Terbinafine- Uses and Drug Interactions

Overview:

Terbinafine is a medication that works against fungal infections of the skin. The drug was discovered in 1991 and is on the World Health Organization's list of essential medicines. The United States (US) Food and Drug Administration (FDA) approved the first generic versions of Terbinafine in December 1995. The FDA also approved Terbinafine for children four years of age and above on 28 th September 2007. The antifungal granules of Terbinafine can be sprinkled on the affected areas to treat tinea capitis or ringworm of the scalp.

What Is Terbinafine?

Terbinafine is an antifungal medication used to manage skin infections, including the following:

• Athlete's Foot - A common fungal infection that causes itchy white patches on the skin between the toes is called athlete's foot.

• Fungal Nail Infections - These infections usually initiate at the edge of the nail, spread to the middle, and make the nails brittle. As a result, the nails break and fall off easily.

• Ringworm - Ringworm is a fungal infection that causes swollen, dry, scaly, and itchy rashes anywhere on the body.

• Jock Itch - It is a fungal infection of the groin.

• Pityriasis Versicolor - It is a condition wherein multiple white patches form on the skin, resulting in the skin's color change.

Terbinafine is usually available as a cream, gel, or spray for treating the conditions, as mentioned earlier. It is also available as a liquid solutions at any pharmacy. Terbinafine can also be taken in the form of tablets for treating fungal infections of the nails. However, the tablets are available only on prescriptions, and the doctor might recommend the tablets only if the liquid, cream, and other modes of application of the drug fail to work.

How Does Terbinafine Work to Treat Fungal Infections?

The mechanism of action of Terbinafine is quite simple as the drug is fungicidal, which implies that it directly kills the fungi producing skin infections. It inhibits the activity of the enzyme squalene monooxygenase, which stimulates the release of sterols in fungi. Therefore, when the drug enters the body, it decreases the ergosterol levels by inhibiting fungal sterol biosynthesis. As a result, it becomes impossible for the fungal membranes to grow because ergosterol is one of the essential components of the fungal cell membrane. In addition, the fungal wall weakens further due to the deficiency of the enzyme squalene monooxygenase. Studies report that the drug is highly effective when taken orally.

What Are the Recommended Dosages of Terbinafine?

The dosage of Terbinafine would be different for different patients. Therefore, the patient must consult his doctor and follow the recommendations to know the exact dose. The dosages of Terbinafine for various conditions are listed below:

What Precautions Must Be Taken Before Taking Terbinafine?

Before taking Terbinafine, the patient must inform the doctor if he or she is:

• Allergic to Terbinafine or its ingredients.

• Taking or has taken medications, vitamins, and herbal supplements.

• Suffering from liver diseases, HIV (human immunodeficiency virus), or AIDS (acquired immunodeficiency syndrome).

• Breastfeeding or planning to breastfeed in the future.

How Should the Patient Take Terbinafine?

The duration of the drug to be taken depends on the severity and extent of the infection. For example, if the area is large and hairy, the patient must use the Terbinafine spray. Similarly, Terbinafine cream, gels, tablets, and liquid solutions can be used for skin infections. The various modes of the drug and their methods of usage are described below:

1. Terbinafine Gel or Cream:

   1. The patient must apply the gel or cream to the affected area twice daily for one to two weeks.

   2. The patient must wash his hands before applying the cream or gel.

   3. Ensure the skin is washed and dried before applying the cream or gel.

   4. Remove the cap and squeeze a small amount of the cream or gel into the hand.

   5. Rub the cream onto the affected area, but do not apply it near the lips, nose, or eyes.

   6. Put on the cap again and wash hands.

2. Terbinafine Spray:

   1. The patient must wash his hands before using the spray and dry the skin where the spray is to be applied.

   2. Remove the cap and spray once or twice before spraying the drug on the skin.

   3. Hold the bottle 10 centimeters away from the skin and spread it until it becomes wet.

   4. Put on the cap again and wash hands.

3. Terbinafine Solution:

   1. The solution comes in a tube that has a nozzle. The tube must be used only once.

   2. The solution must be used only after taking a shower.

   3. Apply the solution to the sole and the sides of the toes.

   4. Leave the solution on the toes for one to two minutes.

   5. The patient must avoid washing his feet for 24 hours after applying the solution.

What Are Some of the Side Effects of Terbinafine?

The patient must take Terbinafine only after consultations with a doctor as more than one out of 100 patients are more likely to experience the side effects. Some of the common side effects of Terbinafine are listed below:

• Itching or peeling of the skin.

• Skin rash.

• Headache.

• Diarrhea.

• Nausea.

• Vomiting.

• Reduced appetite.

• Abdominal pain.

• Muscle pain or joint pain.

• Indigestion.

• Hives.

• Fever.

• Vasculitis (inflammation of the blood vessel).

• Hoarseness.

• Swollen lymph nodes.

• Difficulty in swallowing.

• Skin discoloration.

• Chest pain.

• Hematuria (blood in the urine).

• Irregular heartbeat.

What Are Some of the Drugs That Can Interact With Terbinafine?

Some of the drugs that can interact with Terbinafine are listed below:

1. Amphetamine.
2. Atenolol.
3. Pregabalin.
4. Montelukast.
5. Levothyroxine.
6. Escitalopram.
7. Fluticasone nasal.
8. Diphenhydramine.
9. Aspirin.
10. Ubiquinone.
11. Alprazolam.

Conclusion:

Terbinafine is a commonly used drug because of its safety and efficacy against a wide variety of dermatologic reactions. However, the patient must use Terbinafine only after consulting the doctor, as it can cause serious side effects. Therefore people suffering from fungal infections of the skin must consult a dermatologist at the earliest to know more about the benefits and side effects of Terbinafine.