Oral antifungal medication for fungal nail infections

Examples

Allylamines

Generic Name	Brand Name
terbinafine hydrochloride	Lamisil tablets

Azoles

Generic Name	Brand Name
fluconazole	Diflucan
itraconazole	Sporanox
ketoconazole

All of these medications are by prescription only. Allylamines and azoles are classes of drugs; their effectiveness and side effects may vary.

Terbinafine tablets are taken once each day for 6 weeks for fungal fingernail infections, and 12 weeks or longer for fungal toenail infections. Terbinafine tablets can be used according to a pulse dosing schedule. Pulse dosing refers to taking medication daily for 1 week per month for 2, 3, or 4 months. Some people find it easier to stay with this medication schedule, and the treatment is likely to be cheaper.

Oral azoles (tablets or capsules) are taken daily for 3 to 18 months, depending on the medication.¹ Oral azoles can be used according to a weekly pulse dosing schedule. Pulse dosing refers to taking medication daily for 1 week per month for 2, 3, or 4 months. Some people find it easier to stay with this medication schedule, and the treatment is likely to be cheaper.

How It Works

Allylamines and azoles kill fungi. Killing fungi does not guarantee a normal-looking nail.

Why It Is Used

Oral antifungal medications are used to treat fungal nail infections. Which medication is used often depends on the type of infection you have.

• Terbinafine is a first-line medication for fungal nail infections caused by dermatophytes, including distal subungual onychomycosis and white superficial onychomycosis.² Most fungal nail infections are caused by this type of fungus. Terbinafine may also be effective against some moulds (non-dermatophytes).
• Itraconazole is a preferred medication for infections caused by moulds and yeast (Candida).² It can also be used for dermatophytes.
• Fluconazole is a first-line medication for Candida infections and can also be used against dermatophytes.² It may be used if you are taking a lot of other medications.²
• Ketoconazole is effective against dermatophytes and yeasts.

How Well It Works

Oral antifungals may cure fungal nail infections. Most research has been on using the medications for toenail infections.

Research on oral terbinafine reports that in people with a fungal nail infection caused by dermatophytes, it:³

• Killed fungi in 40% to 90% of the people using it.
• Produced a normal-looking nail in 35% to 50% of the people using it.
• Was more effective than itraconazole or fluconazole.

Research on other oral antifungals reports that:

• Fluconazole improved the appearance of more than 75% of a toenail in 72% to 89% of people using it.² When taken in high doses once a week over 3 months for fingernail infection, oral fluconazole produced a normal-looking fingernail in 90% of people using it and killed the fungi in nearly all the people using it.²
• Itraconazole killed fungi in 45% to 70% of people using it and produced a normal-looking nail in 35% to 80% of the people using it.²
• Ketoconazole has a lower cure rate (up to 50%) and a higher recurrence rate than itraconazole and fluconazole.¹

Oral antifungal medications often kill fungi but do not immediately improve the appearance of the nail.

Side Effects

Oral antifungals have both minor and dangerous side effects.

Minor side effects include:

• Headaches.
• Stomach upset.
• Skin rashes.
• Changes in taste sensation (rare, and with terbinafine only).
• Visual disturbances (rare, and with terbinafine only).

Dangerous side effects of oral antifungals include:⁴

• Drug interactions. Commonly prescribed medications can increase or decrease terbinafine or azole levels in your body. Similarly, other medications can build up in the bloodstream when taken with terbinafine or an azole. Let your health professional know what other medications you are taking before taking oral antifungal medications.
• Liver damage or failure, requiring a liver transplant. A small number of deaths after liver failure have been linked to terbinafine and azoles. Warning signs of liver failure include:
  • Nausea, vomiting, abdominal pain.
  • Fatigue.
  • Loss of appetite.
  • Dark urine.
  • Changes in skin colour.

Itraconazole may cause heart failure. Warning signs of heart failure include:

• Shortness of breath at rest, with mild exertion, or when lying flat.
• Severe swelling of feet, ankles, legs, or abdomen.
• Weight gain.
• Fatigue.
• Coughing up white or pink mucus.
• Faster-than-usual heart rate.

During oral antifungal treatment, your health professional may require blood tests to check your kidney and liver function.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Terbinafine and azoles pass into breast milk; it is not known whether they harm a fetus. If you are pregnant, could become pregnant, or are breast-feeding, consult your health professional before taking oral antifungal medications.

Advanced age decreases your chances of a cure. A study of oral antifungals in people older than 60 reported fungal infection cure rates of about 64%. This lower-than-average cure rate may be due to slowed nail growth and, in some people, poor blood circulation to the feet.⁵

Oral azoles are best absorbed into the body when taken with cola, orange juice, or food. Some medications may decrease your body's absorption of azole medication. These include cimetidine, stomach acid neutralizers, and rifampin (Rifadin).

Some people redevelop a fungal infection (recurrence) after treatment. Recurrence of infection may be a new infection or a regrowth of the original infection that was not eliminated by treatment.

Consider the following about treatment with oral antifungal medication:

• Oral antifungal medications are not recommended if you have liver problems.
• Do not drink alcohol while taking these medications, as this increases your risk of liver damage.
• Itraconazole (Sporanox) is not recommended if you have a history of heart failure.

For more information on deciding whether to use oral antifungal medications, see:

Should I take oral antifungal medication to treat a fungal nail infection?

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.

Author:	Douglas Dana Sabra L. Katz-Wise	Last Updated: October 11, 2006
Medical Review:	Patrice Burgess, MD - Family Medicine Tom Bailey, MD - Family Medicine Randall D. Burr, MD - Dermatology
© 1995-2008 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.