Side effects
Adverse drug reactions associated with fluconazole therapy include:[14]
If taken during pregnancy it may result in harm.[22][23] These cases of harm, however, were only in women who took large doses for most of the first trimester.[22]
Fluconazole is secreted in human milk at concentrations similar to plasma.[2]
Fluconazole therapy has been associated with QT interval prolongation, which may lead to serious cardiac arrhythmias. Thus, it is used with caution in patients with risk factors for prolonged QT interval, such as electrolyte imbalance or use of other drugs that may prolong the QT interval (particularly cisapride and pimozide).[24]
Some people are allergic to azoles, so those allergic to other azole drugs might be allergic to fluconazole.[25] That is, some azole drugs have adverse side-effects. Some azole drugs may disrupt estrogen production in pregnancy, affecting pregnancy outcome. [26]
Oral fluconazole is not associated with a significantly increased risk of birth defects overall, although it does increase the odds ratio of tetralogy of Fallot, but the absolute risk is still low.[27] Women using fluconazole during pregnancy have a 50% higher risk of spontaneous abortion.[28]
Fluconazole should not be taken with cisapride (Propulsid) due to the possibility of serious, even fatal, heart problems.[24] In rare cases, severe allergic reactions including anaphylaxis may occur.[29]
Powder for oral suspension contains sucrose and should not be used in patients with hereditary fructose, glucose/galactose malabsorption or sucrase-isomaltase deficiency. Capsules contain lactose and thus should not be given to patients with glucose-galactose malabsorption.[30]
- Common (≥1% of patients): rash, headache, dizziness, nausea, vomiting, abdominal pain, diarrhea, and/or elevated liver enzymes
- Infrequent (0.1–1% of patients): anorexia, fatigue, constipation
- Rare (<0.1% of patients): oliguria, hypokalaemia, paraesthesia, seizures, alopecia, Stevens–Johnson syndrome, thrombocytopenia, other blood dyscrasias, serious hepatotoxicity including liver failure, anaphylactic/anaphylactoid reactions
- Very rare: prolonged QT interval, torsades de pointes
- In 2011, the US FDA reports that treatment with chronic, high doses of fluconazole during the first trimester of pregnancy may be associated with a rare and distinct set of birth defects in infants.[21]
