Hypertension Meds Flashcards
Nitroprusside (Nipride)
Mechanism of Action
♦ A powerful vasodilator relaxes the vascular smooth muscle and produce consequent dilatation of peripheral arteries and veins.
♦ Sodium nitroprusside is more active on veins than on arteries.
Hydralazine
(mechanism of action)
♦ Causes direct dilation of arterial wall smooth muscle
♦ Hydralazine decreases B/P and reduces cardiac afterload
(result = decreased arterial blood pressure (diastolic more than systolic) and peripheral vascular resistance
Hydralazine
(onset and duration)
Hypotensive effects occur 5—30 minutes after an IV dose.
The antihypertensive effects of an IV dose last 2—6 hours on average
Hydralazine
(side effects)
♦ Hypotension
♦ Tachycardia
* The hydralazine-induced reflex autonomic response increases heart rate, stroke volume, cardiac output, and left ventricular ejection fraction
Hydralazine
(indications)
♦ Severe Hypertension
Hydralazine
(contraindications)
(Precautions), None Listed in Protocol
Hydralazine is excreted mainly in the form of metabolites in the urine. (hydralazine should be used with caution in patients with advanced renal damage)
When hydralazine is used in the presence of increased intracranial pressure, lowering of the blood pressure may result in increased cerebral ischemia.
Hydralazine
(adult dose)
♦ 5mg IV/IO over 2 minutes
may repeat
♦ to Max of 20mg
Hydralazine
(pediatric dose)
Not indicated in current protocols
Hydralazine
(pregnancy safe)
Pregnancy Class C
no adequate human studies have examined the effects of this drug on the fetus, the potential risks to the fetus must be weighed against the potential benefits to the mother.
The American Academy of Pediatrics considers hydralazine to be generally compatible with breast-feeding
Labetolol
(mechanism of action)
Beta Blocker
♦ Competively blocks beta receptors in the heart and blood vessels
♦ minimizes reduction in cardiac output while decreasing B/P
♦ has very little effect on cerebral circulation.
♦ Class II Antiarrhythmic
(**avoid using with cocaine toxicity**)
Labetolol
(onset and duration)
Onset: 2-5 min <> Duration: 16-18 hrs
The maximum effect of each intravenous labetalol dose occurs within 5 minutes.
An initial 0.25 mg/kg injection decreases blood pressure by an average of 11/7 mmHg.
Labetolol
(side effects)
Dizziness,
lightheaded,
headache,
nausea/vomiting,
chest pain,
shortness of breath,
fatigue
Labetolol
(indications)
> Hypertension <
Labetolol
(contraindications)
♦ Bronchial asthma - β2-adrenoceptors promote bronchodilation- (“beta blocker”) - increased risk for status asthmaticus
♦ overt cardiac failure - has negative inotropic effects; can cause acute left ventricular failure given in large doses to pt’s who have impaired function of the left ventricle
♦ cardiogenic shock - due to acute negative inotropic effects
♦ bradycardia - Labetolol slows heart rate
♦ hypotension - slows HR and decreases B/P
Labetolol
(adult dose)
♦ 20 mg IO/IV over 2 minutes
→ give additional 20→ 40→ 80 mg q 10 min PRN (in that progression)
Maximum dose of 300 mg
Labetolol
(pediatric dose)
Not indicated in current protocols
Labetolol
(pregnancy safe)
Pregnancy Class C
Use labetalol during pregnancy only if the potential benefit justifies the potential risk to the fetus.
There are no adequate and well-controlled studies of labetalol use in pregnant women.
Use caution when administering labetalol to a breast-feeding woman. Small amounts of labetalol (approximately 0.004% of the maternal dose) are excreted in human milk.
Metoprolol (Lopressor)
(mechanism of action)
Lopressor is a beta1-selective adrenergic receptor blocker. (often used in pt’s w/ impaired pulmonary function)
(1) reduction in heart rate and cardiac output
(2) reduction of systolic blood pressure,
(3) inhibition of isoproterenol-induced tachycardia,
(4) reduction of reflex orthostatic tachycardia.
