Y50: Central nervous system stimulants, not elsewhere classified

Y50.1: Opioid receptor antagonists

Opioid receptor antagonists represent a specific class of medications that act by blocking opioid receptors in the brain. This mechanism helps to counteract the effects of opioids, a group of substances that includes many pain medications and illicit drugs like heroin. The role of opioid receptor antagonists is especially crucial in treating opioid overdoses, where they can rapidly reverse life-threatening respiratory depression. However, they are also used in managing opioid addiction to prevent opioid effects if the person relapses. Utilization of these antagonists can provoke intense withdrawal symptoms in individuals dependent on opioids. Desired or adverse effects are not associated with any disease but the usage of opioids.