Vorinostat belongs to the class of medications called antineoplastics, or anticancer medications. It is used to treat a type of cancer called cutaneous T-cell lymphoma (CTCL) that gets worse, does not go away, or comes back after treatment with other medications.

CTCL is a type of cancer that affects certain cells of the lymph system and affects your skin. Vorinostat works by reducing the activity of histone deacetylase (HDAC), and this slows or stops the growth of cancer cells or causes the death of cancer cells.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended dose of vorinostat is 400 mg once daily with food. Your doctor may decrease your dose if you experience severe side effects. You should drink at least 2 litres of fluid a day while taking this medication to prevent dehydration. Swallow the capsules whole. Do not open or crush the capsules. Contact of the powder in the capsules with the skin or mucous membranes (e.g., mouth, nose) should be avoided. If contact does occur, wash the area thoroughly.

Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important that this medication be taken exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature and keep it out of the reach of children.

Each white, opaque, hard gelatin capsule with "568" over "100 mg" printed within radial bar in black ink on the capsule body, contains vorinostat 100 mg. Nonmedicinal ingredients: magnesium stearate, microcrystalline cellulose, and sodium croscarmellose; capsule shell: gelatin, titanium dioxide, and may contain sodium lauryl sulfate.

Do not take vorinostat if you:

• are allergic to vorinostat or to any of the ingredients of the medication
• have severely reduced liver function

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 this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. 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.

• abdominal pain
• chills
• constipation
• decrease or loss of appetite
• diarrhea
• dizziness
• dry mouth
• fatigue
• hair loss
• headache
• muscle spasms
• nausea
• taste disturbance
• vomiting
• weight loss

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:

• difficulty breathing
• excessive diarrhea and vomiting
• fainting
• signs of bleeding (e.g., bloody nose, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• signs of heart failure (e.g., shortness of breath, fatigue, swelling in legs, ankles, feet)
• symptoms of anemia (e.g., feeling tired, shortness of breath, paleness, fast heart rate)
• symptoms of dehydration (e.g., thirst, reduced sweating, decreased urine production, dry mouth)
• symptoms of irregular heartbeat (e.g., chest pain, dizziness, rapid, pounding heartbeat, shortness of breath)
• symptoms of low platelet counts (e.g., easy bruising or unusual bleeding)

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

• fainting
• symptoms of a blood clot in the leg or arm (e.g., pain, redness, warmth, swelling)
• symptoms of a blood clot in the lungs (e.g., shortness of breath, chest pain)
• symptoms of bleeding in the stomach or intestines (e.g., black and tarry stools, vomit that looks like coffee grounds, stomach pain)
• symptoms of an infection in the blood (e.g., fever, chills, headache, confusion, rapid breathing)
• symptoms of a stroke (e.g., sudden numbness or weakness in the arms or legs, dizziness, severe headache, difficulty speaking, vision changes)

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 this medication.

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 this medication.

Blood clots: This medication can increase your risk of getting a blood clot in the legs, arms, or lungs. People who have had a blood clot in the past should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. If you experience symptoms of a blood clot in the leg or arm (pain, redness, warmth, swelling), or in the lungs (chest pain, shortness of breath), get immediate medical attention.

Blood effects: This medication can decrease platelets (help with blood clotting) and reduce red blood cells. Your doctor will monitor for these with blood tests. If you experience unusual bleeding or bruising, shortness of breath, tiredness, or paleness while taking this medication, contact your doctor immediately.

Blood sugar: This medication can cause high blood sugar levels (hyperglycemia). Your doctor will monitor your blood sugar levels closely while you are receiving this medication. People with diabetes should report any changes in their blood sugar control to their doctor immediately. Your doctor may suggest dietary and medication changes or may reduce your dose of this medication to help keep your blood sugar levels controlled.

Dehydration: This medication can cause dehydration (too much water loss from your body). In order to prevent this, you should drink at least 2 litres of fluids a day while you are taking this medication. If you experience severe nausea, vomiting, and diarrhea while taking this medication, contact your doctor. These side effects can lead to dehydration.

Dizziness and fainting: This medication can cause dizziness or fainting. Do not drive or operate machinery if you experience these side effects and until you know you can perform these activities safely.

Heart effects: This medication can have an effect on the electrical activity of the heart called QT prolongation. This can lead to a serious abnormal heart rhythm, which can be fatal. People who are at an increased risk of experiencing abnormal heart rhythms (e.g., women, people 65 years of age and older, people with heart disease, a family history of sudden death, abnormal heart rhythms, congenital long QT syndromes, strokes, eating disorders, diabetes, low blood levels of potassium, magnesium, or calcium) should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may check your heart rhythm with an ECG (electrocardiogram) to check for the effects of this medication on your heart.

If you experience symptoms of an abnormal heart rhythm (e.g., dizziness, fainting seizures, pounding or irregular heartbeat) while taking this medication, get immediate medical attention.

Heart rate: This medication can increase your heart rate. If you have heart disease or fast heartbeats, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Kidney function: If you have reduced kidney function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver problems: Decreased liver function or liver disease may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. People with severely reduced liver function should not take this medication.

Surgery: This medication may cause complications with the healing process after bowel surgery. Let all members of your health care team know if you have had recent surgery or are going to be having surgery, to avoid unnecessary complications.

Pregnancy: Women taking this medication should avoid becoming pregnant. This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if this medication passes into breast milk. Women taking this medication should not breast-feed.

Children: The safety and effectiveness of using this medication have not been established for children.

There may be an interaction between vorinostat and any of the following:

• antiarrhythmic medications (e.g., amiodarone, disopyramide, dronedarone, flecainide, procainamide, propafenone, quinidine, sotalol)
• antipsychotic medications (e.g., chlorpromazine, haloperidol, pimozide, ziprasidone)
• "azole" antifungals (e.g., fluconazole, ketoconazole, voriconazole)
• BCG
• bromocriptine
• deferiprone
• diabetes medications (e.g., acarbose, empagliflozin, glyburide, insulin, lixisenatide, metformin, rosiglitazone, saxagliptin)
• laxatives, (e.g., milk of magnesia, bisacodyl)
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• mesalamine
• methadone
• quinine
• sulfasalazine
• valproic acid
• warfarin

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 this medication. 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.