What are the potential side effects of antifungal treatments for oral candidiasis that I should discuss with my patients?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 16 August 2025Updated: 16 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

When discussing antifungal treatments for oral candidiasis with patients, it is important to inform them about potential side effects and drug interactions associated with these medications.

  • Miconazole: Common side effects include local irritation or discomfort in the mouth. Importantly, miconazole can interact with warfarin and statin medications, potentially increasing their effects and risk of adverse events, so patients on these drugs should be monitored closely .
  • Nystatin: As it is not absorbed systemically, side effects are generally limited to local reactions such as mouth irritation or unpleasant taste. It is considered safe but less effective than miconazole or fluconazole .
  • Fluconazole: Being systemically absorbed, fluconazole may cause systemic side effects including gastrointestinal disturbances (nausea, abdominal pain), headache, and, rarely, liver toxicity. It also interacts with immunosuppressants like ciclosporin and tacrolimus by increasing their plasma concentrations, necessitating specialist advice before use in such patients .
  • Itraconazole: Reserved for fluconazole-resistant cases, itraconazole carries a higher risk of drug interactions and adverse effects, including liver toxicity, and should only be initiated with specialist guidance .
  • Ketoconazole: Oral ketoconazole is no longer recommended due to the risk of serious liver damage .

Patients should also be advised about the importance of reporting any unusual symptoms such as persistent mouth soreness, signs of allergic reactions, or systemic symptoms during treatment.

Educational content only. Always verify information and use clinical judgement.