Risk of acute liver injury associated with the use of drugs: a multicentre population survey

BACKGROUND

Acute liver injury of uncertain aetiology is often drug related and quantitative information about the associated risk is scarce.

AIM

To estimate the risk of acute liver injury associated with the use of drugs.

METHODS

In a population survey study, 126 cases of acute liver injury were prospectively assembled from January 1993 to December 1999, in patients over 15 years of age, in 12 hospitals in Barcelona (Spain). We estimated the relative risk for each drug as the ratio between the incidence of acute liver injury among the exposed population to the drug and the incidence of acute liver injury among those not exposed to it. Drug consumption data were used to estimate the exposed population.

RESULTS

Isoniazid, pyrazinamide, rifampicin, amoxicillin with clavulanic acid, erythromicin, chlorpromazine, nimesulide, and ticlopidine presented the highest risk (point relative risk > 25). Amoxicillin, metoclopramide, captopril and enalapril, furosemide, hydrochlorothiazide, fluoxetine, paroxetine, diazepam, alprazolam, lorazepam, metamizole, low-dose acetylsalicylic acid and salbutamol showed the lowest risk (point relative risk < 5).

CONCLUSIONS

This study provides a risk estimation of serious liver disease for various drugs that will be useful in its diagnosis and management, and when comparing with the drug therapeutic benefit in each indication. Some observed associations would be worth specific studies.

Prospective surveillance of acute serious liver disease unrelated to infectious, obstructive, or metabolic diseases: epidemiological and clinical features, and exposure to drugs

BACKGROUND/AIMS

Acute serious liver disease which is unrelated to infectious, obstructive, or metabolic disease is uncommon. Many drugs have been implicated. Data on its epidemiology are scarce. We performed a population-based prospective study of acute serious liver disease in Catalonia (Spain).

METHODS

A collaborating hospital network was set up. All patients with acute serious liver disease and negative viral hepatitis serological markers, without an obvious cause of liver disease, were included.

RESULTS

The incidence of acute serious liver disease was 7.4 per 10(6) inhabitants per year (95% CI; 6.0-8.8), which increased with age. The incidence of hepatocellular acute serious liver disease (3.84 per 10(6) per year) was greater than that of cholestatic and mixed patterns. The case-fatality ratio was 11.9% and mortality 0.8 per million person-years. The risk of death was similar among patients with hepatocellular and cholestatic patterns. Non-steroidal antiinflammatory drugs, analgesics, and antibacterials were the most frequently used drugs.

CONCLUSIONS

Acute serious liver disease which is unrelated to infectious, obstructive, or metabolic disease is rare. Its incidence increases with age. The prognosis of cholestatic acute serious liver disease does not significantly differ from that of the hepatocellular pattern. Non-steroidal antiinflammatory drugs, analgesics, and antibacterials were the most common drugs likely to be responsible for acute liver disease.

An efficient design for verifying disease outcome status in large cohorts with rare exposures and low disease rates

Cohort studies require the use of large samples when the risk of the event is very low. Databases that are large and population-based, such as Medicaid files, are frequently used for cohort studies, since they provide access to the large samples required for adequate statistical power at a relatively affordable cost. Epidemiologic studies using these databases typically require verification of reported diagnoses, however, because of the potential for errors in disease reporting. When exposure prevalence is also low, as in many pharmacoepidemiologic investigations of drug toxicity, there are few exposed cases compared to the number of unexposed cases. Verification of all unexposed presumptive cases through medical records is costly. We investigate the statistical efficiency of a design in which all exposed cases but only a subsample of the unexposed cases are verified. We show that good efficiency can usually be achieved with a small subsample of unexposed cases. Published in 1999 by John Wiley & Sons, Ltd.