Fluconazole is taken by mouth, with or without food, and absorption isn’t affected by what you eat or when you eat it. For most people treating a vaginal yeast infection, it’s a single 150 mg capsule taken once, and that’s it. But dosing varies depending on the type and severity of the infection, and there are a few practical things worth knowing before you take it.
Standard Doses by Infection Type
For an uncomplicated vaginal yeast infection, the standard treatment is one 150 mg dose taken by mouth. The CDC recommends this as the first-line oral option. Most people notice improvement within one to three days, though it can take a full week for symptoms to completely resolve.
Severe yeast infections call for two 150 mg doses, with the second taken 72 hours (three days) after the first. Recurrent infections, meaning four or more episodes in a year, use a different approach: three doses taken on days 1, 4, and 7 to get the infection under control, followed by one dose per week for six months to keep it from coming back.
For oral thrush or esophageal infections, fluconazole is typically prescribed as a daily dose over a longer course, often one to two weeks or more. Your prescriber will set the specific dose and duration based on the infection’s location and severity.
Food, Timing, and Missed Doses
You can take fluconazole at any time of day, on a full stomach or an empty one. It makes no difference to how well the medication is absorbed. If you’re on a multi-dose course and forget a dose, take it as soon as you remember. If your next scheduled dose is coming up soon, skip the missed one and continue your regular schedule. Don’t double up to compensate.
When to Expect Relief
A single dose for a mild yeast infection typically brings noticeable improvement within one to three days. The medication continues working in your body after you take it because fluconazole stays in your system for several days, which is why one pill can treat an entire infection.
If a single dose doesn’t fully clear things up, or the infection is more severe, a three-dose regimen (doses spaced three days apart) generally resolves symptoms within one to two weeks. If you’re still experiencing symptoms after completing your prescribed course, that’s worth following up on, as the infection may involve a strain that doesn’t respond well to fluconazole.
Common Side Effects
Nausea, abdominal pain, and headache are the most frequently reported side effects. For a single-dose treatment, these tend to be mild and short-lived. On longer courses, mild elevations in liver enzymes occur in up to 5% of patients. These are usually temporary and don’t cause symptoms.
Significant liver irritation is uncommon but possible, particularly with treatment lasting several weeks. Warning signs include unusual fatigue, nausea that worsens over time, yellowing of the skin or eyes, and dark urine. These symptoms typically emerge within the first few weeks of a longer course. A single 150 mg dose carries very little risk of liver problems.
Medications That Interact With Fluconazole
Fluconazole affects how your liver processes many other drugs, which can raise or lower their levels in your blood. Some of the most common interactions to be aware of:
- Blood thinners like warfarin: fluconazole can increase bleeding risk
- Cholesterol medications like atorvastatin, lovastatin, or simvastatin: increased risk of muscle damage
- Pain relievers including ibuprofen, naproxen, fentanyl, and methadone
- Diabetes medications like glipizide or glyburide: can cause blood sugar to drop too low
- Seizure medications like carbamazepine or phenytoin
- Heart rhythm medications and other drugs that affect heart rhythm
- Certain antibiotics like rifampin and rifabutin
- Steroids like prednisone
- Some sedatives including midazolam and triazolam
This isn’t a complete list. If you take any prescription medications regularly, make sure your pharmacist or prescriber knows before you start fluconazole, even for a single dose.
Pregnancy and Fluconazole
Even a single 150 mg dose of fluconazole during pregnancy has been linked to an increased risk of miscarriage and birth defects in epidemiological studies. The CDC recommends against using it during pregnancy. If you’re pregnant or think you might be, topical antifungal treatments are the safer alternative for yeast infections.
Storing the Medication
Fluconazole tablets should be stored below 86°F (30°C), so a standard room-temperature cabinet works fine. If you have the liquid suspension, the same temperature range applies to the unmixed powder. Once the liquid is mixed, it needs to be stored between 41°F and 86°F and discarded after two weeks. Don’t freeze the liquid form.