Sodium Nitroprusside

Sodium Nitroprusside

ADMINISTRATION ROUTES: IV

ALTERNATIVE NAMES: Nipride, nitropress

ICU INDICATIONS: 7. afterloadreduction/peripheralvasodilation 8. treatmentofhypertension

PRESENTATION AND ADMINISTRATION:

IV:

50mg of powder in a vial. Add 2-3ml of 5% glucose to dissolve the powder Dilute reconstituted solution of 50mg up to a total of 50ml using 5% dextrose. Sodium nitroprusside is compatible with 5% dextrose ONLY. No other drug may be administered via the side arm or added to the infusion while sodium nitroprusside is being infused. Freshly prepared solution has a very faint brownish tinge Prepare all solutions immediately before use. In aqueous solution, sodium nitroprusside is photosensitive and must be protected from light. Immediately after dilution the solution should be wrapped in aluminium foil to protect it from light. Use yellow tubing. (it is not necessary to cover the tubing or the drip chamber with foil) Any solution not used within 24 hours or preparation should be discarded. Any solution that is high coloured should be discarded. Store at room temperature Protect from light and heat.

DOSAGE:

IV infusion:

IV infusion dose range is 0-20ml/hr (usually used in the lower end of the dose range).

DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY: Dose as in normal renal function; avoid prolonged use.

DOSAGE IN PAEDIATRICS:

IV infusion:

<30kg 3mg/kg in 50ml 5% dextrose at 0.5-4ml/hr (0.5-4mcg/kg/min) >30kg 3mg/kg in100ml 5% dextrose at 1-8ml/hr (0.5-4mcg/kg/min)

CLINICAL PHARMACOLOGY: The principal pharmacological action of sodium nitroprusside is relaxation of vascular smooth muscle and consequent dilation of peripheral arteries and veins.

CONTRAINDICATIONS: 2. knownhypersensitivitytosodiumnitroprusside

Sodium Nitroprusside

Version 30/08/2010

379WARNINGS

Methaemoglobinaemia

Rare patients receiving more than 10mg/kg of sodium nitroprusside will develop methemoglobinemia Cyanide Poisoning Except when used briefly or at low (less than 2micrograms/kg/min) infusion rates, sodium nitroprusside can give rise to important quantities of cyanide ion, which can reach toxic, potentially lethal levels especially those with impaired renal function after prolonged, rapid infusions.

Excessive Hypotension

Sodium Nitroprusside can cause precipitous decreases in blood pressure. Because sodium nitroprusside’s hypotensive effect is very rapid in onset and in dissipation, small variations in infusion rate can lead to wide, undesirable variations in blood pressure.

PRECAUTIONS

General

Sodium nitroprusside may lead to severe hypotension in patients with haemodynamically significant aortic stenosis.

Laboratory Tests

No tests in addition to routine ICU tests are required

Drug/Laboratory Test Interactions

None of note

IMPORTANT DRUG INTERACTIONS FOR THE ICU Amplification of the vasodilatory effects of sodium nitroprusside by sildenafil can result in severe hypotension. Additive effects may be observed when sodium nitroprusside is combined with other antihypertensives

ADVERSE REACTIONS

Body as a Whole:

Allergic reactions

Cardiovascular System:

Tachycardia, hypotension, syncope, rebound hypertension, palpitations

Gastrointestinal System;

Nausea, vomiting, abdominal pain

Central Nervous System:

Headache

Haematological System:

Methemoglobinemia, thiocyanate toxicity