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Active ingredients
Doxazosin
Release form
Pills
Composition
Doxazosin mesilate 4.86 mg, which corresponds to the content of Doxazosin 4 mg. Excipients: microcrystalline cellulose, sodium starch glycolate, magnesium stearate, sodium lauryl sulfate, lactose monohydrate.
Pharmacological effect
Selective α1-adrenoreceptor antagonist. It causes the expansion of peripheral vessels, which leads to a decrease in round focal disease and a decrease in blood pressure. The effect of the drug on the function of the heart is insignificant and is transient. Doxazosin reduces the level of total cholesterol, LDL-C and triglycerides, increases the levels of HD-C-HDL in serum. Thus, the drug helps to prevent the development of atherosclerosis and ischemic heart disease. Doxazosin has a neutral or normalizing effect on the content of insulin and glucose in the blood, so the drug can be used in patients with diabetes. Inhibits platelet aggregation. With prolonged treatment, doxazosin reduces the mass of the left ventricle. Doxazosin prevents contraction of the smooth muscles of the upper urethra and the muscles of the prostate gland that surround the urethra. Relaxation of these muscles leads to relief of urination, which significantly reduces the unpleasant symptoms observed in benign prostatic hyperplasia. The therapeutic effect is manifested already during the first 2 weeks of treatment and is enhanced with subsequent therapy. The effect of doxazosin on normal blood pressure is negligible. Kamiren can be used in patients with renal failure, chronic obstructive pulmonary disease, peripheral angiopathy and gout. With a single dose of Kamiren, the duration of action is 24 hours. The effect on blood pressure is most pronounced within 2-6 hours after taking the drug. The maximum effect is achieved after several weeks of regular use. If the therapeutic effect is not enough, patients can be prescribed other antihypertensive drugs: beta-blockers, diuretics, calcium channel blockers and ACE inhibitors.
Pharmacokinetics
Absorption After oral administration, doxazosin is well absorbed from the gastrointestinal tract. Cmax is reached in 1.5-3 hours. Distribution Doxazosin is almost completely bound to plasma proteins.Metabolism Metabolized in the liver. Withdrawal T1 / 2 is 16-22 hours. Excreted in the feces as metabolites. Less than 10% of the dose is excreted in the urine.
Indications
- treatment of mild and moderate arterial hypertension (as monotherapy or in combination with other antihypertensive drugs); - symptomatic treatment of benign prostatic hyperplasia.
Contraindications
- obstruction of the digestive tract or esophagus; - Constriction of the gastrointestinal tract of any degree; - childhood; - Hypersensitivity to doxazosin and other components of the drug; - hypersensitivity to other derivatives of quinazoline (prazosin, terazosin).
Use during pregnancy and lactation
The use of Kamiren in pregnancy is possible only for health reasons, when the expected benefit of therapy for the mother outweighs the potential risk to the fetus. If you need to use the drug during lactation, breastfeeding should be interrupted, because The safety of Kamiren in infants has not been established.
Dosage and administration
Set individually and adjust depending on the effectiveness of treatment and / or the development of side effects. In hypertension, the initial dose of doxazosin is 1 mg / day. The first dose should be taken in the evening before bedtime. Depending on the effect of the drug on blood pressure, the dose can be gradually increased at intervals of 1-2 weeks to 2 mg, 4 mg, 8 mg 1 time / day. As a rule, average daily doses range from 2 mg to 8 mg. The maximum daily dose is 16 mg. With benign prostatic hyperplasia in patients with normal blood pressure, the initial dose is 1 mg / day. The first dose should be taken in the evening before bedtime. Depending on the response to treatment, the dose can be gradually increased at intervals of 1-2 weeks to 2 mg, 4 mg, 8 mg 1 time / day. The average daily dose ranges from 2 mg to 4 mg. The maximum daily dose is 8 mg. For benign prostatic hyperplasia in patients with arterial hypertension, the drug is prescribed in the same doses as in patients with arterial hypertension only. In patients with hepatic insufficiency, the drug is used in smaller doses (due to the slow metabolism of doxazosin). The drug can be taken before, during or after a meal.If the drug is missed at the usual time, you should take this dose as soon as possible. If the time is right for taking the next dose, you should take it only, without doubling the dose. It is important to take the drug regularly. If the patient has not taken the drug for several days, then the new therapeutic course should be started with the lowest dose.
