Source: Medicines & Healthcare Products Regulatory Agency (GB) Revision Year: 2018 Publisher: Amdipharm UK Limited, Capital House, 85 King William Street, London, EC4N 7BL, UK
Orally administered Hytrin is indicated in adults for the treatment of mild to moderate hypertension. It may be used in combination with thiazide diuretics and/or other antihypertensive drugs or as sole therapy where other agents are inappropriate or ineffective. The hypotensive effect is most pronounced on the diastolic pressure. Although the exact mechanism of the hypotensive action of terazosin is not established, the relaxation of peripheral blood vessels appears to be produced mainly by competitive antagonism of post-synaptic alpha-1-adrenoceptors. Hytrin usually produces an initial gradual decrease in blood pressure followed by a sustained antihypertensive action.
Orally administered Hytrin is also indicated in adults as a therapy for the symptomatic treatment of urinary obstruction caused by benign prostatic hyperplasia (BPH). Terazosin is a selective post synaptic alpha-1-adrenoceptor blocker. Antagonism of alpha-1-receptors on prostatic and urethral smooth muscle has been shown to improve urinary tract flow and relieve the urinary obstruction caused by BPH.
Hytrin Tablets are not recommended for use in children. Safety and efficacy in children has not been established.
Pharmacokinetic studies in the elderly indicate that no alteration in dosage recommendation is required.
Pharmacokinetic studies indicate that patients with impaired renal function need no alteration in the recommended dosages.
The terazosin dose should be titrated with particular caution in patients with impaired liver function since terazosin undergoes extensive hepatic metabolism and is mainly excreted by the biliary tract. As no clinical experience is available in patients with severe hepatic impairment, the use of terazosin is not recommended in these patients.
Postural hypotension has been reported to occur in patients receiving terazosin for the symptomatic treatment of urinary obstruction caused by BPH. In these cases, the incidence of postural hypotensive events was greater in patients aged 65 years and over (5.6%) than those aged less than 65 years (2.6%)
When adding a thiazide diuretic or another antihypertensive agent to a patient’s treatment regimen the dose of Hytrin should be reduced and retitration carried out if necessary. Caution should be observed when Hytrin is administered with thiazides or other antihypertensive agents as hypotension may develop.
Treatment should be initiated using the Starter Pack and response to treatment reviewed at four weeks.
If administration is discontinued for more than several days, therapy should be re-instituted using the initial dose titration regimen.
Initial dose: 1mg before bedtime is the starting dose for all patients and should not be exceeded. Compliance with this initial dosage recommendation should be strictly observed to minimise potential for acute first-dose hypotensive episodes.
Subsequent doses: The single daily dosage may be increased by approximately doubling the dosage at weekly intervals to achieve the desired blood pressure response.
The usual maintenance dose is 2mg to 10mg once daily. Doses over 20mg rarely improve efficacy and doses over 40mg have not been studied.
The dose of terazosin should be adjusted according to the patient’s response. The following is a guide to administration:
Initial dose: 1mg before bedtime is the starting dose for all patients and should not be exceeded. Strict compliance with this recommendation should be observed to minimise acute first-dose hypotensive episodes.
Subsequent dose: The dose may be increased by approximately doubling at weekly or bi-weekly intervals to achieve the desired reduction in symptoms. The maintenance dose is usually 5 to 10mg once daily. Improvements in symptoms have been detected as early as two weeks after starting treatment with terazosin.
At present there are insufficient data to suggest additional symptomatic relief with doses above 10mg once daily.
Transient side effects may occur at each titration step. If any side effects persist, consideration should be given to reducing the dose.
Acute hypotension.
Cardiovascular support is of first importance. Restoration of blood pressure and normalisation of heart rate may be accomplished by keeping the patient in a supine position. If this measure is inadequate, shock should first be treated with volume expanders and if necessary, vasopressors could then be used. Renal function should be monitored and general supportive measures applied as required. Dialysis may not be of benefit since laboratory data indicate that terazosin is highly protein bound.
36 months.
Do not store above 25°C.
Tablets in a blister pack. The 2mg tablets are supplied in a pack of 28 tablets. Blisters are packaged in a carton with a package insert.
Starter Pack for Hypertension: The 2mg tablets form part of a starter pack of 28 tablets which also contains 7 × 1mg tablets. Blisters are packaged in a carton with a package insert.
Starter pack for BPH: Tablets in a blister pack. The starter pack consists of 7 × 1mg, 14 × 2mg and 7 × 5mg tablets. The blisters, of PVC/PVdC, are heat sealed with 20 micron hard tempered aluminium foil and packaged in a carton with a pack insert.
No special requirements.
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