Diflucan 150 mg Tablets

Brand Name

The medication is marketed under the brand name Diflucan, a widely recognized designation in the field of antifungal therapy.

International Nonproprietary Name (INN)

The active ingredient in this product is identified globally as fluconazole, a name standardized for consistency across international pharmacological practices.

Form of Release

Diflucan is available in multiple forms, including oral tablets, capsules, powder for oral suspension, and intravenous solution. Tablets come in strengths of 50 mg, 100 mg, 150 mg, and 200 mg, while capsules and suspension cater to flexible dosing, and the injectable form suits hospital settings.

Composition

Each tablet of Diflucan contains fluconazole as the primary active substance, with dosages varying by strength (50 mg, 100 mg, 150 mg, or 200 mg). The formulation includes several inactive ingredients, such as microcrystalline cellulose, which provides structural integrity, and lactose monohydrate, acting as a filler. Additional excipients like magnesium stearate serve as lubricants, while croscarmellose sodium aids in disintegration. The oral suspension powder includes citric acid and sodium benzoate as preservatives, and the intravenous solution contains sodium chloride for isotonicity. These components ensure stability and effective delivery across all forms.

Pharmacologic Properties

Pharmacodynamics

Diflucan functions as a triazole antifungal agent, exerting its effects by inhibiting the enzyme 14-alpha-demethylase in fungal cells. This enzyme is critical for converting lanosterol to ergosterol, a key component of fungal cell membranes. By blocking this process, the medication disrupts membrane integrity, increasing permeability and impairing fungal growth and replication. It exhibits broad-spectrum activity against Candida species, Cryptococcus neoformans, and certain dermatophytes, making it effective against both superficial and systemic infections.

The fungistatic action predominates at standard doses, though higher concentrations or prolonged exposure may yield fungicidal effects against susceptible strains. Its selectivity for fungal enzymes over human cytochrome P450 systems minimizes systemic toxicity, though some overlap exists. Clinical studies demonstrate rapid symptom relief in conditions like vaginal candidiasis, often within 24 hours, and sustained control in invasive infections with appropriate regimens. This targeted mechanism underpins its versatility in treating fungal pathogens across diverse patient populations.

Pharmacokinetics

Following oral administration, Diflucan is absorbed nearly completely from the gastrointestinal tract, with peak plasma concentrations reached within 1 to 2 hours. Food intake does not significantly affect bioavailability, which exceeds 90%, allowing dosing flexibility. The drug exhibits low plasma protein binding, around 11–12%, enabling wide distribution into body fluids and tissues, including cerebrospinal fluid, saliva, and skin.

Metabolism is minimal, with over 80% of the dose excreted unchanged, primarily via the kidneys. The half-life ranges from 20 to 50 hours, supporting once-daily or single-dose regimens for many indications. Elimination is predominantly renal, with approximately 80% appearing in urine as the active compound and the remainder as minor metabolites. This extensive renal clearance and prolonged half-life ensure sustained antifungal activity, though adjustments may be needed in kidney dysfunction.

Indications for Use

Diflucan is prescribed for a variety of fungal infections in adults and children. It is indicated for vaginal candidiasis, providing rapid relief with a single dose, and for oropharyngeal and esophageal candidiasis, common in immunocompromised patients. The medication is also used to treat systemic candidiasis, including candidemia and disseminated infections, as well as cryptococcal meningitis, a serious condition requiring prolonged therapy.

Prophylactic use is approved in high-risk groups, such as those undergoing bone marrow transplantation or chemotherapy, to prevent Candida infections. It addresses dermatophyte infections like tinea corporis or tinea pedis when topical treatments fail, and it may be employed in fungal urinary tract infections caused by susceptible strains. These diverse applications highlight its role as a cornerstone in antifungal management across acute and preventive settings.

Contraindications

Diflucan is contraindicated in patients with known hypersensitivity to fluconazole or related azole antifungals, where reactions could range from mild rashes to severe anaphylaxis. It is also prohibited in those with a history of significant QT prolongation or torsades de pointes, due to potential cardiac risks, particularly when combined with other QT-prolonging drugs.

Use is restricted in individuals with severe liver dysfunction only if benefits outweigh risks, given its hepatic metabolism, though it is generally well-tolerated. Co-administration with terfenadine, cisapride, or other drugs known to interact dangerously is forbidden due to arrhythmia risks. Pregnancy and breastfeeding women should avoid it unless clearly necessary, as safety data are limited in these contexts.

