페녹시벤자민

동물 종별 용량

투여 경로

금기

• Conditions where hypotension is undesirable (e.g., shock, unless fluid replacement is adequate)
• Horses with clinical signs of colic
• Glaucoma (relative contraindication)
• Diabetes mellitus (relative contraindication)

이상반응

• Hypotension (postural/orthostatic)
• Hypertension (rebound)
• Miosis
• Increased intraocular pressure
• Tachycardia (reflex)
• Sodium retention
• Inhibition of ejaculation
• Nasal congestion
• Weakness or dizziness
• Gastrointestinal effects (nausea, vomiting)
• Constipation (specifically noted in horses)
• Hypotension
• Tachycardia

약물 상호작용

• Epinephrine · Epinephrine reversal: If used with drugs that have both alpha- and beta-adrenergic effects, increased hypotension, vasodilation, or tachycardia may result due to unopposed beta effects.
• Phenylephrine · Phenoxybenzamine will antagonize the effects of alpha-adrenergic sympathomimetic agents.
• Reserpine · Phenoxybenzamine can antagonize the hypothermic effects of reserpine.
• Beta-blockers · Increased risk of first dose hypotensive effect; if used for phaeochromocytoma, beta-blockers must only be started after alpha blockade is in place to avoid hypertensive crisis. · major
• Diuretics · Increased risk of first dose hypotensive effect. · moderate
• Alpha-adrenergic sympathomimetics (e.g., phenylephrine) · Phenoxybenzamine will antagonize the effects of these agents. · major

모니터링

• Clinical efficacy (e.g., adequate urination, ease of voiding)
• Blood pressure (monitor for hypotension)
• Heart rate (monitor for reflex tachycardia)
• Blood pressure
• Heart rate and rhythm
• Urine output and ease of urination

과용량

Overdosage may yield signs of **postural hypotension** (dizziness, syncope), tachycardia, vomiting, lethargy, or shock. **Treatment**: - Empty the gut if ingestion was recent and there are no contraindications. - Treat hypotension with aggressive intravenous fluid support. - **DO NOT USE EPINEPHRINE** (causes paradoxical further drop in blood pressure due to unopposed beta-adrenergic vasodilation). - Most standard vasopressors are ineffective due to the alpha-blockade. Intravenous norepinephrine (levarterenol) may be beneficial if clinical signs are severe.