Assistance may be obtained by contacting the regional poison control center at 1-80 or a special health professional assistance line for APAP overdose at 1-80. Guide treatment in these persons based on APAP serum concentrations and liver function tests (LFTs).

NOTE: The Rumack-Matthew nomogram is ineffective at predicting hepatotoxicity in persons who have ingested repeated supratherapeutic doses of APAP over an extended period of time. If the time of ingestion is unknown, or the APAP serum concentration is not available, cannot be interpreted, or is not available within 8 hours of APAP ingestion, administer acetylcysteine immediately if 24 hours or less have elapsed from the reported time of ingestion, regardless of the quantity reported to have been ingested.

Beginning treatment 15 to 24 hours post-ingestion results in limited efficacy however, it does not appear to worsen the condition and should not be withheld since the reported time of ingestion may not be correct. The efficacy of acetylcysteine diminishes progressively after 8 hours post-ingestion. For extended-release APAP overdoses, if the initial APAP serum concentration was below the possible toxicity line, obtain a second concentration 8 to 10 hours post-ingestion. For regular-release APAP overdoses, obtain serum drug concentration at least 4 hours post-ingestion concentrations obtained earlier than 4 hours may not represent maximum APAP concentrations. For persons whose APAP serum concentrations fall above the possible toxicity line on the nomogram, initiate treatment within 8 hours of suspected APAP ingestion for maximal protection against hepatic injury. NOTE: Use the Rumack-Matthew nomogram to estimate the hepatotoxicity potential from an acute acetaminophen (APAP) overdose in persons with a known APAP concentration, a known APAP ingestion time, and who present within 8 hours of the overdose. For the treatment of acetaminophen overdose to prevent or lessen hepatic injury after ingestion of a potentially hepatotoxic quantity of acetaminophen.

Mucomyst antidote