Sulconazole

Sulconozole, otherwise known by the brand name Exelderm, is a topical antifungal treatment for common dermatological fungal infections such as ringworm and athlete's foot.

Overview

Sulconazole is a topical antifungal medication. It is:

  • widely prescribed to treat many dermatological conditions
  • remarkably safe if used as directed, with no known drug interactions or risk of overdose
  • easy to use, with no need to precisely measure dosage
  • known to occasionally cause skin irritation, usually negligible and never acutely dangerous.

Sulconazole is used to treat a variety of dermatological fungal infections, including tinea corporis (ringworm), tinea cruris (jock itch), tinea pedis (athlete's foot), and tinea versicolor. It is available only by prescription in the United States, meaning it's generally reserved for fungal infections too serious for over-the-counter formulations. Sulconazole is sold in the United States under the brand name Exelderm, and in Canada as Sulcosyn. It is available both as a cream and a liquid solution.

Sulconazole works by inhibiting the synthesis of ergosterol in fungi. Ergosterol is found in the cell membranes of fungi and protozoa, and is required for these organisms to live and reproduce; it serves a function similar to that of cholesterol in animal cells, replacing the cell wall. Sulconazole is thus a fungistatic drug, not explicitly killing the fungi but preventing its reproduction so that the colony rapidly dies off. However, research suggests that it is explicitly fungicidal to two types of fungi, Candida parapsilosis and Candida albicans, because it interrupts their most critical growth phases, but neither of these fungi are known to cause the dermatological conditions treated by topical sulconazole.

Sulconazole is known to effectively treat a wide variety of dermatological fungal infections. Its labeled indications note that it can treat infections caused by Trichophyton rubrum, Trichophyton mentagrophytes, Epidermophyton floccosum, and Microsporum canis. It is also used to treat tinea versicolor, which is most often caused by Malassezia globosa or Malassezia furfur, though this condition is more often treated with topical selenium sulfide. It may effectively treat many more fungi than those listed above; diagnosing the disorders sulconazole treats typically doesn't require identifying the responsible fungi.

Sulconazole has in fact not been clinically proven to effectively treat athlete's foot, but it remains commonly prescribed for it because of anecdotal evidence of its effectiveness.

Sulconazole has been developed only for topical use on the skin; it has not been tested orally, nor is it intended for this. If taken orally, it would likely severely disrupt the balance of fungi and bacteria that naturally live in the stomach and intestines. If sulconazole is accidentally swallowed, the patient should seek medical attention or call the Poison Control line (1-800-222-1222); depending on the amount swallowed, they may be instructed to induce vomiting. A variety of oral antifungal medications do exist to treat internal fungal infections, such as ketoconazole.

Sulconazole was developed by Syntex Research, now part of Roche. It is an azole derivative, a significant class of drugs that contains many medically important antifungal drugs that treat conditions ranging from cosmetic dermatological problems to life-threatening internal infections. Some of the most commonly prescribed azole derivative antifungals include clotrimazole, miconazole, fluconazole, terconazole, and ketoconazole.

Conditions Treated

  • Dermatological fungal infections (tinea corporis, cruris, pedis, and versicolor)

Type of Medicine

  • Topical antifungal

Side Effects

The most common side effect of topical sulconazole is mild skin irritation on the application site, including burning, itching, or redness. If patients experience more serious or ongoing irritation, such as blistering, peeling, or unusual discoloration, they should stop using sulconazole and seek medical attention. While up to ten percent of users experience minor skin irritation with sulconazole, hypersensitive reactions leading to serious or prolonged irritation are very uncommon. Patients who experience this sort of hypersensitive reaction may be directed to try another topical antifungal drug or a different formulation of sulconazole. Hypersensitive reactions leading to anaphylaxis have not been reported but are theoretically possible.

Dosage

The exact dosage of topical sulconazole is imprecise and should be based on the information provided in the accompanying pamphlet or as directed by a healthcare professional.

To use it, patients should gently rub a small amount on and around the affected skin, once or twice a day. The cream formulation sold as Exelderm contains one percent sulconazole, with the remaining amount composed of cetyl alcohol and propylene glycol, while the Exelderm liquid solution also contains only one percent sulconazole, with the remainder being only propylene glycol.

