Fluconazole (Diflucan)

Antifungal medications are many. Amongst the common ones available, fluconazole is a regularly prescribed antifungal medication. In this article, we shall take a brief look at this drug, particularly concentrating on its clinical applications and dosing.

What is fluconazole?

Fluconazole is an antifungal drug that is similar to drugs such as ketoconazole and miconazole. It works by preventing the proliferation of fungus by inhibiting the formation of the protective membrane around them. It is also utilised in treating yeast infections. It belongs to a class of drugs termed ‘azoles’ and is widely utilised all around the world.

Clinical indications

Fluconazole is used in the management of fungal infections that affect the oesophagus, mouth, vagina and other parts of the body. Candida albicans is a common fungus that affects these parts of the body and can be effectively treated with fluconazole. Fungal infections can also affect the bladder and the lungs causing urinary tract infections and pneumonias respectively. In addition, fungal meningitis is an important condition that can be treated with fluconazole. In patients who have undergone chemotherapy for various cancers, fungal infections can occur due to reduced levels of immunity and this can be treated with fluconazole.

Available doses

Fluconazole is available as tablets, suspensions and injections. Doses vary between 50 mg, 100 mg, 150 mg and 200 mg orally or in different concentrations in suspensions. They may be prescribed as a once-a-day or twice a day dose for varying periods of time depending on the infection and the patient’s immune status.

Side-effects

The most common side-effects that fluconazole can cause include nausea, abdominal discomfort, dizziness and headache. Of course, these are rare and are often self-limiting after completing the course of treatment. In extremely rare cases, liver disease and allergic reactions may occur. These require hospitalisation and emergency medical management.

Another recognised side-effect of fluconazole is prolongation of the QT interval on the ECG. While this is a rare, it is essential to bear this in mind especially in patients who have problems with their heart. A prolonged QT interval can result in irregularities in the heart contraction which can be life threatening in some occasions. This is particularly the case if there are accompanying electrolyte abnormalities such as low potassium levels in the blood. Ideally, fluconazole must be avoided in pregnancy.

Clopidogrel is an antiplatelet agent which can interact with fluconazole. Drugs such as quinidine (which is a drug used to treat irregular heart rhythms) can prolong the QT interval and if taken with fluconazole can cause serious irregularities in the heart rate (as described previously), which can sometimes be fatal.

Fluconazole (Diflucan) is a widely utilised antifungal agent that has a variety of different clinical indications. Treatment should be taken only on prescription by a registered medical practitioner for indications that warrant its use. Side-effects are few and must be kept an eye out for during treatment.