Chronic hepatitis C, ibuprofen, and liver damage

Systematic review: ibuprofen-induced liver injury

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are a leading cause of drug-induced liver injury (DILI) across the world. Ibuprofen is one of the most commonly used and safest NSAIDs, nevertheless reports on ibuprofen-induced hepatotoxicity are available.

AIM

To analyse previously published information on ibuprofen-induced liver injury for a better characterisation of its phenotypic expression.

METHOD

A systematic search was performed and information on ibuprofen-induced liver injury included in case series and case reports, in terms of demographic, clinical, biochemical and outcome data, was analysed.

RESULTS

Twenty-two idiosyncratic ibuprofen hepatotoxicity cases were identified in the literature, suggesting a very low prevalence of this type of DILI. These patients had a mean age of 31 years and 55% were females. Mean cumulative dose of ibuprofen and time to onset were 30 g and 12 days, respectively. Hepatocellular injury was the most frequently involved liver injury pattern. Six cases developed vanishing bile duct syndrome. Full recovery occurred in 11 patients after a mean time of 14 weeks, whereas five cases evolved to acute liver failure leading to death/liver transplantation.

CONCLUSIONS

When assessing potential hepatotoxicity cases, physicians should keep in mind that ibuprofen has been associated with hepatotoxicity in the literature. Ibuprofen-associated DILI presents commonly as hepatocellular damage after a short latency period. Published reports on ibuprofen hepatotoxicity leading to liver failure resulting in liver transplantation or death are available. However, due to the apparent low absolute risk of ibuprofen-induced liver complications, ibuprofen can be regarded as an efficacious and safe NSAID.

Drug-Induced Liver Injury: Pattern Recognition and Future Directions

Drug-induced liver injury (DILI) remains a significant clinical challenge and is the leading cause of acute liver failure in most countries. An aging population that uses more medications, a constant influx of newly developed drugs and a growing risk from unfamiliar herbal and dietary supplements will make DILI an increasing part of clinical practice. Currently, the most effective strategy for disease management is rapid identification, withholding the inciting agents, supportive care and having a firm understanding of the expected natural history. There are resources available to aid the clinician, including a new online "textbook" as well as causality assessment tools, but a heightened awareness of risk and the disease's varying phenotypes and good history-taking remain cornerstones to diagnosis. Looking ahead, growing registries of cases, pharmacoepidemiology studies and translational research into the mechanisms of injury may produce better diagnostic tools, markers for risk and disease, and prevention and therapeutics.

Nonsteroidal anti-inflammatory drug-induced hepatoxicity

Nonsteroidal anti-inflammatory drugs are among the most prescribed medications worldwide. After antibiotics and anticonvulsants they are considered the most common medications associated with drug-induced liver injury mainly through an idiosyncratic form of hepatotoxicity. In rare cases severe hepatotoxicity has been described with significant morbidity and mortality. Genetic risk factors have been reported with diclofenac and lumiracoxib. Postmarketing surveillance and monitoring is crucial to identify severe cases of hepatotoxicity.

Review article: prescribing medications in patients with cirrhosis - a practical guide

BACKGROUND

Most drugs have not been well studied in cirrhosis; recommendations on safe use are based largely on experience and/or expert opinion, with dosing recommendations often based on pharmacokinetic (PK) changes.

AIM

To provide a practical approach to prescribing medications for cirrhotic patients.

METHODS

An indexed MEDLINE search was conducted using keywords cirrhosis, drug-induced liver injury, pharmacodynamics (PDs), PKs, drug disposition and adverse drug reactions. Unpublished information from the Food and Drug Administration and industry was also reviewed.

RESULTS

Most medications have not been adequately studied in cirrhosis, and specific prescribing information is often lacking. Lower doses are generally recommended based on PK changes, but data are limited in terms of correlating PD effects with the degree of liver impairment. Very few drugs have been documented to have their hepatotoxicity potential enhanced by cirrhosis; most of these involve antituberculosis or antiretroviral agents used for HIV or viral hepatitis. Paracetamol can be used safely when prescribed in relatively small doses (2-3 g or less/day) for short durations, and is recommended as first-line treatment of pain. In contrast, NSAIDs should be used cautiously (or not at all) in advanced cirrhosis. Proton pump inhibitors have been linked to an increased risk of spontaneous bacterial peritonitis (SBP) in cirrhosis and should be used with care.

CONCLUSIONS

Most drugs can be used safely in cirrhosis, including those that are potentially hepatotoxic, but lower doses or reduced dosing frequency is often recommended, due to altered PKs. Drugs that can precipitate renal failure, gastrointestinal bleeding, SBP and encephalopathy should be identified and avoided.

Management of fever in children: summary of the Italian Pediatric Society guidelines

OBJECTIVE

This article summarizes the Italian Pediatric Society guideline on the management of the signs and symptoms of fever in children, prepared as part of the National Guideline Program (NGLP).

METHODS

Relevant publications in English and Italian were identified through searches of MEDLINE and the Cochrane Database of Systematic Reviews from their inception through December 31, 2007. Based on the consensus of a multidisciplinary expert panel, the strength of the recommendations was categorized into 5 grades (A-E) according to NGLP methodology.

