Antifungal Tablet

Triazole antifungals are widely used for treating a variety of fungal infections. They work by inhibiting the fungal enzyme needed to produce ergosterol, an essential component of the fungal cell membrane. Here's what you need to know about two commonly used triazoles: itraconazole and fluconazole.

Itraconazole

Itraconazole is a versatile antifungal prescribed for conditions like:

• Oral thrush (Candida infections in the mouth).
• Lung infections, including Aspergillus-related fungal diseases.
• fungal nail infections (onychomycosis).
• Pityriasis versicolour (a yeast infection of the skin).

Precautions and Interactions

Itraconazole interacts with many drugs, such as proton pump inhibitors, certain heart medications, and statins. Always inform your doctor or pharmacist about any other medications you are taking to prevent adverse effects.

Itraconazole is not recommended during pregnancy unless it’s essential for life-threatening conditions. It should also be avoided while breastfeeding, as the drug can accumulate in breast milk and potentially affect the baby.

Long-term use may require regular checks of liver function and heart health, as itraconazole can occasionally cause liver toxicity and heart rhythm disturbances.

Fluconazole

Fluconazole is commonly used for treating:

• Vaginal thrush - Typically given as a single 150 mg oral dose. For recurrent infections, a longer-term regimen may be prescribed: 150 mg every 72 hours for three doses, followed by a weekly dose for six months.
• Oral Thrush: A daily 50 mg dose is used for 7–14 days, depending on the severity.

Precautions and Usage

Fluconazole is not advised during pregnancy, as high doses have been linked to birth defects in animal studies.

This medication can be taken while breastfeeding. Its transfer into breast milk is minimal and unlikely to harm the baby.

Recurrent thrush treatment should always be managed under medical supervision, particularly if it requires prolonged therapy.

Key Considerations for Both

Both itraconazole and fluconazole are generally well-tolerated, but potential side effects include nausea, headache, or abdominal discomfort. Serious reactions, like liver issues, are rare but possible, particularly with long-term use.

If you’re considering either itraconazole or fluconazole, always consult your doctor or pharmacist to ensure the treatment is appropriate for your specific situation. Regular monitoring might be needed, especially for long-term or high-dose treatments.

Imidazole antifungals are a group of medications commonly used for treating fungal infections that affect the skin, mouth, and genital areas. This class includes clotrimazole, ketoconazole, econazole, tioconazole, and miconazole.

Uses and Applications

• Clotrimazole, Ketoconazole, Econazole, and Tioconazole - These medications are effective for localised fungal infections, particularly vaginal thrush and various skin conditions, including athlete’s foot and ringworm.
• Miconazole - Beyond treating skin infections, miconazole is also used for oral thrush, applied directly to the mouth in gel form. Additionally, it can help manage fungal gut infections when ingested in specific formulations.

How They Work

Imidazoles target the fungal cell membrane by inhibiting the production of ergosterol, a key component needed for the fungus to survive. This weakens the fungus, causing it to die over time.

Practical Considerations

These treatments are usually well-tolerated when used locally, but side effects like mild skin irritation or redness can occur. When treating oral or gut infections, miconazole may interact with certain medications, particularly blood-thinning drugs, so a pharmacist should review current medications before use.

Polyene antifungals

Polyene antifungals are potent treatments used primarily for fungal infections that cannot be managed with oral formulations. This class includes amphotericin B and nystatin.

Uses and Applications

• Nystatin - This antifungal is applied locally for oral thrush and Candida skin infections. It comes as a liquid suspension for mouth infections or a cream for skin applications.
• Amphotericin B - Reserved for severe systemic fungal infections, amphotericin B is administered intravenously. It is a powerful option against a broad range of fungi and yeasts, particularly in cases where the infection is widespread or life-threatening.

Echinocandins are a specialised class of antifungal medications that target severe fungal infections, particularly those caused by Candida or Aspergillus species. They are typically used in hospital settings for patients who are critically ill or have infections that do not respond to more commonly used antifungals.

How Echinocandins Work

Echinocandins, including caspofungin, micafungin, and anidulafungin, inhibit the synthesis of β-(1,3)-D-glucan, a key component of fungal cell walls. By disrupting the cell wall structure, they weaken the fungus, causing it to die. This mechanism is highly selective, as human cells lack this component, making echinocandins less likely to cause serious side effects compared to some other antifungal drugs.

When Are Echinocandins Used?

Echinocandins are reserved for serious fungal infections that are either life-threatening or resistant to first-line treatments. Some common scenarios where echinocandins may be prescribed include:

• Invasive Candidiasis - Severe bloodstream infections or deep tissue infections caused by Candida.
• Oesophageal Candidiasis - A more serious form of thrush that affects the oesophagus, often in immunocompromised individuals.
• Invasive Aspergillosis - A rare but potentially fatal infection caused by Aspergillus, particularly in people with weakened immune systems.

These medications are typically administered intravenously, which limits their use to hospital environments.

Benefits and Limitations

The key advantage of echinocandins is their efficacy against resistant fungal infections and their relatively mild side effect profile. Common side effects include mild nausea, headache, or fever, though serious reactions are rare. They are often the drug of choice when azole antifungals (like fluconazole) fail or are not tolerated.

However, echinocandins have some limitations:

• Route of Administration: They must be given by injection, making them impractical for outpatient use.
• Limited Spectrum: While effective against most Candida species, they have reduced activity against certain strains, such as Candida parapsilosis. Their efficacy against Aspergillus is also limited to growth inhibition rather than outright fungal death.

Terbinafine tablets are used to treat athlete’s foot, ringworm, sweat rash, fungal nails and pityriasis versicolor but are only given if the creams haven’t worked. In fungal nail infections, this is taken as 250mg once a day for 6 weeks to 3 months or longer. It’s important to check liver function before starting the tablets and one month after as it can cause liver dysfunction. It is best to avoid both in pregnancy and breastfeeding.