Analgesia in the context of "Μ-opioid receptor"

Opium (also known as poppy tears, or Lachryma papaveris) is the dried latex obtained from the seed capsules of the opium poppy Papaver somniferum. Approximately 12 percent of opium is made up of the analgesic alkaloid morphine, which is processed chemically to produce heroin and other synthetic opioids for medicinal use and for the illegal drug trade. Opium's main psychoactive alkaloids, primarily morphine, act on μ-opioid receptors, causing analgesia and addiction with long-term use leading to tolerance, dependence, and increased cancer risk. The latex also contains the closely related opiates codeine and thebaine, and non-analgesic alkaloids such as papaverine and noscapine. The traditional, labor-intensive method of obtaining the latex is to scratch ("score") the immature seed pods (fruits) by hand; the latex leaks out and dries to a sticky yellowish residue that is later scraped off and dehydrated.

The English word for opium is borrowed from Latin, which in turn comes from Ancient Greek: ὄπιον (ópion), a diminutive of ὀπός (opós, "juice of a plant"). The word meconium (derived from the Greek for "opium-like", but now used to refer to newborn stools) historically referred to related, weaker preparations made from other parts of the opium poppy or different species of poppies. The Mediterranean region holds the earliest archaeological evidence of human use of opium poppies dating back to before 5000 BCE, with cultivation beginning around 3400 BCE in Mesopotamia. Opium was widely used for food, medicine, ritual, and as a painkiller throughout ancient civilizations including Greece, Egypt, and Islamic societies up to medieval times.

Post-polio syndrome (PPS, poliomyelitis sequelae) is a group of latent symptoms of poliomyelitis (polio), occurring in more than 80% of polio infections. The symptoms are caused by the damaging effects of the viral infection on the nervous system and typically occur 15 to 30 years after an initial acute paralytic attack. Symptoms include decreasing muscular function or acute weakness with pain and fatigue. The same may also occur years after a nonparalytic polio infection.

The precise mechanism that causes PPS is unknown. It shares many features with myalgic encephalomyelitis/chronic fatigue syndrome, but unlike that disorder it tends to be progressive and can cause loss of muscle strength. Treatment is primarily limited to adequate rest, conservation of available energy, and supportive measures, such as leg braces and energy-saving devices such as powered wheelchairs, analgesia (pain relief), and sleep aids.

Anesthesia (American English) or anaesthesia (British English) is a state of controlled, temporary loss of sensation or awareness that is induced for medical or veterinary purposes. It may include some or all of analgesia (relief from or prevention of pain), paralysis (muscle relaxation), amnesia (loss of memory), and unconsciousness. An individual under the effects of anesthetic drugs is referred to as being anesthetized.

Anesthesia enables the painless performance of procedures that would otherwise require physical restraint in a non-anesthetized individual, or would otherwise be technically unfeasible. Three broad categories of anesthesia exist:

Female genital mutilation (FGM) (also known as female genital cutting, female genital mutilation/cutting (FGM/C) and female circumcision) is the cutting or removal of some or all of the vulva for non-medical reasons. FGM prevalence varies worldwide, but is significantly present in some countries of Africa, Asia and Middle East, and within their diasporas. As of 2024, UNICEF estimates that worldwide 230 million girls and women (144 million in Africa, 80 million in Asia, 6 million in Middle East, and 1-2 million in other parts of the world) had been subjected to one or more types of FGM.

Typically carried out by a traditional cutter using a blade, FGM is conducted from days after birth to puberty and beyond. In half of the countries for which national statistics are available, most girls are cut before the age of five. Procedures differ according to the country or ethnic group. They include removal of the clitoral hood (type 1-a) and clitoral glans (1-b); removal of the inner labia (2-a); and removal of the inner and outer labia and closure of the vulva (type 3). In this last procedure, known as infibulation, a small hole is left for the passage of urine and menstrual fluid, the vagina is opened for intercourse and opened further for childbirth. FGM is commonly performed without any form of anesthesia or analgesia and with non-medical equipment such as razor blades.

An analgesic drug, also called simply an analgesic, antalgic, pain reliever, or painkiller, is any member of the group of drugs used for pain management. Analgesics are conceptually distinct from anesthetics, which temporarily reduce, and in some instances eliminate, sensation, although analgesia and anesthesia are neurophysiologically overlapping and thus various drugs have both analgesic and anesthetic effects.

Analgesic choice is also determined by the type of pain: For neuropathic pain, recent research has suggested that classes of drugs that are not normally considered analgesics, such as tricyclic antidepressants and anticonvulsants may be considered as an alternative.

Morphine, formerly known as morphium, is an opiate found naturally in opium, a dark brown resin produced by drying the latex of opium poppies (Papaver somniferum). It is mainly used as an analgesic (pain medication). There are multiple methods used to administer morphine: oral; sublingual; via inhalation; injection into a muscle, injection under the skin, or injection into the spinal cord area; transdermal; intravenously; or via rectal suppository. It acts directly on the central nervous system (CNS) to induce analgesia and alter perception and emotional response to pain. Physical and psychological dependence and tolerance may develop with repeated administration. It can be taken for both acute pain and chronic pain and is frequently used for pain from myocardial infarction, kidney stones, and during labor. Its maximum effect is reached after about 20 minutes when administered intravenously and 60 minutes when administered by mouth, while the duration of its effect is 3–7 hours. Long-acting formulations of morphine are sold under the brand names MS Contin and Kadian, among others. Generic long-acting formulations are also available.

Common side effects of morphine include drowsiness, euphoria, nausea, dizziness, sweating, and constipation. Potentially serious side effects of morphine include decreased respiratory effort, vomiting, and low blood pressure. Morphine is highly addictive and prone to abuse. If one's dose is reduced after long-term use, opioid withdrawal symptoms may occur. Caution is advised for the use of morphine during pregnancy or breastfeeding, as it may affect the health of the baby.