Nitroprusside
Synonyms :
Nitroferricyanide, Sodium Nitroprusside
Mechanism :
Peripheral vasodilation by direct action on venous and arteriolar smooth muscle thus reducing peripheral resistance; will increase cardiac output by decreasing afterload, reduces aortal and left ventricular impedance.
Indication :
- Management of hypertensive crisis
- CHF
- Controlled hypotension during surgery
- Angina
Contraindications :
Hypersensitivity, Decreased cerebral perfusion, Arteriovenous shunt or coarctation of aorta.
Dosing :
IV continuous infusion: Start 0.3-0.5 mcg/kg/min titrate upwards (usual dose: 3 mcg/kg/min, maximum dose 8-10 mcg/kg/min).
Adverse Effect :
Excessive hypotension, palpitations, substernal distress, tachyarrhythmia, restlessness, disorientation, psychosis, headache, elevated intracranial pressure, thyroid suppression, metabolic acidosis, nausea, vomiting, bowel obstruction, thiocyanate toxicity, neuromuscular & skeletal weakness, muscle twitch, diaphoresis, cyanide toxicity, rash, injection site irritation, oliguria, azotemia.
Interaction :
Alteplase: IV nitroglycerin may decrease the effect of alteplase.
Avanafil: Additive vasodilation. Concomitant therapy is contraindicated.
Azilsartan medoxomil: Pharmacodynamic synergist- increases effects.
Dihydroergotamine: Possible antagonism of action.
Ergonovine: Possible antagonism of action.
Ergotamine: Possible antagonism of action.
Methylergometrine: Possible antagonism of action.
Methysergide: Possible antagonism of action.
Sildenafil: Possible significant hypotension with this combination.
Tadalafil: The vasodilatory effects of Nitroglycerin may be increased by Tadalafil. Severe hypotension may occur. Concomitant therapy is contraindicated.
Treprostinil: Additive hypotensive effect. Monitor antihypertensive therapy during concomitant use.
Udenafil: The vasodilatory effects of Nitroglycerin may be increased by Udenafil. Severe hypotension may occur. Concomitant therapy is contraindicated.
Vardenafil: The vasodilatory effects of Nitroglycerin may be increased by Vardenafil. Severe hypotension may occur. Concomitant therapy is contraindicated.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function. Avoid prolonged use |
| <10 | Dose as in normal renal function. Avoid prolonged use |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Dialysed. Dose as in GFR<10 mL/min |
| HD | Dialysed. Dose as in GFR<10 mL/min |
| HDF/High flux | Dialysed. Dose as in GFR<10 mL/min |
| CAV/VVHD | Unknown dialysability. Dose as in GFR=10–20 mL/min |
Hepatic Dose :
Nitroprusside is metabolized in the liver so use with caution. Since cyanide is metabolized by hepatic enzymes, it may accumulate in patients with severe hepatic impairment.