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Ontario Poison Centre
N-acetylcysteine (NAC) back-order: updated November 16, 2022
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N-acetylcysteine (NAC) back-order: updated November 16, 2022

ALERT: N-acetylcysteine (NAC) back-order

Acetaminophen toxicity is the most common (~10% of all calls) exposure reported to our Poison Centre.

N-acetylcysteine (NAC), the antidote for acetaminophen toxicity, is supplied as a 20% solution (200 mg NAC per mL of diluent). It is usually supplied in 10 mL or 30 mL vials.

The Ontario, Manitoba & Nunavut Poison Centres have recently been made aware of a back-order of the 30 mL vials (Sandoz or Hikma suppliers) and the 10 mL vials (Hikma pharmaceutical). A new supply is expected to be available by mid to late December 2022.

What does this mean for you?

  1. Do NOT start NAC based on a history of an acetaminophen exposure.
  2. Draw an acetaminophen level and plot the level against time on the Rumack-Matthew nomogram to determine whether NAC is actually indicated.
  3. Call the Poison Centre for advice in all cases where an acetaminophen level is not available within 8 hours of ingestion.
  4. Consider preparing 500 mL 3% NAC solutions (instead of 1L) as per the Patient Care Resource page.
  5. Never start High Risk NAC unless prompted to by the Poison Centre. In many cases, routine
    dosing is adequate & will prevent NAC wastage.
  6. Health Canada has approved the extension of expiry dates for NAC sold in Canada. Any vials of NAC that expired in October 2022 and are set to expire in November 2022 have officially been given extensions of expiry dates and CAN be used.
  7. Consider approaching Health Canada Special Access program for the purchase of NAC from Pfizer/Cumberland or other US pharmaceutical companies FOR FUTURE USE.



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