RITEMED Terazosin Hydrochloride Dihydrate 2mg Tablet 30's
RXDRUG-DRP-5057-02
Discreet Packaging
FDA-registered Products
FDA-licensed Pharmacies
Indications/Uses
Terazosin tablets are indicated for: The treatment of mild to moderate hypertension; The symptomatic treatment of urinary obstruction caused by benign prostatic hyperplasia (BPH).
Dosage/Direction for Use
Adults: For the treatment of hypertension: The dose of terazosin should be managed according to each patient's response. For the different dosage regimens, suitable strengths are available.
The starting dose for all patients is 1 mg before bedtime and this should not be exceeded during the first week of treatment. Patients should be advised to comply in order to avoid first-dose hypotensive effect. The dose can be increased by approximately doubling the dose at weekly intervals until effective control of blood pressure is established.
The usual maintenance dose is 2 mg daily. However, for certain patients, an increased dose may become necessary. A maximum dose of 20 mg should not be exceeded. Reduction of dose should be undertaken when adding other antihypertensive medication followed by re-titration if required.
For the symptomatic treatment of urinary obstruction caused by BPH: The dose of terazosin should be managed according to each patient's response.
Patients should be advised to comply in order to avoid first-dose hypotensive effect.
The starting dose for all patients is 1 mg at night-time for 7 days and this should not be exceeded during the first week of treatment. The dose can then be increased to 2 mg daily for 14 days, followed by 5 mg daily for 7 days. Response to treatment must be reviewed at four weeks. Transient side effects may occur at each titration step. If any side effects persist, consideration should be given to reducing the dose.
The usual recommended dose is 5 mg once daily. The maximum daily dose is 10 mg.
Terazosin therapy of hypertension is a long-term treatment, which should only be interrupted on medical advice. If it is necessary to stop terazosin therapy, the dose should be re-titrated starting with 1 mg terazosin at bedtime.
Use in patients with impaired renal function or the elderly: In general, terazosin should not be used in patients with a reduced urinary outflow or anuria or an advanced renal deficiency.
No dosage adjustments are required in the elderly.
Use in patients with hepatic impairment: 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 dysfunction, the use of terazosin is not recommended in these patients.
Use in children and adolescents: There are no reports regarding the efficacy and safety of the medicinal product in children and adolescents under the age of 18 years. Therefore, the use of terazosin is not recommended for this group.
Method of administration: Terazosin tablets should be swallowed whole and not chewed and can be taken with or without food.
The starting dose for all patients is 1 mg before bedtime and this should not be exceeded during the first week of treatment. Patients should be advised to comply in order to avoid first-dose hypotensive effect. The dose can be increased by approximately doubling the dose at weekly intervals until effective control of blood pressure is established.
The usual maintenance dose is 2 mg daily. However, for certain patients, an increased dose may become necessary. A maximum dose of 20 mg should not be exceeded. Reduction of dose should be undertaken when adding other antihypertensive medication followed by re-titration if required.
For the symptomatic treatment of urinary obstruction caused by BPH: The dose of terazosin should be managed according to each patient's response.
Patients should be advised to comply in order to avoid first-dose hypotensive effect.
The starting dose for all patients is 1 mg at night-time for 7 days and this should not be exceeded during the first week of treatment. The dose can then be increased to 2 mg daily for 14 days, followed by 5 mg daily for 7 days. Response to treatment must be reviewed at four weeks. Transient side effects may occur at each titration step. If any side effects persist, consideration should be given to reducing the dose.
The usual recommended dose is 5 mg once daily. The maximum daily dose is 10 mg.
Terazosin therapy of hypertension is a long-term treatment, which should only be interrupted on medical advice. If it is necessary to stop terazosin therapy, the dose should be re-titrated starting with 1 mg terazosin at bedtime.
Use in patients with impaired renal function or the elderly: In general, terazosin should not be used in patients with a reduced urinary outflow or anuria or an advanced renal deficiency.
