Hypertension Deck 1

Question 1

Nitroprusside (Nipride)

Mechanism of Action

Answer 1

♦ 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.

Question 2

Hydralazine

(mechanism of action)

Answer 2

♦ 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

Question 3

Hydralazine

(onset and duration)

Answer 3

Hypotensive effects occur 5—30 minutes after an IV dose.

The antihypertensive effects of an IV dose last 2—6 hours on average

Question 4

Hydralazine

(side effects)

Answer 4

♦ Hypotension

♦ Tachycardia

* The hydralazine-induced reflex autonomic response increases heart rate, stroke volume, cardiac output, and left ventricular ejection fraction

Question 5

Hydralazine

(indications)

Answer 5

♦ Severe Hypertension

Question 6

Hydralazine

(contraindications)

Answer 6

(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.

Question 7

Hydralazine

(adult dose)

Answer 7

♦ 5mg IV/IO over 2 minutes

may repeat

♦ to Max of 20mg

Question 8

Hydralazine

(pediatric dose)

Answer 8

Not indicated in current protocols

Question 9

Hydralazine

(pregnancy safe)

Answer 9

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

Question 10

Labetolol

(mechanism of action)

Answer 10

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**)

Question 11

Labetolol

(onset and duration)

Answer 11

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.

Question 12

Labetolol

(side effects)

Answer 12

Dizziness,

lightheaded,

headache,

nausea/vomiting,

chest pain,

shortness of breath,

fatigue

Question 13

Labetolol

(indications)

Answer 13

> Hypertension <

Question 14

Labetolol

(contraindications)

Answer 14

♦ 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

Question 15

Labetolol

(adult dose)

Answer 15

♦ 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

Question 16

Labetolol

(pediatric dose)

Answer 16

Not indicated in current protocols

Question 17

Labetolol

(pregnancy safe)

Answer 17

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.

Question 18

Metoprolol (Lopressor)

(mechanism of action)

Answer 18

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**)

Question 19

Metoprolol (Lopressor)

(onset and duration)

Answer 19

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.

Question 20

Metoprolol (Lopressor)

(side effects)

Answer 20

Hypotension,

Bradycardia,

Headache,

GI discomfort,

Shortness of breath

Question 21

Metoprolol (Lopressor)

(indications)

Answer 21

Acute Coronary Syndromes

Hypertesnion

Tachydysrhythmias

Question 22

Metoprolol (Lopressor)

(contraindications)

Answer 22

Bradycardia

Heart Block

Cardiogenic Shock/Heart Failure

Question 23

Metoprolol (Lopressor)

(adult dose)

Answer 23

♦ 5mg IV bolus,

may be repeated two times (_two minutes apart_) while monitoring heart rate, BP, and EKG

Question 24

Metoprolol (Lopressor)

(pediatric dose)

Answer 24

Not currently indicated

Question 25

**Metoprolol** (Lopressor) ## Footnote **(pregnancy safe)**

Answer 25

Pregnancy **Class C** ## Footnote *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.

Question 26

**Cardene / Nicardipine** **(mechanism of action)**

Answer 26

♦ ***Calcium channel blocker*** with direct action on arterial and coronary vascular smooth muscle **♦ Vasodilates** and *increases myocardial oxygen delivery* in patients with vasospastic angina

Question 27

**Cardene / Nicardipine** **(onset and duration)**

Answer 27

IV: Within minutes (constant infusion) Duration = IV: ≤8 hours

Question 28

**Cardene / Nicardipine** **(side effects)**

Answer 28

## Footnote **Hypotension**

Question 29

**Cardene / Nicardipine** **(indications)**

Answer 29

♦ Systolic BPm **\> 180** mHg **_OR_** ♦ Diastolic BP **\> 110** mmHg

Question 30

**Cardene / Nicardipine** **(contraindications)**

Answer 30

**_PATIENTS WHO HAVE AORTIC VALVE STENOSIS_**

Question 31

**Cardene / Nicardipine** **(adult dose)**

Answer 31

♦ 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***

Question 32

**Cardene / Nicardipine** **(pediatric dose)**

Answer 32

**Not indicated in current protocol**

Question 33

**Cardene** / Nicardipine ## Footnote **(pregnancy safe)**

Answer 33

Pregnancy **Class C** There are no adequate and well-controlled studies of nicardipine use in pregnant women.

Question 34

**Nitroprusside (Nipride)** **Onset and Duration**

Answer 34

**Onset**: Rapid **Duration**: 1 - 10 min after infusion is stoped

Question 35

**Nitroprusside (Nipride)** **Side Effects**

Answer 35

Headache / Dizziness / Hypotension / Coma / Dilated Pupils / Diaphoresis / GI Distress / Acidosis / Cyanide Toxicity / Tachycardia

Question 36

**Nitroprusside (Nipride)** **Indications**

Answer 36

## Footnote **Hypertension**

Question 37

**Nitroprusside (Nipride)** **Contraindications**

Answer 37

Hypersensitivity Compensatory hypertension secondary to AV shunt or aortic insufficiency

Question 38

**Nitroprusside (Nipride)** **Adult Dose**

Answer 38

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*)

Question 39

**Nitroprusside (Nipride)** **Pediatric Dose**

Answer 39

Not Indicated for pediatrics

Question 40

**Nitroprusside (Nipride)** **Pregnancy Safe**

Answer 40

Pregnancy category C ## Footnote *(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)*

Question 41

## Footnote **Treatment Goal is to lower MAP**

Answer 41

**by 20 - 25 % over 30 - 60 mins**

Question 42

**While treating hypertension, avoid sudden or precipitous changes in MAP of\_\_\_**

Answer 42

**\> 25% or 50 mmHg from known baseline** ***(maintain MAP \> 90)***