Ketoconazole
Used in the following combined preparations None
GENERAL INFORMATION
Ketoconazole is prescribed for severe, internal systemic fungal infections. It is also given to treat serious infections of the skin and mucous membranes caused by the Candida yeast. People with rare fungal diseases (for example, paracoccidioidomycosis, histoplasmosis, and coccidioidomycosis) may also be given this antifungal drug.
Ketoconazole is applied as a cream to treat fungal skin infections, and as a shampoo for the treatment of scalp infections and seborrhoeic dermatitis.
The most common side effect with ketoconazole is nausea, which can be reduced by taking the drug at bedtime or with meals. Ketoconazole may also cause liver damage.
INFORMATION FOR USERS
Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.
How taken
Tablets, liquid, cream, shampoo.
Frequency and timing of doses
Once daily with food (by mouth); 1 -2 x daily (cream); 1 -2 times weekly (shampoo used for seborrhoeic dermatitis)
Dosage range
Adults 200-400mg daily (by mouth). Children Reduced dose according to age and weight.
Onset of effect
The drug begins to work within a few hours; full beneficial effect may take several days.
Duration of action
Up to 24 hours.
Diet advice
None.
Storage
Keep in a closed container in a cool, dry place out of the reach of children.
Missed dose (oral)
Take as soon as you remember. If your next dose is due within 6 hours, take a single dose now and skip the next.
Stopping the drug
Take the full course. Even if you feel better, the original infection may still be present and symptoms may recur if treatment is stopped too soon.
Exceeding the dose
An occasional unintentional extra dose is unlikely to be a cause for concern. Large overdoses may cause gastric problems. Notify your doctor.
POSSIBLE ADVERSE EFFECTS
Nausea is the most common side effect of ketoconazole; liver damage is a rare but
serious adverse effect causing jaundice that may necessitate stopping the drug.
INTERACTIONS (administration by mouth only)
Antacids, cimetidine, and ranitidine
These drugs may reduce the effectiveness of ketoconazole if they are taken within 2 hours before or after ketoconazole.
Rifampicin
This drug reduces the effect of ketoconazole.
Warfarin
Ketoconazole increases the effect of warfarin.
Cyclosporin
Ketoconazole increases the level of cyclosporin in the blood.
Phenytoin
Levels of ketoconazole may be reduced by phenytoin.
Antihistamines
There is an increased risk of terfenadine and astemizole causing adverse effects on the heart.
QUICK REFERENCE
Drug group Antifungal drug
Overdose danger rating Medium
Dependence rating Low
Prescription needed Yes
Available as generic No
SPECIAL PRECAUTIONS
Be sure to tell your doctor if:
You have long-term liver or kidney problems.
You have porphyria.
You have previously had an allergic reaction to antifungal drugs.
You are taking other medications.
Pregnancy
Not usually prescribed. May cause defects in the developing baby. Discuss with your doctor.
Breast-feeding
The drug passes into the breast milk and may affect the baby. Discuss with your doctor.
Infants and children
Reduced dose necessary.
Over 60
No special problems.
Driving and hazardous work
No special problems.
Alcohol
Avoid. Alcohol may interact with this drug to cause flushing and nausea.
PROLONGED USE
The risk of liver damage increases with use for more than 14 days.
Monitoring Periodic blood tests are usually performed to check the effect of the drug on the liver.