Method of Administration and Dosage

Administration Guidelines

The tablets or capsules should be taken orally, swallowed whole with water to ensure proper absorption. They can be consumed with or without food, offering ease of use. The oral suspension requires shaking before measuring with a provided device, and the intravenous form is administered by healthcare professionals over 1–2 hours. Consistency in timing enhances efficacy for multi-dose regimens.

Dosage for Adults and Children

For adults, the dosage of Diflucan varies by indication. Vaginal candidiasis typically requires a single 150 mg dose, while oropharyngeal candidiasis uses 200 mg on day 1, followed by 100 mg daily for 1–2 weeks. Systemic infections like candidemia may demand 400 mg daily, adjusted based on response, and cryptococcal meningitis starts at 400 mg daily, tapering to 200 mg for maintenance. Children’s doses are weight-based, typically 3–12 mg/kg daily, with a maximum mirroring adult limits (e.g., 400 mg), guided by age and severity.

Dose Adjustment in Specific Conditions

In renal impairment, doses are reduced based on creatinine clearance: halved for 21–50 mL/min and quartered for below 20 mL/min, with dialysis patients receiving a full dose post-session. Mild to moderate liver dysfunction rarely requires adjustment, but severe cases warrant caution. Single-dose treatments need no alteration, while multi-dose regimens in renal compromise benefit from tailored schedules to prevent accumulation.

Side Effects

Diflucan may trigger a range of side effects, though many patients experience only mild reactions. Common issues include nausea, abdominal discomfort, or headache, often resolving without intervention. Skin rashes or mild diarrhea are also reported, typically transient as the body adjusts.

Less frequent effects include elevated liver enzymes, particularly with prolonged use, necessitating monitoring in at-risk groups. Rare but serious reactions, such as hepatotoxicity (e.g., jaundice), severe allergic responses (e.g., angioedema), or QT prolongation leading to arrhythmias, require immediate cessation and medical evaluation. Seizures or exfoliative skin disorders occur infrequently but demand urgent attention. Regular check-ups help balance efficacy with safety during treatment.

Overdose

Symptoms of Overdose

Excessive intake of Diflucan may amplify typical side effects rather than cause acute toxicity, given its wide therapeutic index. Reported symptoms include severe nausea, vomiting, diarrhea, and rare instances of hallucinations or confusion, reflecting central nervous system involvement. Specific overdose thresholds are not well-defined, but effects align with exaggerated pharmacology.

First Aid Measures

In case of overdose, medical consultation is advised, though emergency measures are rarely needed. No specific antidote exists, so treatment focuses on supportive care, such as hydration for gastrointestinal upset or monitoring for cardiac changes. Hemodialysis can accelerate clearance in severe cases, leveraging its renal excretion profile, until stability is restored.

Drug Interactions

Effects on Other Medications

Diflucan inhibits cytochrome P450 enzymes, notably CYP2C9, CYP2C19, and CYP3A4, affecting drugs metabolized by these pathways. It can increase levels of warfarin, heightening bleeding risk, or elevate phenytoin and cyclosporine concentrations, requiring dose adjustments. Co-use with QT-prolonging drugs like erythromycin or amiodarone may enhance arrhythmia risk, necessitating caution.

Drugs like rifampin, which induce CYP3A4, may reduce fluconazole levels, potentially decreasing efficacy, though this is less common. Patients should provide a full medication list to their healthcare provider to manage these interactions effectively.

Compatibility with Alcohol and Food

Moderate alcohol consumption does not directly impair the drug’s antifungal action, though excessive use may strain the liver, a consideration given its metabolism. Food intake has negligible effect on absorption, allowing tablets to be taken with meals or on an empty stomach, enhancing patient convenience.

Special Precautions

Use During Pregnancy and Breastfeeding

Diflucan should be avoided in pregnancy, particularly at high doses or prolonged use, due to potential teratogenic risks, such as congenital anomalies reported in rare cases. Single-dose therapy for vaginal candidiasis may be considered if benefits outweigh risks, guided by medical advice. During breastfeeding, it passes into milk at concentrations similar to plasma, so use is discouraged unless essential, with alternatives preferred to minimize infant exposure.

Women of childbearing age should confirm non-pregnant status before multi-dose regimens and use contraception during treatment to avoid unintended fetal exposure.

Impact on Driving and Operating Machinery

The medication does not typically affect cognitive or motor skills, making it safe for most patients to drive or operate machinery. Rare reports of dizziness or confusion suggest caution during initial use or at higher doses until individual tolerance is clear.

Considerations for Elderly and Pediatric Populations

Elderly patients tolerate Diflucan well, with no significant differences in efficacy, though renal function declines may require dose adjustments. Children, including neonates, can use it safely with weight-based dosing, showing comparable safety to adults, though careful monitoring is key in premature infants due to slower clearance.