Sodium Nitroprusside Dihydrate
Indications
Sodium Nitroprusside Dihydrate is used for:
Heart failure, Severe hypertension, Hypertensive crises
Adult Dose
Intravenous
Hypertensive crisis
Adult: For patients not receiving any antihypertensives, initially 0.3-1.5 mcg/kg/min, adjust gradually according to response. Usual range 0.5-6 mcg/kg/min. Lower doses should be used in patients receiving antihypertensives. Max rate: 8 mcg/kg/min, discontinue infusion if there is no response after 10 min. May continue for a few hr if there is response. Introduce oral antihypertensive as soon as possible.
Elderly: Lower doses may be required.
Induction of hypotension during anaesthesia
Adult: Recommended max dose: 1.5 mcg/kg/min.
Heart failure
Adult: Intially 10-15 mcg/min, may increase by 10-15 mcg/min every 5-10 min according to response; usual range 10-200 mcg/min. Max: 280 mcg/min.
Child Dose
Intravenous
Hypertensive crisis
Child: Initially, 250-500 nanograms/kg/min, rate may be repeatedly doubled at intervals of 15-20 min until the desired effect is achieved or treatment is judged ineffective. Max rate: 6 mcg/kg/min.
Renal Dose
Renal impairment: Dosage adjustments may be necessary.
Administration
Contra Indications
Hypersensitivity, compensatory hypertension.
Precautions
Hypothyroidism, renal and hepatic impairment, ischaemic heart disease, impaired cerebral circulation, elderly. Monitor blood thiocyanate concentration if treatment is longer than 3 days and should not exceed 100 mcg/ml. Monitor acid-base balance, venous oxygen concentration and BP. Caution to avoid extravasation. To be diluted with sterile dextrose 5% solution before infusion. Avoid sudden withdrawal. Leber's optic atrophy, low plasma-cobalamin concentrations, impaired pulmonary function. Pregnancy and lactation.
Pregnancy-Lactation
Pregnancy Category: C
Lactation: not known if distributed into milk
Interactions
Additive effect when used with other antihypertensives. May prolong the fibrinolytic activity of alteplase. Risk of severe hypotension if used with phosphodiesterase inhibitors. May reduce serum digoxin levels.
Adverse Effects
Side effects of Sodium Nitroprusside Dihydrate :
Common
Bradyarrhythmia, hypotension, palpitations, tachyarrhythmia
Apprehension, restlessness, confusion, dizziness, headache, somnolence
Rash, sweating
Thyroid suppression, Injection site irritation, Muscle twitch, Oliguria, renal azotemia
Serious
Cardiac dysrhythmia, hemorrhage, decreased platelet aggregation, excessive hypotensive response
Raised intracranial pressure, Metabolic acidosis, Bowel obstruction, Methemoglobinemia, Cyanide poisoning, Thiocyanate toxicity
Mechanism of Action
Sodium nitroprusside is a short-acting antihypertensive that acts directly on the venous and arteriolar smooth muscle causing peripheral vasodilation, thus decreasing peripheral resistance. It is also used to reduce preload and afterload in severe heart failure.