Drug Action Flashcards
Acetazolamide
Action: Inhibits hydrogen ion excretion in renal tubule,
increasing sodium,
potassium,
bicarbonate,
and water excretion and producing alkaline diuresis
Acetaminophen
Action: May work peripherally to block pain impulse generation; may also inhibitprostaglandin synthesis in CNS
Acetic acid
Mechanism of action: Provides an acidic medium
during irrigation of the ear that minimizes
bacterial and fungal promulgation,
Stabilizes nematocyst discharge in non-United States jellyfish, thus decreasing pain
Acetylcysteine
Mechanism of action: Lowers mucus viscosity,
restores glutathione concentrations within
the liver,
Acts as sulfhydryl group donor to restore liver glutathione; may also scavenge free radicals to prevent delayed hepatotoxicity as antioxidant; encourages sulfation pathway of metabolism for acetaminophen
Activated Charcoal
Mechanism of action: Adsorbs toxic substances
from the GI tract
Absorbs a variety of drugs and chemicals (e.g., physical binding of a molecule to the surface of charcoal particles); desorption of bound particles may occur unless the ratio of charcoal to toxin is exceptionally high
Adenosine
Mechanism of action: Slows conduction through
the AV node; can interrupt reentrant AV nodal
pathways
Albuterol
Mechanism of action: Selective beta-2 agonist
that stimulates adrenergic receptors of the
sympathomimetic nervous system. Results in
smooth-muscle relaxation in the bronchial tree
and peripheral vasculature
Amiodarone
Mechanism of action: Blocks sodium, potassium,
and calcium channels; prolongs the action
potential and repolarization; decreases AV
conduction and sinoatrial (SA) node function
Amyl Nitrite
Mechanism of action: Converts hemoglobin to
methemoglobin, which reacts with cyanide and
chemically binds with it, preventing any toxic
effects
Aspirin
Mechanism of action: Prevents the formation
of thromboxane A2, which causes platelets to
clump together (aggregate) and form plugs that
cause obstruction or constriction; has antipyretic
and analgesic properties
Atropine
Mechanism of action: Inhibits the action of
acetylcholine at postganglionic parasympathetic
neuroeffector sites. Increases heart rate in
symptomatic bradydysrhythmias
Competitively inhibits the action of acetylcholinesterase on autonomic effectors innervated by postganglionic nerves
Calcium Chloride
Mechanism of action: Increases cardiac contractile
state (positive inotropic effect). May enhance
ventricular automaticity
Bone mineral component; cofactor in enzymatic reactions, essential for neurotransmission, muscle contraction, and many signal transduction pathways
Calcium Gluconate
Mechanism of action: Counteracts the toxicity of
hyperkalemia by stabilizing the membranes
of the cardiac cells, reducing the likelihood of
fibrillation
Bone mineral component; cofactor in enzymatic reactions, essential for neurotransmission, muscle contraction, and many signal transduction pathways
Cimetidine
Mechanism of action: Blocks the effects of
histamine at H2 receptors of gastric parietal cells,
leading to a reduction of gastric acid volume
and gastric acidity
Dexamethasone
Action: Potent glucocorticoid with minimal to no mineralocorticoid activity Decreases inflammation by suppressing migration of polymorphonuclear leukocytes (PMNs) and reducing capillary permeability; stabilizes cell and lysosomal membranes, increases surfactant synthesis, increases serum vitamin A concentration, and inhibits prostaglandin and proinflammatory cytokines; suppresses lymphocyte proliferation through direct cytolysis, inhibits mitosis breaks down granulocyte aggregates, and improves pulmonary microcirculation
Diazepam
Action: Modulated postsynaptic effects of GABA-A transmission, increasing presynaptic inhibition. It appears to act on the part of the limbic system, as well as on the thalamus and hypothalamus, to induce a calming effect
Diltiazem
Action: Inhibits extracellular calcium ion influx across membranes of myocardial cells and vascular smooth muscle cells, resulting in inhibition of cardiac and cascular smooth muscle contrction and thereby dilating main coronary and systemic arteries; no effect on serum calcium concenrations; substantial inhibitory effects on cardiac conduction system, acting principally at AV node with some effects at the sinus node
Diphenhydramine
Action: Histamine H1-receptor antagonist of effector cells in the respiratory tract, blood vessels, and GI smooth muscle
Dopamine
Action: Endogenous catecholamine, acting on both dopaminergic and adrenergic neurons. Low dose stimulates mainly dopaminergic receptors, producing renal and mesenteric vasodilation; higher dose stimulates both beta-1-adrenergic and dopaminergic receptors, producing cardiac stimulation and renal vasodilation; large dose stimulates alpha-adrenergic receptors
Droperidol
Action: Antiemesis: dopamine receptor blockade in brain, predominantly dopamine-2 receptor.
When reuptake is prevented, a strong antidopaminergic, antiserotonergic response occurs
Droperidol reduces motor activity anxiety and causes sedation; it also possesses adrenergic-blocking, antifibrillatory, antihistaminic, and anticonvulsive properties
Epinephrine
Action: Strong alpha-adrenergic effects, which cause an increase in cardiac output and heart rate, a decrease in renal perfusion and peripheral vascular resistance, and a variable effect on BP, resulting in systemic vasoconstriction and increased vascular permeability. Strong beta-1-and moderate beta-2-adrenergic effects, resulting in bronchial smooth muscle relaxation
Secondary relaxation effect on the smooth muscle of stomach, intestine, uterus, and urinary bladder
Famotidine
Action: Blocks H2 receptors of gastric parietal cells, leading to inhibition of gastric secretions
Fentanyl
Action: Narcotic agonist-analgesic of opiate receptors; inhibits ascending pain pathways, thus altering response to pain; increases pain threshold; produces analgesia, respiratory depression and sedation
Glucagon
Action: Insulin antagonist. Stimulates cAMP synthesis to accelerate hepatic glycogenolysis and gluconeogenesis.
Glucagon also relaxes smooth muscles of the GI tract
Haloperidol
Action: Antagonizes dopamine-1 and dopamine-2 receptors in the brain; depresses reticularactivating system and inhibits the release of hypothalamic and hypophyseal hormones