Ketoconazole (Nizoral®)

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About This Drug

Ketoconazole is used to treat fungal infections, but is also used to treat prostate cancer in high doses. It is given by mouth (orally).

Possible Side Effects

  • Headache
  • Nausea
  • Loose bowel movements (diarrhea)
  • Pain in your abdomen
  • Changes in your liver function

Note: Not all possible side effects are included above.

Warnings and Precautions

  • Severe changes in your liver function which can cause liver failure, and be life-threatening
  • Abnormal heart beats which can be life-threatening
  • Effects on the adrenal glands. Some hormones may not be produced.
  • Decreased testosterone levels. You may have swelling of your breasts and/or impotence (erectile dysfunction).
  • Allergic reactions, including anaphylaxis are rare but may happen in some patients. Signs of allergic reaction to this drug may be swelling of the face, feeling like your tongue or throat are swelling, trouble breathing, rash, itching, fever, chills, feeling dizzy, and/or feeling that your heart is beating in a fast or not normal way. If this happens, do not take another dose of this drug. You should get urgent medical treatment.

Note: Some of the side effects above are very rare. If you have concerns and/or questions, please discuss them with your medical team.

Important Information

  • Ketoconazole may cause intolerance to alcohol. Do not drink alcohol while taking ketoconazole.

How to Take Your Medication

  • Swallow the medicine whole with or without food.
  • Missed dose: If you vomit or miss a dose, take your next dose at the regular time. Do not take 2 doses at the same time, instead, continue with your regular dosing schedule and contact your physician.
  • Storage: Store this medicine in the original container at room temperature. Discuss with your nurse or your doctor how to dispose of unused medicine

Treating Side Effects

  • Drink plenty of fluids (a minimum of eight glasses per day is recommended).
  • If you throw up or have loose bowel movements, you should drink more fluids so that you do not become dehydrated (lack water in the body from losing too much fluid).
  • To help with nausea and vomiting, eat small, frequent meals instead of three large meals a day. Choose foods and drinks that are at room temperature. Ask your nurse or doctor about other helpful tips and medicine that is available to help or stop lessen these symptoms.
  • If you have diarrhea, eat low-fiber foods that are high in protein and calories and avoid foods that can irritate your digestive tracts or lead to cramping.
  • Ask your nurse or doctor about medicine that can lessen or stop your diarrhea.
  • Keeping your pain under control is important to your well-being. Please tell your doctor or nurse if you are experiencing pain.

Food and Drug Interactions

  • There are known interactions of ketoconazole with alcohol.
  • This drug may interact with grapefruit and grapefruit juice. Talk to your doctor as this could make side effects worse.
  • Check with your doctor or pharmacist about all other prescription medicines and over-the-counter medicines and dietary supplements (vitamins, minerals, herbs and others) you are taking before starting this medicine as there are known drug interactions with ketoconazole. Also, check with your doctor or pharmacist before starting any new prescription or over-the-counter medicines, or dietary supplements to make sure that there are no interactions.
  • Drugs that treat heartburn and stomach upset such Maalox®, Mylanta®, Protonix®, Nexium®, Prilosec®, Pepcid®, Tagamet®, and Zantac® may lower the effect of your cancer treatment if taken with ketoconazole. Call your doctor to find out what drug you may take with ketoconazole to help with heartburn or stomach upset.
  • Avoid the use of St. John’s Wort while taking ketoconazole as this may lower the levels of the drug in your body, which can make it less effective.

When to Call the Doctor

Call your doctor or nurse if you have any of these symptoms and/or any new or unusual symptoms:

  • A headache that does not go away
  • Feeling that your heart is beating in a fast or not normal way (palpitations)
  • Fatigue that interferes with your daily activities
  • Feeling dizzy or lightheaded
  • Nausea that stops you from eating or drinking and/or is not relieved by prescribed medicines
  • Pain in your abdomen that does not go away
  • Loose bowel movements (diarrhea) 4 times a day or loose bowel movements with lack of strength or a feeling of being dizzy
  • Signs of possible liver problems: dark urine, pale bowel movements, bad stomach pain, feeling very tired and weak, unusual itching, or yellowing of the eyes or skin
  • Signs of allergic reaction: swelling of the face, feeling like your tongue or throat are swelling, trouble breathing, rash, itching, fever, chills, feeling dizzy, and/or feeling that your heart is beating in a fast or not normal way
  • If you think you may be pregnant or may have impregnated your partner

Reproduction Warnings

  • Pregnancy warning: It is not known if this drug may harm an unborn child. For this reason, be sure to talk with your doctor if you are pregnant or planning to become pregnant while receiving this drug. Let your doctor know right away if you think you may be pregnant (or may have impregnated your partner.)
  • Breastfeeding warning: Women should not breast feed during treatment because this drug could enter the breast milk and cause harm to a breastfeeding baby.
  • Fertility warning: Human fertility studies have not been done with this drug. Talk with your doctor or nurse if you plan to have children. Ask for information on sperm or egg banking.

Revised April 2018

This patient information was developed by Via Oncology, LLC © 2018. This information is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have.

CLIENT acknowledges that the Via Pathways and Via Portal are information management tools only, and that Via Oncology, LLC has not represented the Via Pathways or Via Portal as having the ability to diagnose disease, prescribe treatment, or perform any other tasks that constitute the practice of medicine. The clinical information contained in the Via Pathways and Via Portal are intended as a supplement to, and not a substitute for, the knowledge, expertise, skill, and judgment of physicians, pharmacists and other healthcare professionals involved with patient care at CLIENT facilities.