Preparations Acting on the Prostate
= Additional active ingredients
Phenoxybenzamine HCl 10 mg.
PRESENTATION AND DOSSAGE
CAPS: 30 X 10 mg
Pheochromocytoma, urinary retention, Benign Prostatic Hypertrophy (BPH) and neurogenic bladder.
Phenoxybenzamine should not be used in patients who have had a cerebrovascular accident; or in the recovery period (usually 3-4 weeks) after acute myocardial infarction.
Phenoxybenzamine should be used with great caution in patients in whom a fall in blood pressure and/or tachycardia may be undesirable, such as the elderly or those with severe heart disease, congestive heart failure, cerebrovascular disease or renal damage. The mode of action should be borne in mind, if used concurrently with α- sympatho-mimetics or myocardial depressants. Phenoxybenzamine is carcinogenic in the rat and has shown mutagenic activity in the bacterial Ames test and mouse lymphoma assay. It should only be used after very careful consideration of the risks, in patients in whom alternative treatment is inappropriate.
Side effects are generally mild and transient, but may include postural hypotension with dizziness and compensatory tachycardia, nasal congestion, inhibition of ejaculation, miosis and lassitude. Gastrointestinal upset has also been reported.
See under Special Precautions and Warnings.
Adults: The usual starting dose is 10 mg daily. This may be increased by 10 mg daily until control of hypertensive episodes is achieved, or postural hypotension occurs. Usually the dosage required is 1-2 mg/kg body weight split into 2 doses. Concomitant beta-adrenergic blockade may be necessary to control tachycardia and arrythmias notably when tumours are secreting an appreciable amount of adrenaline as well as noradrenaline.
Elderly: Use with caution, 10 mg daily dose should be sufficient.
Children: There is little experience in children but, doses of 1 to 2 mg/kg daily have been used successfully.
The main effect of overdosage is profound hypotension, which may last several hours, tachycardia and collapse. Treatment consists of the induction of vomiting and/or gastric lavage together with appropriate symptomatic and supportive measures. Hypotension should be treated with plasma expanders and placing the patient in the “head down” position. Noradrenaline is of little value when α-adrenergic receptors are blocked. Adrenaline should not be used since stimulation of β-adrenergic receptors will further increase blood pressure.
PREGNANCY & LACTATION
There is little evidence of safety of Dibenyline in pregnancy and it should not be used in pregnancy or during breastfeeding unless essential.
MANUFACTURER & DISTRIBUTER:
Manufacturer: Goldshield Pharmaceuticals Ltd., UK
License Holder: Rafa Laboratories Ltd.