Health Canada is warning some take-home naloxone kits come with bad instructions that should be ignored in favour of the correct guidance.

The agency said Friday that naloxone kits by Canadian Hospital Specialties Ltd. may contain incorrect naloxone dosing information on the included "SAVE ME" instructional card, which could impact the efficacy of the treatment.

A dose of naloxone administered as either a nasal spray or an injectable temporarily reverses the effects of an opioid overdose to help restore breathing, and can be used without a prescription or medical certification.

The product labelling for naloxone states that, if necessary, a second dose of the product can be administered two to three minutes after the first dose. However, the "SAVE ME" instructional card provided in the Canadian Hospital Specialties Ltd. kits may falsely recommend re-administration after three to five minutes.

Anyone with a kit containing the false instructions should contact the company at recalls@chsltd.com, or the store where they obtained it, to request a revised "SAVE ME" instructional card with the correct information.

This applies to both nasal spray and injectable kits.