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1. any substance that interferes with a chemical reaction, growth, or other biologic activity.
2. a chemical substance that inhibits or checks the action of a tissue organizer or the growth of microorganisms.
3. an effector that reduces the catalytic activity of an enzyme.
ACE i's (angiotensin-converting enzyme i's) see angiotensin-converting enzyme inhibitors.
angiogenesis inhibitor a group of drugs that prevent growth of new blood vessels into a solid tumor.
aromatase i's a class of drugs that inhibit aromatase activity and thus block production of estrogens; used to treat breast cancer and endometriosis.
C1 inhibitor (C1 INH) a member of the serpin group, an inhibitor of C1, the initial component activated in the classical complement pathway. Deficiency of or defect in the protein causes hereditary angioedema.
carbonic anhydrase inhibitor an agent that inhibits the enzyme carbonic anhydrase; used in treatment of glaucoma and sometimes for epilepsy, familial periodic paralysis, acute mountain sickness, and kidney stones of uric acid.
cholinesterase inhibitor anticholinesterase.
COX-2 i's (cyclooxygenase-2 i's) a group of nonsteroidal antiinflammatory drugs that act by inhibiting cyclooxygenase-2 activity; they have fewer gastrointestinal side effects than other NSAIDs. Two members of the group are celecoxib and rofecoxib.
gastric acid pump inhibitor an agent that inhibits gastric acid secretion by blocking the action of H+,K+-ATPase at the secretory surface of gastric parietal cells; called also proton pump i.
HIV protease inhibitor any of a group of antiretroviral drugs active against the human immunodeficiency virus; they prevent protease-mediated cleavage of viral polyproteins, causing production of immature viral particles that are noninfective. Examples include indinavir sulfate, nelfinavir mesylate, ritonavir, and saquinavir.
HMG-CoA reductase i's a group of drugs that competitively inhibit the enzyme that catalyzes the rate-limiting step in cholesterol biosynthesis, and are used to lower plasma lipoprotein levels in the treatment of hyperlipoproteinemia. Called also statins.
MAO inhibitor monoamine oxidase inhibitor.
membrane inhibitor of reactive lysis (MIRL) protectin.
monoamine oxidase inhibitor any of a group of drugs that inhibit the action of monoamine oxidase, the enzyme that breaks down norepinephrine and serotonin, prescribed for their antidepressant action; the most widely used ones are isocarboxazid, phenelzine, and tranylcypromine. They are also used in the prevention of migraine.
α2-plasmin inhibitor α2-antiplasmin.
plasminogen activator inhibitor (PAI) any of several regulators of the fibrinolytic system that act by binding to and inhibiting free plasminogen activator. Their concentration in plasma is normally low, but is altered in some disturbances of bodily hemostasis. PAI-1 is an important fast-reacting inhibitor of t-plasminogen activator and u-plasminogen activator. Its synthesis, activity, and release are highly regulated; elevated levels of it have been described in a number of disease states. PAI-2 is a normally minor inhibitor that greatly increases in concentration during pregnancy and in certain disorders. PAI-3 is protein C inhibitor.
platelet inhibitor any of a group of agents that inhibit the clotting activity of platelets; the most common ones are aspirin and dipyridamole. See also antiplatelet therapy.
protein C inhibitor the primary inhibitor of activated anticoagulant protein C; it is a glycoprotein of the serpin family of proteinase inhibitors and also inhibits several other proteins involved in coagulation (thrombin, kallikrein, and coagulation factors X and XI) and urokinase. Called also plasminogen activator inhibitor 3.
proton pump inhibitor gastric acid pump i.
reverse transcriptase inhibitor a substance that blocks activity of the reverse transcriptase of a retrovirus and is used as an antiretroviral agent. Some are nucleosides or nucleoside analogues, and those that are not are therefore often called non-nucleoside reverse transcriptase inhibitors.
selective serotonin reuptake inhibitor (SSRI) any of a group of drugs that inhibit the inactivation of serotonin by blocking its absorption in the central nervous system; used as antidepressants and in the treatment of obsessive-compulsive disorder and panic disorder.
serine protease inhibitor (serine proteinase inhibitor) serpin.
topoisomerase i's a class of antineoplastic agents that interfere with the arrangement of DNA in cells.
an agent or medication with effects that inhibit the enzyme responsible for the reuptake of acetylcholine at cholinergic synapses, thus perpetuating its action at the receptor; most notable therapeutic application is in the treatment of myasthenia gravis or after nondepolarizing neuromuscular relaxants have been administered.
cholinesterase inhibitorPharmacology Any agent–eg, pyridostigmine, ambenonium, neostigmine, that inhibits acetylcholinesterase, the enzyme which breaks down acetylcholine, thereby preventing transmission of nerve impulses to a muscle
cho·lin·es·ter·ase in·hib·i·tor(kō'lin-es'tĕr-ās in-hib'i-tŏr)
A drug, such as neostigmine, which, by inhibiting biodegradation of acetylcholine, restores myoneural function in myasthenia gravis or after nondepolarizing neuromuscular relaxants have been administered.
cholinesterase inhibitorA drug or agent that blocks the action of CHOLINESTERASE so that acetylcholine accumulates, often dangerously. The insecticides malathion and parathion are cholinesterase inhibitors, as are the drugs physostigmine (eserine), neostigmine, edrophonium, pyridostigmine, tacrine, demecarium and ambendonium. Other cholinesterase inhibitors are the nerve gases sarin, soman and tabun. Sarin has a lethal dose in humans of less than 1 mg.
an enzyme that splits acetylcholine into acetic acid and choline. Called also acetylcholinesterase.
This enzyme is present throughout the body, but is particularly important at the neuromuscular junction, where the nerve fibers terminate. Acetylcholine is released when a nerve impulse reaches a neuromuscular junction. It diffuses across the synaptic cleft and binds to cholinergic receptors on the muscle fibers, causing them to contract. Cholinesterase splits acetylcholine into its components, thus stopping stimulation of the muscle fibers. The end products of the metabolism of acetylcholine are taken up by nerve fibers and resynthesized into acetylcholine.
the drugs neostigmine, physostigmine and pyridostigmine inhibit cholinesterase. These drugs are used to treat myasthenia gravis, a disease in which the cholinergic receptors are attacked by autoantibodies. The drugs extend the effect of acetylcholine on the muscle fiber.
choline-reactivating oximes are effective antidotes in organophosphorus insecticide poisoning, a state of acetylcholine excess because of cholinesterase inhibition. 2-PAM (2-pyridine aldoxime methchloride) is the most popular oxime for this purpose.