Adult: Initially, 10 mg once daily or bid, gradually increased daily by 10 mg increments, according to patient’s response. Maintenance: 1-2 mg/kg daily in 2 divided doses. Child: 1-2 mg/kg daily. Elderly: 10 mg daily.
Chống chỉ định
CVA, recovery period (usually 3-4 weeks) after acute MI, conditions where a decrease in blood pressure may be undesirable (e.g. coronary artery disease, stroke).
Patient with heart failure, CHF, cerebrovascular diseases, cerebral or coronary atherosclerosis, respiratory infections. Renal impairment. Elderly. Children. Pregnancy and lactation.
Phản ứng phụ
Significant: Postural hypotension with dizziness, compensatory tachycardia. Eye disorders: Miosis. Gastrointestinal disorders: Gastrointestinal upset. General disorders and admininistration site conditions: Fatigue. Psychiatric disorders: Drowsiness. Reproductive system and breast disorders: Inhibition of ejaculation. Respiratory, thoracic and mediastinal disorders: Nasal congestion.
This drug may cause dizziness and drowsiness, if affected, do not drive or operate machinery.
Regularly monitor blood pressure especially after each dose adjustment; pulse, orthostatics.
Symptoms: Profound hypotension leading to dizziness or fainting, tachycardia, collapse, vomiting, lethargy, shock. Management: Symptomatic and supportive treatment. Induce vomiting and/or gastric lavage. Treat hypotension with plasma expanders and by postural measures.
Increased hypotensive effect and tachycardia with stimulators of both α- and β-receptors (e.g. epinephrine).
Description: Phenoxybenzamine covalently binds to α-receptors causing long lasting non-competitive inhibition of postganglionic synapses thus blocking the effects of epinephrine and norepinephrine at α1 and α2 receptors causing arterial and venous vasodilation and reflex tachycardia. Onset: Within 2 hr. Duration: ≥3-4 days. Pharmacokinetics: Absorption: Incompletely and variably absorbed from the gastrointestinal tract. Bioavailability: 20-30%. Distribution: Distributed and accumulates in the adipose tissues. Metabolism: Metabolised in the liver via dealkylation into N-phenoxyisopropyl-benzylamine. Excretion: Mainly via urine and bile. Elimination half-life: Approx 24 hour.
Store between 20-25°C.
Avoid contact with skin or mucous membranes by wearing gloves and protective equipment. Wash hands before and after handling.
C04AX02 - phenoxybenzamine ; Belongs to the class of other peripheral vasodilators.
Anon. Phenoxybenzamine. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 31/10/2017.Buckingham R (ed). Phenoxybenzamine Hydrochloride. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 18/10/2017.Joint Formulary Committee. Phenoxybenzamine Hydrochloride. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 18/10/2017.McEvoy GK, Snow EK, Miller J et al (eds). Phenoxybenzamine Hydrochloride. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 18/10/2017.Phenoxybenzamine Hydrochloride Capsule (West-Ward Pharmaceuticals Corp.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 31/10/2017.