Last Modified: January 19, 2007
Vorinostat is the first in a new class of anti-cancer therapies called histone deacetylase (HDAC) inhibitors. Histone deacetylation is a biochemical process that is thought to play a role in promoting tumor growth. It does this by silencing some tumor suppressor genes, as well as other genes that are responsible for cell cycle progression, cell proliferation, programmed cell death (apoptosis), and differentiation (transformation of young cells into specialized cells). Thus, blocking histone deacetylation may allow the body to block this tumor growth and prevent progression.
Vorinostat is given orally (as a capsule), once a day. Vorinostat should be taken with food. Do not open or crush vorinostat capsules.
Treatment can be continued as long as the cancer is responding to the treatment and the patient is able to tolerate any side effects.
Some of the possible side effects and suggestions for dealing with them include:
There are many effective drugs that will prevent, eliminate, or lessen the severity of nausea and vomiting. If you need to use them, just ask your doctor which is best for you. In addition, dietary adjustments may help: avoid foods that worsen the symptoms; try antacids like milk of magnesia and calcium tablets (like Tums); and/or have saltines or ginger ale to lessen symptoms. Smaller, more frequent meals may be better tolerated than larger meals.
Your doctor or nurse can recommend medication to relieve diarrhea. Also, try eating low fiber bland foods, such as white rice and boiled or baked chicken. Avoid raw fruits, vegetables, whole grain breads and cereals, and seeds. Soluble fiber is a type of fiber found in some foods. Soluble fiber absorbs fluid and can help relieve diarrhea. Foods high in soluble fiber include: applesauce, bananas (ripe), canned fruit, orange and grapefruit sections, boiled potatoes, white rice and products made with white flour, oatmeal, cream of rice, cream of wheat, and farina. Drink 8-10 glasses of non-alcoholic fluid a day to prevent dehydration.
Vorinostat may affect your appetite or change the way things taste. See "Nutrition During Cancer Treatment" for tips on dealing with these side effects.
Platelets help your blood clot, so when the platelet count is low, you are at a higher risk of bleeding. You should avoid using a razor (an electric razor is fine), playing any contact sports, or taking aspirin or ibuprofen products (as these can also increase the risk of bleeding). Let your doctor or nurse know if you have any bleeding, including nose bleeds or bleeding gums. If the count becomes too low, you may require and receive a transfusion of platelets.
Your red blood cells are responsible for carrying oxygen to the tissues in your body. When the red cell count is low, you may feel tired or weak. You should let your doctor or nurse know if you experience any shortness of breath, difficulty breathing, or pain in your chest. If the count gets too low, you may receive a blood transfusion.
Diabetics may find that their blood sugar levels are higher while on this medication, and so those diabetics who require insulin may need higher doses to control their blood sugar while on therapy.
See OncoLink's section on fatigue for helpful tips for dealing with this side effect.
Blood clots are a rare side effect of vorinostat that can occur anywhere in the body. They occur most frequently in the calves or the lungs. People at increased risk for developing blood clots include those with a family history of blood clots, smokers, those who have an inactive lifestyle, older age, and those with other medical problems.
Signs of a blood clot in the leg may include any of the following: leg pain, warmth, swelling of one leg more than the other. Signs of a blood clot in the lung could include: fever, shortness of breath that comes on very quickly, racing heart, chest pain (that tends to be worse when you take a deep breath).
If you have any of these signs or symptoms of blood clots, you will need to be seen immediately so that you can be treated. Blood thinners can be given. Call your doctor or nurse.
While taking vorinostat, the levels of electrolytes (potassium, magnesium and calcium) in your blood can become low, particularly if you experience vomiting or diarrhea. Your healthcare team will monitor your blood electrolytes before and during therapy.
Changes can be seen on an electrocardiogram (EKG). Your healthcare team may check an EKG periodically while on treatment. Some patients experienced chills, fever, and/or muscle aches.