Fluconazole (Diflucan): thrush and fungal infection treatment

Fluconazole is an antifungal medicine. The NHS says it works by killing the fungus or yeast causing the infection, by making holes in the fungal cell membrane so the contents leak out.

It covers a wide range. Commonly it treats candida infections such as vaginal thrush, balanitis and oral thrush; in hospital or under specialist care it treats infections in the bloodstream and elsewhere in the body and cryptococcal meningitis, and it prevents fungal infection in vulnerable patients. It comes as capsules, an oral liquid and a hospital injection.

The NHS lists 150 mg taken once for vaginal thrush or balanitis; 50 mg a day for 7 to 14 days for oral thrush; for recurrent vaginal thrush, 150 mg every 72 hours for the first 3 doses and then once a week for 6 months; and 200 mg to 800 mg a day for several weeks for systemic infections.

Capsules are swallowed whole with water, with or without food, ideally at the same time each day. Liquid is measured with the plastic spoon supplied. Some infections need weeks, months or even years of treatment, and the course should be finished even if you feel better.

• Missed dose: take it when you remember unless the next is near; do not double up. Alarms or a calendar can help if you often forget.

• One or two extra doses usually cause no harm; call NHS 111 if you or your child exceeded the dose and feel unwell.

The NHS says most adults can take fluconazole, and that those aged 16 and over can use it for vaginal thrush or balanitis without a prescription, while younger children need a doctor for other conditions.

Tell the prescriber about any earlier allergic reaction, heart conditions including arrhythmia, kidney or liver problems, acute porphyria, or abnormal blood levels of potassium, calcium or magnesium.

More than 1 in 100 people get a headache, stomach pain, diarrhoea, nausea or vomiting, or a rash. Rest and fluids help a headache, and the NHS advises not drinking too much alcohol. Drink plenty of fluids for diarrhoea.

• Call NHS 111 or a doctor for yellow skin or eyes with pale stools and dark urine, easy bruising or frequent infections, or a faster or irregular heartbeat.

• Call 999 for swelling of the lips, mouth, throat or tongue, severe breathing difficulty, blue, grey or pale skin, severe confusion or loss of consciousness.

The NHS names pimozide, quetiapine, amisulpride, haloperidol, lithium and risperidone; escitalopram and venlafaxine; erythromycin and clarithromycin; ergotamine; amiodarone; warfarin, dabigatran and clopidogrel; carbamazepine; losartan; and statins.

The list is not complete, and the NHS cannot say herbal products are safe alongside it. Always give the prescriber or pharmacist a full list of what you take.

In pregnancy fluconazole is only a second-line option. The NHS recommends trying clotrimazole or a similar antifungal first, as a cream or pessary, before considering oral treatment. You can take it while breastfeeding a healthy baby, though the amounts are fairly high compared with most medicines; the NHS notes a long safety record. There is no evidence it reduces fertility.

It generally does not affect contraception, although rare breakthrough bleeding has been reported. You can drive unless you feel dizzy or light-headed, and there are no food or alcohol restrictions. If it has not worked after 7 days, tell your doctor.