tests and other necessary assessments to monitor your response to treatment and detect any potential side effects early.

Always follow your healthcare provider’s instructions and communicate any concerns or questions you have about cobimetinib or your treatment plan. They can provide personalized guidance based on your medical history and individual circumstances.

What special dietary instructions should I follow?

• Grapefruit: Avoid consuming grapefruit or grapefruit juice during treatment, as it can interact with Cobimetinib and increase the risk of side effects.
• High-Fat Meals: Take Cobimetinib on an empty stomach or with a low-fat meal, as high-fat meals can increase the absorption of the medication and the risk of side effects.

What should I do if I forget a dose?

• If you miss a dose of Cobimetinib, take it as soon as you remember on the same day.
• If it’s almost time for your next dose, skip the missed dose and take your next dose at the regular time.
• Do not take extra doses to make up for a missed one.

What side effects can this medication cause?

Cobimetinib, like many medications, can cause a range of side effects. These can vary in severity and may affect individuals differently. Here are some common side effects associated with Cobimetinib:

• Gastrointestinal Effects:
  • Nausea
  • Vomiting
  • Diarrhea
  • Constipation
  • Abdominal pain
• Skin Reactions:
  • Rash (including acneiform rash, which resembles acne)
  • Photosensitivity (increased sensitivity to sunlight, leading to sunburn more easily)
• Fatigue: Feeling tired or weak.
• Liver Function Changes:
  • Increased liver enzymes (detected through blood tests)
  • Hepatotoxicity (liver damage, though rare)
• Eye Problems:
  • Retinal vein occlusion (blockage of a vein in the eye, which can lead to vision problems)
  • Vision changes
• Other Common Side Effects:
  • Fever
  • Headache
  • Muscle pain
  • Decreased appetite
• Cardiovascular Effects:
  • Hypertension (high blood pressure)
  • Decreased left ventricular ejection fraction (reduced ability of the heart to pump blood)
• Serious Side Effects:
  • Severe allergic reactions (rare but possible)
  • Severe skin reactions (Stevens-Johnson syndrome or toxic epidermal necrolysis)

It’s important to note that not all patients will experience these side effects, and some may experience them to varying degrees of severity. Your healthcare provider will monitor you closely for any signs of adverse effects during treatment with Cobimetinib. If you notice any unusual symptoms or side effects while taking this medication, it’s crucial to inform your doctor promptly.

What should I know about storage and disposal of this medication?

Storage and Disposal of Cobimetinib:

• Storage:
  • Store Cobimetinib tablets at room temperature between 20°C to 25°C (68°F to 77°F).
  • Keep the medication in its original container and away from moisture and heat.
  • Do not store in the bathroom.
• Disposal:
  • Dispose of any unused or expired Cobimetinib properly according to local regulations or guidelines.
  • Do not flush medications down the toilet or pour them into a drain unless instructed to do so.
  • Ask your pharmacist or healthcare provider about the proper disposal of Cobimetinib.

In case of emergency/overdose

• Emergency:
  • In case of any serious side effects or symptoms of overdose (such as severe dizziness, difficulty breathing, fainting), seek immediate medical attention.
  • Have emergency contact numbers readily available, such as local poison control centers or emergency medical services (911 in the US).
• Overdose:
  • There is no specific antidote for Cobimetinib overdose.
  • Treatment would typically involve supportive care and management of symptoms.

What other information should I know?

• Monitoring: Your doctor will regularly monitor your condition, including blood tests to check liver function and other parameters. Report any new or worsening symptoms promptly to your healthcare provider.
• Pregnancy/Breastfeeding: Cobimetinib can cause harm to an unborn baby, so use effective birth control during treatment and avoid breastfeeding. Discuss family planning and contraceptive options with your healthcare provider.
• Drug Interactions: Inform your doctor about all medications you are taking, including prescription drugs, over-the-counter medications, vitamins, and herbal supplements. Some medications can interact with Cobimetinib, affecting how it works or increasing the risk of side effects.
• Follow-up: Attend all scheduled appointments with your healthcare provider to monitor your response to Cobimetinib and manage any potential side effects effectively.
• Special Situations: If you have any surgeries planned, inform your surgeon or healthcare provider that you are taking Cobimetinib, as it may affect anesthesia and recovery.

Always follow your healthcare provider’s instructions and guidance regarding the use of Cobimetinib. If you have any questions or concerns about your medication, storage, or any aspect of your treatment plan, do not hesitate to discuss them with your healthcare team.