Safety and effectiveness of acetadote for acetaminophen toxicity

Acetaminophen (APAP) toxicity is commonly encountered in the Emergency Department. Until 2004, treatment consisted of either oral N-acetylcysteine (NAC) or filtered oral NAC administered intravenously (i.v.). Intravenous acetylcysteine (Acetadote) is a new Food and Drug Administration-approved i.v. formulation of acetylcysteine manufactured by Cumberland Pharmaceuticals in Nashville, Tennessee. Little post-marketing data exists on the effectiveness and safety of i.v. acetylcysteine.

We evaluated the clinical presentations and outcomes of patients treated with i.v. acetylcysteine for APAP toxicity.

We performed a retrospective chart review of patients treated with i.v. acetylcysteine for APAP ingestion. The primary outcome measures were: adverse reactions to and effectiveness of i.v. acetylcysteine, as defined by elevation of transaminases, liver failure, renal failure, death, and hospital length of stay (LOS). Data collected included: comorbidities, allergies, intentionality, timing and dosing of i.v. acetylcysteine, hospital LOS, transaminases > 1000 IU/L, development of liver failure requiring transplant, development of renal failure requiring hemodialysis, death, and anaphylactoid reactions.

Sixty-four patients met our study criteria. Overall, 16 (25%) patients developed transaminases > 1000 IU/L, 4 (6%) of them died and 2 (3%) received liver transplants. Of the 15 patients (23%) treated within 8 h, none died or developed liver or renal failure, and only 1 developed transient transaminase elevation > 1000 IU/L. In the patients treated outside of 8 h, the median LOS was 3 days, whereas the group treated within 8 h had a median LOS of only 1 day. Six (9%) patients developed anaphylactoid reactions, 2 of whom received the i.v. acetylcysteine bolus over 15 min. Five of these patients were treated pharmacologically and completed treatment, and one had treatment discontinued for undocumented reasons.

Intravenous acetylcysteine seemed to be a safe and effective formulation of N-acetylcysteine.