Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Tafinlar (Dabrafenib). If you are concerned about side effects, discuss the risks and benefits of Tafinlar (Dabrafenib) with your doctor.

The following side effects have been reported by at least 1% of people taking Tafinlar (Dabrafenib). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• acne-like skin condition
• Constipation
• cough
• decreased appetite
• Diarrhea
• Dry Mouth
• dry skin
• hair loss or thinning
• headache
• increased sensitivity of skin to sunlight
• increased sweating
• itching
• lack of energy
• mouth sores or ulcers
• nausea
• nail changes
• rash
• skin tags
• stomach pain
• thickened skin
• tingling, burning pain on palms
• vomiting
• weakness
• weight changes

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• blood pressure changes (high or low)
• changes to skin colour, thickness, or texture
• chills
• Fever
• flu-like symptoms (sudden lack of energy, fever, cough, sore throat)
• inflammation inside the nose
• joint or muscle pain
• new lesions on skin
• night sweats
• redness and swelling of fingers, palms, soles of feet
• signs of a blood clot in the arm or leg (tenderness, pain, swelling, warmth, or redness in the arm or leg) or lungs (difficulty breathing, sharp chest pain that is worse when breathing in, coughing, coughing up blood, sweating, or passing out)
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• signs of dehydration (e.g., decreased urine, dry skin, dry and sticky mouth, sleepiness, dizziness, headache, thirst, confusion)
• signs of infection (symptoms may include fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness)
• signs of kidney problems (e.g., increased urination at night, decreased urine production, blood in the urine)
• signs and symptoms of changes in heart rhythm including feeling dizzy or faint, seizures, palpitations, or a rapid, pounding, or irregular heartbeat
• symptoms of high blood sugar (e.g., frequent urination, increased thirst, excessive eating, unexplained weight loss, poor wound healing, infections, fruity breath odour)
• symptoms of low sodium levels in the blood (e.g., achy, stiff or uncoordinated muscles, confusion, tiredness, weakness)
• symptoms of lung inflammation (e.g., shortness of breath, cough, fatigue, loss of appetite, unintentional weight loss)
• vision changes (e.g., redness, swelling, blurred vision, eye pain, pain or irritation by light)
• wart-like growths

Stop taking the medication and seek immediate medical attention if any of the following occur:

• fever with chills, dizziness or dehydration, or Low Blood Pressure
• signs of bleeding in the stomach (e.g., bloody, black, or  tarry stools, spitting up of blood, vomiting blood or material that looks like coffee grounds)
• signs of pancreatitis (e.g., abdominal pain on the upper left side, back pain, nausea, fever, chills, rapid heartbeat, swollen abdomen)
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of Stroke (e.g., sudden or severe headache; sudden loss of coordination; vision changes; sudden slurring of speech; or unexplained weakness, numbness, or pain in arm or leg)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Tafinlar (Dabrafenib).

50 mg
Each opaque, dark red capsule, monogrammed with "GSTEW" and "50 mg" contains 50 mg of Tafinlar (Dabrafenib) as Tafinlar (Dabrafenib) mesylate. Nonmedicinal ingredients: magnesium stearate, colloidal silicon dioxide, and microcrystalline cellulose. Capsule shells contain hypromellose, red iron oxide (E172), and titanium dioxide (E171). Monogramming ink contains black iron oxide, shellac, and propylene glycol.

75 mg
Each opaque, dark pink capsule, monogrammed with "GSLHF" and "75 mg" contains 75 mg of Tafinlar (Dabrafenib) as Tafinlar (Dabrafenib) mesylate. Nonmedicinal ingredients: magnesium stearate, colloidal silicon dioxide, and microcrystalline cellulose. Capsule shells contain hypromellose, red iron oxide (E172), and titanium dioxide (E171). Monogramming ink contains black iron oxide, shellac, and propylene glycol.

Do not take Tafinlar (Dabrafenib) if you are allergic to Tafinlar (Dabrafenib) or any ingredients of the medication.

There may be an interaction between Tafinlar (Dabrafenib) and any of the following:

