Antifungal medicines - Side effects of antifungal medicines and interactions with other medicines

Antifungal medicines can cause side effects. These will differ depending on the type of antifungal medicine you are using.

Side effects of topical antifungals

Topical antifungal medicines, such as creams, can cause:

• itching
• a mild burning sensation
• redness

Stop using the medicine if any of these side effects are severe and see your GP or pharmacist to find an alternative.

Side effects of oral antifungals

Side effects of oral antifungals, such as capsules, include:

• feeling sick
• abdominal (tummy) pain
• diarrhoea 
• flatulence (wind)
• headache
• a rash
• indigestion 

These side effects are usually mild and only last for a short period of time.

Antifungals can also cause severe reactions, such as:

• an allergic reaction – swelling of your face, neck or tongue or difficulty breathing
• a severe skin reaction – such as peeling or blistering skin

If you experience any of these reactions, stop taking your medicine and contact your GP immediately.

If you are having difficulty breathing, visit the accident and emergency (A&E) department of your nearest hospital or call 999 for an ambulance.

Liver damage from antifungal medicines

Liver damage is a rare, but more serious, side effect of oral antifungals.

Stop taking your medicine and contact your GP if you experience:

• loss of appetite
• vomiting
• feeling sick for a long time
• jaundice – yellowing of your skin or the whites of your eyes 
• unusually dark urine or pale faeces (stools)
• unusual tiredness or weakness

Side effects of intravenous antifungals

Amphotericin B is the most commonly used intravenous antifungal. This is usually given in hospital as an intravenous infusion (a continuous drip of medicine into a vein in your arm).

Side effects of amphotericin include:

• loss of appetite 
• feeling sick
• vomiting
• diarrhoea
• epigastric pain (pain in the upper part of your tummy)
• a high temperature (fever)
• chills
• headache 
• muscle and joint pain
• anaemia (a reduced number of red blood cells)
• a rash

Amphotericin can also affect your:

• kidneys – causing abnormally low levels of some minerals in your blood, such as potassium or magnesium  

More rarely it can cause problems with your

• heart – causing an irregular heartbeat or changes in your blood pressure
• liver – affecting the way your liver functions, for example, causing a build-up of bilirubin in the blood; bilirubin is a yellow substance that is produced when red blood cells are broken down  

As amphotericin is given in hospital under supervision, any adverse effects are usually quickly detected and treated.

Antifungal medicine interactions with other medicines