Cardio: Drugs for Aortic Dissection Flashcards
What four drugs are first line for aortic dissection?
Labetalol, esmolol, nitroprusside, nicardipine
MOA of labetalol
Blocks both a1 and non-selective B
-decreases PVR
Indications for labetalol
Arterial HTN (emergencies to stable HTN) -also used in combo with other HTN drugs
Contraindications of labetalol/esmolol?
HF, 2nd-3rd degree AV block, bradycardia, cardiogenic shock, severe hypotension
What are some precautions when prescribing labetalol?
Hepatic injury (monitor LFTs) Cardiac failure Withdrawl syndrome Bronchospasm and DM (decreases B2 activity) Pheochromocytoma
What are some drugs to look out for when prescribing labetalol?
Tricyclic antidepressants (tremor) B-blockers Cimetidine* Halothane Nitroglycerin (hypotension) CCBs (verapamil) Digitalis
What special population (2) may require an adjusted dose when prescribing labetalol?
Geriatric patients
-elimination is reduced, so may have to decrease dose
Pregnancy
-clearance increases, so may have to increase dose
MOA of Esmolol?
B1 specific B-blocker
Indications for Esmolol?
Control of rapid heart beats, especially indicated around surgery
Should you prescribe esmolol during pregnancy?
It can be used, but it can cause fetal bradycardia
-have to monitor pts closely, or switch drugs
Does esmolol interact with other drugs?
yes, many interactions
What special population may require a lower dose when prescribing esmolol?
The elderly
-clearance decreases, so may have to reduce
Main adverse effects of esmolol?
Hyperkalemia
-especially in renal failure pts
Hypotension
-must monitor them closely within 30min of dosage
Which B-blocker is very short acting?
Esmolol
-half life 9 mins
Nitroprusside MOA
Releases NO when broken down
- NO activates guanylate cyclase, which increase cGMP
- cGMP increases PKG=inactivation of myosin light chains (phosphorylation)
- -decreases contraction=vasodilation
Should you prescribe nitroprusside with PDE-5 inhibitors?
No way, Jose
-both work to vasodilate, and can cause massive drops in BP
Indications for nitroprusside
Hypertensive emergencies!
-can also use it during surgeries and HF
Adverse effects of nitroprusside
Bradyarrythmias
Hypotension
Palpitations
Tachyarrhythmias (reflex)
and many more, dude lists like 50
What is the major toxicity of nitroprusside?
Nitroprusside is broken down into Cyanide
-so look out for seizures and lactic acidosis
What hematological issue can nitroprusside cause?
Methemoglobinemia
-sequesters hemoglobin, so patients may develop blue skin and “chocolate brown” blood
When would nitroprusside cause thyiocyante toxicity?
Pts w renal impairment
-CN- binds to thiosulfate, which is normally excreted in urine
Renal failure means less is excreted
MOA of Nicardipine
dihyropyridine CCB
-causes vasodilation
Indications for Nicardipine
IV: short-term tx of hypertension, but switch to oral ASAP
Oral: long term BP control
Contraindications for Nicardipine?
Pts w advanced aortic stenosis
Adverse effects of nicardipine?
Headache, hypotension, tachycardia (reflexive), N/V
What are some precautions to think about when prescribing nicardipine?
Can cause hypotension
Can worsen angina
Can worsen HF (due to negative inotropic effects)
In someone with hepatic or renal impairment, what should you think about when giving nicardipine?
Hepatic impairment: Lower doses and monitor blood flow
Renal: Can significantly lower clearance and increase AUC curve (?)
Where should you administer nicardipine?
In large peripheral/central veins rather than smaller ones of wrist/hand
-minimizes risk of thrombophlebitis, local irritation
Is nicardipine safe in kids?
No, safety has not been established yet
What should you do w doses of nicardipine in elderly?
Lower the doses!
What drugs do nicardipine interact with?
Those that inhibit CYP3A4: Cimitidine, cyclosporines, tacrolimus
-increases concentration
Is nicardipine safe to give w B-blockers?
yes, but need to monitor in those with HF
