Differences in the ways dosages are expressed on epinephrine labels for human or animal use could result in confusion and errors, according to an alert from the FDA.

To avoid dosing errors in animals, the FDA recommends that veterinarians carefully review an epinephrine product’s labeling before administering the drug to determine if strength is expressed as mg/mL or as a ratio, such as 1:1,000 and 1:10,000. The FDA also recommends that veterinary emergency dosage charts include epinephrine products that are labeled both ways (mg/mL and ratio) to reduce confusion and potential dosing errors.

The new alert updates a notice from June 20, 2017, in which the FDA announced labeling changes to three critical care medications that are approved for use in people and are also used in animals in the practice of veterinary medicine. Those labeling changes affect epinephrine injection, isoproterenol hydrochloride injection, and neostigmine methylsulfate injection for use in people. In that notice, the FDA notified drug manufacturers to remove ratio expressions of strength from the labeling of those products, with strength to be expressed only as the amount per unit of volume.

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