Side effects
On the part of the cardiovascular system: at the beginning of treatment and with an increase in the dose of the drug, there may be a tendency to fainting (especially when moving from a prone or sitting position to a standing position), dizziness, headache. These effects disappear on their own, but if they are severe or persist for a long time, the dose should be reduced or discontinued; in some cases, possible tachycardia, palpitations. Rarely (the connection with the administration of doxazosin is not clearly established) - exacerbation of angina, myocardial infarction, cerebrovascular stroke, cardiac arrhythmias. From the side of the central nervous system and peripheral nervous system: a possible feeling of fatigue, drowsiness, muscle weakness. On the part of the digestive system: nausea is possible; rarely - violations of liver function, cholestasis, hepatitis. On the part of the respiratory system: possible bronchitis, shortness of breath, a feeling of nasal congestion, nasal discharge. On the part of the blood coagulation system: rarely - thrombocytopenia, purpura, nosebleeds. From the urinary system: rarely - hematuria; in some cases, urinary incontinence. Other: possible swelling of the ankles and legs, flu-like symptoms; rarely, skin rash; in isolated cases (the connection with the administration of doxazosin is not clearly established) - impotence.
Overdose
Symptoms: excessive hypotension, dizziness, possible fainting. Treatment: in most cases, a dose reduction or temporary interruption of therapy is sufficient. The patient should be given a supine position with a low head and slightly raised legs. Do not induce vomiting. To remove an unabsorbed drug from the gastrointestinal tract, gastric lavage should be performed, activated charcoal should be prescribed, laxative. Assign α-adrenoreceptor agonists (for example, norepinephrine).Hemodialysis is ineffective (since doxazosin is almost completely bound to plasma proteins).
Interaction with other drugs
With simultaneous use of Kamiren with other antihypertensive agents (β-adrenoreceptor blockers, diuretics, calcium channel blockers, ACE inhibitors), the antihypertensive effect is enhanced (this combination is possible, but caution should be exercised, especially at the beginning of treatment). With simultaneous use of Kamiren with nitrates, anesthetics, tricyclic antidepressants, as well as with ethanol may increase the hypotensive effect (the use of such a combination is possible, but caution should be exercised, especially at the beginning of treatment). With simultaneous use of Kamiren with drugs that affect the metabolic rate in the liver, it is possible to slow down or accelerate the metabolism of doxazosin (should be used with caution).
special instructions
Doxazosin does not affect the concentration of PSA (prostate specific antigen). When taking Kamiren, especially the first dose, orthostatic hypotension (fainting) is possible. In order to avoid such phenomena, treatment should begin with a dose of 1 mg in the evening before bedtime. The dose should be increased gradually at intervals of 1-2 weeks. The patient should be warned about the possibility of orthostatic hypotension and should be carefully raised from a prone or sitting position. This is especially true for elderly patients and patients receiving other antihypertensive drugs or diuretics at the same time. With caution used in combination with other antihypertensive drugs, especially at the beginning of treatment, because may increase antihypertensive effect. Doxazosin is not recommended for use in patients with arterial hypotension. Before starting therapy, patients with symptoms caused by benign prostatic hyperplasia should undergo a urological examination. In patients with hepatic insufficiency, doxazosin is metabolized more slowly, so an increase in the dose of the drug should be carried out with caution. Use in Pediatrics Safety and efficacy in pediatrics has not been established, so the drug is not recommended for children. Influence on the ability to drive motor vehicles and control mechanisms At the beginning of treatment with Kamiren and with a dose change, an excessive decrease in blood pressure is possible, which may be accompanied by dizziness.Therefore, in such cases it is not recommended to drive a car and engage in potentially hazardous activities.