No dosage adjustments are required in the elderly.
Use in patients with hepatic impairment: 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 dysfunction, the use of terazosin is not recommended in these patients.
Use in children and adolescents: There are no reports regarding the efficacy and safety of the medicinal product in children and adolescents under the age of 18 years. Therefore, the use of terazosin is not recommended for this group.
Method of administration: Terazosin tablets should be swallowed whole and not chewed and can be taken with or without food.
Overdosage
Should administration of terazosin lead to 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.
Administration
May be taken with or without food: Swallow whole, do not chew.
Contraindications
Hypersensitivity to terazosin, or to a structurally similar alpha-adrenergic antagonist or to any of the excipients.
Special Precautions
As with other alpha adrenoreceptor antagonists, terazosin is not recommended in patients with a history of micturition syncope.
Terazosin, in common with other alpha-adrenoreceptor antagonists, may cause syncope. Syncopal episodes have occurred within 30 to 90 minutes of the initial dose of the drug. Syncope has occasionally occurred in association with rapid dosage increases or the introduction of another antihypertensive agent.
In clinical studies in hypertension, the incidence of syncopal episodes was approximately one percent. In most cases, this was believed to be due to an excessive postural hypotensive effect although occasionally the syncopal episode has been preceded by a bout of tachycardia with heart rates of 120 to 160 beats per minute. If syncope occurs, the patient should be placed in a recumbent position and given supportive treatment as necessary.
Dizziness, light-headedness or fainting may occur when standing up quickly from a lying or sitting position. Patients should be advised of this possibility and instructed to lie down if these symptoms appear and then sit for a few minutes before standing to prevent re-occurrence.
These adverse effects are self-limiting and, in most cases, do not recur after the initial period of therapy or during subsequent titration.
First dose effect might occur after the first terazosin dose or during the initial period of treatment. This consists of marked reduction of blood pressure mainly as orthostatic hypotension (vertigo, unsteadiness, syncope). Volume depletion, restricted salt intake and advanced age (i.e. 65 years of age or over) increase the risk of postural hypotension. It should be borne in mind that this is also likely to happen when terazosin treatment is re-started after a few days break. In such cases, the 1 mg initial dose should be prescribed.
Concomitant use of phosphodiesterase-5-inhibitors (e.g. sildenafil, tadalafil, vardenafil) and terazosin may lead to symptomatic hypotension in some patients. In order to minimise the risk for developing postural hypotension, the patient should be stable on the alpha-blocker therapy before initiating use of phospodiesterase-5-inhibitors.
The "Intraoperative Floppy Iris Syndrome" (IFIS, a variant of small pupil syndrome) has been observed during cataract surgery in some patients on or previously treated with tamsulosin. Isolated reports have also been received with other alpha-1 blockers and the possibility of a class effect cannot be excluded. As IFIS may lead to increased procedural complications during the cataract operation, current or past use of alpha-1 blockers should be made known to the ophthalmic surgeon in advance of surgery.
Because of its vasodilator action, terazosin should be used with caution in patients with any of the following cardiac conditions: pulmonary oedema due to aortic or mitral stenosis; high-output cardiac insufficiency; right-ventricular heart failure caused by pulmonary embolism or pericardial effusion; left ventricular heart failure with low filling pressure.
Effects on ability to drive and use machines: Terazosin tablets have a major influence on the ability to drive and use machines.
Dizziness, light-headedness or drowsiness may occur with the initial dose or in association with missed doses and subsequent reinitiation of Terazosin therapy. Patients should be cautioned about these possible adverse effects and the circumstances in which they may occur and advised to avoid driving or hazardous tasks for approximately 12 hours after initial dose or when the dose is increased.
Terazosin, in common with other alpha-adrenoreceptor antagonists, may cause syncope. Syncopal episodes have occurred within 30 to 90 minutes of the initial dose of the drug. Syncope has occasionally occurred in association with rapid dosage increases or the introduction of another antihypertensive agent.
