Antifungals (Oral)

Medication Information Leaflet

What is this medication for?

This class of medications is used to treat infections caused by fungus. These organisms can infect the skin, scalp, fingernails, toenails, mouth, intestinal tract and vagina.

Oral antifungal medication includes:
  • Griseofulvin
  • Nystatin
  • Terbinafine
  • Itraconazole
  • Fluconazole
  • Ketoconazole

Oral antifungals may also be used for conditions as determined by your doctor.

How should I take/use this medication?

  • Do not stop taking your medication without checking with your healthcare professional.
  • Griseofulvin, Itraconazole and Ketoconazole should be taken with or after food.
  • Terbinafine and Fluconazole may be taken with or without food. 
  • Nystatin suspension: 
    • You may take this medication with or without food.
    • Shake the suspension well before measuring a dose.
    • Use a dose-measuring dropper to measure the specified dose of the suspension. 
    • Swish the suspension around in your mouth. Keep the suspension in the mouth for as long as possible and swallow the medication.
  • Complete the course as prescribed by the doctor.

What should I do if I forget to take/use this medication?

If you forget to take a dose, take it as soon as you remember. Then take your next dose at the usual time. Do not take two doses to make up for the missed dose. 

What precautions should I take?

Inform your healthcare professional if: 
  • You are allergic to this medication or any of the other ingredients of this medication.
  • You are pregnant, planning to become pregnant, or breastfeeding.
    • Effective contraception is recommended for any woman who is taking itraconazole or ketoconazole who could potentially become pregnant during treatment and for 2 months following the end of treatment.
  • You are taking any other medications, including supplements, traditional medications and herbal remedies. 
    • There are potential interactions between itraconazole or ketoconazole with other medications. 
      • The blood concentration of digoxin, midazolam and cyclosporine may be increased when taken with itraconazole or ketoconazole.
      • There is a risk of muscle weakness if combined with cholesterol lowering drugs such as simvastatin or atorvastatin. 
      • Medications such as phenytoin and rifampicin can decrease the blood level of itraconazole and ketoconazole, making them less effective. 

What are some common side-effects of this medication?

Some side effects of these medications include: 
  • Nausea, vomiting, stomach upset 
    • Take the medication with food to relieve these effects. 
  • Diarrhoea
  • Headache
    • If it is mild, you may continue taking the medication and the symptoms may improve over time. 
    • If the headache is severe, stop the medication and consult your doctor.

If any of these side effects do not go away or are serious, please see your doctor.

  • ​Reduced effectiveness of oral contraceptives and higher risk of unwanted pregnancy
    • Use a different or additional non-hormonal means of birth control while you are taking griseofulvin and for one month after stopping griseofulvin.
  • Griseofulvin may affect sperm quality and production. It is recommended that you avoid planning for a child with your partner during treatment with griseofulvin and for 6 months following therapy. 
  • Increased sensitivity to sunlight, and severe burning may result. 
    • Avoid prolonged exposure to sunlight. Use a sunscreen and wear protective clothing when exposure to the sun is unavoidable.
​Taste disturbances or a loss of taste

What are some rare but serious side-effects that I need to seek medical advice immediately?

  • High fever or chills 
  • Unexplained bruising or bleeding
  • Heart failure
  • Chest pain
  • Abnormal or fast heartbeat
  • Burning, numbness, or abnormal tingling feeling 
  • Feeling confused 
  • Dark urine or light coloured stools
  • Nausea, vomiting
  • Loss of appetite
  • Stomach pain
  • Yellowing of eyes or skin
  • Unusual tiredness or weakness
  • Muscle pain or weakness
  • Symptoms of a drug allergy: 
    • Swollen face/eyes/lips/tongue
    • Difficulty in breathing
    • Itchy skin rashes over your whole body

If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

What food or medication should I avoid when I take this medication?

  • Avoid alcoholic drinks while you are taking any of these medications. 
    • Alcohol, terbinafine, itraconazole and ketoconazole can affect the liver. 
      • It is important that you check with your doctor immediately if you persistently experience any discomforts of liver disease (e.g., nausea or vomiting, lack or loss of appetite, general feeling of tiredness or weakness, stomach pain, yellow eyes or skin, dark urine, or pale stools).
    • Alcoholic drinks may also cause stomach pain, nausea, vomiting, headache, or flushing or redness of the face when taken with ketoconazole. 
    • The combination of alcohol and griseofulvin may cause flushing and a fast heart rate.

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children. 

How should I throw away this medication safely?

Pack this medication into a black trash bag and seal it tightly before throwing into the rubbish chute or bin. 

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on Apr 2021 

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