Special Warning : אזהרת שימוש

4.4.   Special warnings and precautions for use

Terazosin hydrochloride, like other alpha-adrenoceptor blockers, can cause marked lowering of blood pressure, especially postural hypotension and syncope in association with the first dose or first few doses of therapy. A similar effect can be anticipated if therapy is interrupted for more than a few doses and then re-started. Syncope has also been reported with other alpha-adrenoceptor blockers in association with rapid dosage increases or the introduction of another antihypertensive drug. Syncope is believed to be due to an excessive postural hypotensive effect, although occasionally the syncopal episode has been preceded by a bout of severe supraventricular tachycardia with heart rates of 120 to 160 beats per minute.

In clinical trials, the incidence of postural hypotension was greater in BPH patients than in those with hypertension. In these cases, the incidence of postural hypotension events was greater in patients aged 65 years and over (5.6%) than those aged less than 65 years (2.6%).

If administration is discontinued for more than several days, therapy should be re-instituted using the initial dosing regimen. Do not start treatment after discontinuation if it is not possible to reach a dose of 1 mg and 2 mg.

Before treating the symptoms of benign prostatic hyperplasia (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. Patients with benign prostatic hyperplasia, who simultaneously suffer from congestion of the upper urinary tract, chronic urinary tract infection or bladder stones, should not be treated with terazosin.
Terazosin should not be given to patients with bladder overflow, anuria or advanced renal failure.
Due to the risk of an excessive decrease in blood pressure, caution is advised for the concomitant administration of terazosin and thiazides or other antihypertensive medications.
If a thiazide diuretic or another antihypertensive medication is added during treatment with terazosin, the terazosin dose must be reduced or the drug discontinued. A new dose-titration is essential. When administering terazosin in addition to other antihypertensives, the dose of the other antihypertensives should be reduced before commencement of therapy and adjusted after discontinuation of terazosin.
Due to the vasodilatory effect of terazosin, it should be administered with caution if the following cardiac conditions are present:
• Pulmonary oedema due to aortic or mitral valve stenosis
• High output cardiac insufficiency
• Right-sided cardiac insufficiency due to pulmonary embolism or pericardial effusion
• Left-sided cardiac insufficiency with low filling pressure In patients with severe coronary heart disease, a very rapid or excessive decrease in blood pressure can lead to an exacerbation of angina pectoris.
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.
Caution is also recommended, when terazosin is administered concomitantly with drugs, which may influence hepatic metabolism.
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- adrenoceptor blocker therapy before initiating use of phosphodiesterase-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-adrenoceptor blockers and the possibility of a class effect cannot be excluded. As IFIS may lead to increased procedural complications during cataract operation current or past use of alpha-adrenoceptor blockers should be made known to the ophthalmic surgeon in advance of surgery.

Hytrin 5 mg and 10 mg Tablets contain lactose
Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine.

Effects on Driving