Velafaks pills 75 mg 28 pieces
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Active ingredients
Venlafaxine
Release form
Pills
Composition
Active ingredient: Venlafaxin Concentration of active ingredient (mg): 75 mg
Pharmacological effect
An antidepressant chemically not related to any class of antidepressants (tricyclic, tetracyclic, or other) is the racemate of two active enantomers. The mechanism of antidepressant action of the drug is associated with its ability to potentiate the transmission of nerve impulses to the central nervous system. Venlafaxine and its major metabolite O-desmethylvenlafaxine (EFA) are strong inhibitors of serotonin and noradrenaline reuptake and weak dopamine reuptake inhibitors. In addition, venlafaxine and EFA reduce beta-adrenergic reactivity, both after a single injection, and with continuous use. Venlafaxine has no affinity for m-cholinergic, histamine H1 receptors and α1-adrenergic receptors of the brain. Does not inhibit the activity of MAO. The drug does not affect the release of norepinephrine from brain tissue.
Pharmacokinetics
AbsorptionAfter taking the drug inside venlafaxine is well absorbed from the gastrointestinal tract. After a single dose of the drug in a dose of 25-150 mg Cmax is achieved within about 2.4 hours and amounts to 33-172 ng / ml. After taking the drug while eating, the time to reach Cmax in the blood plasma is increased by 20-30 minutes, but the values of Cmax and absorption do not change. Distribution The binding of venlafaxine and EFA to plasma proteins is 27% and 30%, respectively. With repeated intake of Css, venlafaxine and EFA are achieved within 3 days. Metabolism Exposure to intensive metabolism during the first passage through the liver. The main metabolite is O-desmethylvenlafaxine. Cmax EFA in plasma is reached approximately 4.3 hours after administration and amounts to 61-325 ng / ml. In the range of daily doses of 75-450 mg, the pharmacokinetics of venlafaxine and EFA is linear. EFA and other metabolites, as well as unchanged venlafaxine, are excreted by the kidneys. With repeated administration of Css, venlafaxine and EFA are achieved within 3 days. Pharmacokinetics in special clinical situations. Patients with liver cirrhosis plasma plasma concentrations of venlafaxine and EFA are increased, and their elimination rate is reduced. min) the total clearance of venlafaxine and EFA is reduced, and T1 / 2 increases. The age and sex of the patient do not affect the pharmacokinetics of the drug.
Indications
Depression of various etiologies, treatment and prevention
Contraindications
Hypersensitivity. Simultaneous administration of MAO inhibitors (see also the “Interaction” section). Severe disorders of the kidneys and / or liver (glomerular filtration rate (GFR) less than 10 ml / min). Age up to 18 years (safety and efficacy for this age groups not proven). Established or suspected pregnancy. Lactation period.
Precautionary measures
Do not exceed the recommended dozy.S care to apply in the case of recent myocardial infarction, unstable angina, hypertension, tachycardia, convulsive syndrome history, elevated intraocular pressure, angle-closure glaucoma, manic state history, hyponatremia, hypovolemia, dehydration, simultaneous administration of diuretics , suicidal tendencies, predisposition to bleeding (on the part of the skin and mucous membranes), with initially reduced body weight.
Use during pregnancy and lactation
During pregnancy (including before childbirth), venlafaxine is contraindicated, because the safety of its use during this period has not been determined. Venlafaxine and the EFA metabolite are excreted in breast milk. The safety of these substances for newborns is not proven, so if you need to take the drug during lactation, you should stop breastfeeding for the duration of treatment.
