Antiemetic in the context of "Motion sickness"

Vomiting (also known as emesis, puking, barfing, and throwing up) is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. The substance so produced (the erstwhile contents of the stomach, now expelled) is also known as vomit or vomitus.

Vomiting can be the result of ailments like food poisoning, gastroenteritis, pregnancy, motion sickness, or hangover; or it can be an after effect of diseases such as brain tumors, elevated intracranial pressure, or overexposure to ionizing radiation. The feeling that one is about to vomit is called nausea; it often precedes, but does not always lead to vomiting. Impairment due to alcohol or anesthesia can cause inhalation of vomit. In severe cases, where dehydration develops, intravenous fluid may be required. Antiemetics are sometimes necessary to suppress nausea and vomiting. Self-induced vomiting can be a component of an eating disorder such as bulimia nervosa, and is itself now classified as an eating disorder on its own, purging disorder.

Premedication is using medication before some other therapy (usually surgery or chemotherapy) to prepare for that forthcoming therapy. Typical examples include premedicating with a sedative or analgesic before surgery; using prophylactic (preventive) antibiotics before surgery; and using antiemetics or antihistamines before chemotherapy.

Premedication before chemotherapy for cancer often consists of drug regimens (usually 2 or more drugs, e.g. dexamethasone, diphenhydramine and omeprazole) given to a patient minutes to hours before the chemotherapy to avert side effects or hypersensitivity reactions (i.e. allergic reactions).

Nabilone, sold under the brand name Cesamet among others, is a synthetic cannabinoid with therapeutic use as an antiemetic and as an adjunct analgesic for neuropathic pain. It mimics tetrahydrocannabinol (THC), the primary psychoactive compound found naturally occurring in Cannabis.

The Food and Drug Administration (FDA) in the United States has indicated nabilone for chemotherapy-induced nausea/vomiting. In other countries, such as Canada, it is widely used as an adjunct therapy for chronic pain management. Numerous trials and case studies have demonstrated modest effectiveness for relieving fibromyalgia and multiple sclerosis.

5-HT receptors, 5-hydroxytryptamine receptors, or serotonin receptors, are a group of G protein-coupled receptor and ligand-gated ion channels found in multiple tissues including the central and peripheral nervous systems. They mediate both excitatory and inhibitory neurotransmission. The serotonin (i.e., 5-hydroxytryptamine, hence "5-HT") receptors are activated by the neurotransmitter serotonin, which acts as their natural ligand.

The serotonin receptors modulate the release of many neurotransmitters, including glutamate, GABA, dopamine, epinephrine / norepinephrine, and acetylcholine, as well as many hormones, including oxytocin, prolactin, vasopressin, cortisol, corticotropin, and substance P, among others. Serotonin receptors influence various biological and neurological processes such as aggression, anxiety, appetite, cognition, learning, memory, mood, nausea, sleep, and thermoregulation. They are the target of a variety of pharmaceutical and recreational drugs, including many antidepressants, antipsychotics, anorectics, antiemetics, gastroprokinetic agents, antimigraine agents, psychedelics (hallucinogens), and entactogens.