Treatment of Acute Aortic dissection Flashcards
what are the main affects of Beta blockers
1.Beta blockers work by blocking the effects of
the hormone epinephrine (aka; adrenaline)
2.Beta blockers cause your heart to beat more
slowly and with less force, which lowers blood
pressure
3.Beta blockers also open your veins and
arteries up to help improve blood flow
what are 4 common examples of Beta bockers
- Labetalol
- Esmolol
- Nitroprusside
- Nitrocardipine
MOA of Labetalol
• Typically given as a racemic mixture
• Achieves both a- and b-receptor
blocking activity
decreases peripheral vascular resistance without significant alteration of HR or CO
Contraindictions of Labetalol
• Overt cardiac failure • Greater-than-first-degree heart block • Severe bradycardia • Cardiogenic shock • Severe hypotension • Anyone with a history of obstructive airway disease including asthma • Those with hypersensitivity to the drug
Adverse effects of Labetalol
- dizziness
- tingling scalp or skin
- lightheadedness
- excessive tiredness
- headache
- upset stomach
- stuffy nose
Drug interactions of Labetalol
• Tricyclic antidepressants - may experience tremor
• Beta-receptor agonist-
• Drugs in patients with bronchospasm - greater doses than normal
of the beta-agonist drug may be required
• Cimetidine
• Halothane anesthesia - notify anesthesiologist when a patient is
receiving Labetalol
• Nitroglycerin - additional antihypertensive effects may occur
• Calcium antagonists- of the verapamil type
• Digitalis glycosides - increase risk of bradycardia
how does Labetalol affect pregnancy and pediatric patients
Pregnancy Category C:
Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and wellcontrolled
studies in humans, but potential benefits may warrant use of the drug in pregnant women despite
potential risks
• Nursing Mothers: Small amounts are excreted in
human milk
Ø Use caution when administered to a nursing
woman
• Pediatric Patients: Safety and effectiveness have
not been established
how is clearance affected in Labetalol
goes up in pregnancy making it fall below therapeutic value
how are geriatric patients affected by Labetalol
Geriatric Patients:
§ Caution elderly patients about the possibility of
orthostatic symptoms during treatment
§ Elimination of Labetalol is reduced in elderly
patients
§ May require a lower maintenance dosage (100-200
mg twice daily) than non-elderly patients
are there any black box warnings with Labetalol?
None
How is Labetalol metabolized? and distributed
absorbed via oral
distributed to the Plasma protein binding, found in breast milk, and crosses the placenta
Metabolized via conjugation to glucuronide and excreted via urine, bile and feces
is elimination of Labetalol reduced in elderly patients?
Yes
Mechanism of Action of Esmolol?
Affects the response to nerve impulses in heart
-Decreased Heart beat and lowers blood pressure
Class II anti-arrhythmic
-blocks response to B1-adrenergic stimulation (little to no effect of B2 receptors except at high doses
what are the indications for Esmolol
Control rapid heartbeats or abnormal heart rhythms
used to treat fast heartbeat and high blood pressure during surgery, after surgery, or during other medical procedures
Esmolol Contraindictions
• Contraindications • Bronchial asthma • Overt cardiac failure • Cardiogenic shock • Severe sinus bradycardia • Other conditions associated with severe and prolonged hypotension
History of, hypersensitivity, Obstructive airway disease including asthma, and Heart block greater than first degree
(except patients with a functioning artifical pacemaker)
Decompensated heart failure
IV administration of calcium channel blockers
Pulmonary hypertension