Pharmacology Flashcards
Prazosin
Alpha 1 adrenoceptor antagonist selectively and competitively inhibits the postsynaptic alpha 1 adrenoceptor -> produces smooth muscle relaxation
Diazepam
Benzodiazepine
MOA: Facilitation of GABA-ergic inhibition and therefore increased intracellular Chloride flux.
Route of Admin: IV, IN, CRI, or PR
Side Effects: Vascular/Perivascular irritation, Bradycardia, sedation, ataxia, weakness, nausea
Midazolam
Benzodiazepine
MOA: Facilitation of GABA-ergic inhibition and therefore increased intracellular Chloride flux.
Route of Admin: IV, IN (with atomizer), IM, or CRI
Side Effects: Sedation, Nausea, ataxia, weakness, hyperactivity, hepatopathy in cats when given oral.
Levetiracetam
Anticonvulsant
MOA: binding to synaptic vesicle protein SV2A -> decreased release of neurotransmitter into the synapse
Side effects: Hypersalivation, Ataxia, vomiting, anorexia, restlessness
Phenobarbital
Barbiturate Anticonvulsant
MOA: Facilitating GABA-ergic activity by prolonging the opening of the Cl channel associated with the GABA-A receptor
Route of Admin: IV, PO
Side Effects: Sedation, Ataxia, PU/PD/PP, hepatotoxicity, bone marrow suppression, ALP elevations
Propofol
Class: anesthetic agent
MOA: positive modulation of the inhibitory function of GABA
Side effects: Respiratory depression, hypotension
Lactulose
-Nonabsorbable disaccharides
-fermented by GI bacteria resulting in production of volatile fatty acids, decreased colonic pH, movement water into the colon by osmosis
-traps ammonium ions in colon -> decreased absorption of ammonia
Propanolol
Beta 1 and beta 2 blocker
Propranolol, a non-selective β-blocker, exerts an indirect effect on the vasculature by leaving α-adrenergic receptors unopposed, resulting in peripheral vasoconstriction
Clopidogrel
Antiplatelet drug
Irreversibly inhibits platelet ADP receptor P2Y12
Terbutaline
Beta-2-adrenergic agonist, tocolytic, can push potassium into cells via stimulation of endogenous insulin release
Terbutaline MOA in hyperkalemia
Stimulates sodium potassium ATPase pump which moves potassium intracellularly
What effect does dopamine have on the afferent and efferent arterials respectively?
Relaxation, constriction
Desmopressin
DDAVP
Induces significant elevations in plasma FVIII:vWf complex, vWf antigen, and FVIII:RC
Mechanisms of action of anti-emetics
-5-HT3 antagonist
-neurokinin1 (NK1) antagonist
-Dopamine2 (D2) antagonist
Ondansetron
5-HT3 antagonist
Cerenia
NK1 antagonist
TXA
Anti-fibrinolytic agent, works by blocking the lysine binding site on plasmidogen
Opioid receptors
- Mu
- Kappa
- Delta
- g protein coupled receptors
- results in inhibition of neurotransmission signaling
- located in the brain and spinal cord
Mu effects
Analgesia > sedation, respiratory and cardiovascular depression, GI hypomotility
Kappa receptors
Sedation > analgesia, less effects on respiratory CV and GI
Opioid mechanism of action
Mu receptor:
-inhibits pre-synaptic release of substance p and other excitatory neurotransmitters
-inhibits postsynaptic response to excitatory neurotransmitters
-analgesia at a level of the brain and spinal cord
Opioid coupling with Gi/o proteins:
-decreased intracellular cAMP synthesis -> diminished calcium channel phosphorylation -> closes voltage-gated calcium channels and opens potassium channels to inhibit threshold potential
-hyperpolarization of neurons and blockade of substance p and to reduce neurotransmitter release by decreasing calcium influx
Inhibits neurotransmission at the dorsal horn of the spinal cord
Opioid tolerance and resistance occurs if the calcium channels remain open despite the presence of an opioid
Opiod Drugs
Acepromazine
Central dopamine D1 and D2 receptor competitive antagonist -> blocks excitatory dopamine receptors in the CNS
Peripheral alpha-1 receptor antagonist -> vasodilation -> hypotension
Causes hematocrite to be reduced due to splenic sequestration -> splenomegaly
Benzodiazepines
Mechanism of action: gaba receptor competitive agonism
GABA is the #1 inhibitory CNS neurotransmitter
Benzodiazepines bind to GABAa causing hyperpolarization of neurons -> increases the threshold to action potential