♦ Class II Antiarrhythmic
(**avoid in presence of cocaine toxicity**)
Metoprolol (Lopressor)
(onset and duration)
Onset: Immediate
Half Life: 3 - 7 hrs
Duration: 5 - 8 hrs
After IV infusion over 10 minutes, the maximal beta blockade occurs within 20 minutes.
Metoprolol (Lopressor)
(side effects)
Hypotension,
Bradycardia,
Headache,
GI discomfort,
Shortness of breath
Metoprolol (Lopressor)
(indications)
Acute Coronary Syndromes
Hypertesnion
Tachydysrhythmias
Metoprolol (Lopressor)
(contraindications)
Bradycardia
Heart Block
Cardiogenic Shock/Heart Failure
Metoprolol (Lopressor)
(adult dose)
♦ 5mg IV bolus,
may be repeated two times (_two minutes apart_) while monitoring heart rate, BP, and EKG
Metoprolol (Lopressor)
(pediatric dose)
Not currently indicated
Metoprolol (Lopressor)
(pregnancy safe)
Pregnancy Class C
Metoprolol crosses the placenta.
Available data for published studies have not demonstrated an association of adverse developmental outcomes with the maternal use of metoprolol during pregnancy.
Cardene / Nicardipine
(mechanism of action)
♦ Calcium channel blocker with direct action on arterial and coronary vascular smooth muscle
♦ Vasodilates and increases myocardial oxygen delivery in patients with vasospastic angina
Cardene / Nicardipine
(onset and duration)
IV: Within minutes (constant infusion)
Duration = IV: ≤8 hours
Cardene / Nicardipine
(side effects)
Hypotension
Cardene / Nicardipine
(indications)
♦ Systolic BPm > 180 mHg
OR
♦ Diastolic BP > 110 mmHg
Cardene / Nicardipine
(contraindications)
PATIENTS WHO HAVE AORTIC VALVE STENOSIS
Cardene / Nicardipine
(adult dose)
♦ Infusion at 5-15 mg/hr. (25-75 cc/hr.)
(50 mg/250 ml NS =0.2 mg/ml).
♦ Start at 5 mg/hr then î by 2.5 mg up to 15 mg/hr
once target BP is achieved → titrate back down to a target of 3 mg/hr
Cardene / Nicardipine
(pediatric dose)
Not indicated in current protocol
Cardene / Nicardipine
(pregnancy safe)
Pregnancy Class C
There are no adequate and well-controlled studies of nicardipine use in pregnant women.
Nitroprusside (Nipride)
Onset and Duration
Onset: Rapid
Duration: 1 - 10 min after infusion is stoped
Nitroprusside (Nipride)
Side Effects
Headache / Dizziness / Hypotension / Coma / Dilated Pupils / Diaphoresis / GI Distress / Acidosis / Cyanide Toxicity / Tachycardia
Nitroprusside (Nipride)
Indications
Hypertension
Nitroprusside (Nipride)
Contraindications
Hypersensitivity
Compensatory hypertension secondary to AV shunt or aortic insufficiency
Nitroprusside (Nipride)
Adult Dose
0.5 - 10 mcg/kg/min IV/IO
titrated to goal B/P
(overdosage of nitroprusside can be manifested as excessive hypotension or cyanide toxicity or as thiocyanate toxicity)
Nitroprusside (Nipride)
Pediatric Dose
Not Indicated for pediatrics
Nitroprusside (Nipride)
Pregnancy Safe
Pregnancy category C
(prolonged use of large doses of nitroprusside during pregnancy may lead to cyanide toxicity that may be fatal to the fetus, only give if benifits outweigh risks)
Treatment Goal is to lower MAP
by 20 - 25 % over 30 - 60 mins
While treating hypertension, avoid sudden or precipitous changes in MAP of___
> 25% or 50 mmHg from known baseline
(maintain MAP > 90)