SUMMARY

In the health care setting, axillary measurement of body temperature using a digital thermometer is recommended in children aged <4 weeks; for children aged > or =4 weeks, axillary measurement using a digital thermometer or tympanic measurement using an infrared thermometer is recommended. When body temperature is measured at home by parents or care-givers, axillary measurement using a digital thermometer is recommended for all children. Children who are afebrile when seen by the clinician but are reported to have had fever by their caregivers should be considered febrile. In special circumstances, high fever may be a predictive factor for severe bacterial infection. Use of physical methods of reducing fever is discouraged, except in the case of hyperthermia. Use of antipyretics-paracetamol (acetaminophen) or ibuprofen-is recommended only when fever is associated with discomfort. Combined or alternating use of antipyretics is discouraged. The dose of antipyretic should be based on the child's weight rather than age. Whenever possible, oral administration of paracetamol is preferable to rectal administration. Use of ibuprofen is not recommended in febrile children with chickenpox or dehydration. Use of ibuprofen or paracetamol is not contraindicated in febrile children with asthma. There is insufficient evidence to form any recommendations concerning fever in children with other chronic conditions, but caution is advised in cases of severe hepatic/renal failure or severe malnutrition. Newborns with fever should always be hospitalized because of the elevated risk of severe disease; paracetamol may be used, with the dose adjusted to gestational age. Use of paracetamol or ibuprofen is not effective in preventing febrile convulsion or the adverse effects of vaccines.

Review article: The use of potentially hepatotoxic drugs in patients with liver disease

BACKGROUND

Misconceptions surround the use of hepatotoxic drugs in chronic liver disease. While many prescription and over-the-counter (OTC) agents can be used safely, this often runs counter to labelled warnings/contraindications, especially for the statins and other commonly used agents.

AIM

To evaluate published data on the use of hepatotoxic drugs in chronic liver disease including pharmacokinetic changes in cirrhosis and drug interactions, where available, to formulate recommendations on their use.

METHODS

Using a combination of PubMed searches, review texts, the Physicians' Desk Reference and expert opinion, drugs considered at higher risk of hepatotoxicity in chronic liver disease were evaluated.

RESULTS

Most drugs and OTC products including herbals have not been formally studied in chronic liver disease, but available data suggest that several of the most commonly used agents, especially the statins, can be used safely. While there is an increased risk of drug-induced liver injury for drugs used in the treatment of tuberculosis and HIV patients with hepatitis B or C, recommendations for their safe use are emerging.

CONCLUSIONS

Although many clinicians remain hesitant to use hepatotoxic drugs in chronic liver disease, the database supporting this view is limited to just a few agents. Most medications can be used safely in patients with chronic liver disease with appropriate monitoring.

Hepatitis C and arthritis: an update

Extrahepatic symptoms during chronic hepatitis C virus (HCV) infection are common and varied. Arthritis can be seen either as part of autoimmune processes (eg, associated with cryoglobulinemia) or independently. Whether the manifestation is specifically attributable to HCV infection or rather to the nonspecific result of a chronic inflammatory process is not clear. The literature available at this time is insufficient to guide the most appropriate course of treatment of HCV arthritis. Standard antirheumatic treatment can be considered, but with caution, because some of these medications occasionally may be hepatotoxic and response to therapy seems variable. Treatment decisions should be determined on a case-by-case basis.

Causality assessment in drug-induced hepatotoxicity

Drugs are currently an important cause of liver disease, ranked as the most frequent reason for acute liver failure. Despite recent advances in knowledge of the mechanisms implicated in drug-induced hepatocellular damage and cholestasis, as well as the identification of several risk factors, the diagnosis of hepatotoxicity remains a difficult task because specific tests are not available. In a step-by-step approach, the incrimination of a drug in liver symptoms requires a high degree of suspicion on the part of the physician, temporal eligibility, awareness of the drug's hepatotoxic potential, the exclusion of alternative causes of liver damage, and the ability to detect the presence of subtle data that favour a toxic aetiology. Ultimately, the use of diagnostic algorithms may add consistency to the diagnostic process either by translating the suspicion into a quantitative score or by providing a framework that emphasises the features that merit attention in cases of suspected hepatic adverse reactions.

Animal models of human disease in drug safety assessment

Animal models of human disease have been widely used in drug discovery, but they are rarely utilized in toxicological research and screening (except for transgenic models in carcinogenicity testing). Although genetic and/or acquired pathophysiological alterations associated with a particular disease may greatly exacerbate toxic responses to drugs in certain patient subsets, these pre-existing pathological conditions are usually not considered in preclinical safety assessment. Examples of disease-related determinants of susceptibility include disruption of the cytokine network in pro-inflammatory conditions, mitochondrial alterations and oxidative stress in certain neurodegenerative diseases, altered antioxidant defense in certain viral infections, and altered gene expression and mitochondrial dysfunction in type 2 diabetes. Hence, if cellular stress caused by drugs or metabolites and the disease-related effects are superimposed, then an individual can become sensitized to potential drug toxicity. Animal models of modest inflammation indeed can potentiate the toxicity of certain drugs. Similarly, rodent models of type 2 diabetes predispose the animals to hepatotoxic effects of thiazolidinediones antidiabetics. In conclusion, it is suggested that tailor-made and simplified models be adopted and increasingly used, in spite of clear limitations, as optimal substrates for satellite toxicity studies to facilitate candidate selection, help predict rare and unexpected toxicity, and identify new biomarkers.