Drug information of Amyl Nitrite


Amyl Nitrite

Drug group:

Amyl Nitrite is an antihypertensive medicine. Amyl nitrite is employed medically to treat heart diseases such as angina and to treat cyanide poisoning.

Mechanism of effect

Amyl nitrite's antianginal action is thought to be the result of a reduction in systemic and pulmonary arterial pressure (afterload) and decreased cardiac output because of peripheral vasodilation, rather than coronary artery dilation.

Amyl nitrite is a source of nitric acid, which accounts for the mechanism described above. As an antidote (to cyanide poisoning), amyl nitrite promotes formation of methemoglobin, which combines with cyanide to form nontoxic cyanmethemoglobin.

Pharmacodynamic

Amyl nitrite, in common with other alkyl nitrites, is a potent vasodilator. It expands blood vessels, resulting in lowering of the blood pressure. Alkyl nitrite functions as a source of nitric oxide, which signals for relaxation of the involuntary muscles.

Physical effects include decrease in blood pressure, headache, flushing of the face, increased heart rate, dizziness, and relaxation of involuntary muscles, especially the blood vessel walls and the anal sphincter. There are no withdrawal symptoms.

Pharmacokinetics

  • Onset: 10-30 sec
  • Duration: 3-15 min (angina)
  • Peak: 3 min

Dosage

Adult

Acute Relief of Angina

0.3 mL by inhalation of crushed ampule, may repeat q3-5min

Wave crushed ampule under nose multiple times for 2-6 nasal inhalations

Cyanide Poisoning

0.3 mL ampule crushed and contents poured onto a gauze and placed in front of patient's mouth or endotracheal tube, if patient intubated, to inhale over 15-30 sec; repeat qMin until IV sodium nitrite available

Each ampul lasts ~3 min; separate administration by at least 30 sec to allow patient to adequate oxygenate

Pediatric

Angina Pectoris

Safety & efficacy not established

Cyanide Poisoning (Off-label)

0.3 mL ampule crushed and contents poured onto a gauze and placed in front of patient's mouth or endotracheal tube if patient intubated to inhale over 15-30 sec; repeat qMin until IV sodium nitrite available

Each ampul lasts ~3 min; separate administration by at least 30 sec to allow patient to adequate oxygenate

Drug contraindications

severe anemia

Alerts

  • AMI, alcohol use, hyperthyroidism, cardiomyopathy, incr ICP (eg, head, trauma, cerebral hemorrhage-potential contraindication), incr IOP, postural hypotension, volume depletion, low systolic BP
  • Inability to relieve chest pain after 3 doses may mean AMI-rush to ER if possible
  • Withdraw gradually to avoid acute angina
  • Patient should be sitting down during & immediately after inhaling
  • Do not change brands unintentionally as not all are bioequivalent
  • Treat drug-induced headache with aspirin or acetaminophen
  • Provide nitrate-free interval (10-12 hr or overnight) to avoid development of tolerance
  • Protect from light

Points of recommendation

  • To lower the chance of feeling dizzy or passing out, rise slowly if you have been sitting or lying down. Be careful going up and down stairs.
  • Talk with your doctor before you drink alcohol.
  • If you have been taking amyl nitrite for a long time or at high doses, it may not work as well and you may need higher doses to get the same effect. This is known as tolerance. Call your doctor if amyl nitrite stops working well. Do not take more than ordered.
  • This medicine may catch on fire. Do not use near an open flame or while smoking.
  • This medicine may cause harm to the unborn baby if you take it while you are pregnant. If you are pregnant or you get pregnant while taking amyl nitrite, call your doctor right away.
  • Tell your doctor if you are breast-feeding. You will need to talk about any risks to your baby.

Pregnancy level

C


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