EPHEDRINE HYDROCHLORIDE

EPHEDRINE HYDROCHLORIDE (e-fed'rin) Efedron EPHEDRINE SULFATE Ectasule, Ephedsol, Vatronol Classifications: alpha- and beta-adrenergic agonist; bronchodilator; Therapeutic: bronchodilator Prototype: Epinephrine HCl Pregnancy Category: C

Availability

25 mg capsules; 50 mg/mL injection; 0.25% nasal spray; 1% nasal gel

Action

Both indirect- and direct-acting sympathomimetic amine. Thought to act indirectly by releasing tissue stores of norepinephrine and directly by stimulation of alpha-, beta₁-, and beta₂-adrenergic receptors. Like epinephrine, contracts dilated arterioles of nasal mucosa, thus reducing engorgement and edema and facilitating ventilation and drainage.

Therapeutic Effect

Ephedrine relaxes bronchial smooth muscle by the stimulation of beta₂-receptors, relieving mild bronchospasm, improving air exchange and increasing vital capacity.

Uses

Temporary relief of congestion of hay fever, allergic rhinitis, and sinusitis; and in treatment and prophylaxis of mild cases of acute asthma and in patients with chronic asthma requiring continuing treatment. Also has been used for its CNS stimulant actions in treatment of narcolepsy, to improve respiration in narcotic and barbiturate poisoning, to combat hypotensive states, especially those associated with spinal anesthesia; in management of enuresis or impaired bladder control; as adjunct in treatment of myasthenia gravis; as mydriatic; to relieve dysmenorrhea; and for temporary support of ventricular rate in Adams-Stokes syndrome; for peripheral edema secondary to type I diabetic neuropathy.

Contraindications

History of hypersensitivity to ephedrine or other sympathomimetics; narrow-angle glaucoma; angina pectoris, coronary insufficiency, chronic heart disease, uncontrolled hypertension, cardiac arrhythmias, cardiomyopathy; hypovolemia; concurrent MAOI therapy; pregnancy (category C), lactation.

Cautious Use

Hypertension, arteriosclerosis, closed-angle glaucoma; diabetes mellitus; hyperthyroidism; prostatic hypertrophy.

Route & Dosage

Bronchodilator, Nasal Decongestant Adult: PO 25–50 mg q3–4h prn (max: 150 mg/24 h) IM/IV/SC 12.5–25 mg Child: PO >2 y, 2–3 mg/kg/d in 4–6 divided doses; 6–12 y, 6.25–12.5 mg q4h (max: 75 mg/24 h) Hypotension Adult: PO 25 mg 1–4 times/d (max: 150 mg/24 h) IM/SC/IV 10–50 mg IM/SC or 10–25 mg slow IV, may repeat in 5–10 min if necessary (max: 150 mg/24 h) Child: PO/IM/SC/IV 3 mg/kg/d in 4–6 divided doses (max: 75 mg/24 h) Myasthenia Gravis Adult: PO 25 mg t.i.d. or q.i.d. Enuresis Adult: PO 25 mg h.s. Urinary Incontinence Geriatric: PO 25–50 mg q6h. Nasal Decongestant Adult: Intranasal 2–4 drops or a small amount of jelly in each nostril no more than q.i.d. for 3–4 consecutive days

Administration

Oral

• Administer last dose a few hours before bedtime, if possible, to minimize insomnia.
• Store at 15°–30° C (59°–86° F) in tightly closed, light-resistant containers unless otherwise directed by the manufacturer.

Intranasal

• Have patient clear nose before instilling drops. Instruct patient to blow gently with both nostrils open. Generally, nose drops are instilled with head in lateral, head-low position to avoid entry of drug into throat. Check with physician.

Intravenous PREPARE: Direct: Give undiluted.   ADMINISTER: Direct: Direct IV at a rate of 10 mg or fraction thereof over 30–60 sec.   INCOMPATIBILITIES Solution/additive: Hydrocortisone, pentobarbital, phenobarbital, secobarbital, thiopental. Y-site: Thiopental.

• Store in tightly closed, light-resistant containers. Do not use liquid formulation unless it is absolutely clear.

Adverse Effects (≥1%)

CNS: Headache, insomnia, nervousness, anxiety, tremulousness, giddiness. CV: Palpitation, tachycardia, precordial pain, cardiac arrhythmias. GU: Difficult or painful urination, acute urinary retention (especially older men with prostatism). GI: Nausea, vomiting, anorexia. Body as a Whole: Sweating, thirst, overdosage: euphoria, confusion, delirium, convulsions, pyrexia, hypertension, rebound hypotension, respiratory difficulty. Skin: Fixed-drug eruption. Topical use: burning, stinging, dryness of nasal mucosa, sneezing, rebound congestion.

Diagnostic Test Interference

Ephedrine is generally withdrawn at least 12 h before sensitivity tests are made to prevent false-positive reactions.

Interactions

Drug: mao inhibitors, tricyclic antidepressants, furazolidone, guanethidine may increase alpha-adrenergic effects (headache, hyperpyrexia, hypertension); sodium bicarbonate decreases renal elimination of ephedrine, increasing its CNS effects; epinephrine, norepinephrine compound sympathomimetic effects; effects of alpha and beta blockers and ephedrine antagonized.

Pharmacokinetics

Absorption: Readily absorbed from GI tract. Peak: 15 min–1 h. Duration: Bronchodilation 2–4 h; cardiac & pressor effects up to 4 h PO and 1 h IV. Distribution: Widely distributed; crosses blood–brain barrier and placenta; distributed into breast milk. Metabolism: Small amounts metabolized in liver. Elimination: In urine. Half-Life: 3–6 h.

Nursing Implications

Assessment & Drug Effects

• Supervise continuously patients receiving ephedrine IV. Take baseline BP and other vital signs. Check BP repeatedly during first 5 min, then q3–5min until stabilized.
• Monitor I&O ratio and pattern, especially in older male patients. Encourage patient to void before taking medication (see ADVERSE EFFECTS).
• Monitor for systemic effects of nose drops that can occur because of excessive dosage from rapid absorption of drug solution through nasal mucosa. This is most likely to occur in older adults.

Patient & Family Education

• Note: Ephedrine is a commonly abused drug. Learn adverse effects and dangers; take medication ONLY as prescribed.
• Do not take OTC medications for coughs, colds, allergies, or asthma unless approved by physician. Ephedrine is a common ingredient in these preparations.

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Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug