Review article: drug‐induced liver injury in the context of nonalcoholic fatty liver disease – a physiopathological and clinical integrated view

<jats:title>Summary</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Nonalcoholic fatty disease (<jats:styled-content style="fixed-case">NAFLD</jats:styled-content>) is the most common liver disease, since it is strongly associated with obesity and metabolic syndrome pandemics. <jats:styled-content style="fixed-case">NAFLD</jats:styled-content> may affect drug disposal and has common pathophysiological mechanisms with drug‐induced liver injury (<jats:styled-content style="fixed-case">DILI</jats:styled-content>); this may predispose to hepatoxicity induced by certain drugs that share these pathophysiological mechanisms. In addition, drugs may trigger fatty liver and inflammation <jats:italic>per se</jats:italic> by mimicking <jats:styled-content style="fixed-case">NAFLD</jats:styled-content> pathophysiological mechanisms.</jats:p></jats:sec><jats:sec><jats:title>Aims</jats:title><jats:p>To provide a comprehensive update on (a) potential mechanisms whereby certain drugs can be more hepatotoxic in <jats:styled-content style="fixed-case">NAFLD</jats:styled-content> patients, (b) the steatogenic effects of drugs, and (c) the mechanism involved in drug‐induced steatohepatitis (DISH).</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>A language‐ and date‐unrestricted Medline literature search was conducted to identify pertinent basic and clinical studies on the topic.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Drugs can induce macrovesicular steatosis by mimicking <jats:styled-content style="fixed-case">NAFLD</jats:styled-content> pathogenic factors, including insulin resistance and imbalance between fat gain and loss. Other forms of hepatic fat accumulation exist, such as microvesicular steatosis and phospholipidosis, and are mostly associated with acute mitochondrial dysfunction and defective lipophagy, respectively. Drug‐induced mitochondrial dysfunction is also commonly involved in DISH. Patients with pre‐existing <jats:styled-content style="fixed-case">NAFLD</jats:styled-content> may be at higher risk of <jats:styled-content style="fixed-case">DILI</jats:styled-content> induced by certain drugs, and polypharmacy in obese individuals to treat their comorbidities may be a contributing factor.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>The relationship between <jats:styled-content style="fixed-case">DILI</jats:styled-content> and <jats:styled-content style="fixed-case">NAFLD</jats:styled-content> may be reciprocal: drugs can cause <jats:styled-content style="fixed-case">NAFLD</jats:styled-content> by acting as steatogenic factors, and pre‐existing <jats:styled-content style="fixed-case">NAFLD</jats:styled-content> could be a predisposing condition for certain drugs to cause <jats:styled-content style="fixed-case">DILI</jats:styled-content>. Polypharmacy associated with obesity might potentiate the association between this condition and <jats:styled-content style="fixed-case">DILI</jats:styled-content>.</jats:p></jats:sec>