inhibitor
[in-hib´ĭ-tor] 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.
angiogenesis inhibitor a group of drugs that prevent growth of new blood vessels into a solid tumor.
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. 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.
membrane inhibitor of reactive lysis (MIRL)
protectin.
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. 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.
serine protease inhibitor (
serine proteinase inhibitor)
serpin.
topoisomerase i's a class of antineoplastic agents that interfere with the arrangement of DNA in cells.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
protease inhibitor
a class of synthetic drug used in the treatment of human immunodeficiency virus (HIV-1) infection.
HIV-1 protease activity is critical for the terminal maturation of infectious virions. Protease inhibitors specific for HIV-1 competitively inhibit this enzyme, thereby preventing the maturation of virions capable of infecting other cells. These agents can reduce the plasma viral load (level of HIV RNA in the circulation) in a patient with AIDS below the measurable level. Their use has been shown to decrease the risk of disease progression and mortality in patients with HIV infection. They have also been found to improve CD4 counts and reverse AIDS dementia in some patients. Protease inhibitors are administered in combination with nucleoside analogues (nucleoside reverse transcriptase inhibitors) to exploit the different modes of action of these two classes of antiviral drug. Because of increasing viral resistance to protease inhibitors, combination regimens including three agents are standard. A few strains of HIV show resistance to all available protease inhibitors. Significant side-effects of protease inhibitors include elevation of cholesterol and triglyceride levels, insulin resistance and emergence of frank DM, and cosmetically objectionable lipodystrophy (excessive accumulation of fat in the abdomen and breasts accompanied by fat wasting in the face, extremities, and buttocks). Protease inhibitors currently in use include amprenavir, indinavir, nelfinavir, ritonavir, and saquinavir.
Farlex Partner Medical Dictionary © Farlex 2012