Terazosin 5mg Tablets
SUMMARY OF PRODUCT CHARACTERISTICS
1 NAME OF THE MEDICINAL PRODUCT
Terazosin 5 mg Tablets
2. QUALITATIVE AND QUANTITATIVE COMPOSITION
Each tablet contains 5 mg terazosin (as terazosin monohydrochloride dihydrate). Excipient with known effect: Each tablet contains 117.12 mg of lactose (as lactose monohydrate).
For the full list of excipients, see section 6.1.
3 PHARMACEUTICAL FORM
Tablet.
Light pink coloured, round flat, tablets with bevelled edges and score line on one side of the tablet.
The score line is only to facilitate breaking for ease of swallowing and not to divide into equal doses.
4 CLINICAL PARTICULARS
4.1 Therapeutic indications
Terazosin tablets are indicated for:
• the treatment of mild to moderate hypertension
• symptomatic treatment of urinary obstruction caused by benign prostatic hyperplasia (BPH).
4.2 Posology and method of administration
Posology
For oral use.
For the different dosage regimens suitable strengths are available.
The dose of terazosin should be adjusted according to the patient's response. The following is a guide to administration:
Initial dose
The lowest single dose of 1 mg before bedtime for all patients, which should not be exceeded during the first week of treatment. Strict compliance with this recommendation should be observed to minimise potential acute first-dose hypotensive episodes.
Subsequent doses
Treatment of mild to moderate hypertension:
The single daily dosage may be increased by approximately doubling the dosage at weekly intervals to achieve the desired blood pressure response.
The maintenance dose needs to be adjusted to the patient’s response. 2 mg/day may be sufficient with increases up to 10 mg if necessary (clinical studies support the use of 2 - 10 mg as maintenance dose).
The maximum dose is 20 mg of terazosin per day and should not be exceeded.
Use with thiazide diuretics and other antihypertensive agents in the treatment of hypertension:
When adding a thiazide diuretic or another antihypertensive agent to a patient's regimen the dose of terazosin should be reduced or discontinued and retitration carried out if necessary. Caution should be observed when terazosin is administered with thiazides or other antihypertensive agents as hypotension may develop.
Treatment of Benign Prostatic Hyperplasia:
The dose may be increased by approximately doubling the dose at weekly or bi-weekly intervals to achieve the desired reduction in symptoms. The maintenance dose is usually 5 to 10 mg 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 10 mg once daily.
Treatment should be initiated using the 1 mg tablets during seven days, 2 mg tablets during 14 days and 5 mg tablets during 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.
Renal insufficiency
Pharmacokinetic studies indicate that patients with impaired renal function need no alteration in recommended dosage.
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.
Elderly
Pharmacokinetic studies in the elderly indicate that no major alteration in dosage recommendation is required. However, particular caution should be taken with the titration of the terazosin dose.
If administration is discontinued for more than several days, therapy should be re-instituted using the initial dosing regimen.
Use in patients with hepatic insufficiency:
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.
Method of administration
The first tablet of defined dose strength should be taken in the evening at bedtime. The following tablets of the same strength may be taken in the morning. The tablets should be taken with a sufficient amount of liquid (i.e. 1 glass of water).
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.
4.3 Contraindications
Terazosin is contra-indicated:
in patients with known hypersensitivity to the active ingredient, terazosin, to other quinazolines (e.g. prazosin, doxazosin, alfuzosin, indoramin or tamsulosin) or to any of the excipients.
history of micturition syncope
4.4 Special warnings and precautions for use
In clinical trials, the incidence of postural hypotension was greater in patients who received terazosin for BPH than in patients who received terazosin for hypertension. In this BPH indication, 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%).
Patients should be warned for symptoms of postural hypotension and be advised to sit or lay down in case they occur (see section 4.7 and 4.8).
Before treating the symptoms of BPH with alpha-blockers, other causes of impaired urinary flow or urinary symptoms should be excluded. Also where the diagnosis of BPH has been established, it should be confirmed that there is no concomitant obstruction of the upper urinary tract or any signs of infection before treating with terazosin.
Terazosin therapy requires regular medical monitoring.
In the initial phase of therapy (especially after the first dose or when the terazosin dose is increased) patients may experience a pronounced drop in blood pressure.
Dizziness, light-headedness, weakness, drowsiness and, in rare cases, syncope may occur.
This has also to be assumed in association with missed doses and subsequent re-initiation of terazosin therapy. Patients should be cautioned about these possible adverse events and the circumstances in which they may occur.
To minimise the risk of postural hypotension, patients should be monitored at the start of therapy. As the likelihood of such responses is greater with a higher than recommended starting dose, the recommended dosage regimen should be followed carefully. The patient should take the first dose of terazosin at bedtime and should avoid abrupt changes in position or activities, which could be harmed by dizziness or weariness. This especially applies to the elderly.
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
Caution is also recommended, when terazosin is administered concomitantly with drugs, which may influence hepatic metabolism.
Use in patients with hepatic insufficiency:
As for all medicaments metabolised in the liver, terazosin should be used with particular caution in patients with impaired hepatic function. As there is no data available in patients with severe hepatic dysfunction, use of terazosin in these patients is not recommended.
Patients with benign prostatic hyperplasia and having a simultaneous obstruction of the upper urinary tract, chronic infection of the urinary tract or bladder stone should not be treated with terazosin. In general, terazosin should not be used in patients with a reduced urinary outflow or anuria or an advanced renal deficiency.
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 increase 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.
This medicinal product should not be administered to patients with rare hereditary problems of galactose intolerance; the Lapp lactase deficiency or glucose-galactose malabsorption.
If administration is discontinued for more than several days, therapy should reinstituted using the initial dosing regime.
4.5 Interactions with other medicinal products and other forms of interaction
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.
As for other antihypertensive agents, non-steroidal antirheumatics or estrogens may reduce the antihypertensive effect of terazosin.
Sympathomimetics may reduce the antihypertensive effect of terazosin.
Terazosin may reduce blood pressure and vasculare reactions to dopamine, ephedrine, epinephrine, metaraminol, methoxamine and phenylephrine.
Terazosin may reduce the anti-hypertensive effect of intravenously administered clonidine.
Terazosin may influence plasma renin activity and urinary excretion of vanillymandelic acid. This should be considered when interpreting laboratory data.
Concomitant use of Phosphodiesterase-5-inhibitors (e.g. sildenafil, tadalafil, vardenafil) and terazosin may lead to symptomatic hypotension in some patients (see section 4.4).
4.6 Fertility, pregnancy and lactation
Although no teratogenic effects were seen in animal testing, the safety during pregnancy and lactation has not yet been established. Furthermore, data from animal studies show that terazosin may increase the duration of pregnancy or inhibit labour. Terazosin should not be used in pregnancy unless the potential benefit out weighs the risk.
It is not known whether terazosin is excreted in breast milk. Preclinical studies show that terazosin is excreted in the milk of rats. Caution should be exercised when terazosin is administered to a breast-feeding woman.
4.7 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 events and the circumstances in which they may occur and advised to avoid driving or hazardous tasks for approximately the first 12 hours after the initial dose or when the dose is increased.
4.8 Undesirable effects
Terazosin, in common with other alpha-adrenoreceptor antagonists, may cause syncope. Syncope episodes may occur within 30-90 minutes of the initial dose of the medicinal product. Occasionally the syncope episode may be preceded by tachycardia with heart rates of 120 to 160 beats per minute. First-dose hypotension might occur which could lead to vertigo and in severe cases syncope. To avoid hypotension, terazosin treatment should be started with a 1 mg dose at bed-time.
The incidence of undesirable effects is based on 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)
Blood and the lymphatic system disorders:
Very rare: thromobocytopenia
Immune system disorders:
Very rare: anaphylactic reactions
Nervous system disorders:
Common: nervousness, somnolence, paraesthesia, vertigo Uncommon: depression Eye disorders:
Common: blurred vision/ amblyopia, colour anomaly Cardiac disorders:
Common: palpitations, tachycardia, chest pain, postural hypotension Very rare: atrial fibrillation
Respiratory, thoracic and mediastinal disorders:
Common: dyspnoea, nasal congestion/rhinitis, sinusitis, epistaxis
Gastrointestinal disorders:
Common: nausea, constipation, diarrhoea, vomiting
Skin and subcutaneous tissue disorders:
Common: pruritus, rash Uncommon: urticaria
Musculoskeletal, connective tissue and bone disorders:
Common: back pain
Renal and urinary disorders:
Rare: urinary tract infection and urinary incontinence, (primarily reported in post-menopausal women)
Reproductive system and breast disorders:
Common: impotence Uncommon: decreased libido Rare: priapism
General disorders and administration site conditions:
Common: Dizziness, light-headedness, fainting (especially when standing up quickly from a lying or a sitting position - postural hypotension), asthenia, oedema, headache, pain in the extremities.
