Miconazole

Miconazole is an antifungal used to treat several types of fungal and yeast infections, depending on the product form and route.

• Vaginal yeast infections: Vaginal creams, suppositories, and combination kits treat vulvovaginal candidiasis (vaginal yeast infection) and relieve external itching and irritation.
• Oral yeast infection (thrush): Oravig buccal tablet is indicated for oropharyngeal candidiasis — a yeast infection of the mouth and throat — in adults.
• Athlete's foot (tinea pedis): Topical creams, ointments, and powders treat this common fungal skin infection.
• Jock itch (tinea cruris): Topical creams and powders treat fungal infection of the groin area.
• Ringworm (tinea corporis): Topical creams and powders treat this fungal skin infection.
• Superficial yeast skin infections (Candida albicans): Certain topical creams and powders treat skin infections caused by yeast.
• Topical forms are not effective on the scalp or nails.

Miconazole works by blocking a key fungal enzyme called cytochrome P450 14α-demethylase. This enzyme is essential for making ergosterol — the structural backbone of the fungal cell membrane. Without ergosterol, the membrane falls apart and the fungal cell can no longer survive. Miconazole also disrupts the production of fats inside the fungal cell and disables enzymes that normally protect it from damage, causing a toxic buildup of reactive oxygen species (harmful molecules) inside the cell.

Some Candida strains that become resistant to one azole antifungal may also show reduced sensitivity to others — a phenomenon called cross-resistance. Resistance can happen through several mechanisms at once, including changes in the target enzyme or in proteins that pump the drug out of the cell.

The right way to take miconazole depends entirely on the form prescribed or purchased.

• Oravig buccal tablet: One tablet applied to the upper gum once every morning after brushing teeth, for 14 consecutive days. It sticks in place and dissolves — do not chew or swallow it.
• Vaginal creams (7-night regimens): One applicatorful inserted into the vagina at bedtime for 7 nights in a row; external cream from the same tube can be applied to irritated skin outside the vagina twice daily for up to 7 days as needed.
• Topical creams/ointments for skin: Applied to clean, dry skin twice daily; treatment lasts 4 weeks for athlete's foot and ringworm, and 2 weeks for jock itch.
• Topical powders: Applied regularly; continue for at least 10 days after symptoms clear to prevent recurrence. If you miss a dose, skip it — do not double up.

Most people tolerate miconazole well, but some side effects can occur depending on the form used.

• Diarrhea, nausea, vomiting
• Upper abdominal pain
• Headache
• Altered or lost sense of taste (dysgeusia or ageusia)
• Local mouth or gum discomfort, burning, or pain (Oravig buccal tablet)
• Mild vaginal burning, itching, or irritation (vaginal products)
• Dry mouth (Oravig)

Seek medical attention right away if you develop signs of a severe allergic reaction — such as hives, rash, difficulty breathing, or facial swelling — as serious allergic reactions (anaphylaxis) have been reported with miconazole products.

• Serious allergic reactions: Anaphylaxis (a life-threatening allergic reaction) has been reported. Stop use immediately and get emergency help if you develop hives, difficulty breathing, or swelling.
• Vaginal product precautions: Do not use if this is your first-ever vaginal yeast infection without a doctor's diagnosis. Stop and see a doctor if symptoms don't improve in 3 days or last more than 7 days.
• Potential signs of a more serious condition: Fever, chills, lower abdominal pain, or foul-smelling discharge with a vaginal product may mean something more than a yeast infection — see a doctor.
• Condoms and diaphragms: Vaginal creams may damage latex condoms and diaphragms, reducing their effectiveness at preventing pregnancy or STDs.
• Oravig in children: Not recommended for those under 16 years old, partly due to choking risk.
• Liver disease: Oravig should be used with caution in people with liver impairment, since miconazole is processed by the liver.

Miconazole can interact with several medications, even when used topically or vaginally — so always tell your pharmacist and doctor what you're taking.

• Warfarin (blood thinner): Miconazole can increase warfarin's anticoagulant effect, raising the risk of bleeding and bruising. Your doctor should closely monitor your clotting levels (prothrombin time/INR).
• Oral diabetes medications (oral hypoglycemics): Potential interaction via liver enzymes CYP2C9 and CYP3A4 cannot be ruled out.
• Phenytoin (seizure medication): Metabolized through the same liver pathways; potential interaction possible.
• Ergot alkaloids (migraine treatments): Potential interaction via CYP enzyme pathways cannot be ruled out.

This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.

• Do not use Oravig if you are allergic to miconazole or milk protein concentrate.
• Tell your doctor if you have ever had an allergic reaction to any azole antifungal (such as fluconazole or clotrimazole).
• Tell your doctor if you take warfarin or any other blood thinner.
• Vaginal products: do not use if this is your first-ever yeast infection without a confirmed diagnosis from a doctor.
• Vaginal products: tell your doctor if you get yeast infections frequently, are pregnant, or think you may be pregnant — you could have an underlying condition such as diabetes or a weakened immune system.
• Pregnancy: animal data suggest Oravig may cause fetal harm. Discuss risks with your doctor before using any miconazole product while pregnant.
• Breastfeeding: there is no data on miconazole passing into human milk from Oravig use; discuss with your healthcare provider.
• Children under 16: safety and effectiveness of Oravig have not been established; use in younger children is not recommended due to choking risk.
• Liver disease: use Oravig with caution; the drug is metabolized by the liver.
• Kidney disease: no dose adjustment is needed, as less than 1% of miconazole is excreted unchanged in urine.

Overdose with miconazole in humans has not been reported in the medical literature. Systemic absorption from Oravig buccal tablets is minimal, making significant overdose unlikely with that form. If accidental ingestion occurs (especially in children), seek medical help or contact Poison Control (1-800-222-1222) right away; care is supportive.

Miconazole disrupts the fungal cell membrane by blocking production of ergosterol, an essential structural component. Without a stable membrane, fungal cells lose their integrity and die. It also interferes with fungal fat synthesis and inhibits protective enzymes, increasing toxic reactive oxygen species inside the cell — hitting the fungus through multiple mechanisms at once.

When Oravig buccal tablets are applied to the gum, miconazole is released locally into saliva over roughly 15 hours. Systemic (blood) absorption is minimal — plasma concentrations were below detectable limits in 97% of healthy volunteers after a single dose. Most miconazole that is absorbed is metabolized by the liver; less than 1% leaves the body unchanged in the urine. The terminal half-life (the time it takes the body to clear half the drug) is about 24 hours after systemic administration, and there are no active breakdown products.

store at 20°-25°C (68°-77°F)