Camiren

Kamiren is a selective antagonist that acts on α1-adrenergic receptors.

Indications Camirena

It is used to reduce elevated blood pressure. In many patients, it is the most commonly used drug to control blood pressure. People who cannot reduce blood pressure to the required level using only one antihypertensive drug are allowed to combine doxazosin with other drugs, such as calcium antagonists, thiazide-type diuretics, ACE inhibitors, and β-blockers.

In addition, the drug is used to eliminate urinary retention, as well as symptoms caused by BPH. People with BPH are allowed to use Kamiren both in the case of high blood pressure and with normal blood pressure.

Release form

The release occurs in the form of tablets, in the amount of 10 pieces inside a blister plate. In the package - 2 or 3 blisters with tablets.

Pharmacodynamics

Increased blood pressure readings.

The use of doxazosin in people with elevated blood pressure causes a significant decrease in this indicator, reducing peripheral vascular resistance. This effect is due to the selective blockade of α1-adrenoreceptors located inside the vessels. In the case of using the drug once a day, the clinically noticeable antihypertensive effect continues for 24 hours. Basically, the maximum decrease in blood pressure values is noted after 2-6 hours after taking a single dose.

Compared with non-selective α1-adrenergic blockers, no drug tolerance development is observed during long-term administration of doxazosin.

As a result of long-term use of Kamiren, an increase in the activity of the substance renin in the plasma is sometimes observed, as well as the development of tachycardia.

Doxazosin has a positive effect on blood lipids, significantly increasing the ratio of high-density lipids to total values, and significantly reducing the total number of triglycerides and total cholesterol values. This factor is the advantage of the drug over β-adrenergic receptors and diuretics, because they have a negative effect on these indicators.

Since a link has been found between elevated blood pressure and lipid metabolism disorders and the development of coronary heart disease, the positive effect of doxazosin on both blood pressure and atherogenic lipid levels helps reduce the likelihood of developing coronary heart disease.

Doxazosin therapy reduces left ventricular hypertrophy, slows down platelet aggregation, and increases plasminogen activity within tissues. At the same time, the drug increases the sensitivity of peripheral tissues to insulin in individuals with disorders in this area.

Doxazosin has almost no negative metabolic reactions, so it is allowed to be used by people with diabetes and bronchial asthma, as well as with hyperkeratosis and disorders in the functioning of the left ventricle.

Men with elevated blood pressure also showed improvement in erectile function when taking the drug. Such individuals had a reduced incidence of erectile problems (compared to men taking other antihypertensive drugs).

Prostate adenoma.

Taking doxazosin by people with signs of prostate adenoma causes a significant improvement in urodynamics, a decrease in symptoms and manifestations of pathology. Such an effect of the drug is due to the selective blockade of α1-adrenoreceptors located inside the stroma of the muscles and capsule of the prostate, and in addition inside the neck of the bladder.

Doxazosin is a powerful blocker that acts on α1-adrenoreceptors, which are part of the AI subgroup (they make up approximately 70% of all receptor subcategories located in the prostate). This explains the effect of the drug on men with prostate adenoma.

The drug has demonstrated consistent safety and efficacy in long-term therapy in individuals with BPH (up to 4 years).

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Pharmacokinetics

After oral administration of the medicinal dosage, Kamiren is well absorbed with peak values reached after approximately 2 hours.

Excretion from plasma occurs in 2 stages, and the final half-life is 22 hours. This allows the tablets to be taken once a day. The active substance undergoes active biotransformation - only less than 5% of the dosage is excreted unchanged.

Because the drug is metabolized in the liver, people with liver problems should use doxazosin with caution.

Approximately 98% of the substance undergoes protein synthesis in blood plasma.

Doxazosin is metabolized primarily by hydroxylation and O-demethylation processes.

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Dosing and administration

The medicine can be taken either in the morning or in the evening.

With elevated blood pressure.

It is allowed to take within 1-16 mg of doxazosin per day. It is recommended to drink 1 mg once per day at the initial stage of treatment. Such a regimen is used for 1-2 weeks to minimize the possibility of syncope or postural hypertension. After this time, it is allowed to increase the dosage to 2 mg per day. If necessary, the daily dosage can be gradually increased with the above intervals to 4, 8 and 16 mg. But it is necessary to constantly monitor the patient's therapeutic response in order to achieve the necessary decrease in blood pressure. The standard daily dose is 2-4 mg.

For prostate adenoma.

At the initial stage, it is recommended to take 1 mg of the drug per day (once). Taking into account the individual characteristics of urodynamics, as well as signs of pathology, the dose is then allowed to be increased to 2, and then 4 mg. The maximum permitted daily dose is 8 mg. The intervals after which it is allowed to increase the dosage are 1-2 weeks. Often the dosage per day is within 2-4 mg.

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Use Camirena during pregnancy

Since there are no adequate, well-controlled tests of the drug during pregnancy or lactation, it is impossible to determine its safety in these groups of patients. As a result, Kamiren is allowed to be taken only in situations where the probable benefit of therapy, in the opinion of the doctor, exceeds the possibility of complications in the baby.

Although the drug was not teratogenic in animal tests, its use in extremely high doses (approximately 300 times the maximum dose for humans) resulted in a reduction in fetal life expectancy.

Since there has been no study of the drug safety of Kamiren, it cannot be used during lactation. If it is still necessary to use doxazosin, it will be necessary to stop breastfeeding for the duration of treatment.

