A B C D E F G H I J K L M N O P R S T U V W

ANTIFUNGAL DRUGS

What are the types of Antifungal Drugs ?

In this leaflet we are talking about amphotericin, nystatin, clotrimazole, econazole, ketoconazole, miconazole, fluconazole, itraconazole, griseofulvin, amorolfine, fenticonazole, flucytosine, isoconazole, terbenafine and tioconazole.

What are Antifungal Drugs for ?

We are normally protected from the fungi that surround us. Most fungi cannot survive for long inside the healthy human body. They can, however, be "caught" from other people or from animals. They can also live in the mouth, skin, hair or nails, without you knowing it. Sometimes, fungi that normally live harmlessly in these areas of your body (or occasionally inside your body) can multiply more than usual. This causes an infection. The most common example of this is candida, a yeast, that can cause thrush of the mouth, vagina or bowel, with marked irritation and discharge. Normally you need to take anti-fungus (antifungal) drugs because your body cannot get rid of them itself. The most common fungus infections are tinea pedis (athlete's foot), tinea cruris (jock itch), tinea capitis (scalp ringworm) and thrush.

How do Antifungal Drugs work ?

Antifungals damage the walls of the fungus cells. This allows the contents to leak out and the cells will then die.

How should Antifungal Drugs be used ?

If you get a fungal infection which just affects one area of your skin, you will probably be advised to put an antifungal cream or ointment directly on to the skin. You may get a fungal infection that is more serious and widespread: it may also affect your internal organs or your nails. In these cases, you will probably be advised to take a course of tablets or capsules. Very serious fungal infections need to be treated by injections. Antifungals put on the surface of the infection might be given to you in different forms. Creams, mouth pastilles or lozenges, liquids to swill round your mouth, lotions, shampoos or vaginal pessaries are all used, depending on where the infection is. Use them in exactly the way your doctor explains, or ask your pharmacist if you are not clear. The label should also help. It is important that you use or take your antifungal drug regularly: the correct number of times each day (or week), and the correct length of time (even if you feel better!). If you stop too soon, the fungus will begin to multiply again. If you are in any doubt, check with the doctor or pharmacist.

During Treatment

The time it takes for antifungals to work depends on what type of infection you have. If you are using them for a fungal infection in your mouth, on your skin or in your vagina, then it will normally improve within a week. If you are using an antifungal for an infection in your nails, it will take several months. You have to wait for your nails to grow. Antifungals that you put on to the surface of the infection don't usually cause side-effects, but they might irritate your skin. Sometimes antifungals used for mouth infections can cause mild nausea or diarrhoea. If you have to take tablets or capsules you might feel like being sick. You might get stomach pains, diarrhoea or constipation, flatulence, indigestion, headache, dizziness, rashes or itching. Some antifungals can damage your liver. This would give you yellow skin (jaundice). If you get a rash, jaundice or any other persistent symptom, stop taking your antifungal and contact your doctor immediately.

Drug Interference

Antifungals that you put on the surface of the body do not usually interfere with any other drugs which you may be taking by mouth. If you are taking antifungal tablets or capsules they can interfere with other drugs:

ANTIHISTAMINES (astemizole, and sometimes other drugs of this type): there is a risk of causing irregular heartbeats. Do not take these without first checking with your doctor.

BLOOD THINNERS (warfarin): if you take this at the same time as fluconazole, itraconazole, ketoconazole or miconazole, your dose of blood thinners may need to be reduced. Without this you could risk bleeding. On the other hand if you take them with griseofulvin, you might need a higher dose of your blood thinners to avoid the risk of blood clots.

CONTRACEPTIVES (the pill): these tend to be less effective: you might need to use additional contraceptive protection. Discuss this with your doctor or family planning clinic.

IMMUNE-SUPPRESSIVE DRUGS (tacrolimus and cyclosporin): these become more active when used with floconazole, itraconazole or ketoconazole; their dose may be reduced by your doctor.

DIABETIC MEDICATION (except metformin): your blood sugar might be lowered more than usual: your doctor will advise you about dose reduction.

CHOLESTEROL-LOWERING MEDICATION (simvastatin, cerivastatin, atorvastatin and possibly other drugs of this type): these increase the risk of developing muscle weakness when used together.

DIGOXIN: this becomes more active if you take itraconazole. This combination must be avoided, or the dose of digoxin reduced with guidance from your doctor.

EPILEPSY MEDICATION (phenytoin) : when used with fluconazole or miconazole, the epilepsy medication becomes more active. You may need to take less phenytoin.

INDIGESTION REMEDIES OR ANTI-ULCER DRUGS: these can reduce the effectiveness of ketoconazole and itraconazole, so you should take them at least 2 hours apart. Since this is not a full list, it is worth checking with your doctor about any other drugs which you take at the same time as your antifungal. Do not change the dose of any other medication unless your doctor tells you to.

What if Antifungal Drugs are not taken ?

Without antifungal treatment, the infection will probably linger and may become more difficult to get rid of. If you stop using antifungals before finishing the full course, or if you do not use or take them regularly, your infection may return. If you forget a dose, apply or use it as soon as you remember.

General advice on the use of Antifungal Drugs

Tell your doctor if you have liver or kidney problems: you are more likely to get side-effects. Some antifungals may not be suitable for you. Tell him or her also if you are pregnant or breast-feeding because some antifungals are not safe for your baby. Your doctor also needs to know if you have had an allergic reaction to an antifungal before. An alternative drug should be available for you.