Sodium nitroprusside in 2014: A clinical concepts review

Abstract

Sodium nitroprusside has been used in clinical practice as an arterial and venous vasodilator for 40 years. This prodrug reacts with physiologic sulfhydryl groups to release nitric oxide, causing rapid vasodilation, and acutely lowering blood pressure. It is used clinically in cardiac surgery, hypertensive crises, heart failure, vascular surgery, pediatric surgery, and other acute hemodynamic applications. In some practices, newer agents have replaced nitroprusside, either because they are more effective or because they have a more favorable side-effect profile. However, valid and adequately-powered efficacy studies are sparse and do not identify a superior agent for all indications. The cyanide anion release concurrent with nitroprusside administration is associated with potential cyanide accumulation and severe toxicity. Agents to ameliorate the untoward effects of cyanide are limited by various problems in their practicality and effectiveness. A new orally bioavailable antidote is sodium sulfanegen, which shows promise in reversing this toxicity. The unique effectiveness of nitroprusside as a titratable agent capable of rapid blood pressure control will likely maintain its utilization in clinical practice for the foreseeable future. Additional research will refine and perhaps expand indications for nitroprusside, while parallel investigation continues to develop effective antidotes for cyanide poisoning.

The Role of Nitroglycerin and Other Nitrogen Oxides in Cardiovascular Therapeutics

“…There are several antidotes available to treat cyanide toxicity, including sodium thiosulfate, sodium nitrite, amyl nitrite, and hydroxycobalamin, as well as potential antidotes that are undergoing development, such as sulfanegen sodium. Sodium thiosulfate is available intravenously, and by increasing thiosulfate concentration in plasma, acts as a sulfur donor to rhodanase, an enzyme that transforms cyanide to thiocyanate, which is non-toxic (164). Intravenous sodium nitrite and inhaled amyl nitrite are methemoglobin generators, and methemoglobin’s strong affinity for cyanide binding is the rationale for their use as antidotes (165).…”

“…Hydroxycobalamin is a vitamin B derivative that is available intravenously and contains a cobalt moiety that avidly binds to intracellular cyanide forming cyanocobalamin (165–167). Sulfanegen sodium is a prodrug of 3-mercaptopyruvate that converts cyanide to thiocyanate (164,168). It was shown to be effective in reversing cyanide toxicity in a juvenile pig model, but work is ongoing to develop it into a antidote that is safe for use in humans (169).…”

The cyclic GMP/protein kinase G pathway as a therapeutic target in head and neck squamous cell carcinoma

“…For example, selective PDE5 inhibitors such as Tadalafil (Cialis), Sildenafil (Viagra) and Vardenafil (Levitra) are used to treat erectile dysfunction [15]. Sodium nitroprusside (SNP), a nitric oxide donor, is used as an acute vasodilator [16], while Riociguat, an NO-independent sGC stimulator, is approved for the treatment of pulmonary hypertension [17]. There is significant potential for repurposing these drugs as antineoplastic agents in many cancers.…”

Effect of Hydroalcoholic Extract of Ribes khorasanicum on Acute Hypertension Induced by L-NAME in Rat

“…SNP is an antihypertensive drug that by an increased in the release of nitric oxide, relaxed smooth muscle of vessels and reduces blood pressure [18, 19]. In this study pretreatment of SNP significantly attenuate the effect of L-NAME on SBP and MAP.…”