• Abiraterone
• alpha-blockers (e.g., Alfuzosin, Doxazosin, Tamsulosin)
• Amiodarone
• amphotericin B
• antacids (e.g., aluminum hydroxide, calcium carbonate, magnesium hydroxide, sodium bicarbonate)
• antihistamines (e.g., cetirizine, doxylamine, Diphenhydramine, Hydroxyzine, Loratadine)
• antipsychotics (e.g., Aripiprazole, Chlorpromazine, Clozapine, Haloperidol, Olanzapine, Quetiapine, Risperidone)
• Apalutamide
• Apixaban
• Aprepitant
• "azole" antifungals (e.g., itraconazole, ketoconazole, Voriconazole)
• barbiturates (e.g., Phenobarbital, secobarbital)
• benzodiazepines (e.g., Clonazepam, Diazepam, Lorazepam)
• Bicalutamide
• birth control pills (estrogen/progestin)
• Bisoprolol
• Bosentan
• Buprenorphine
• Bupropion
• Buspirone
• Calcitriol
• calcium channel blockers (e.g., Amlodipine, Diltiazem, Nifedipine, Verapamil)
• cancer medications (e.g., Busulfan, Cyclophosphamide, Tamoxifen, Vinblastine)
• Celecoxib
• chloroquine
• Clopidogrel
• Codeine
• conivaptan
• Cyclosporine
• Cyproterone
• Dantrolene
• Dapsone
• Darifenacin
• Deferasirox
• Degarelix
• Dexamethasone
• diabetes medications (e.g., chlorpropamide, glipizide, Glyburide, insulin, Metformin, Rosiglitazone)
• Digoxin
• Disopyramide
• dofetilide
• Domperidone
• Dronedarone
• Eltrombopag
• Enzalutamide
• estrogens (e.g., Estradiol, Estropipate)
• Everolimus
• Fentanyl
• Flecainide
• Flutamide
• Fesoterodine
• Gemfibrozil
• grapefruit juice
• Guanfacine
• H2-antagonists (antacids; e.g., Famotidine, Ranitidine)
• Hepatitis C antivirals (e.g., daclatasvir, dasabuvir, ledipasvir, paritaprevir, ombitasvir, sofosbuvir)
• HIV non-nucleoside reverse transcriptase inhibitors (e.g., delavirdine, efavirenz, etravirine, nevirapine)
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• Irbesartan
• isosorbide dinitrate/mononitrate
• lidocaine
• Lomitapide
• Losartan
• lumacaftor
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• maraviroc
• Mefloquine
• Methadone
• Metronidazole
• mifepristone
• Mirtazapine
• Moclobemide
• Modafinil
• Montelukast
• Naloxegol
• nefazodone
• Oxycodone
• pentamidine
• praziquantel
• Primaquine
• procainamide
• progestins (e.g., Levonorgestrel, Progesterone, mestranol)
• Propafenone
• other protein kinase inhibitors (e.g., Bosutinib, Dasatinib, imatinib, Nilotinib)
• proton pump inhibitors (e.g., Lansoprazole, Omeprazole, Pantoprazole)
• quinidine
• quinine
• quinolone antibiotics (e.g., ciprofloxacin, Norfloxacin, Ofloxacin)
• rifabutin
• rifampin
• rilpivirine
• Riociguat
• Rivaroxaban
• Roflumilast
• Romidepsin
• St. John's wort
• Selegiline
• seizure medications (e.g., Carbamazepine, Clobazam, Ethosuximide, Levetiracetam, phenobarbital, Phenytoin, primidone, Topiramate, Valproic acid, zonisamide)
• selective serotonin reuptake inhibitors (SSRIs; e.g., Citalopram, Fluoxetine, Paroxetine, Sertraline)
• serotonin antagonists (anti-emetic medications; e.g., Granisetron, Ondansetron)
• Sildenafil
• simeprevir
• Sirolimus
• Solifenacin
• Sotalol
• "statin" anti-cholesterol medications (e.g., Atorvastatin, Lovastatin, Simvastatin)
• sulfonamide antibiotics ("sulfas"; e.g., sulfisoxazole, sulfamethoxazole)
• Tacrolimus
• Tetrabenazine
• Tetracycline
• Ticagrelor
• Ticlopidine
• Tolterodine
• Tolvaptan
• Tramadol
• Trazodone
• tretinoin
• tricyclic antidepressants (e.g., Amitriptyline, Clomipramine, Desipramine, Trimipramine)
• Trimethoprim
• Ulipristal
• Venlafaxine
• Warfarin
• Zafirlukast
• Zolpidem
• Zopiclone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Tafinlar (Dabrafenib). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Tafinlar (Dabrafenib).

Bleeding: People taking the combination of trametinib and Tafinlar (Dabrafenib) may be more likely to have difficulty stopping cuts from bleeding. If you notice any signs of bleeding, such as frequent nosebleeds, unexplained bruising, or black and tarry stools, notify your doctor as soon as possible. Your doctor will order routine blood tests to make sure potential problems are caught early.

Blood Clots: People who take Tafinlar (Dabrafenib) in combination with trametinib may be at increased risk of developing blood clots, causing a reduction of blood flow to organs or the extremities.

If you have a history of clotting you may be at increased risk of experiencing blood-clot-related problems such as Heart Attack, stroke, or clots in the deep veins of your leg. Discuss with your doctor how Tafinlar (Dabrafenib) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Tafinlar (Dabrafenib), and whether any special monitoring is needed.

