Lamisil (terbinafine) is an oral medication used to treat fungal infections. Unfortunately, it can sometimes harm the liver and damage liver cells. This is why experts recommend blood tests before starting Lamisil, and also periodically during treatment. Even with precautions, serious injury can occur — including liver failure that requires a liver transplant, or in rare cases causes death.
Lamisil (terbinafine) is an oral tablet medication that is used to treat fungal infections, usually in the toenails, fingernails, skin of feet hands, or scalp. It is also used to treat fungal infections in the groin (jock itch) and feet (athlete’s foot). In some cases, the fungal infection may not be cured until several months after Lamisil is discontinued. This is because it takes months to grow a healthy nail.
Lamisil was created and sold by the drug company Novartis. It was approved by the U.S. Food and Drug Administration (FDA) in May 1996. The patent on Lamisil expired in 2007 and the drug is now available as a generic medication.
Lamisil and the Liver
Lamisil can cause serious liver problems, liver damage, or liver failure. This is why routine liver function tests are recommended as a precaution. It is also recommended that patients have a blood test to check for elevated liver enzymes before they start taking Lamisil.
The label on Lamisil warns: “Rare cases of liver failure, some leading to death or liver transplant, have occurred with the use of Lamisil.” For this reason, “Treatment with Lamisil should be discontinued if biochemical or clinical evidence of liver injury develops.” Lamisil is not recommended for patients with chronic or active liver disease.
The liver is an organ that has many functions. One of the most important functions is cleaning the blood — it removes toxic substances from the bloodstream. It also deactivates and removes drugs, including Lamisil. Sometimes, the liver has problems cleaning drugs from the bloodstream, which causes the liver to become inflamed. This can cause blood tests to show elevated liver enzyme levels.
Lamisil and Elevated Liver Enzymes
Certain enzymes inside liver cells help the liver perform properly. These enzymes are supposed to stay inside a liver cell. When liver cells are damaged or inflamed, the cells can leak enzymes into the bloodstream. When a doctor performs a blood test, the test will show higher-than-normal liver enzymes.
Elevated liver enzymes often indicate liver damage, which may be temporary or chronic. They may occur suddenly after Lamisil is started, or after a few weeks of using the drug. This is why routine blood tests are recommended.
The two liver enzymes that are usually elevated are:
- Alanine transaminase (ALT)
- Aspartate transaminase (AST)
In most cases, elevated liver enzymes are only temporary. Normal levels usually return after Lamisil is discontinued.
Lamisil Side Effects
Lamisil has been linked to some serious side effects — including a life-threatening allergic reaction known as anaphylaxis. It can also cause severe liver damage, including liver failure. Contact your doctor right away if you experience any of the following symptoms:
- Allergic reaction
- Liver damage
- Liver failure
- Upset stomach that does not go away
- Loss of appetite
- Extreme tiredness
- Pain in the upper right part of the stomach
- Dark urine
- Pale stools
- Skin rash that gets worse (could be a sign of Stevens-Johnson Syndrome, or toxic epidermal necrolysis)
- Fever, sore throat, or other symptoms of infection