Amyl nitrite

PHARMACOLOGIC CATEGORY
Antidote
Vasodilator

DOSING: ADULTS
Angina: Inhalation: 1-6 inhalations from 1 crushed ampul; may repeat in 3-5 minutes

Cyanide poisoning: Inhalation: Inhale the vapor from a 0.3 mL crushed ampul every minute for 15-30 seconds until I.V. sodium nitrite infusion is available

DOSING: ELDERLY — Refer to adult dosing.

DOSAGE FORMS — Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Vapor for inhalation [crushable covered glass capsules]: Amyl nitrite USP (0.3 mL)

DOSAGE FORMS: CONCISE
Vapor for inhalation [crushable covered glass capsules]: Amyl nitrite USP (0.3 mL)

GENERIC EQUIVALENT AVAILABLE — Yes

ADMINISTRATION — Administer nasally. Patient should not be sitting. Crush ampul in woven covering between fingers and then hold under patient's nostrils.

USE — Coronary vasodilator in angina pectoris; adjunct in treatment of cyanide poisoning; produce changes in the intensity of heart murmurs

ADVERSE REACTIONS SIGNIFICANT — Frequency not defined.

Cardiovascular: Postural hypotension, cutaneous flushing of head, neck, and clavicular area, palpitations, tachycardia, sinus tachycardia, vasodilation

Central nervous system: Headache, incoherent speech, restlessness

Dermatologic: Contact dermatitis

Gastrointestinal: Nausea, colitis, vomiting

Genitourinary: Penile erection enhanced, retarded ejaculation

Hematologic: Heinz body hemolysis/hemolytic anemia

Ocular: Increased intraocular pressure, blurred vision

Respiratory: Tracheobronchitis

CONTRAINDICATIONS — Hypersensitivity to nitrates; severe anemia; head injury; angle-closure glaucoma; postural hypotension; head trauma or cerebral hemorrhage; pregnancy

WARNINGS / PRECAUTIONS
Disease-related concerns: Cardiovascular disease: Use with caution in patients with coronary artery disease and patients with hypotension. Increased intracranial pressure: Use with caution in patients with increased intracranial pressure.

Special populations: Pediatrics: Safety and efficacy have not been established in children.

DRUG INTERACTIONS — There are no known significant interactions.

PREGNANCY RISK FACTOR — C (show table)

LACTATION — Excretion in breast milk unknown/not recommended

MONITORING PARAMETERS — Monitor blood pressure during therapy

INTERNATIONAL BRAND NAMES — Amyl Nitrite (NZ)

MECHANISM OF ACTION — Relaxes vascular smooth muscle; decreased venous ratios and arterial blood pressure; reduces left ventricular work; decreases myocardial O2 consumption; in cyanide poisoning, amyl nitrite converts hemoglobin to methemoglobin that binds with cyanide to form cyanate hemoglobin

PHARMACODYNAMICS / KINETICS
Onset of action: Angina: Within 30 seconds

Duration: 3-15 minutes

PATIENT INFORMATION — Lie down during administration. Crush ampul between fingers and then inhale through nostrils. May cause dizziness. Call paramedics or have someone take you to the hospital immediately if pain is not relieved after 3 doses.