Drug-Induced Liver Disease
Medicines used to treat different diseases can sometimes cause liver injury. This is known as drug-induced liver injury (DILI) or drug-induced liver disease.
- Drug-induced reactions account for approximately 25–30% of hepatitis cases, and can even lead to hepatic failure.
- Approximately 10% of cases of acute hepatitis in adults may be related to drug reactions.
- About 15% of people with autoimmune hepatitis may have drug-induced liver disease.
The severity and progression of drug-induced liver disease depend on several factors, including:
- The specific medicine being used
- The person's overall health
- Genetic susceptibility
- Age
- Sex
- The presence and severity of existing liver disease
Types of Drug-Related Liver Damage
Acute Hepatocellular Injury
Some medicines can cause sudden damage to liver cells, known as acute hepatocellular injury. Medicines associated with this type of liver injury include:
- Anti-tubercular drugs
- Diclofenac
- Halothane
- Phenytoin
- Anticonvulsant medicines
- Paracetamol
- Amiodarone
- Methotrexate
- Azathioprine
- Trazodone
- Nefazodone
- Venlafaxine
- Lovastatin
The risk and severity of liver injury vary depending on the medicine, dose, duration of treatment, and individual patient factors.
Chronic Active Hepatitis
Some medicines can cause long-term inflammation of the liver that may resemble chronic active hepatitis. Examples include:
- Isoniazid
- Nitrofurantoin
- Methyldopa
Long-term use may require medical monitoring, particularly in people who have other risk factors for liver disease.
Liver Cirrhosis
Long-term exposure to certain substances or medicines can contribute to liver scarring and, in some cases, cirrhosis. Examples include:
- Alcohol
- Methotrexate
Cirrhosis develops when repeated or long-term liver injury causes permanent scarring.
Liver Tumors and Cancer
Certain substances and medicines have been associated with an increased risk of liver tumors. Examples include:
- Anabolic steroids
- Combined oral contraceptive pills (birth control pills)
The risks associated with these medicines vary, and they should be used under appropriate medical guidance.
Hepatic Cholestasis
Cholestasis occurs when the normal flow of bile from the liver is reduced or blocked. Medicines associated with cholestatic liver injury include:
- Carbimazole
- Erythromycin
- Phenothiazines
- Anabolic steroids
- Azathioprine
- Chlorpromazine
- Estrogens
Cholestasis may cause symptoms such as jaundice, dark urine, pale stools, and itching.
Fatty Liver
Some medicines and medical treatments can contribute to the development of fatty liver. Examples include:
- Parenteral nutrition
- Methotrexate
- Griseofulvin
- Tamoxifen
- Steroids
- Valproate
- Amiodarone
The risk depends on the specific medicine, treatment duration, dose, and the person's individual health factors.
Liver Granulomas
A liver granuloma is a small area of inflammation in the liver that can develop in response to certain medicines, infections, or other conditions. Medicines that have been associated with liver granulomas include:
- Allopurinol
- Phenylbutazone
- Quinidine
- Sulfonamides
- Diltiazem
Gallstones
Certain medicines or hormones may increase the risk of gallstones. Examples include:
- Clofibrate
- Estrogens
Liver Fibrosis
Fibrosis occurs when repeated liver injury causes scar tissue to build up in the liver. Medicines and substances associated with liver fibrosis include:
- Methotrexate
- Excessive vitamin A
Long-term exposure can increase the risk of progressive liver scarring in susceptible individuals.
Microvesicular Fatty Change
Some medicines can cause microvesicular steatosis, a condition in which very small droplets of fat accumulate inside liver cells. Medicines associated with this type of liver injury include:
- Tetracycline
- Didanosine
- Acetylsalicylic acid (aspirin)
- Valproate
This type of liver injury can sometimes become serious and requires appropriate medical evaluation.
Liver Complications Caused by Chemotherapy
Chemotherapy medicines used to treat different types of cancer can sometimes cause liver injury and other liver complications. Important examples include:
- 5-Fluorouracil (5-FU)
- Irinotecan
- Oxaliplatin
Some chemotherapy medicines can cause hepatic steatosis (fatty liver) and steatohepatitis, which is inflammation and injury associated with fat buildup in the liver. The type and severity of liver injury depend on the specific chemotherapy medicine, treatment dose, duration, and the patient's overall condition.