Risks vs Benefits of Rx Toenail Fungus Medication

Are there risks associated with oral prescription toenail fungus medication? Do topical or over-the-counter treatments work just as well? If you’re concerned about the safety and are looking for the most effective options for treating your toenail fungus, our resident medical expert and world-renowned dermatologist Dr. Neil Sadick addresses these questions and concerns.

Authored By Neil Sadick, MD FAAD, FAACS, FACP, FACPH

Toenail fungal nail infections are a very common condition affecting anywhere from 10- 50% of the general population, depending on age, as well as certain medical conditions. Many people are bothered by its unsightly appearance and social implications Most of those afflicted find themselves trying to hide their feet as much as possible, which is no easy task especially if you’re a woman wearing shoes that are designed to show off your toes. You can try to cover up with nail polish but even this has its limitations, as the infection worsens and the nails become brittle, cracked and uneven. Going to the nail salon is usually an embarrassing experience that you’d probably rather avoid. 

Most of us strive to be our best selves, which as a cosmetic dermatologist is something I am extremely passionate about. From a medical standpoint, a medical condition untreated is never a good idea. Untreated toenail fungus infections can lead to other infections and unwanted medical problems, as well as the risk of spreading to others. As a doctor, I always balance the risk with the benefit and use treatments with the greatest efficacy and highest safety profiles, and I recommend treating this ideally when it first starts.

Allergic reaction, fungal infection, stomach pain, lamisil terbinafine, weight loss, unusual bleeding, liver problems, skip the missed dose, doctor or pharmacist, prescription label tell your doctor, call your doctor, missed dose, skin rash

Can I use a topical treatment for my toenail fungus?

In a previous blog I covered many of the common treatment options for toenail infections, so for this blog, I’d like to discuss a topic I often hear from my patients when I prescribe a treatment that is worth discussing. It goes something like this, “Can’t I just use something topical to treat this?” or “I heard oral fungal medicines can cause liver failure?”

Do oral fungal medicines cause liver failure?

LEARN MORE: The Dermatologist Guide to Recognizing and Treating Toenail Fungus

To the first question, the answer is “Yes, you can use a prescription topical-only treatment but the caveat is that this alone works less than half the time and has a high recurrence rate. The results are even more disappointing when it comes to purchasing an over-the-counter treatment you buy at the pharmacy or supermarket”. To put it another way, topical treatments alone fall in the category of “Can’t hurt might help” they also fall in the category of “the most expensive drug or treatment, is the one that doesn’t work”. 

After some additional questions, I tend to find that they believe there is a risk of taking these oral medications. In medicine, there is always a risk-benefit ratio that doctors have to consider before deciding on a treatment. If the benefit significantly outweighs the risk, you do it. In this case, the winner is that oral antifungals are the most effective treatments and one of them should be part of the treatment algorithm for curing toenail fungus. The clinical data on this is very clear however there’s a perception regarding the risk, so let’s dig to see why and if it’s warranted.  

lamisil side effects, upper stomach pain, missed dose, tell your doctor, call your doctor, stomach pain, abnormal liver function tests, skin rash, allergic reaction, lamisil terbinafine

What are the oral medication options used to Treat Toenail Fungus?

Fluconazole and Terbinafine are two oral antifungal medications that are both safe and effective and used to treat infections caused by certain types of fungal and yeast infections. They can be administered orally or topically, with the oral route being the most effective form to cure fungal infections like toenail fungus. 

Fluconazole requires patients to take one 150- 450mg tablet once per week for 6-12 months, whereas terbinafine typically requires patients to take one 250 mg tablet daily for 12 weeks.  These drugs act by disrupting the fungal cell membranes and resulting in cell death.

Terbinafine is the most commonly used as it is very effective as well as a shorter duration of treatment, which helps with patient compliance. One of the most common side effects are skin rash. Fluconazole can be substituted for patients that may have a history of liver disease, side effects or be on other medications that can interact. What are the treatments and risks of each?

An ample amount of data and research exists when looking at how safe these drugs are for consumers, especially those who need relief from toenail fungal infections. . The risk of liver disease with terbinafine is considered very rare, occurring once every 50,000 to 120,000 prescriptions. 

Ultimately, findings have determined that preexisting liver problems can affect the susceptibility of the user to liver damage from these medications. Equally, those who are genetically disposed to liver ailments also have a high risk of this side effect, but in one study, this carrier trait was found in less than 1% of the participants. If doctors prioritize screening individuals for  pre-existing liver disease, in addition to potential interacting medications, the chances of liver damage solely from toenail fungus medication are extremely low.  

Call your doctor, drug reaction, lamisil terbinafine, doctor for medical advice, seek medical treatment, pain muscle aches painful, butterfly shaped skin rash, treat infections caused, severe skin reaction, side effects, doctor for medical advice, call your doctor,

Signs and Symptoms of Liver Complications

As with all treatments its you should call your doctor or tell your doctor immediately if you experience any of the following symptoms:

  • Jaundice
  • Pain in your upper right abdomen (stomach pain)
  • Ascites, or a swollen stomach
  • Nausea
  • Vomiting
  • Disorientation, confusion, or any other changes in awareness
  • Sudden mental or personality changes
  • The breath may have a musty or sweet odor
  • Tremors
  • Dark urine
  • Pruritus, or itching
  • Urticaria, or hives


  • Nail fungus is extremely common, affecting 20% of the general population and 3 in 4 people over the age of 60.
  • Nail fungus is transmittable, so be sure to wear sandals when walking in a public shower or locker room.
  • Left untreated, nail fungus can lead to other health complications like foot pain, loss of toenails, and widespread infection.

Click to get your prescription toenail fungal treatment