Uncommon: weight gain, syncope.
Additional adverse events reported in clinical trials or during marketing experience, but which are not clearly associated with the use of terazosin include the following: facial oedema, fever, abdominal, neck and shoulder pain, vasodilation, arrhythmia, dry mouth, dyspepsia, flatulence, gout, arthralgia, arthritis, joint disorders, myalgia, anxiety, insomnia, bronchitis, flu symptoms, pharyngitis, rhinitis, cold symptoms, increased cough, sweating, abnormal vision, conjunctivitis, tinnitus, urinary frequency (increased micturition)
Laboratory tests: Small but statistically significant decreases in haematocrit, haemoglobin, white blood cells, total protein and albumin were observed in controlled clinical trials. These laboratory findings suggest the possibility of haemodilution. Treatment with terazosin for up to 24 months had no significant effect on prostate specific antigen (PSA) levels.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via Yellow Card Scheme. Website: www.mhra.gov .uk/yellowcard.
4.9 Overdose
Should administration of terazosin lead to acute hypotension; cardiovascular support is of first importance. Restoration of blood pressure and normalization 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.
5 PHARMACOLOGICAL PROPERTIES
5.1 Pharmacodynamic properties
Pharmacotherapeutic group: alpha-adrenoreceptor antagonist
ATC code: G04C A03
Use in hypertension:
Although the exact mechanism of the hypotensive action is not established, the relaxation of peripheral blood vessels appears to be produced mainly by competitive antagonism of post-synaptic alpha-1-adrenoceptor. Terazosin usually produces an initial gradual decrease in blood pressure followed by a sustained anti hypertensive action.
Clinical experience indicates that a 2-5% decrease in total cholesterol plasma concentration and a 3-7% decrease in the combined LDLc + VLDLc fraction
plasma concentration from pretreatment values are associated with the administration of therapeutic doses of terazosin.
Use in benign Prostatic Hyperplasia:
Studies suggest that alpha-1-adrenoreceptor antagonism is useful in improving the urodynamics in patients with chronic obstruction such as in benign prostatic hyperplasia (BPH).
The symptoms of BPH are caused mainly by the presence of an enlarged prostate and by the increased smooth muscle tone of the bladder outlet and prostate, which is regulated by alpha-1-adrenergicreceptors.
In in-vitro experiments, terazosin has been shown to antagonize phenylephrine-induced contractions of human prostatic tissue. In clinical trials terazosin has been shown to improve the urodynamics and symptomatology in patients with BPH.
5.2 Pharmacokinetic properties Absorption
Terazosin is well absorbed (80-100%). Terazosin has a minimal “first pass” effect and almost the complete dose of terazosin is systematically available. Peak plasma concentrations are reached approximately 1-2 hours after oral dosing in the fasted state. Bioavailability is not significantly affected by food uptake.
Distribution
Approximately 90-94% of terazosin is bound to plasma proteins. Protein binding is independent of total active substance concentrations.
Main metabolites of terazosin are caused by demethylation and conjugation.
Elimination
Approximately 10% and 20% of orally administered terazosin is excreted as unchanged active substance in urine and in faeces, respectively. Approximately 40% of the administered dose of terazosin is eliminated in urine and 60% in faeces. The total elimination half-life is approximately 8-13 hours.
Linearity / non-linearity of pharmacokinetics
After oral dosing of terazosin AUC and Cmax increase in proportion with dose over the recommended dose range (2-10 mg).
5.3 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 > 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.
6 PHARMACEUTICAL PARTICULARS
6.1 List of excipients
Lactose monohydrate
Maize starch Talc
Magnesium stearate Iron oxide red E172
6.2 Incompatibilities
Not applicable.
6.3 Shelf life
2 years
6.4 Special precautions for storage
Store in the original package in order to protect from light.
6.5 Nature and contents of container
Blister of PVC/PVdC and Aluminium Packs of 28 & 98 tablets.
Not all package sizes may be marketed.
6.6 Special precautions for disposal
Any unused product or waste material should be disposed of in accordance with local requirements.
7 MARKETING AUTHORISATION HOLDER
Accord Healthcare Limited Sage House,
319, Pinner Road,
North Harrow, Middlesex, HA1 4HF, United Kingdom
8 MARKETING AUTHORISATION NUMBER(S)
PL 20075/0093
9 DATE OF FIRST AUTHORISATION/RENEWAL OF THE AUTHORISATION
30/11/2013
10 DATE OF REVISION OF THE TEXT
30/11/2013