On Oct. 18, 2021, the Food and Drug Administration approved ZIMHI (naloxone hydrochloride) injection as an additional option to treat opioid overdose. ZIMHI is administered using a single-dose, prefilled syringe that delivers 5 milligrams (mg) of naloxone hydrochloride solution through intramuscular (in the muscle) or subcutaneous (under the skin) injection.

FDA previously approved injectable naloxone hydrochloride products in 0.4 mg and 2 mg doses under the trade name, NARCAN.