Ketoconazole Dosages: Your GoodRx Guide for Oral and Topical Ketoconazole
Key takeaways:
Ketoconazole is an antifungal medication used to treat different types of fungal infections. It’s available in a variety of oral and topical forms.
Your ketoconazole dosage will depend on what you’re treating and whether you’re taking it by mouth or applying it topically. Certain drug interactions may also influence your ketoconazole dosage.
If you miss a ketoconazole dose, take (or apply) it as soon as you remember. But if it’s almost time for your next dose, skip your missed dose and resume your usual schedule. Talk to your healthcare team if you have questions about steps you should take.
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Table of contents
Ketoconazole is an antifungal medication used to treat certain kinds of fungal infections. It comes as a pill that you take by mouth and in several topical forms, such as creams, shampoos, and foams.
Your specific ketoconazole dosage and length of treatment can be influenced by several factors. These can include other medications you take, what you’re treating, and how you respond to treatment. Below, we’ll discuss typical oral and topical ketoconazole dosages and what to do if you miss your dose.
Ketoconazole dosage forms
Ketoconazole comes in several different dosage forms. The form you’ll be prescribed depends on the type of fungal infection you’re treating.
There are several topical ketoconazole options available, which are used to treat skin infections such as ringworm, jock itch, and athlete’s foot. Topical ketoconazole is also available over the counter (OTC) for dandruff.
Examples of these topical dosage forms include:
Ketoconazole 2% cream (Ketozole)
Ketoconazole 2% foam (Extina)
Ketoconazole 1% shampoo (OTC Nizoral A-D)
Ketoconazole oral tablets are typically reserved for infections that don’t respond to other treatment options. It’s more likely to cause serious side effects compared to other antifungals or topical products and has many interactions.
Each ketoconazole dosage form has specific uses and instructions to follow. Your prescriber will determine which one best meets your needs.
What’s the typical ketoconazole dosage for adults?
The typical ketoconazole dosage depends on the form you’re taking, what you’re treating, and other factors.
Topical ketoconazole
Your topical ketoconazole dosage usually depends on the type and size of the infection being treated. Most topical ketoconazole products are applied to the affected area once or twice daily for several weeks. Typical dosages are detailed in the table below.
Dosage form(s) | Use(s) | Dosage |
Cream | Ringworm Athlete’s foot Jock itch Tinea versicolor Candidiasis | Apply to the affected area once daily for 2 to 4 weeks, depending on use and response. |
Cream and foam | Seborrheic dermatitis | Apply to the affected area twice daily for 4 weeks. |
Gel | Seborrheic dermatitis | Apply to the affected area once daily for 4 weeks. |
Shampoo | Tinea versicolor | Wet hair and scalp. Apply and lather ketoconazole shampoo. Leave it in for 5 minutes before rinsing off with water. A single use should be all you need. |
Shampoo (OTC) | Dandruff | Same instructions as above. Repeat application every 3 to 4 days for up to 8 weeks. After that, you can use it as needed for dandruff flare-ups. |
Your prescriber will determine how long you need to use ketoconazole and how much to apply. Your pharmacist can also discuss how to apply each product.
You should continue to use topical ketoconazole for the full length of treatment, even if your condition improves. If you stop treatment too soon, it’s likely your fungal infection will return.
Oral ketoconazole
The usual adult oral ketoconazole dosage is 200 mg by mouth once daily. Your prescriber may increase the dosage to 400 mg by mouth once daily if needed. Treatment usually lasts about 6 months.
Oral ketoconazole is absorbed best in an acidic environment. If you take it with medications that lower stomach acid, such as proton pump inhibitors, take your ketoconazole dose with non-diet soda or another acidic drink.
You should also avoid taking oral ketoconazole at the same time as antacids, such as aluminum hydroxide / magnesium hydroxide / simethicone (Mylanta). Otherwise, ketoconazole won’t be absorbed properly. If you need to take an antacid, take it at least 1 hour before or 2 hours after taking ketoconazole.
What’s the typical ketoconazole dosage for children?
Some topical ketoconazole products are approved for use in children ages 12 and older. This includes ketoconazole foam for seborrheic dermatitis and OTC ketoconazole shampoo for dandruff. The dosage and instructions for use are the same as those detailed above for adults.
Are there any dosage adjustments for health conditions or interactions?
Drug interactions are common with oral ketoconazole due to how it’s broken down in the liver. In most cases, ketoconazole can increase levels of other medications in the body. But there are some situations where an interaction can cause higher or lower ketoconazole levels.
Some medications, such as tamsulosin (Flomax), shouldn’t be taken with ketoconazole due to an interaction. However, some combinations can be managed by adjusting the dose of the other medication. Examples of these medications include:
Digoxin (Lanoxin)
Aripiprazole (Abilify)
Vardenafil
Buspirone (Buspar)
Keep your healthcare team up to date with your current medication list. That way, they can manage potential ketoconazole interactions up front.
Good to know: When applying ketoconazole topically, very little is absorbed into your body. So dose adjustments are not usually recommended for topical ketoconazole.
What happens if you miss a dose of ketoconazole?
If you forget to take an oral ketoconazole dose, take it as soon as you remember. This is also the case if you forget to apply topical ketoconazole. But if it’s almost time for your next dose, skip your missed dose and resume your usual dosage schedule. Don’t double up on doses. Speak with your healthcare team if you have questions about what to do.
Ketoconazole is used to treat fungal infections, so it’s best to take all of your doses as prescribed. But if you’re having trouble remembering to take your dose on time, a medication adherence tool, such as a medication reminder app, may help.
What should you do if you take too much ketoconazole?
Taking too much oral ketoconazole may increase your risk of serious side effects. These can include liver damage and QT prolongation, which is when your heart takes longer to reset between beats. Using too much of a topical product could cause or worsen skin irritation.
If you think you may have taken too much ketoconazole, contact your prescriber right away. You can also call Poison Control at 1-800-222-1222 for guidance. Go to the nearest ER if you have a fast or irregular heartbeat, and call 911 if you think you’re about to faint.
The bottom line
Ketoconazole is an antifungal medication used to treat fungal infections. It’s available as an oral tablet, usually taken as 200 mg by mouth once daily. There are also several topical ketoconazole products that are typically applied to the affected area once or twice daily.
Take care to follow your healthcare team’s dosage instructions. Talk to your prescriber or pharmacist if you have any questions about ketoconazole or your dosage.
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References
A-S Medication Solutions. (2023). Ketoconazole shampoo, suspension [package insert]. DailyMed.
MedlinePlus. (2016). Ketoconazole topical.
MedlinePlus. (2017). Ketoconazole.
Preferred Pharmaceuticals Inc. (2023). Ketoconazole cream [package insert].
Taro Pharmaceutical Industries Ltd. (2023). Ketoconazole tablets [package insert].
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