If you experience symptoms such as sharp pain and swelling in the leg, difficulty breathing, chest pain, blurred vision or difficulty speaking, contact your doctor immediately.

Diabetes: Tafinlar (Dabrafenib) may cause an increase in blood sugar levels and glucose tolerance may change. If you have diabetes, you may find it necessary to monitor your blood sugar more frequently while using Tafinlar (Dabrafenib).

If you have diabetes or are at risk for developing diabetes, discuss with your doctor how Tafinlar (Dabrafenib) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Tafinlar (Dabrafenib), and whether any special monitoring is needed.

Eye inflammation: Tafinlar (Dabrafenib) may cause eye inflammation. If you experience eye pain, changes in your vision, or eye pain when you are exposed to light, contact your doctor as soon as possible.

Fertility: Men who take Tafinlar (Dabrafenib) may develop a decreased sperm count that may not return to normal levels after you stop taking Tafinlar (Dabrafenib). Discuss your concerns with your doctor before starting to take Tafinlar (Dabrafenib).

Fever: Tafinlar (Dabrafenib) may cause an increase in body temperature (fever) that is not related to infection. This may be more likely to happen to people who take trametinib along with Tafinlar (Dabrafenib). If you experience a fever while taking Tafinlar (Dabrafenib), contact your doctor as soon as possible.

Heart rhythm: Tafinlar (Dabrafenib) can cause changes to the normal rhythm of the heart, including an irregular heartbeat called QT prolongation. QT prolongation is a serious life-threatening condition that can cause fainting, seizures, and sudden death. If you are at risk for heart rhythm problems (e.g., have heart failure, Angina, or low potassium or magnesium levels), discuss with your doctor how Tafinlar (Dabrafenib) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Tafinlar (Dabrafenib), and whether any special monitoring is needed.

Infection: People taking Tafinlar (Dabrafenib) along with trametinib, may be more likely to experience a reduced number of cells that fight infection in the body (white blood cells), and are more likely to develop severe infections. If possible, avoid contact with people with contagious infections. Tell your doctor immediately if you notice signs of an infection, such as fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness. Your doctor will do blood tests regularly to monitor the number of specific types of blood cells in your blood.

Kidney function: Tafinlar (Dabrafenib) may cause kidney failure, as a result of high fever and dehydration. Your doctor will do blood tests to monitor kidney function while you are using Tafinlar (Dabrafenib). If you have kidney problems, discuss with your doctor how Tafinlar (Dabrafenib) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Tafinlar (Dabrafenib), and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause Tafinlar (Dabrafenib) to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how Tafinlar (Dabrafenib) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Tafinlar (Dabrafenib), and whether any special monitoring is needed.

Other cancers: New cancerous lesions on the skin, such as squamous cell cancer or new melanomas can occur while you are taking Tafinlar (Dabrafenib). It is important to have your skin examined before starting Tafinlar (Dabrafenib), every 2 months while you are taking Tafinlar (Dabrafenib), and until 6 months after stopping the medication. Signs of squamous cell cancer include sores, Warts, or bumps that bleed or do not heal. Signs of melanoma include moles with an irregular shape, border, or colour that are changing shape or are growing. If you notice any of these signs, contact your doctor as soon as possible.

It is also possible to develop other cancers while taking Tafinlar (Dabrafenib). Discuss your concerns with your doctor before starting to take Tafinlar (Dabrafenib).

Pancreatitis: Tafinlar (Dabrafenib) can cause the pancreas to become inflamed. If you have a history of pancreatitis, discuss with your doctor how Tafinlar (Dabrafenib) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Tafinlar (Dabrafenib), and whether any special monitoring is needed.

Report signs of pancreatitis such as abdominal pain on the upper left side, back pain, nausea, fever, chills, rapid heartbeat, or swollen abdomen to your doctor immediately.

Pregnancy: Tafinlar (Dabrafenib) may cause harm to an unborn fetus and should not be used during pregnancy. If you become pregnant while taking Tafinlar (Dabrafenib), contact your doctor immediately. Women of childbearing age who are taking Tafinlar (Dabrafenib) should use an effective method of birth control such as condoms during treatment and for 4 weeks after stopping the medication. Tafinlar (Dabrafenib) is likely to decrease the effectiveness of birth control pills, which should not be used as the only form of birth control.

Breast-feeding: It is not known if Tafinlar (Dabrafenib) passes into breast milk. Because there is a high likelihood of causing harm to a nursing infant if Tafinlar (Dabrafenib) does pass into breast milk, you should either stop either breast-feeding or not use Tafinlar (Dabrafenib). Talk to your doctor about the risks and benefits of breast-feeding.

Children: The safety and effectiveness of using Tafinlar (Dabrafenib) have not been established for children.

Seniors: Seniors may be more likely to experience side effects of Tafinlar (Dabrafenib) and may require a lower dose.