In clinical studies in hypertension, the incidence of syncopal episodes was approximately one percent. In most cases, this was believed to be due to an excessive postural hypotensive effect although occasionally the syncopal episode has been preceded by a bout of tachycardia with heart rates of 120 to 160 beats per minute. If syncope occurs, the patient should be placed in a recumbent position and given supportive treatment as necessary.
Dizziness, light-headedness or fainting may occur when standing up quickly from a lying or sitting position. Patients should be advised of this possibility and instructed to lie down if these symptoms appear and then sit for a few minutes before standing to prevent re-occurrence.
These adverse effects are self-limiting and, in most cases, do not recur after the initial period of therapy or during subsequent titration.
First dose effect might occur after the first terazosin dose or during the initial period of treatment. This consists of marked reduction of blood pressure mainly as orthostatic hypotension (vertigo, unsteadiness, syncope). Volume depletion, restricted salt intake and advanced age (i.e. 65 years of age or over) increase the risk of postural hypotension. It should be borne in mind that this is also likely to happen when terazosin treatment is re-started after a few days break. In such cases, the 1 mg initial dose should be prescribed.
Concomitant use of phosphodiesterase-5-inhibitors (e.g. sildenafil, tadalafil, vardenafil) and terazosin may lead to symptomatic hypotension in some patients. In order to minimise the risk for developing postural hypotension, the patient should be stable on the alpha-blocker therapy before initiating use of phospodiesterase-5-inhibitors.
The "Intraoperative Floppy Iris Syndrome" (IFIS, a variant of small pupil syndrome) has been observed during cataract surgery in some patients on or previously treated with tamsulosin. Isolated reports have also been received with other alpha-1 blockers and the possibility of a class effect cannot be excluded. As IFIS may lead to increased procedural complications during the cataract operation, current or past use of alpha-1 blockers should be made known to the ophthalmic surgeon in advance of surgery.
Because of its vasodilator action, terazosin should be used with caution in patients with any of the following cardiac conditions: pulmonary oedema due to aortic or mitral stenosis; high-output cardiac insufficiency; right-ventricular heart failure caused by pulmonary embolism or pericardial effusion; left ventricular heart failure with low filling pressure.
Effects on ability to drive and use machines: Terazosin tablets have a major influence on the ability to drive and use machines.
Dizziness, light-headedness or drowsiness may occur with the initial dose or in association with missed doses and subsequent reinitiation of Terazosin therapy. Patients should be cautioned about these possible adverse effects and the circumstances in which they may occur and advised to avoid driving or hazardous tasks for approximately 12 hours after initial dose or when the dose is increased.
Use In Pregnancy & Lactation
The safety during pregnancy and lactation has not yet been established. Terazosin should not be used therefore in pregnancy unless the potential benefit outweighs the risk.
Adverse Reactions
Adverse reactions are listed by system organ class and the following frequencies: Very common (1/10); Common (1/100 to <1/10); Uncommon (1/1,000 to <1/100); Rare (1/10,000 to <1/1,000); Very rare (<1/10,000); Not known (cannot be estimated from the available data). (See table.)
There was no significant effect on the prostate specific antigen (PSA) levels for up to 24 months reported after treatment with terazosin.
There was no significant effect on the prostate specific antigen (PSA) levels for up to 24 months reported after treatment with terazosin.
Drug Interactions
Some caution is required when prescribing terazosin with other antihypertensive agents as significant hypotension has been observed. Dose re-titration may be required when diuretics or antihypertensives are added to the medication regimen.
Combination of terazosin with other alpha-receptor blockers is not recommended.
Furthermore, the antihypertensive effect may be increased when terazosin is administered concomitantly with vasodilators and nitrates.
Concomitant administration of PDE-5-inhibitors (such as sildenafil, tadalafil and vardenafil) and terazosin may lead to symptomatic hypotension in some patients (see Precautions).
