Is Fluconazole (an antifungal medication) causing pruritus (itching)?

From the Guidelines

Fluconazole can cause skin itching as a side effect in some patients, and if you're experiencing itching while taking fluconazole, you should contact your healthcare provider, as this could be a mild allergic reaction. According to the British Association of Dermatologists' guidelines for the management of onychomycosis 2014 1, the common adverse effects of fluconazole include headache, skin rash, gastrointestinal complaints, and insomnia, with adverse effects leading to treatment discontinuation occurring in 20% of patients receiving fluconazole 150 mg per week, which increases to 58% for higher weekly doses (300–450 mg).

Management of Fluconazole-Induced Itching

• For mild itching, your doctor might recommend continuing the treatment while adding an antihistamine like diphenhydramine (Benadryl) 25-50mg every 6 hours or cetirizine (Zyrtec) 10mg daily to manage symptoms.
• Applying a fragrance-free moisturizer may also help.
• However, if you develop a rash, hives, facial swelling, or difficulty breathing along with the itching, seek immediate medical attention as these could indicate a severe allergic reaction.

Risk Factors for Fluconazole-Induced Itching

• The risk of this side effect increases with higher doses and longer treatment durations, as noted in the clinical practice guidelines for the management of candidiasis: 2016 update by the Infectious Diseases Society of America 1.
• Fluconazole-induced itching occurs because the drug can trigger histamine release in some individuals, activating nerve endings in the skin that signal itching.

Importance of Medical Advice

• Don't stop the medication without medical advice, as untreated fungal infections can worsen.
• It is essential to consult your healthcare provider for proper evaluation and management of fluconazole-induced itching, as they can provide personalized guidance and recommend alternative treatments if necessary, as suggested by the clinical practice guidelines for the management of candidiasis: 2009 update by the Infectious Diseases Society of America 1.

From the FDA Drug Label

Fluconazole tablets may cause serious side effects including: ... serious allergic reactions: ... skin rash, hives, blisters or skin peeling ... serious skin problems. Some people with serious medical problems have developed serious skin problems that have caused death while taking fluconazole tablets. Tell your healthcare provider right away if you develop a rash while taking fluconazole tablets serious liver problems ... symptoms of serious liver problems including: ... severe skin itching

Fluconazole can cause skin itching as a symptom of serious liver problems or as part of a serious allergic reaction or serious skin problem. 2

From the Research

Fluconazole and Skin Itching

• Fluconazole is an antifungal medication that can cause various side effects, including skin-related issues 3.
• A study published in the International Journal of Dermatology found that patients treated with fluconazole for coccidioidomycosis reported more moderate to severe dry lips, dry skin, and alopecia compared to untreated patients 3.
• The study suggests that fluconazole may be associated with cutaneous effects, including dry skin, which can lead to itching 3.
• However, it is essential to note that the study does not prove causality, and more research is needed to confirm the relationship between fluconazole and skin itching 3.

Comparison with Other Antifungal Agents

• Other antifungal agents, such as voriconazole, itraconazole, and posaconazole, have also been studied for their efficacy and side effects 4, 5, 6, 7.
• Voriconazole, for example, has been shown to have a higher risk of adverse effects, including skin cancers, with prolonged use 4.
• Itraconazole and posaconazole have also been associated with various side effects, including drug interactions and adverse events 5, 6.
• Fluconazole, on the other hand, is generally considered safe and well-tolerated, but its efficacy and side effects can vary depending on the specific fungal infection being treated 6, 7.

Mechanism of Action and Pharmacokinetics

• Fluconazole works by inhibiting the growth of fungi, but its mechanism of action and pharmacokinetics can affect its efficacy and side effects 6, 7.
• The drug's pharmacokinetics, including its absorption, distribution, and elimination, can influence its concentration in the body and its potential to cause side effects 5, 6.
• Understanding the pharmacokinetics and mechanism of action of fluconazole can help healthcare providers optimize its use and minimize its side effects, including skin itching 5, 6.