Treatment with sulconazole typically lasts for three or four weeks, depending on the type of infection being addressed. Symptoms generally improve after a few days of using sulconazole, but patients should continue using it for the entire course of treatment - even after all symptoms are gone - to reduce the likelihood of recurrence.

If a patient forgets a dose, they should administer it as soon as they remember, unless it is nearly time for the next dose. Patients should never use extra sulconazole to make up for a missed dose.

Before applying sulconazole, patients should wash the infected area(s) with soap and water and make sure that the skin is thoroughly dry. After application, patients should not wear excessively tight clothing around the treated area; clothing that is too tight or causes too much sweating could increase the risk of irritation and delay healing. Ideally, the treated area should be left exposed to the air after application if possible. Occlusive (airtight) dressings, such as compression bandages or clothing, are particularly not advisable after applying sulconazole.

There are no reported cases of overdose with topical sulconazole, and they would likely not be acutely dangerous. However, if anyone accidentally swallows any amount, they should seek immediate medical attention or call the Poison Control line at 1-800-222-1222. Oral doses of sulconazole have never been clinically studied, but it is believed that the drug would severely disrupt digestion and cause extreme discomfort.

Interactions

No drugs, supplements, or foods are known to interact with topical sulconazole, but this does not mean that no such interactions exist. Sulconazole should be applied to completely clean skin, so using lotions or makeup on the affected areas may impact its effectiveness. No clinical trials have explored how sulconazole reacts when combined with other antifungal treatments, so it is not known if other antifungal drugs would amplify or attenuate its effects, or cause a dangerous reaction.

Warnings

Sulcanazole is only safe to use on external skin; it should never be eaten or allowed to touch other body parts. If sulconazole gets into a patient's eyes, mouth, or vagina, the area should be thoroughly rinsed with water as soon as possible. If sulconazole touches these areas or is swallowed, it could cause extreme irritation or discomfort. If even a moderate amount of sulconazole has been swallowed, the patient should seek immediate medical attention or call the Poison Control line (1-800-222-1222).

Sulconazole should not be used by patients who are allergic to it. Patients who have had allergic reactions to other antifungal medicines, such as miconazole, sertaconazole, terconazole, or clotrimazole, may be more likely to have a similar reaction to sulconazole and should be monitored closely for symptoms of a reaction if they begin treatment.

Sulconazole is classified under pregnancy risk factor "C," meaning it is not known whether or not it is harmful to a developing human fetus. Animal trials have indicated that very large doses (125 times the average human dose in mg/kg) administered orally have led to birth defects, but these circumstances do not mirror normal topical use. It is also unknown whether or not sulconazole secretes into breast milk. Due to the lack of information, sulconazole should be avoided if possible by women who are pregnant or breastfeeding.

Sulconazole has not been approved for use by patients younger than eighteen years old. It has also not been studied specifically in geriatric patients, but it is expected to work much the same as for younger adults.

Storage

Sulconazole should be stored at room temperature (approximately 59 to 77 degrees Fahrenheit, or 15 to 25 Celsius). It should be protected from direct light and excessive heat, above 104 degrees Fahrenheit (40 Celsius). While sulconazole doesn't require a specific humidity range, it should be kept out of excessive moisture, and thus not stored in a bathroom that gets steamy during bathing.

Sulconazole should also be kept out of reach of children and pets in a locked cabinet.

Prescriptions of sulconazole should typically be used until the medicine is gone, but in the event that a patient has unneeded sulconazole, they should dispose of it in at a designated drug drop-off location, such as at a police department or fire station; flushing or throwing out drugs can disrupt local ecosystems.

Summary

Sulconazole is a remarkably safe drug to use: it has no known adverse interactions with other drugs, no dangerous side effects except for skin irritation (unless eaten), and virtually no risk of overdose if used as directed.

Sulconazole also has a very wide therapeutic index: it can treat so many different fungal conditions so effectively that it is commonly prescribed as a first-line medication even without a specific diagnosis of the species of fungi.

The only significant complications that could arise from using sulconazole are if it is accidentally eaten or touches the eyes or other sensitive areas. The most serious adverse side effect reported is severe skin irritation, but even this has never been life threatening, and its symptoms have always subsided once the patient stops using sulconazole.

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Last Reviewed:
December 22, 2017
Last Updated:
December 22, 2017
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