Which antiretroviral drugs are associated with abnormal liver function tests?

Antiretroviral Drugs Causing Deranged Liver Function Tests

All marketed NNRTIs (non-nucleoside reverse transcriptase inhibitors) and PIs (protease inhibitors) have been associated with serum transaminase elevation, with nevirapine carrying the highest risk of clinical hepatitis among NNRTIs, while nucleoside analogs (NRTIs) can cause hepatic steatosis with lactic acidosis. 1

Drug Classes and Hepatotoxicity Risk

Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs)

Nevirapine poses the greatest hepatotoxicity risk among NNRTIs:

• 12.5% incidence of hepatotoxicity overall, with 1.1% developing clinical hepatitis 1
• 9.4% experienced grade 4 liver enzyme elevation in African trials (compared to 0% with efavirenz), with 2 deaths from liver failure 1
• Women have twice the risk of men (12% vs 6%) 1
• Two-thirds of cases occur within the first 12 weeks of therapy 1
• Can present as hypersensitivity syndrome with rash, fever, and eosinophilia 1
• Fulminant hepatic necrosis and death have been reported, with progression to hepatomegaly, jaundice, and hepatic failure occurring within days 1
• Patients who experience severe hepatotoxicity should never receive nevirapine again 1

Efavirenz has significantly lower hepatotoxicity risk than nevirapine 1

Protease Inhibitors (PIs)

PI-associated hepatotoxicity differs from NNRTI patterns:

• Can occur at any time during treatment (not just early) 1
• Ritonavir and ritonavir/saquinavir combinations show higher rates of severe hepatotoxicity (>5-fold transaminase elevation) compared to indinavir, nelfinavir, or saquinavir alone 1
• Majority of patients remain asymptomatic, with some cases resolving spontaneously without therapy modification 1

Nucleoside Reverse Transcriptase Inhibitors (NRTIs)

NRTIs cause a distinct pattern of liver injury:

• Hepatic steatosis with lactic acidosis is a rare but serious adverse effect 1
• Associated with mitochondrial toxicity 1
• Stavudine specifically identified as a risk factor for hepatotoxicity 1
• Grade-1 hepatic dysfunction occurred in 14.3% of patients in one cohort, predominantly in men aged 31-45 years on therapy >5 years 2

Contemporary Antiretroviral Drugs

Newer agents (doravirine, ibalizumab, fostemsavir, cabotegravir) appear to have minimal substantial hepatotoxicity risk, though data is less robust 3

Major Risk Factors for Hepatotoxicity

Viral Hepatitis Coinfection

• Hepatitis C virus coinfection is a major risk factor for hepatotoxicity after PI initiation 1
• 69% of severe hepatotoxicity cases occurred in patients with chronic viral hepatitis 4
• Hepatitis B infection also increases risk 1
• However, 84% of patients with chronic HCV or HBV did not experience severe hepatotoxicity 4

Other Risk Factors

• Concurrent protease inhibitor use (82% of severe cases) 4
• Alcohol abuse 1
• Baseline elevated liver enzymes 1, 5
• Prolonged prior antiretroviral exposure 5
• Preexisting anemia (OR 1.90,95% CI 1.02-3.57) 2
• Thrombocytopenia (aOR 2.583,95% CI 1.127-5.917) 6
• Concomitant hepatotoxic medications 1

Clinical Monitoring Algorithm

For Nevirapine Initiation

Due to the potential for fulminant hepatic failure:

• Every 2 weeks for the first month 1
• Monthly for the first 12 weeks 1
• Every 1-3 months thereafter 1
• Use two-week lead-in dosing (200 mg once daily before escalating to twice daily) to potentially reduce hepatotoxicity incidence 1

For Protease Inhibitors

• Monitor liver enzymes and clinical symptoms at baseline and regularly throughout treatment, as hepatotoxicity can occur at any time 1
• More frequent monitoring (every 3-6 months) for patients with hepatitis C coinfection, especially those using recreational drugs 1

For All HAART Regimens

• Baseline liver function tests before initiating therapy 1
• Patients with alcohol consumption history and thrombocytopenia require more frequent monitoring 6

Critical Clinical Pitfalls

Do not rechallenge patients who experienced severe nevirapine-associated hepatotoxicity 1

Recognize that most hepatotoxicity is asymptomatic - many cases resolve spontaneously without therapy interruption 1

Be vigilant for nevirapine hypersensitivity syndrome - look for the constellation of hepatitis, rash, fever, and eosinophilia occurring within the first 12 weeks 1

Drug-induced liver injury (DILI) is the predominant cause of severe liver damage in HIV patients - accounting for 68% (43/63) of severe cases in one cohort 6

Immune reconstitution rather than direct drug toxicity may cause liver decompensation in hepatitis B/C coinfected patients 1