By: Ala'a Fadhel Hassan

5th stage, Pharmacy dept.

Hospital Training

Supervised by: Dr.Anas

Definition

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Malignant hypertension is very high blood pressure that comes on suddenly and quickly. The lower (diastolic) blood pressure reading, which is normally around 80 mmHg, is often above 130 mmHg (1)

It is a rare but very serious form of high blood pressure. Officially, defined as severe hypertension that occurs along with internal bleeding of the retinas in both eyes and swelling of optic nerves behind the retinas (2)

Alternative Names Accelerated hypertension; arteriolar nephrosclerosis; Hypertension - malignant; High blood pressure – malignant (1)

Causes, incidence & risk factors Malignant hypertension is not a single disease entity but rather, asyndrome in which the hypertension can be either primary (essential) or secondary to any one of a number of different causes (3)

The disorder affects about 1% of people with high blood pressure, including both children and adults. It is more common in younger adults,( which is the opposite of the risk profile for essential hypertension), especially African-American men(1) in which the underlying cause is almost always essential hypertension that has entered a malignant phase (2)Anyone with a history of kidney failure or a renal artery stenosis (narrowing of arteries in the kidney) has a greatly increased risk(3) .History of primary renal parenchymal disorders is The most common secondary causes of malignant hypertension( Chronic glomerulonephritis is thought to be the cause of malignant hypertension in up to 20% of cases)(2)Pregnant women with gestational hypertension, or women experiencing certain pregnancy related complications (toxemia of pregnancy) appear to have an increased risk(3)It also occurs in people with Collagen vascular disorders(1)Drug Related Malignant Hypertension(MAO Inhibitors, Cold Preparations, Withdrawal Antihypertensive Medicines as" Clonidine, b-Blockers"&“Street drugs" Cocaine, PCP)(4)

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Clinical presentation

Symptoms of Malignant Hypertension Because malignant hypertension affects organ systems that are directly sensitive to blood pressure (kidneys, eyes, brain, cardiovascular system), the symptoms of the disease tend to be those associate with problems in these other organ systems. For example, some symptoms include:

Blurry visionChest painSeizureDecreased urine outputWeakness or strange tingling/numbness in the arms, legs, or faceHeadacheShortness of breath

These symptoms are not exclusive to malignant hypertension, but are generally associated with a number of potentially serious medical conditions like heart attack, stroke, or kidney problems (2)

Physical Examinations and TestsMalignant hypertension is a medical emergency in which the physical exam commonly shows:

Extremely high blood pressureSwelling in the lower legs and feetAbnormal heart sounds and fluid in the lungsChanges in thinking, sensation, muscle ability, and reflexes

An eye examination will reveal changes that indicate high blood pressure, including:

Bleeding of the retina

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Narrowing of the blood vessels in the eye areaSwelling of the optic nerveOther problems with the retina

Kidney failure, as well as other complications, may develop. (1)

Tests to determine damage to the kidneys may include:Arterial blood gas analysisBUNCreatinineUrinalysis

A chest x-ray may show congestion in the lung and an enlarged heart.This disease may also affect the results of the following tests:

Aldosterone levelCardiac enzymes (markers of heart damage)CT scan of the brainElectrocardiogram (EKG)Renin levelUrinary sediment(1)

Principles of TherapyLower B.P. over hours, Initial goal B.P. » 160’s/90’s

Too rapid lowering may cause dire consequences (CVA, MI)

May take several days to get to reasonable levels

Avoid medications that cannot be controlled (sublingual nifedipine)

For most patients the greatest risk of treating a hypertensive emergency is the risk of accompanying hypotension.

Treat with short acting, easily titratable, I.V. drug(4)

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Drug Dosage

Onset

Duration

AdverseEffects

Indication(I)Contraindication(C)

Vasodilators

Nitropru-sside

0.3-10 mcg/kg/minIV infusion

1-2 min

1-2 min

N/V, muscle twitching ,cyanide, Thiocyanide tox. & intracranial pressure

I: CHF, aortic dissect, Catechol.C: hepatic, renal insufficiency

Nitrogly-cerin (IV)

5-100mcg/kg/min

2-5 min

3-5 min

Head ache, dizziness,vomiting, methemgl-obin &tolerance

I: coronary dis., CHFC: CVA, Intracranial pressure

Diazoxide ( IV)

1-3 (mg/kg) IV bolus, q5-15 /min; repeat every 4-24 hr as needed

2-4 min

3-12 hr

Nausea, hypoten-sion , flushing, tachycardia, hypergly-cemia, aggravat-ion of angina& fluid retention

C: Syndromes of coronary insufficiency, (unless used with beta-blocking agent), cerebrovascular accident& hypersensi-tivity to sulfonamides

Fenoldo-pam mesylate

0.1-1.7 mcg/kg/min (IV infusio

5-15 min

1-4 hr Headache, dizziness, flushing,

I: Severe hyperten-sion with renal insufficiency

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n) increased intraocular pressure,Hypokal-emia& dose related tachycardia

C: Glaucoma

Hydrala-zine HCl

10-20 mg IV or IM bolus, (maximum dose, 40 mg)

10-20 min

3-8 hr Tachy-cardia, flushing, headache,vomiting & aggravat-ion of angina

I: CHFC: Coronary insufficiency, aortic dissection, cerebrovascular accident (may increase intracranial pressure)

Enalaprilat(IV)

1.25-5 mg q6 hr IV

15 min 6 hr Precipi

t-ous drop in blood pressure in high renin st.

I: CHFC: Use with caution in patients with severe renal insufficiency (not receiving dialysis)

Nicardi-pine HCl

5-15 mg/hr IV infusion

5-20 min

1-2 hr Tachycardia, headache,flushing, local phlebitis

C: Greater than first-degree heart block, CHF

Adrenergic Inhibitors

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Phentol-amine a-blocker

5-20 mg IV, repeat as necess-ary

1-2 min

10-30 min

Tachycardia, nausea, flushing, abdominal pain& aggr-avation of angina

I: Catecholamine excessC: Syndromes of coronary insufficiency

Esmolol HCl

200-500 mcg/kg/min over 1-4 min, then 50-300 mcg/kg/min IV infusion

1-2 min

10-20 min

Hypoten-sion, nausea, bradycar-dia or heart block& dizziness

I: Syndromes of coronary insufficiencyC: Greater than first-degree heart block, CHF

Labetalol HCl a-b blocker

20-80 mg IV bolus, (maximum dose, 300 mg

2-10 min

2-4 hr Hypoten-sion, nausea, itching, scalp tingling& dizziness

I: Syndromes of coronary insuffi-ciency, catechol-amine excessC: first-degree heart block, CHF, bronchial asthma

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References:

(1) Medline Plus-A service of the U.S. national library of medicine

Malignant hypertension, causes, symp . &…http://www.nlm.nih.gov/medlineplus/druginformation.html

(2) A.D.A.M. Medical Encyclopedia. Malignant hypertension http://www.ncbi.nlm.nih.gov/pubmedhealth/

(3) Hypertension & The KidneyChapter 8 (Hypertensive Crises) by Charles R. Nolan

(4) Hypertension Emergencies & UrgenciesBy Stephen S. Levin, D.O.

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