Introduction: Because many medications are metabolized through the liver, it is important for the medical provider to know all of the medications a patient is taking, including over-the-counter medications. A current medication list should be solicited frequently.
Acetaminophen: Acetaminophen (Tylenol) is a known hepatotoxin that can cause clinically important hepatotoxicity, either through an acute overdose or when taken on a regular basis (even at lower doses): in one large study that examined causes of acute liver failure, patients taking a dose less than 4 grams per day accounted for 7% of the total cases and in some were taking doses as low as 1 gram per day. Among healthy volunteers taking 4 grams per day for 14 days, more than 30% developed alanine aminotransferase (ALT) values in excess of 3 times the upper limit of normal. Concurrent alcohol use greatly increases the chance of acute or chronic acetaminophen-induced hepatotoxicity. Studies have also shown an increased risk of acute liver injury in patients with chronic hepatitis C following acetaminophen overdose, but none have examined the safety of long-term, low dosages of acetaminophen in patients with chronic hepatitis C. Guidelines for the safe use of acetaminophen in HCV-infected persons do not exist. Considering many patients with chronic hepatitis C have limited pain treatment options, most experts believe low dosages of acetaminophen (up to two grams per day) can safely be used in most patients with chronic hepatitis C infection without cirrhosis; those with cirrhosis should limit their intake of acetaminophen to one gram per day. Patients drinking excess alcohol should avoid taking acetaminophen altogether. Clinicians should remind patients that many narcotic combination pills and over-the-counter cold and flu medications may contain acetaminophen. Patients taking acetaminophen should have laboratory monitoring for hepatotoxicity every 3 to 6 months.
Aspirin and Nonsteroidal Anti-inflammatory Medications: Aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) are generally safe for patients with hepatitis C when taken at standard doses. The one exception is in patients who have cirrhosis: NSAIDS and aspirin are best avoided in patients with cirrhosis, especially those with decompensated cirrhosis. In patients with decompensated cirrhosis, the use of NSAIDS and aspirin may further increase the inherent risk these patients have for developing nephrotoxicity and gastrointestinal bleeding. Patients with chronic hepatitis C who do not have cirrhosis may take aspirin or NSAIDs at low or standard recommended dosages, with food and water. Those with cirrhosis who have short-term, minor pain should, in general, avoid taking aspirin or NSAIDs, but can take acetaminophen in this setting as long as the dose does not exceed one gram per day. In the unfortunate situation involving a patient with cirrhosis who has joint or musculoskeletal pain unresponsive to acetaminophen, NSAIDs can be used for a very brief period of time if given at the lowest daily dose possible.
Iron: Patients with chronic hepatitis C infection may store excess iron in their liver and excess hepatic iron has been associated with poor outcomes. Therefore, patients should limit foods high in iron and avoid cooking in cast iron pans. Patients taking a daily multivitamin should make sure the multivitamin does not contain iron, unless a compelling reason exists to regularly take iron, such as iron deficiency anemia from gastrointestinal bleeding.
Vitamin D: Vitamin D deficiency is common in patients with chronic hepatitis C and levels of vitamin D may correlate inversely with liver disease severity. Several studies have shown patients with low vitamin D levels have poorer responses to interferon-based therapy, suggesting an important immunomodulatory role for vitamin D in patients with chronic hepatitis C infection. A more recent study, however, did not show any correlation with vitamin D levels and sustained virologic responses. Supplementation of vitamin D in patients who have 25(OH) Vitamin D levels less than 20 ng/mL is recommended, with initial therapy consisting of 50,000 IU of vitamin D once weekly for 8 weeks, to reach 25(OH) vitamin D levels of approximately 30 ng/mL. Thereafter, patients can take 1500 to 2000 IU per day for maintenance. For otherwise healthy adults, the Institute of Medicine recommends 600 IU per day of Vitamin D.
Vitamin A: Intake of vitamin A at levels contained in a multivitamin is considered safe. Vitamin A is a fat-soluble vitamin and should only be taken at standard doses of less than 10,000 units per day. Ingestion of mega-doses of vitamin A may potentially cause hepatotoxicity and is not recommended.