Adrenergic agonists Flashcards
Adrenergic agonists
- direct acting
- indirect acting
- mixed action
Direct acting - albuterol (b2) - clonidine (a2) - dobutamine (CA, b1) - dopamine (CA, b, a, D1, D2) - epinephrine (CA, a, b1, b2) - NE (CA, a, b1) - isoproterenol (CA, b) - metaproterenol (b2) - oxymethazoline (a) - methoxamine (a1 > a2) - phenylephrine (a1 > a2) - ritrodrine - terbutaline (b2) - Salmeterol (b2) NOTE: non-catecholamines are taken orally -> longer duration
Indirect acting (a, b) -> can enter nerve terminals and displace the stored NE, acting on adrenoceptors
- amphetamine
- tyramine
Mixed action (a, b) -> induce release of NE from presynaptic nerve terminals, activate Rs on postsynaptic Ms
- ephedrine
- metaraminol
Epinephrine
CA
R: a1, a2, b1, b2
PK:
- i.v. (emergency)
- sc, endotracheal tube, inhalation
- topically to the eye
TU:
- bronchospasm, powerful bronchodilator (b2) and in acute asthma treatment
- open angle glaucoma
- anaphylatic shock
- in local anesthetics (to increase duration of action by vasoconstriction)
- positive inotropic and chronotropic (b1) -> increase CO
- increase SBP and decrease DBP -> increase pulse pressure
- hyperglycemic effect
- increase glycogenolysis (b2) and lipolysis (b3)
AE:
- CNS disturbances: anxiety, tear, tension headache, tremor
- cerebral hemorrage (due to big increase of BP)
- cardiac arrhythmias and digitalis
- pulmonary edema
DI:
- hyperthyroidism
- cocaine
Norepinephrine
CA
R: a1, a2, b1
TU:
- treatment of shock (increase BP), however dopamine is better to treat shock bc doesn’t decrease BF to kidneys
- reflex bradycardia stimulation
AE:
- life-threatning low BP
- during CPR
Isoproterenol
Synthetic CA
R: b1, b2, b3
TU:
- rarely used
- bronchodilator in asthma
- cardiac stimulant in AV block and cardiac arrest
Dopamine
CA
R: b, a, D1, D2
TU: increase CO in congestive HF
AE:
- caution in AF, bc it increases AV conduction
- tolerance w/ prolonged use -> dependence
Dobutamine
Synthetic CA
R: b1
PK: parenteral
TU:
- shock = drug of choice
- increase BP, enhances kidney perfusion and GFR
Oxymethazoline
Non-CA
R: a non-selective
PK:
- short-acting
- over the counter
TU:
- nasal spray decongestant
- ophthalmic drops -> mydriasis
AE:
- rebound congestion
- dependence
Phenylephrine
Non-CA
R: a1 > a2
TU:
- increase BP (vasoconstriction)
- nasal decongestant -> constriction of blood vessels in nasal passages
- SV tachycardia
AE:
- hypertensive headache
- cardiac irregularities in high doses
Methoxamine
Non-CA
R: a1 > a2
TU:
- increase BP
- inhibit vagus-mediated bradycardia
- relieve attacks of SV paroxysmal tachycardia
Clonidine
Non-CA
R: a2
TU:
- used in essential HT to decrease BP due to its action in CNS
- minimize symptoms that accompany withdrawal from opiates and BZP
Metaproterenol
Non-CA
R: b2
PK: orally / sc
TU:
- bronchodilator
- decrease uterine contraction in premature labor
Albuterol + Terbutaline
Non-Ca
R: b2
PK: orally / sc
TU:
- bronchodilator in asthma - reverse bronchospasm
- decrease uterine contractions
Salmeterol
Non-CA
R: b2
TU: bronchodilator in asthma
Amphetamine
R: a, b
TU:
- increase BP (a), stimulates heart (b)
- depression therapy
- narcolepsy and appetite control
Tyramine
TU: not useful clinically