Sympathomimetics may reduce the antihypertensive effect of terazosin; terazosin may reduce blood pressure and vascular reactions to dopamine, ephedrine, epinephrine, metaraminol, methoxamine and phenylephrine.
Terazosin may influence plasma renin activity and urinary excretion of vanillylmandelic acid. This should be considered when interpreting laboratory data.
Terazosin reduces the hypertensive effect of intravenously administered clonidine.
Combination of terazosin with other alpha-receptor blockers is not recommended.
Furthermore, the antihypertensive effect may be increased when terazosin is administered concomitantly with vasodilators and nitrates.
Concomitant administration of PDE-5-inhibitors (such as sildenafil, tadalafil and vardenafil) and terazosin may lead to symptomatic hypotension in some patients (see Precautions).
Sympathomimetics may reduce the antihypertensive effect of terazosin; terazosin may reduce blood pressure and vascular reactions to dopamine, ephedrine, epinephrine, metaraminol, methoxamine and phenylephrine.
Terazosin may influence plasma renin activity and urinary excretion of vanillylmandelic acid. This should be considered when interpreting laboratory data.
Terazosin reduces the hypertensive effect of intravenously administered clonidine.
Caution For Usage
Incompatibilities: Not applicable.
Storage
2 mg: Store at temperatures not exceeding 30°C.
5 mg: Store at temperatures not exceeding 25°C.
5 mg: Store at temperatures not exceeding 25°C.
Action
Pharmacotherapeutic group: Alpha-adrenoreceptor antagonists. ATC Code: G04C A03.
Pharmacology: Pharmacodynamics: Terazosin, the active ingredient of terazosin tablets, is a selective peripheral α1-adrenergic blocking agent. Its antihypertensive effects may result from postsynaptic α1-adrenergic blockade, leading to vasodilatation, decreased total peripheral resistance and venous return. Terazosin is a long-acting oral agent that is useful when given once daily to hypertensives. Long-term treatment with terazosin does not usually cause reflex tachycardia; while cardiac output, renal perfusion and glomerular filtration rate hardly become affected.
Although it has no effect on the underlying pathophysiologic mechanism involved in BPH, terazosin has been shown to significantly increase urinary flow rates and decrease outflow obstruction. It is also effective in easing BPH-related symptoms by preventing stimulation of α1-adrenergic receptors and consequent smooth muscle contractions in the bladder and prostatic urethra. Urodynamic improvement may help reduce urinary tract infection. The medicinal product, however, does not affect the size of the prostate.
A significant antihypertensive effect has been observed 3 hours following oral administration of terazosin. The medicinal product's antihypertensive effect has been reported to persist for 24 hours after oral administration.
Effects of terazosin on cardiovascular morbidity and mortality have not been investigated.
Pharmacokinetics: Absorption: Terazosin is rapidly and almost completely absorbed from the gastrointestinal tract without being affected by food intake. It has a 90% bioavailability.
Onset and duration: Following administration, mean peak serum levels are achieved within approximately 1 to 2 hours. 36 hours following drug intake, terazosin could still be traced in plasma.
Distribution, metabolism and excretion: Terazosin is 90-94% plasma protein-bound. It is extensively metabolised in the liver via hydrolysis, demethylation and dealkylation with five different metabolites identified. The plasma clearance is approximately 80mL/min. Mean elimination half-life of the parent compound is 12 hours. 10% of the orally administered terazosin is excreted unchanged in the urine and 30% as inactive metabolites. Faecal elimination accounts for 55-60% of the oral dose of which 20% is in the form of unchanged terazosin. There are no reports on possible terazosin excretion in breast milk. The elimination of terazosin seems not to be affected by renal function.
Toxicology: Preclinical safety data: Preclinical data reveal no special hazards for humans based on conventional studies of safety pharmacology.
No evidence of a genotoxic effect of terazosin has been reported from in vitro and in vivo investigations of the mutagenic potential of the substance.
