Ephedrine

Ephedrine: Uses, Dosage and Side Effects

Overview

• Non-catecholamine sympathomimetic directly activates alpha- and beta-adrenergic receptors and indirectly releases noradrenaline.
• also causes bladder relaxation and internal urethral sphincter contraction.
• Compared with more powerful sympathomimetics, e.g. oxymetazoline and xylometazoline, there is less of a rebound effect.

Uses of Ephedrine

• Treatment of hypotension during anaesthesia.
• Also used orally in the treatment of urinary incontinence.
• Proposed for treatment of nasal congestion.
• Use with caution in dogs and cats with cardiovascular disease, partial urethral obstruction, hypertension, diabetes mellitus, hyperadrenocorticism, hyperthyroidism or other metabolic disorders.

Dose of Ephedrine in Dogs and Cats

Dogs:

• Hypotension: 0.05–0.2 mg/kg i.v.; repeat as necessary; duration of effect is short (5–15 min). Effects tend to wane after 2–3 doses have been administered.
• Urinary incontinence: 1 mg/kg p.o. q12h. The dose should be adjusted according to effect but there is a maximum dose of 2.5 mg/kg p.o. q12h.
• Nasal congestion: No dose determined. Suggest starting at 1 drop of 0.5% solution intranasally q12h. If given orally, suggest 0.5 mg/kg p.o. q12h.

Cats:

• Hypotension: 0.05–0.1 mg/kg i.v.; repeat as necessary; duration of effect is short (5–15 min). Effects tend to wane after 2–3 doses have been administered.
• Nasal congestion: 1 drop of 0.5% solution intranasally q12h. Oral formulations are not convenient for administration to most cats.

Side Effects of Ephedrine in Dogs and Cats

• (panting, mydriasis, CNS stimulation) and cardiovascular effects (tachycardia, atrial fibrillation, vasoconstriction) are possible.
• Also has the potential to reduce the motility and tone of the intestinal mucosa.

Contraindications of Ephedrine in Dogs and Cats

• Do not use it in pregnant or lactating patients or those with glaucoma.

Some Notes:

• Synergistic with other sympathomimetic.
• Volatile anaesthetics will enhance the sensitivity of the myocardium to the effects of ephedrine.
• Concomitant use with cardiac glycosides (digoxin) and tricyclic antidepressants (amitriptyline) can cause arrhythmias.
• Will enhance the effects of theophylline and may cause hypertension when given with MAO inhibitors (e.g. selegeline).