Diflucan Side Effects
Generic name: fluconazole
Note: This document contains side effect information about fluconazole. Some of the dosage forms listed on this page may not apply to the brand name Diflucan.
Some side effects of Diflucan may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.
For the Consumer
Applies to fluconazole: oral powder for reconstitution, oral tablet
Get emergency medical help if you have any of these signs of an allergic reaction while taking fluconazole (the active ingredient contained in Diflucan) hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have any of these serious side effects:
nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);
fever, chills, body aches, flu symptoms;
severe blistering, peeling, and red skin rash;
easy bruising or bleeding, unusual weakness; or
Less serious side effects of fluconazole may include:
mild stomach pain, diarrhea, upset stomach;
unusual or unpleasant taste in your mouth.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.
For Healthcare Professionals
Applies to fluconazole: intravenous solution, oral powder for reconstitution, oral tablet
Fluconazole is generally well tolerated. Changes in renal and hematological function test results and hepatic abnormalities have been reported during treatment with fluconazole (the active ingredient contained in Diflucan) and comparative agents in some patients, primarily those with serious underlying diseases such as AIDS and cancer; however, the clinical significance and relationship to therapy is uncertain.
During clinical trials of single dose therapy, side effects possibly related to fluconazole were reported in 26% of patients. In patients receiving active comparative agents, the incidence was 16%. The most common side effects reported in patients receiving a single 150 mg dose of fluconazole for vaginitis were headache, nausea, and abdominal pain. Most side effects were of mild to moderate severity.
During clinical trials of multiple dose therapy, side effects were reported in 16% of patients. Treatment discontinuation occurred in 1.5% and 1.3% of patients due to adverse clinical events and laboratory test abnormalities, respectively. Clinical adverse events were reported more frequently in HIV patients than in non-HIV patients (21% versus 13%); however, the patterns in HIV and non-HIV patients were similar.
Rare cases of seizures have been reported, but a causal relationship was difficult to establish, since some of these patients had cryptococcal meningitis or severe underlying disease. Nonetheless, at least one case of seizure following a 100 mg oral dose has been reported.
Nervous system side effects have included headache (up to 13%) and dysesthesias. Seizures, dizziness, insomnia, paresthesia, somnolence, tremor, and vertigo have been reported during postmarketing experience.
Gastrointestinal side effects have included nausea (up to 7%), abdominal pain (up to 6%), diarrhea (up to 3%), vomiting (1.7%), dyspepsia (1%), taste perversion (1%), anorexia, and general abdominal discomfort. Dry mouth, dyspepsia, vomiting, and taste perversion have been reported during postmarketing experience.
Hepatic side effects have included rare cases of serious hepatic reactions ranging from mild transient transaminase elevations to clinical hepatitis, cholestasis, and fulminant hepatic failure (including fatalities). Transient hepatic reactions (including hepatitis and jaundice), elevated liver function tests (transient and asymptomatic), hepatitis, cholestatic jaundice, and fatal hepatic necrosis have been reported. Serum transaminase elevations (greater than 8 times the upper limit of normal; approximately 1%) and statistically significant increases in AST (SGOT) have been reported. Cholestasis and hepatocellular damage have been reported during postmarketing experience.
Fatal hepatic reactions have occurred primarily in patients with serious underlying medical conditions (primarily AIDS or malignancy) and often taking multiple concomitant medications. One reported patient with AIDS experienced acute hepatic necrosis and hepatic failure approximately 3 weeks after beginning fluconazole therapy.
Transient hepatic reactions have been reported in patients with no other identifiable risk factors. Liver function returned to baseline following fluconazole discontinuation.
Serum transaminase elevations have been reported primarily in patients with serious underlying medical conditions (primarily AIDS or malignancy) and often taking multiple concomitant medications, including agents known to be hepatotoxic.
Dermatologic side effects have included skin rash (1.8%) and reversible alopecia. Exfoliative skin disorders (including fatalities) have been reported rarely. Acute generalized exanthematous pustulosis, drug eruption, increased sweating, exfoliative skin disorders (including Stevens-Johnson syndrome and toxic epidermal necrolysis), and alopecia have been reported during postmarketing experience.
Reversible alopecia has been associated with long-term (2 months or longer) therapy.
In patients with serious underlying diseases (primarily AIDS and malignancy), exfoliative skin disorders have rarely resulted in a fatal outcome.
A 52-year-old female experienced a fixed drug eruption (FDE) when administered a single oral 400 mg dose of fluconazole (the active ingredient contained in Diflucan) therapy for extensive pityriasis versicolor. Within a 12-hour period, she noticed 3 oval, painful, eroded, pigmented patches over her trunk with diameters of 3 cm to 4 cm and erythematous halos. A clinical diagnosis of FDE caused by fluconazole therapy was made. The FDE was confirmed when the patient was rechallenged with an oral dose of fluconazole 25 mg.
Hypersensitivity side effects have rarely included angioedema and anaphylactic reaction. Rare cases of exfoliative dermatitis and ulcerative eruptions consistent with Stevens-Johnson syndrome have been reported in association with hypersensitivity reactions to fluconazole. Anaphylaxis, generalized edema, stridor, hypotension, and fixed drug eruption have been reported. In rare cases, anaphylaxis (including angioedema, face edema, and pruritus) has been reported during postmarketing experience.
Most reports of QT interval prolongation and torsades de pointes involved seriously ill patients with multiple confounding risk factors, such as structural heart disease, electrolyte abnormalities, and concomitant medications that may have been contributory.
An 11-year-old male with neurofibromatosis-1 presented to the hospital in septic shock secondary to a perforated gastric volvulus. After initial stabilization, the patient underwent total gastrectomy and multiple peritoneal lavages. Culture of peritoneal fluid showed infection with Candida albicans. Therapy was initiated with fluconazole (the active ingredient contained in Diflucan) 150 mg intravenously every 12 hours. After initiating fluconazole therapy, the patient developed QT prolongation and complex ventricular arrhythmia. Fluconazole was discontinued. Over the subsequent 36-hours, the patient remained in sinus rhythm except for one brief run of ventricular bigeminy. An ECG recorded 5 months after admission (and approximately 4 months after cessation of all QT-prolonging medications) showed sinus rhythm with normal heart rate and corrected QT interval.
Cardiovascular side effects have included prolongation of the QT interval on the electrocardiogram (ECG) and palpitations. QT prolongation and torsades de pointes have been reported during postmarketing experience.
Anemia, eosinophilia, leukopenia, neutropenia, and thrombocytopenia have been reported, often in patients with severe deep fungal infections or underlying disease.
Spontaneous reports of anemia were more frequent in patients 65 years of age or older than in those between 12 and 65 years of age; however, there is a natural increase in the incidence of anemia in the elderly. A causal relationship to drug exposure could not be determined.
Hematologic side effects have included anemia, leukopenia, neutropenia, agranulocytosis, and thrombocytopenia during postmarketing experience. Eosinophilia has been reported.
A 58-year-old female with a history of hypertension and cervical cancer experienced membranous nephropathy coincident with fluconazole (the active ingredient contained in Diflucan) therapy. The patient presented with increasing generalized edema accompanied by nausea and indigestion for 3 weeks. Clinical findings showed the patient had stage I membranous nephropathy. At initial presentation, the patient's medication history included amlodipine, hydrochlorothiazide, metoclopramide, and levosulpiride. She did not admit to taking fluconazole therapy. Five months after the initial presentation, the patient returned with reports of increasing pedal edema. At that point, the patient admitted to taking fluconazole once weekly for tinea pedis. Off fluconazole, the patient went into complete remission.
Spontaneous reports of acute renal failure were more frequent in patients 65 years of age or older than in those between 12 and 65 years of age; however, there is a natural increase in the incidence of renal failure in the elderly. A causal relationship to drug exposure could not be determined.
Renal side effects have included at least one case of membranous nephropathy. Acute renal failure has been reported during postmarketing experience.
Metabolic side effects have included hypercholesterolemia, hypertriglyceridemia, and hypokalemia during postmarketing experience.
Other side effects have included fever, asthenia, fatigue, and malaise during postmarketing experience.
Respiratory side effects have included respiratory disorders.
Musculoskeletal side effects have included back and joint pain. Finger stiffness has been reported, although the association to therapy was questionable. Myalgia has been reported during postmarketing experience.
More Diflucan resources
- Diflucan Prescribing Information (FDA)
- Diflucan Consumer Overview
- Diflucan Monograph (AHFS DI)
- Diflucan MedFacts Consumer Leaflet (Wolters Kluwer)
- Diflucan Advanced Consumer (Micromedex) - Includes Dosage Information
- Fluconazole Prescribing Information (FDA)
- Fluconazole Professional Patient Advice (Wolters Kluwer)
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