Dosage and administration
Velafax pills are recommended to be taken with meals. The recommended starting dose is 75 mg in two doses (37.5 mg each) daily. If after several weeks of treatment there is no significant improvement, the daily dose can be increased to 150 mg (2 × 75 mg per day). If, according to the doctor, a higher dose is necessary (severe depressive disorder or other conditions requiring inpatient treatment), 150 mg can be immediately administered in two doses (2 × 75 mg per day). After that, the daily dose can be increased by 75 mg every 2-3 days until the desired therapeutic effect is achieved. The maximum daily dose of Velafax is 375 mg. After achieving the desired therapeutic effect, the daily dose can be gradually reduced to the minimum effective level.Supportive therapy and prevention of relapse: Supportive treatment may last 6 months or more. Assigned to the minimum effective dose used in the treatment of a depressive episode. Renal failure: in case of mild renal insufficiency (glomerular filtration rate (GFR) of more than 30 ml / min), no dosage regimen correction is required. With moderate renal failure. (GFR 10-30 ml / min) the dose should be reduced by 25-50%. In connection with the prolongation of the half-life of venlafaxine and its active metabolite (EFA), such patients should take the entire dose once a day. It is not recommended to use venlafaxine in severe renal failure (GFR less than 10 ml / min), since there is no reliable data on such therapy. Hemodialysis patients can receive 50% of the usual daily dose of venlafaxine after completion of hemodialysis. Hepatic impairment: in case of mild hepatic impairment (prothrombin time (PT) less than 14 sec) correction of the dosing regimen is not required. With moderate liver failure (PF from 14 to 18 seconds), the dose should be reduced by 50%. It is not recommended to use venlafaxine in case of severe hepatic failure, since there is no reliable data on such therapy. Elderly patients: in itself, the elderly patient does not require changing the dose, but (as with the appointment of other drugs), the treatment of elderly patients requires caution, for example, in connection with the possibility of impaired renal function. The smallest effective dose should be applied. At higher doses, the patient must be under close medical supervision.
Side effects
Most of the side effects listed below are dose dependent. With prolonged treatment, the severity and frequency of most of these effects is reduced, and there is no need to cancel therapy. In order of decreasing frequency: frequent> 1%, infrequent> 0.1% - <1%, rare> 0.01% - <0.1%, very rare <0.01%. General symptoms: weakness, fatigue, Gastrointestinal tract: loss of appetite, constipation, nausea, vomiting, dry mouth, rarely hepatitis. On the part of the metabolism: an increase in serum cholesterol, weight loss; infrequent: changes in laboratory tests of liver function, hyponatremia, syndrome of insufficient secretion of antidiuretic hormone.Since the cardiovascular system: hypertension, hyperemia of the skin; infrequent: postural hypotension, tachycardia, Nervous system: unusual dreams, dizziness, insomnia, anxiety, paresthesia, stupor, increased muscle tone, tremor, yawning; unclean: apathy, hallucinations, muscle spasms, serotonin syndrome; rare: epileptic seizures, manic reactions, as well as symptoms resembling neuroleptic malignant syndrome (MNS). On the part of the urogenital system: disturbances of ejaculation, erection, anorgasmia, dysuric disorders (mainly - difficulty at the beginning of urination); infrequent: decreased libido, menorrhagia, urinary retention. From the sense organs: accommodation disturbances, mydriasis, visual disturbances; infrequent: violation of taste sensations. On the part of the skin: sweating; infrequent: photosensitivity reactions; rare: erythema multiforme, Stevens-Johnson syndrome. From the hematopoietic system: infrequent: hemorrhages into the skin (ecchymosis) and mucous membranes, thrombocytopenia; rare; lengthening bleeding time. Hypersensitivity reactions: infrequent: skin rash; very rare: anaphylactic reactions. After abrupt cancellation of venlafaxine or reduction of its dose, there may be observed: fatigue, drowsiness, headache, nausea, vomiting, anorexia, dry mouth, dizziness, diarrhea, insomnia, anxiety, increased irritability, disorientation, hypomania, paresthesia, sweating. These symptoms are usually mild and go away without treatment. Due to the likelihood of these symptoms, it is very important to gradually reduce the dose of the drug.
Overdose
Symptoms (often occur while taking ethanol): dizziness, decrease in blood pressure, ECG changes (prolongation of the QT interval, blockade of the bundle of the His bundle, expansion of the QRS complex), sinus and ventricular tachycardia or bradycardia, impairment of consciousness (from drowsiness to coma), convulsions , death. Treatment: carry out symptomatic therapy, under continuous monitoring of ECG and functions of vital organs. Do not induce vomiting due to the risk of aspiration. It is recommended to provide airway patency, adequate pulmonary ventilation and oxygenation. Hemodialysis is ineffective becausevenlafaxine and EFA are not displayed during dialysis. Specific antidotes are unknown.
