Inappropriate pemoline therapy leading to acute liver failure and liver transplantation

Drug-induced liver injury

Many drugs and environmental chemicals are capable of evoking some degree of liver injury. The liver represents a primary target for adverse drug reactions due to its central role in biotransformation and excretion of foreign compounds, its portal location within the circulation exposing it to a wide variety of substances, and its anatomic and physiologic structure. Drug-induced liver injury (DILI) remains the single most common adverse indication leading to drug candidate failure or withdrawal from the market. However, the absolute incidence of DILI is low, and this presents a challenge to mechanistic studies. DILI remains unpredictable making prevention very difficult. In this chapter, we focus on the current understanding of DILI. We begin with an overview regarding the significance and epidemiology of DILI and then examine the clinical presentation and susceptibility factors related to DILI. This is followed by a review of the current literature regarding the proposed pathogenesis of DILI, which involves the participation of a drug, or most often a reactive metabolite of the drug, that either directly affects cellular function or elicits an immune response. It is our hope that this chapter will shed light on the major problems associated with DILI in regards to the pharmaceutical industry, drug regulatory agencies, physicians and pharmacists, and patients.

Effectiveness of risk management plans: a case study of pemoline using pharmacy claims data

PURPOSE

To assess the effectiveness of a pharmaceutical risk management plan using pemoline as a case study and pharmacy claims as the data source.

METHODS

Prescription claims from a continuously enrolled US population (September 1, 2000-September 30, 2002) from Caremark, a pharmacy benefit manager, were evaluated for patients with one or more pemoline claims. Patients were categorized using pemoline as second-line or first-line therapy depending on presence or absence of other central nervous system (CNS) stimulants prescriptions 90 days prior to the first pemoline claim. Logistic regression was performed to compare second-line and first-line usage with regard to patient age, gender and prescribing physician specialty and region of practice.

RESULTS

Of 1,279,296 prescription claims for CNS stimulants, 17,256 (1.3%) were for pemoline. Nine hundred thirteen patients received pemoline and had 90 days or more prior enrollment. Overall, 10% of patients receiving pemoline received it as second-line therapy (95%CI: 8-12%). After adjusting for age, gender, specialty, and region, the odds of receiving pemoline as second-line therapy were significantly greater in pediatrics relative to adults (OR = 2.82, 95%CI: 1.58-5.03), and among those whose prescribers were psychiatrists versus primary care physicians (OR = 2.48, 95%CI: 1.37-4.50). Children treated by a psychiatrist had the greatest likelihood for use as second-line therapy (36%, 95%CI: 19-56%).

CONCLUSIONS

Among patients who received pemoline, concordance with second-line therapy recommendations was low, even among the primary target audience of children. These results in a large geographically diverse patient population are consistent with an earlier regional study.