Decreased fertility and testicular atrophy were seen in rats at repeated administration of doses a ≥20-30 times higher than the maximum recommended human dose. Foetal resorptions, decreased foetal weights, increased number of supernumerary ribs and decreased post-natal survival were noted in reproductive toxicity studies in rats and rabbits at maternally toxic doses (60-280 times the maximum recommended human dose).
No carcinogenic effect of terazosin was seen in studies in mice or female rats. In male rats, terazosin induced benign adrenal medullary tumours at the highest administered dose corresponding to 175 times the maximum human dose. The clinical relevance of this finding is unknown.
Pharmacology: Pharmacodynamics: Terazosin, the active ingredient of terazosin tablets, is a selective peripheral α1-adrenergic blocking agent. Its antihypertensive effects may result from postsynaptic α1-adrenergic blockade, leading to vasodilatation, decreased total peripheral resistance and venous return. Terazosin is a long-acting oral agent that is useful when given once daily to hypertensives. Long-term treatment with terazosin does not usually cause reflex tachycardia; while cardiac output, renal perfusion and glomerular filtration rate hardly become affected.
Although it has no effect on the underlying pathophysiologic mechanism involved in BPH, terazosin has been shown to significantly increase urinary flow rates and decrease outflow obstruction. It is also effective in easing BPH-related symptoms by preventing stimulation of α1-adrenergic receptors and consequent smooth muscle contractions in the bladder and prostatic urethra. Urodynamic improvement may help reduce urinary tract infection. The medicinal product, however, does not affect the size of the prostate.
A significant antihypertensive effect has been observed 3 hours following oral administration of terazosin. The medicinal product's antihypertensive effect has been reported to persist for 24 hours after oral administration.
Effects of terazosin on cardiovascular morbidity and mortality have not been investigated.
Pharmacokinetics: Absorption: Terazosin is rapidly and almost completely absorbed from the gastrointestinal tract without being affected by food intake. It has a 90% bioavailability.
Onset and duration: Following administration, mean peak serum levels are achieved within approximately 1 to 2 hours. 36 hours following drug intake, terazosin could still be traced in plasma.
Distribution, metabolism and excretion: Terazosin is 90-94% plasma protein-bound. It is extensively metabolised in the liver via hydrolysis, demethylation and dealkylation with five different metabolites identified. The plasma clearance is approximately 80mL/min. Mean elimination half-life of the parent compound is 12 hours. 10% of the orally administered terazosin is excreted unchanged in the urine and 30% as inactive metabolites. Faecal elimination accounts for 55-60% of the oral dose of which 20% is in the form of unchanged terazosin. There are no reports on possible terazosin excretion in breast milk. The elimination of terazosin seems not to be affected by renal function.
Toxicology: Preclinical safety data: Preclinical data reveal no special hazards for humans based on conventional studies of safety pharmacology.
No evidence of a genotoxic effect of terazosin has been reported from in vitro and in vivo investigations of the mutagenic potential of the substance.
Decreased fertility and testicular atrophy were seen in rats at repeated administration of doses a ≥20-30 times higher than the maximum recommended human dose. Foetal resorptions, decreased foetal weights, increased number of supernumerary ribs and decreased post-natal survival were noted in reproductive toxicity studies in rats and rabbits at maternally toxic doses (60-280 times the maximum recommended human dose).
No carcinogenic effect of terazosin was seen in studies in mice or female rats. In male rats, terazosin induced benign adrenal medullary tumours at the highest administered dose corresponding to 175 times the maximum human dose. The clinical relevance of this finding is unknown.
MedsGo Class
Drugs for Bladder & Prostate Disorders / Other Antihypertensives
Features
Brand
RiteMed
Full Details
Dosage Strength
2mg
Drug Ingredients
- Terazosin
Drug Packaging
Tablet 30's
Generic Name
Terazosin Hydrochloride Dihydrate
Dosage Form
Tablet
Registration Number
DRP-5057-02
Drug Classification
Prescription Drug (RX)
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