CV Stimulants Flashcards
Which receptors are linked to the Gq proteins?
alpha-1
Muscarinic-1
Muscarinic-3
Which receptors are linked to the Gi proteins
Alpha-2
Dopaminergic-2
Muscarinic-2
Which receptors are linked to the Gs proteins
Beta-1 and 2
Dopaminergic-1
effect of reserpine om Direct-acting stimulants
Responses NOT reduced by prior tx
- response may even increase
Drug that depletes NE from sympathetic neurons
Reserpine
Effect of reserpine on Indirectly acting stimulants
Responses are terminated by prior tx
effects of reserpine on mixed-acting
Responses are blunted but not terminated
Dobutamine (receptor and uses)
Receptors: B1 > B2
Uses:
Dopamine
Receptors: D1 and D2 > B> a
D1/D2 at low doses, B at intermediate, a at high doses
Uses: Unstable bradycardia, HF, shock, (inotropic & chronotropic effects at high doses)
Epinephrine Infusion:
pulse rate, pulse pressure and TPR
Receptors: a1 = a2 ; b1 =b2*
Uses: Anaphylaxis, cardiac arrest, hypotension
- Pulse rate: Increases
- pulse pressure: Widens (b2-vasodilation)
- TPR: slight decrease (slightly due to a1)
Isoproterenol
pulse rate, pulse pressure and TPR
Receptors: B1=B2
Uses: Electrophysiological evaluation of tachyarrhthmia
*can worsen ishemia
- Pulse rate: Increases
- pulse pressure: Widens (lower DBP-b2, small rise in SBP-b1)
- TPR: Large decrease
Norepinephrine
pulse rate, pulse pressure and TPR
Receptors: a1 > a2 > b1
Uses: Hypotension, but decreased renal perfusion
Pulse rate: slight decrease
Pulse pressure: Same (DBP and SBP increas, so increase MAP)
TPR: *INCREASES - due to a1
Phenylephrine
Receptors: a1 > a1
Uses: Hypotension (vasoconstrictor)
Ephedrine
Receptors: a1 > a2 > b1 (indirectly)
Uses: Hypotension of anesthesia, narcolepsy, nasal congestion, asthma, bronchospasm
Adverse effects of Epinephrine
- cerebral hemorrhage (especially w/ non-specific beta-blockers)
- Ventricular arrhythmias
- Angina