Contraindications

Main contraindications:

• the presence of intolerance to the active substance, quinazoline derivatives (such as prazosin or terazosin) or other components of the drug;
• prostate adenoma, against the background of which there is obstruction in the upper part of the urinary system, as well as chronic forms of infections in the urinary system and the presence of stones inside the bladder;
• decreased blood pressure (applies only to men with prostate adenoma);
• history of orthostatic collapse;
• the drug is prohibited for monotherapy in individuals with bladder overflow or anuria, which may lead to progressive renal failure;
• It is prohibited to use it on children, because no tests of Kamiren have been performed on this category of patients.

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Side effects Camirena

Taking the medication can lead to the following side effects:

• infectious or invasive lesions - often there are disorders in the urinary or respiratory system;
• diseases in the area of systemic blood flow or lymph - leukopenia or thrombocytopenia occurs occasionally;
• immune disorders - sometimes allergic symptoms appear;
• alimentary disorders and problems with metabolic processes - sometimes there is an increase or loss of appetite, as well as the development of gout;
• mental problems – sometimes there are feelings of nervousness, excitement or anxiety, and in addition to this, insomnia or depression;
• damage to the nervous system function - headaches, drowsiness and dizziness are often observed. Sometimes a stroke, tremor, syncope or hypoesthesia develops. Paresthesia or orthostatic dizziness are observed sporadically;
• visual function disorders - visual blurring is observed sporadically. Intraoperative syndrome may develop in the area of the atonic iris;
• disturbances in the functioning of the auditory organs - vertigo often occurs. Sometimes tinnitus appears;
• damage to cardiac function - tachycardia often develops or the heart rate increases. Sometimes myocardial infarction or angina develops. Arrhythmia or bradycardia appear occasionally;
• vascular diseases - a decrease in blood pressure (also orthostatic type) is often observed. Hot flashes are occasionally noted;
• reactions of the respiratory organs, as well as the sternum with the mediastinum - dyspnea, cough or runny nose often appear, or bronchitis develops. Sometimes nosebleeds are noted. Sometimes existing bronchial spasms intensify;
• symptoms of gastrointestinal dysfunction – dyspeptic symptoms, abdominal pain, nausea and dry mouth often appear. Sometimes bloating, constipation, diarrhea, gastroenteritis or vomiting develop;
• damage to the hepatobiliary system - sometimes deviations of liver function values from the norm are observed. Jaundice, cholestasis or hepatitis appear sporadically;
• reactions of the subcutaneous layer and skin - itching often appears. Sometimes a rash is noted on the surface of the skin. Purpura, urticaria or alopecia develops sporadically;
• dysfunction of the musculoskeletal system and connective tissues - myalgia or back pain often occurs. Sometimes arthralgia develops. Muscle weakness or spasms occasionally occur;
• disorders of the urinary system and kidneys - urinary incontinence or cystitis is often detected. Frequent urination, dysuria or hematuria sometimes occur. Polyuria occasionally develops. Urination disorders, increased diuresis or nocturia occasionally appear;
• lesions of the mammary glands and reproductive organs - sometimes impotence develops. Priapism or gynecomastia appears occasionally. Retrograde ejaculation may occur;
• systemic disorders - often develop pain in the sternum, asthenia, flu-like symptoms and edema of the peripheral form. Sometimes swelling of the face and pain in the body appear. A state of general malaise or increased fatigue is noted singly;
• Lab tests - weight gain is sometimes observed.

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Overdose

If the blood pressure readings have dropped significantly as a result of intoxication, the victim must be laid on his back and his head must be lowered. If necessary, other medical procedures may be performed. Given the high rate of protein synthesis of drugs, the dialysis procedure will be ineffective.

If symptomatic supportive therapy is insufficient to eliminate shock, plasma substitutes must be used first. Then, if necessary, vasoconstrictor drugs are used. It is necessary to monitor kidney function and conduct supportive treatment measures, if necessary.

Interactions with other drugs

Use with PDE-5 inhibitors (PDE-5 element).

Taking doxazosin with PDE-5 inhibitors should be done with caution, because some people may experience signs of decreased blood pressure.

Tests of doxazosin in extended-release formulations have not been performed.

Other medicines.

Almost all doxazosin undergoes protein synthesis in blood plasma (98%). In vitro tests using human plasma have shown that the drug has almost no effect on the protein synthesis of substances such as warfarin and indomethacin, as well as phenytoin and digoxin.

Clinical data demonstrate the absence of negative interactions in case of combined administration of the drug with thiazide diuretics, β-blockers, furosemide, NSAIDs, antibiotics, oral hypoglycemic drugs, and anticoagulants. However, no studies have been conducted on the interaction of the above-mentioned drugs.

Doxazosin enhances the antihypertensive properties of other α-blockers and other antihypertensive drugs.

Data obtained from clinical trials involving male volunteers showed that a single dose of 1 mg of Kamiren on the first day of a 4-day course of oral cimetidine (with twice-daily administration of 400 mg of this drug) caused a 10% increase in the mean AUC values of doxazosin and did not affect the mean peak concentration and half-life of this substance. Such an increase in the mean AUC values of the substance when combined with cimetidine is within the limits of interindividual variations (27%) in the mean AUC values of the drug compared to placebo.

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Storage conditions

Kamiren should be kept in a place inaccessible to children, which is completely closed from moisture and sunlight. The maximum temperature limits are 30°C.

Special instructions

Reviews

Kamiren is usually used to treat high blood pressure. It demonstrates high efficiency in eliminating this disorder, although there are reviews from those who did not benefit from the drug. Patients consider the drug's rather high cost to be a disadvantage, although for most of them its efficiency justifies the price.

Shelf life

Kamiren can be used for 5 years from the date of manufacture of the drug.