Does Lamisil cause allergic reactions? (+3 factors)

In this article, we will discuss whether Lamisilis associated with causing allergic reactions or not. We will further dig into the potential side effects caused by Lamisil. We will look into the factors that may trigger allergic reactions due to Lamisil. we will also ponder over the ways to ensure the safe use of this drug. 

Does Lamisil cause allergic reactions?

Lamisil may cause allergic reactions. Although very rare studies have supported that Lamisil is associated with causing allergic reactions due to rarely reported incidents.

Lamisil (terbinafine) is an antifungal medication used to treat various fungal infections, particularly of the toenails and fingernails. It is an FDA-approved medication in adults but is used off-label in children for onychomycosis caused by dermatophyte organisms (1). 

However, allergic reactions to Lamisil are rare. If you suspect any allergic reactions such as rash, severe itching, swelling, or difficulty breathing after initiating Lamisil treatment, consult your doctor. 

What does research suggest?

According to the research studies, it is stated that adverse effects due to Lamisil are reported in about 10% of patients while cutaneous side effects have been reported in about 2% of patients (2). 

A rare case of a 25-year-old patient was reported who was diagnosed with fingernail onchomycosis for which he was prescribed oral Lamisil 250mg per day for 18 days (2). 

Within 4 days of Lamisil therapy, he came with the complaint of a rash on his chest which progressed to his entire body. He was then withdrawn from Lamisil and was given supportive management. Within 4 days, the rash started to disappear and the patient was also discharged (2). 

Another case of a 58-year-old patient who started Lamisil 250mg per day for toe onchomycosis. On the 5th day of Lamisil treatment, she observed a photoallergic reaction with an itching rash on the sun-exposed areas while in a swimming pool. On stopping the lamisil, the rash was immediately suppressed (3). 

Lamisil may commonly cause urticaria, rash, and pruritis, within a month of therapy. However, very rare photoallergic reactions or pityriasis rosacea may occur in patients taking Lamisil (2).  

What are the potential side effects of Lamisil?

Some potential side effects of Lamisil are (4):

  • Diarrhoea
  • Headache
  • Itching
  • Mood changes
  • Loss of energy
  • Sleep disturbances

Some rare and serious side effects may also occur such as (4):

  • Nausea
  • Vomiting
  • extreme tiredness
  • Yellowing of the skin
  • Severe skin rash
  • Dark urine and pale stools
  • Hoarseness
  • Hives
  • Chest pain
  • Blood in urine

However, it is important to note that not all patients taking Lamisil may experience these side effects. If you suffer from such side effects which keep on worsening your condition then you must seek medical help. 

What risk factors may trigger allergic reactions while on Lamisil?

Some of the risk factors that may contribute to allergic reactions while taking Lamisil are: 

  • Age and gender- Some allergic reactions due to medicines may occur at any age or gender. If you are prone to allergies, discuss with your doctor beforehand to avoid adverse drug reactions. 


  • Previous Lamisil reaction- If a patient has previously taken Lamisil and struck an allergic reaction. Such patients are more prone to develop allergic reactions upon restarting Lamisil treatment. 


  • Drug interactions- Taking Lamisil along with other medications may trigger allergic reactions. Therefore, discuss your concomitant medications with your doctor before starting Lamisil treatment. 


  • Liver problems- Lamisil is metabolized by the liver. Taking Lamisil with any pre-existing liver condition may exacerbate your condition and lead to severe consequences. Therefore, careful monitoring is required with liver patients while taking Lamisil to ensure liver safety

However, it is important to discuss your pre-existing health conditions, allergies,  and medication history with your doctor before starting any new treatment to avoid any potential adversities. 

What alternatives to use if Lamisil causes an allergic reaction?

If Lamisil does not suit you well and is causing an allergic reaction, then your doctor might switch you to another antifungal medication based on your condition. Some common Lamisilalternatives can be as follows:

  • Itraconazole
  • Fluconazole
  • Ketoconazole
  • Griseofulvin
  • Ciclopirox

However, do not start taking any of these medications without consulting your healthcare provider. Lamisil is a prescription medication and must be started, switched, or stopped under your doctor’s guidance 

How to ensure safe and effective use of Lamisil?

To ensure the safe and effective use of Lamisil, you must observe your signs and symptoms closely. If you suspect any allergic reactions due to Lamisil, then consult your doctor immediately and seek medical help. 

To ensure the safe use of Lamisil, you must discuss your previous medical and medication history with your doctor before starting Lamisil treatment to avoid any adversities.

As Lamisil is a prescription medication, you must always follow the prescribed dosage of Lamisil at the prescribed time to avoid any adverse conditions. Always follow any special instructions given by your doctor before starting Lamisil. 

Lamisil is metabolized by the liver and may be harmful or hepatotoxic for some patients. Your doctor must conduct your liver function tests to ensure safety regarding Lamisil use. 

Avoid alcohol intake while being on Laisil treatment as it may exacerbate or worsen liver metabolization and may cause severe adversities. 

In the end, I would suggest always relying upon and following your doctor’s recommendation before starting Lamisil treatment to ensure safe and effective treatment. Always discuss your concerns with your doctor to avoid adversities. 

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Maxfield L, Preuss CV, Bermudez R. Terbinafine. [Updated 2023 May 29]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:


George, Anisha, Anuradha Bhatia, Bimal Kanish, and Abhilasha Williams. “Terbinafine Induced Pityriasis Rosea-like Eruption.” Indian Journal of Pharmacology 47, no. 6 (2015): 680-681. Accessed December 31, 2023.


Bacle, Astrid, Sorya Belaz, Sophie Potin, and Pierre Gangneux. “A Case Report of Photodermatoses Induced by the Antifungal Drug Terbinafine.” European Journal of Hospital Pharmacy 26, no. 5 (2019): 288-289. Accessed December 31, 2023.


AHFS Patient Medication Information [Internet]. Bethesda (MD): American Society of Health-System Pharmacists, Inc.; c2019. Terbinafine; [updated 2020 Jun 24; reviewed 2018 Jul 5; cited 2020 Jul 1]; [about 5 p.]. Available from: