Fluconazole is a broad-spectrum azole antifungal medication prescribed for the treatment and prevention of various fungal and yeast infections. It is available in oral and intravenous forms. The medication functions by disrupting the fungal cell membrane’s integrity. Specifically, it inhibits a fungal enzyme called 14-alpha demethylase, which is necessary for producing ergosterol, a compound that maintains the structure of the fungal cell membrane. This inhibition leads to a buildup of other substances that increase the membrane’s permeability, causing the cell’s contents to leak out and stopping fungal growth.
Common Fungal Infections Treated
Fluconazole is effective against a range of fungal infections, with candidiasis being one of the most frequently treated conditions. Candidiasis is a yeast infection caused by Candida species. It can manifest in several ways, including vaginal candidiasis, which is a common yeast infection affecting the vagina. Another prevalent form is oropharyngeal candidiasis, commonly known as thrush, which develops in the mouth and throat. The infection can also extend down into the esophagus, a condition called esophageal candidiasis.
Beyond these localized yeast infections, fluconazole is used to manage more serious, systemic fungal diseases. One such condition is cryptococcal meningitis, a fungal infection that causes inflammation of the membranes surrounding the brain and spinal cord. Because fluconazole can penetrate the cerebrospinal fluid, it is an effective treatment for this type of meningitis. The medication is also prescribed for other systemic Candida infections that can affect the bloodstream, bladder, and abdominal cavity.
Standard Dosage Regimens
The dosage of fluconazole is determined by the specific type and severity of the fungal infection being treated. For uncomplicated vaginal yeast infections (vaginal candidiasis), the standard treatment is often a single oral dose of 150 mg.
For infections like oropharyngeal candidiasis (thrush) or esophageal candidiasis, a multi-day treatment regimen is required. Treatment for thrush commonly begins with a loading dose of 200 mg on the first day, followed by a daily dose of 100 mg for at least two weeks. Esophageal candidiasis generally requires a longer treatment course of at least three weeks, with similar daily dosing, to ensure the infection is fully cleared and to prevent relapse.
More severe systemic infections, such as cryptococcal meningitis, demand a significantly higher and longer-term dosage plan. Initial treatment often starts with a high loading dose, sometimes administered intravenously in a hospital setting, which can be around 400 mg. This is followed by a maintenance dose that continues for 10 to 12 weeks after cerebrospinal fluid cultures are negative.
Factors Influencing Dosage Adjustments
A standard fluconazole dosage is not a one-size-fits-all prescription; healthcare providers adjust it based on several patient-specific factors. One of the primary considerations is kidney function. Since fluconazole is predominantly cleared from the body through the kidneys, individuals with impaired renal function may not eliminate the drug effectively. This can lead to an accumulation of the medication in the bloodstream, increasing the risk of side effects.
To prevent this, doctors often order a creatinine clearance test, which measures how well the kidneys are filtering waste from the blood. If a patient’s creatinine clearance is below 50 mL/minute, a dose reduction is typically required. The adjusted dose ensures that the medication remains at a safe and effective level in the body without overburdening the kidneys.
Age is another factor that influences dosing, particularly in the pediatric population. Doses for children are not simply scaled-down adult doses. Instead, they are carefully calculated based on the child’s body weight, typically in milligrams per kilogram (mg/kg), and the specific type of fungal infection being treated.
Administration and Missed Doses
Oral fluconazole tablets or suspension can be taken with or without food, as food does not significantly affect its absorption into the bloodstream. It is important to follow the prescribed schedule to maintain a consistent level of the drug in the body, which helps in effectively fighting the fungal infection.
If a dose is missed, the general guidance is to take it as soon as it is remembered. However, if the time is close to the next scheduled dose, the missed dose should be skipped to avoid taking too much medication at once. Patients should then resume their regular dosing schedule. It is important not to “double up” on doses to make up for a missed one, as this can increase the risk of adverse effects.
In the event of a suspected overdose, which may cause symptoms such as hallucinations or paranoid behavior, it is advised to contact a poison control center or seek immediate emergency medical attention. Patients should always adhere to the specific instructions provided by their doctor and pharmacist, as these are tailored to their individual health needs and the specific infection being treated.