Fluconazole

How Does Fluconazole Work?

Fluconazole works by targeting a key enzyme called lanosterol 14-alpha-demethylase (ERG11/CYP51) that fungi need to produce ergosterol — the primary sterol in the fungal cell membrane. Ergosterol is analogous to cholesterol in human cells and is essential for maintaining the fungal membrane's structure and function.

By inhibiting this enzyme, fluconazole prevents the fungus from building a stable cell membrane. Without ergosterol, abnormal sterols accumulate, the membrane becomes dysfunctional, and the fungus cannot grow or reproduce. Fluconazole is primarily fungistatic (stops growth) rather than fungicidal (kills directly), relying on the patient's immune system to clear the weakened fungal infection.

The drug's selectivity is its key safety advantage — the human equivalent of the ERG11 enzyme is far less sensitive to fluconazole than the fungal enzyme, allowing fluconazole to target fungal cells while leaving human cells relatively unaffected. Fluconazole also inhibits human CYP enzymes (CYP2C9, CYP2C19, CYP3A4) in the liver, which is the source of its many drug-drug interactions.

How Hard Is It to Find Fluconazole in Stock?

Fluconazole is generally one of the most accessible prescription drugs in the United States. It is not on the FDA's drug shortage list as of 2026, and dozens of generic manufacturers supply the market, keeping availability robust at the national level. Most major chain pharmacies (CVS, Walgreens, Walmart, Costco) and supermarket pharmacies routinely stock the 150 mg tablet.

Localized stock gaps can still occur — particularly for the oral suspension formulations (10 mg/mL and 40 mg/mL), which are less commonly stocked, and for higher-dose tablets used for complex infections. Independent or rural pharmacies may run out temporarily during periods of high demand.

If your pharmacy is out of stock, medfinder can call pharmacies near you to identify which ones can fill your prescription, texting you the results. This is the fastest way to locate fluconazole in stock without spending time on hold.

Who Can Prescribe Fluconazole?

Fluconazole is not a controlled substance, so any licensed prescriber can prescribe it without special DEA registration or quantity restrictions. It can be prescribed by:

• Primary care physicians (MDs and DOs)
• OB/GYNs (frequently for vaginal candidiasis and recurrent yeast infection prophylaxis)
• Nurse practitioners (NPs) and physician assistants (PAs)
• Infectious disease specialists (for systemic and resistant infections)
• Oncologists and hematologists (for antifungal prophylaxis in cancer patients)
• Urgent care providers and emergency medicine physicians

Telehealth is widely available for uncomplicated infections. Platforms like Wisp, Teladoc, MDLive, and Hims & Hers can prescribe fluconazole for vaginal yeast infections and oral thrush through online consultations, often on the same day, making access faster and more convenient for most patients.

Is Fluconazole a Controlled Substance?

No. Fluconazole is not a controlled substance under the DEA Controlled Substances Act. It is classified as a prescription-only medication, meaning you need a valid prescription from a licensed healthcare provider to obtain it, but there are no federal restrictions on quantities, refill limits, or prescribing methods.

Prescriptions for fluconazole can be issued electronically (e-prescribe), called in to the pharmacy, faxed, or written on a paper prescription. Patients can receive refills without restrictions, and the prescription can be easily transferred between pharmacies without additional paperwork. Long-term prophylaxis prescriptions can be written for 90-day supplies through mail-order pharmacies.

Common Side Effects of Fluconazole

Common side effects (occurring in ≥1% of patients):

• Nausea
• Headache
• Dizziness
• Abdominal pain
• Diarrhea
• Vomiting
• Rash (report any rash to your provider immediately)
• Elevated liver enzymes

Serious side effects (seek immediate medical attention):

• Liver damage (hepatotoxicity): jaundice, dark urine, severe fatigue, upper right abdominal pain
• Stevens-Johnson Syndrome / Toxic Epidermal Necrolysis: rapidly spreading painful rash, skin blistering
• QT prolongation / cardiac arrhythmia: palpitations, dizziness, fainting
• Severe allergic reactions (anaphylaxis): facial swelling, difficulty breathing
• Seizures (rare)

Final Thoughts on Fluconazole

Fluconazole is one of medicine's most important antifungal agents — a single-dose oral pill that can resolve a yeast infection in days, and a lifesaving treatment for patients with HIV-related cryptococcal meningitis. Its combination of efficacy, safety, oral bioavailability, and remarkably low cost makes it a first-line choice for a broad range of fungal infections.

The main clinical challenges in 2026 are growing antifungal resistance (particularly Candida auris and resistant C. glabrata), the drug's significant interaction profile via CYP enzyme inhibition, and safety concerns in pregnancy. Providers and patients should be aware of these considerations when using fluconazole.

If you're having difficulty finding fluconazole at your local pharmacy, medfinder can call pharmacies near you to identify which ones have your specific dose in stock — and text you the results. With generic fluconazole available for as little as $3–5 with a coupon, cost should rarely be a barrier to access.