Gray death

Gray death is a slang term which refers to a potent mixture of synthetic opioids. Samples have been found to contain heroin, fentanyl, carfentanil, and the designer drug U-47700. It is taken by injection, smoking, snorting, or oral ingestion. The substance first appeared in America and was thought to be a unique chemical compound before being identified as a mixture of drugs.
As with other illicit narcotics, gray death carries a higher risk of serious adverse effects than prescribed opioids due to the unknown and inconsistent composition of the product. As such, even experienced opioid users risk serious injury or death when taking this drug mixture.
Reversing a gray death overdose may require multiple doses of naloxone. By contrast, an overdose from morphine or from high-purity heroin would ordinarily need only one dose. This difficulty is regularly encountered when treating overdoses of high-affinity opioids in the fentanyl chemical family or with buprenorphine. The greater affinity of these substances for the μ-opioid receptor impedes the activity of naloxone, which is an antagonist at the receptor. Increasing the dosage of naloxone or its frequency of administration may be required to counteract respiratory depression.