Details About Overdose or Poisoning Generic Salt :: Nitrite, Sodium And Amyl
Nitrite, Sodium and Amyl
Drug Pharmacology ::
I. Pharmacology. Sodiumnitrite injectable solution and amyl nitrite crushable ampules forinhalation are components of the cyanide antidote package. The value ofnitrites as an antidote to cyanide poisoning is twofold: They oxidizehemoglobin to methemoglobin, which binds free cyanide, and they mayenhance endothelial cyanide detoxification by producing vasodilation.Inhalation of an ampule of amyl nitrite produces a methemoglobin levelof about 5%. Intravenous administration of a single dose of sodiumnitrite is anticipated to produce a methemoglobin level of about 20–30%.
Drug Indications ::
Indications
Symptomaticcyanide poisoning (see Cyanide). Nitrites are not usually used forempiric treatment unless cyanide is suspected very strongly, and theyare not recommended for smoke inhalation victims.
Nitrites are possibly effective for hydrogen sulfide poisoning if given within 30 minutes of exposure (see Hydrogen Sulfide).
Drug Contra-Indications ::
III. Contraindications./b>
Significant preexisting methemoglobinemia (> 40%).
Severe hypotension is a relative contraindication as it may be worsened by nitrites.
Administrationto patients with concurrent carbon monoxide poisoning is a relativecontraindication; generation of methemoglobin may further compromiseoxygen transport to the tissues. Hydroxocobalamin (seeHydroxocobalamin) has supplanted the use of nitrites for smokeinhalation victims (patients often have mixed carbon monoxide andcyanide poisoning) in countries where it is available.
Drug Adverse Effects ::
IV. Adverse effects
Headache,facial flushing, dizziness, nausea, vomiting, tachycardia, and sweatingmay occur. These side effects may be masked by the symptoms of cyanidepoisoning.
Rapid intravenous administration may result in hypotension.
Excessive and potentially fatal methemoglobinemia may result.
Use in pregnancy. Noassigned FDA category. These agents may compromise blood flow andoxygen delivery to the fetus and may induce fetal methemoglobinemia.Fetal hemoglobin is more sensitive to the oxidant effects of nitrites.However, this does not preclude their acute, short-term use for aseriously symptomatic patient (see Table III–1).
Drug Lab Interactions ::
Drug or laboratory interactions
Hypotension may be exacerbated by the concurrent presence of alcohol or other vasodilators or any antihypertensive agent.
Methyleneblue should not be administered to a cyanide-poisoned patient becauseit may reverse nitrite-induced methemoglobinemia and theoreticallyresult in release of free cyanide ions. However, it may be consideredwhen severe and life-threatening excessive methemoglobinemia is present.
Binding of methemoglobin to cyanide (cyanomethemoglobin) may lower the measured free methemoglobin level.
Drug Dose Management ::
Dosage and method of administration
Amyl nitrite crushable ampules. Crushone to two ampules in gauze, cloth, or a sponge and place under thenose of the victim, who should inhale deeply for 30 seconds. Rest for30 seconds, then repeat. Each ampule lasts about 2–3 minutes. If thevictim is receiving respiratory support, place the ampules in thefacemask or port access to the endotracheal tube. Stop ampule use whenadministering intravenous sodium nitrite.
Sodium nitrite parenteral
1. Adults. Administer 300 mg of sodium nitrite (10 mL of 3% solution) IV over 3–5 minutes.
2. Children.Give 0.15–0.33 mL/kg to a maximum of 10 mL. Pediatric dosing should bebased on the hemoglobin concentration if it is known (see TableIII–12). If anemia is suspected or hypotension is present, start withthe lower dose, dilute in 50–100 mL of saline, and give over at least 5minutes.
3. Oxidationof hemoglobin to methemoglobin occurs within 30 minutes. If no responseto treatment occurs within 30 minutes, an additional half-size dose ofintravenous sodium nitrite may be given.
Drug Chemical Formulations ::
Formulations
Amyl nitrite. Acomponent of the cyanide antidote package, 0.3 mL in crushable ampules,12 per kit. The drug may also be acquired separately in Aspirols. Note: The ampules have a shelf life of only 1 year and may disappear because of the potential for abuse (as “poppers”).
Sodium nitrite parenteral. A component of the cyanide antidote package, 300 mg in 10 mL of sterile water (3%), two ampules per kit.
The suggested minimum stocking levelto treat a 70-kg adult for the first 24 hours is two cyanide antidotepackages or the equivalent (one package should be kept in the emergencydepartment). Available from Taylor Pharmaceuticals.
Table III–12. Pediatric Dosing of Sodium Nitrite Based on Hemoglobin Concentration
Hemoglobin (g/dL) Initial Dose (mg/kg) Initial Dose of 3% Sodium Nitrite (mL/kg) 75.80.1986.60.2297.50.25108.30.27119.10.312100.331310.80.361411.60.39
