drugs #1 8-18-15 Flashcards
Metyrosine
Indication: Hypertension
MOA: Competitive inhibition of tyrosine hydroxylase
-rate limiting step in the production of catecholamines
Reserpine
Indication: Hypertension
MOA: Inhibits VMAT uptake of monoamines
- VMATs transport monoamines into synaptic vesicles-keeps them from being degraded
- can cross BBB and lead to depression
Bretylium
Indication: Ventricular Arrhythmia
MOA: Inhibit action potential generation and calcium dependent synaptic vesicle fusion
Cocaine
Indication: Analgesia in surgery
MOA: Blocks monoamine reuptake
-re-uptake is the primary mode of terminating monoamines actions
Amphetamine or Ephedrine
Indication: Narcolepsy, ADHD
MOA: Reverse monoamine reuptake transporters
Naloxone, Naltrexone
Indication: Opioid overdose or dependence
MOA: Non- peptide blockers of opioid receptors in the CNS
SSRI
Indication: Depression/Anxiety
MOA: Selective inhibition of serotonin reuptake transporter
ACE inhibitors (eg. lisinopril)
Indication: Hypertension
MOA: Inhibit peptide cleavage of Angiotensin 1 to Angiotensin 2
Phenylephrine
Indication: Hypotension during surgery
MOA: Direct agonist of adrenergic receptor
MOA inhibitors
Indication: Depression
MOA: blockade of cytoplasmic metabolism of monoamines
L-DOPA
Indication: Parkinson’s Disease
MOA: precursor of dopamine, stimulates dopamine production
Carbidopa
Indication: Parkinson’s Disease
MOA: Blocks L-DOPA conversion to dopamine, does not cross BBB, so protects peripheral adrenergic neurons from producing too much dopamine and norepinephrine
Tyramine
Indication: Ingested in diet, not therapeutic
MOA: competes with NE for transport into synaptic vesicle
- normally tyramine is subject to first pass metabolism by MAO in the liver
- when MOAs are inhibited such as treatment for depression-tyramine accumulates and is transported into adrenergic cells
- it competes with NE for transport into synaptic vesicles resulting in even higher levels of cytoplasmic NE than with MAO inhibitors alone
- reversal of uptake transporter
- excessive release of NE–>hypertensive crisis because of excessive vasoconstriction by NE in periphery
- newer drugs can selectively block MAO-a leaving MAO-B intact, allowing for tyramine degradation in the gut
What are 6 indirect acting sympathomimetics?
- amphetamine
- methamphetamine
- methylphenidate
- ephedrine
- pseudoephedrine
- tyramine
What are the PTIC for indirect acting sympathetics?
P:
- Increased TPR and diastolic BP (a1+a2)
- Positive ionotrophic and chronotropic effects, increased systolic pressure (B1)
- CNS stimulant (probably increased NE)
- Anorexia (probably increased DA)
T:
Tachycardia (b1)
I:
Attention Deficit Disorder
Narcolepsy
Nasal congestion
C:
Rx with MAO inhibitors within 2 weeks
What are 3 Non-selective B-blockers?
- Propranolol
- Nadolol
- Timolol
Non-selective B-blockers
PTIC
P: Decreased HR Decreased contractility Decreased renin release Reduced sympathetic activation Inhibition of aqueous humor production
T:
Bronchospasm
Mask symptoms of hypoglycemia
Bradycardia
I: Hypertension Angina Glaucoma Early to moderate heart failure Arrhythmia Thyrotoxicosis Anxiety
C: Bronchospasm during asthma Sinus bradycardia 2nd and 3rd degree heart block cardiogenic shock
What are 3 cardioselective B1 blockers?
metoprolol, atenolol, esmolol
cardioselective B1-blockers
PTIC
P: decreased HR decreased contractility decreased renin release decreased sympathetic activation
T:
hypotension
bradycardia
I:
hypertension
angina
arrhythmia
C:
sinus bradycardia
2nd and 3rd degree heart block
cardiogenic shock
Pindolol
PTIC
partial agonist b-blocker P: decrease BP decrease contractility decrease renin release decreased sympathetic activation
T:
Hypotension
I:
Hypertension
C:
sinus bradycardia
2nd and 3rd degree heart block
cardiogenic shock
What are two non-selective alpha blockers?
Phentolamine (reversible)
Phenoxybenzamine (irreversible)
Non-selective alpha blockers?
PTIC
P: Decreased BP (alpha blockade +unmasks b effects) Increased chronotropy and inotropy -->increased release of NE and reflex increase in NE release in response to hypotension -unmasks vasodilator effect of EPI (which has both alpha and beta effects)
