Drug-induced liver injury (DILI) and herbal/dietary supplements (HDS) related liver injury present unique diagnostic challenges. Collaboration between the clinician and the pathologist is required for an accurate diagnosis and management.

To report our experience on the clinical-pathological findings of hepatic injury caused by drugs/HDS.

A retrospective review of clinically proven cases of DILI/HDS who presented to our institution from January 1, 2013 to December 31, 2017 was performed. Slides were reviewed for histopathological patterns of injury and correlated with the causative agent. Out of 600 patients presenting with unexplained rise in liver enzymes undergoing biopsy, 107 were suspected to have DILI/HDS. Of these, 53 had a directly linked exposure to drug/herbal supplements. Fifteen patients were excluded for concurrent known liver disease. Thirty-eight patients with clinically proven DILI/HDS were finally included.

Thirty-eight cases of DILI/HDS with a male:female of 1:1.5 and mean age of 51 ± 3 years were identified. DILI was identified in 84.2% cases while HDS injury in 15.8%. Acute hepatitis (42.1%) was the most common pattern of injury while granulomatous hepatitis (2.6%) was the least common. We found one case of acute-cholestasis due to rivaroxaban and two cases of cholestatic-hepatitis due to rizatriptan and trimethobenzamide-hydrochloride that, to the best of our knowledge, have not been previously reported. One case of steatohepatitis due to trimethoprim-sulfamethoxazole and three unusual cases of cholestatic-hepatitis with bile duct injury and steatosis due to dronedarone, C4-Extreme and hydroxycut, were also seen. Of our cohort, 81.6% of the patients fared well with discontinuation of drug and 18.4% underwent transplant; of which 42.9% were deceased.

We describe the clinical findings, histopathological patterns of injury and clinical outcomes caused by drugs. In particular, we report a few previously unreported/ rarely observed clinical and histopathological patterns of hepatic injury.

Trimethoprim/sulfamethoxazole is well known to cause intra-hepatic cholestasis which in rare instances can be prolonged and lead to vanishing bile duct syndrome. The risk regarding the potential for cross-reactivity between structurally related molecules such as dapsone and trimethoprim/sulfamethoxazole in causing hepatotoxicity is scarce. Herein, we report a case of vanishing bile duct syndrome following dapsone use in a patient with HIV infection and a recent history of trimethoprim/sulfamethoxazole-induced cholestasis. The patient had severe and protracted cholestasis during 2 years of follow-up and eventually died of liver failure.

Studies of boceprevir and telaprevir based antiviral therapy in liver transplant (LT) recipients with hepatitis C genotype 1 infection have demonstrated dramatic increases in tacrolimus, cyclosporine, and mTOR inhibitor exposure. In addition to empiric dose reductions, daily monitoring of immunosuppressant blood levels is required when initiating as well as discontinuing the protease inhibitors to maximize patient safety. Although improved suppression of HCV replication is anticipated, 20 to 40% of treated subjects have required early treatment discontinuation due to various adverse events including anemia (100%), infection (30%), nephrotoxicity (20%) and rejection (5 to 10%). Simeprevir and faldaprevir will likely have improved efficacy and safety profiles but potential drug interactions with other OATP1B1 substrates and unconjugated hyperbilirubinemia are expected. In contrast, sofosbuvir and daclatasvir based antiviral therapy are not expected to lead to clinically significant drug-drug interactions in LT recipients but confirmatory studies are needed. Liver transplant recipients may also be at increased risk of developing drug induced liver injury (DILI). Establishing a diagnosis of DILI in the transplant setting is very difficult with the variable latency, laboratory features and histopathological manifestations of hepatotoxicity associated with a given drug, the need to exclude competing causes of allograft injury, and the lack of an objective and verifiable confirmatory test. Nonetheless, a heightened awareness of the possibility of DILI is warranted in light of the large number of medications used in LT recipients and the potential adverse impact that DILI may have on patient outcomes.

To discuss the effect of certain factors on the occurrence of Adverse Drug Reactions (ADRs).

A systematic review of the literature in the period between 1991 and 2012 was made based on PubMed, the Cochrane database of systematic reviews, EMBASE and IDIS. Key words used were: medication error, adverse drug reaction, iatrogenic disease factors, ambulatory care, primary health care, side effects and treatment hazards.

Many factors play a crucial role in the occurrence of ADRs, some of these are patient related, drug related or socially related factors. Age for instance has a very critical impact on the occurrence of ADRs, both very young and very old patients are more vulnerable to these reactions than other age groups. Alcohol intake also has a crucial impact on ADRs. Other factors are gender, race, pregnancy, breast feeding, kidney problems, liver function, drug dose and frequency and many other factors. The effect of these factors on ADRs is well documented in the medical literature. Taking these factors into consideration during medical evaluation enables medical practitioners to choose the best drug regimen.

Many factors affect the occurrence of ADRs. Some of these factors can be changed like smoking or alcohol intake others cannot be changed like age, presence of other diseases or genetic factors. Understanding the different effects of these factors on ADRs enables healthcare professionals to choose the most appropriate medication for that particular patient. It also helps the healthcare professionals to give the best advice to patients. Pharmacogenomics is the most recent science which emphasizes the genetic predisposition of ADRs. This innovative science provides a new perspective in dealing with the decision making process of drug selection.