opiaat

Opiaat refers to a class of drugs derived from opium or produced synthetically that act on the opioid receptors in the nervous system. In strict pharmacology, opiates are the natural alkaloids found in the opium poppy (Papaver somniferum), including morphine, codeine, thebaine, and noscapine. Some sources use the term opiates more broadly to include semi-synthetic and synthetic opioids such as heroin (diacetylmorphine), hydromorphone, oxycodone, hydrocodone, oxymorphone, fentanyl, and methadone. The term opioids is often used for this wider group.

Most opiates and opioids act as agonists at mu-opioid receptors, with additional activity at kappa and delta receptors in some compounds. They produce analgesia and sedation, and can induce euphoria, cough suppression, and antidiarrheal effects. Common side effects include constipation, nausea, pinpoint pupils (miosis), and respiratory depression. Repeated use can lead to tolerance and physical dependence; abrupt cessation may cause withdrawal symptoms.

Medical use: opiates are used for moderate to severe pain relief, perioperative anesthesia, cough suppression (codeine, in some formulations), and sometimes control of severe diarrhea. Due to their potential for misuse, dependence, and overdose, they are regulated as controlled substances in most jurisdictions.

History and context: opium has been used for millennia; morphine was isolated in the early 19th century, leading to wide medical use and later dependence issues. In recent decades, concerns about misuse and overdose have shaped public health responses, policy, and harm-reduction efforts.

See also: opioid epidemic, opioid receptor, withdrawal, naloxone.