Tolnalftate: What is it? Chemical Formula, Presentation, Indications, Dosage, Side Effects and Warnings

It is an antifungal that works by preventing the growth of fungi on the skin.

Tolnaftate is a drug with antifungal properties of the group of thiocarbamates and is used to treat fungal infections in the skin such as athlete’s foot, jock itch, and ringworm.

Chemical formula

  • C19H17NOS.
  • 2-Naphthyl N-methyl-N-(3-tolyl) thiocarbamate.


Tolnaftate is a synthetic antifungal agent sold without a prescription, with presentations in the form of cream, powder, aerosol or topical.


Topical Tolnaftate treats skin infections such as athlete’s foot, itching, and infections caused by ringworm.

Tolnaftate is also used, combined with other antifungals, in treating infections of the nails, the scalp, the palms of the hands, and the soles of the feet.

Dust and spray are most often used to prevent an athlete’s foot.

In general, fungal infections where Tolnaftate is used are:

Dermatomyositis, tinea foot or athlete’s foot, ringworm of the hand or Tinea manum, the body or Tinea corporis, the groin or Tinea cruris of the scalp and perianal area or Tinea capitis and the beard, of the nails or onychomycosis.


Mechanism of action

Tolnaftate is a topical fungicide. Currently, the exact mechanism of action is unknown; it is believed that it can prevent the biosynthesis of ergosterol by inhibiting squalene epoxidase.

It has also been reported that it can distort the hyphae’s structures and hinder the mycelium’s development in susceptible organisms.

Es altamente activo frente a dermatofitos como Trichophyton rubrum, T. mentagrophytes, T. tonsurans, Microsporum canis, M. audouini y Epidermophyton flocossum.

However, this is not active against Malassezia furfur, the causative agent of pityriasis Versicolor.

Dosage and method of application

  • This medicine is prescribed only for external use.
  • It should not be swallowed, and avoid contact with the eyes or nose.
  • This treatment must be accompanied by measures of body hygiene and proper clothing.
  • Hands should be washed before and after use.
  • The affected area is always cleaned and dried thoroughly.
  • Applying a thin product layer covers the part of the affected skin and the area adjacent to the lesion.
  • The area can be covered with a sterile gauze dressing (bandage), but never use an airtight bandage.
  • This medication is used for the entire period indicated on the package or as prescribed by the doctor.

Usually, the way to use it is:

In adults and children over 12 years old:

An application is made every 12 hours in the morning and at night for 2 to 6 weeks.

The symptoms of redness, swelling, and itching disappear after 24 hours, but in an athlete’s foot, the results are usually observed after four weeks.

To avoid relapse, treatment should be continued for two more weeks once the symptoms have disappeared.

Side effects

It is doubtful that a severe allergic reaction to this drug will develop, but if the symptoms of this allergic reaction appear, they can be:

  • Itching, rash, swelling, especially in the throat, tongue, and face, intense dizziness, and difficulty breathing.
  • Adverse effects of this drug are generally transient and very mild.

Among the most common side effects are:

  • Dermatological alterations include erythemapruritus, burning sensation, and less frequent
  • contact dermatitis.
  • Allergic reactions include swelling of the face, rash, tongue or lips, hives, or itching.
  • Increased inflammation, redness, or pain in the affected area.

There may also be some side effects that usually do not require medical attention, such as:

  • Dry Skin.
  • Mild irritation, burning, or itching of the skin in the affected area.

Warnings and contraindications

This medication should not be administered in case of allergies to the product or any other drug component.

Tolnaftate may contain inactive ingredients, which can cause allergic reactions or other problems.

The doctor should be informed if the symptoms do not subside or do not start to improve or if they get worse because the cutaneous infection may not respond to this medication.

Before using this medicine, you should consider and report during the diagnosis the existence of problems in the immune system such as an organ transplant, AIDS, and diabetes.

This medicine should be used only if needed during pregnancy or breastfeeding.

You should not wear tight-fitting or made with synthetic materials; this should be preferably loose and cotton, in the same way, clean socks, and cotton.

Also, try to wear sandals or shoes with good ventilation.

Special care should be taken not to apply this medication to the eyes, nose, mouth, or vagina.


Usually, there are no interactions. However, care must be taken not to use other products for the skin in the affected area.