Interaction with other drugs
The simultaneous use of MAO inhibitors and venlafaxine contraindicated. Reception venlafaksina can begin no earlier than 14 days after the end of therapy with MAO inhibitors. If a reversible MAO inhibitor (moccobemide) was used, this interval may be shorter (24 hours). Therapy with MAO inhibitors can be started no earlier than 7 days after venlafaxine is discontinued. With simultaneous use of venlafaxine with lithium preparations, an increase in the level of lithium in the blood is possible. When used simultaneously with imipramine, the pharmacokinetics of venlafaxine and its EFA metabolite do not change. Venlafaxine does not affect the metabolism of imipramine and its metabolite 2-hydroxyimipramine, however, it increases the value of AUC and Cmax in the plasma of desipramine (the main metabolite of imipramine), and also reduces the renal clearance of 2-hydroxydizipramine. The clinical significance of this phenomenon is unknown. With simultaneous use with neuroleptics, symptoms resembling the malignant neuroleptic syndrome may appear. Venlafaxine reduces the renal clearance of haloperidol by 42%, while the AUC and Cmax values increase by 70% and 88%, respectively. The effects of haloperidol may be enhanced. When used simultaneously with diazepam, the pharmacokinetics of drugs and their main metabolites do not change significantly. If used simultaneously with clozapine, there may be an increase in plasma levels and side effects (for example, epileptic seizures). If used simultaneously with risperidone, despite the increase in the AUC of the drug, the pharmacokinetics of the sum of the active components (risperidone and its active metabolite) did not change significantly. Simultaneous administration ethanol and venlafaxine was not accompanied by a decrease in mental and physical activity. Despite this (as in the case of taking other drugs that affect the central nervous system), ethanol use is not recommended during venlafaxine therapy. Cimetidine inhibits venlafaxine metabolism during the first passage through the liver and does not affect the EFA pharmacokinetics. In the majority of patients, only a slight increase in the total pharmacological activity of venlafaxine and EFA is expected (more pronounced in elderly patients and in impaired liver function).In elderly patients and in patients with impaired liver function, simultaneous use of cimetidine and venlafaxine should be carried out under medical supervision. No clinically significant interaction of venlafaxine with antihypertensive drugs (including beta-adrenergic blockers, ACE inhibitors and diuretics) and hypoglycemic drugs has been found. the binding of plasma proteins venlafaxine and EFA is, respectively, 27% and 30%; no drug interaction due to the competitive release of other drugs is assumed effective preparations of bonds with plasma proteins. Venlafaxine metabolism occurs with the participation of the cytochrome P450 system, CYP2D6 and CYP3A4 isoenzymes. Taking the drug with CYP2D6 isoenzyme inhibitors or patients with a genetically determined decrease in the activity of the CYP2D6 isoenzyme was not accompanied by significant changes in the concentration of the active substance and metabolite (venlafaxine and EFA), which allows not to reduce the dose of antidepressant. However, simultaneous administration with inhibitors of the CYP3A4 isoenzyme is accompanied by an increase in plasma venlafaxine concentration. Therefore, special care should be taken when prescribing venlafaxine with drugs that are inhibitors of the isoenzyme CYP3 apf aprs (ketoconazole, erythromycin) or of both isoenzymes (CYP2D6 and CYP3A4). In vivo studies did not reveal the effect of venlafaxine on the metabolism of alprazolam (CYP3A4 isoenzyme), caffeine (CYP1A2 isoenzyme), carbamazepine (CYP3A4 isoenzyme) and diazepam (CYP3A4 and isopenzymes CYP3A4) and. prolonged prothrombin time, expressed through MHO. When taken simultaneously with indinavir, a decrease in the AUC value of indinavir by 28% and a decrease in its Cmax in plasma by 36% is observed, while the pharmacokinetic parameters of venlafaxine and EFA do not and change. The clinical significance of this effect is unknown. Venlafaxine may affect the pharmacodynamics of other drugs acting at the level of the serotonergic neurotransmitter system, so care should be taken when it is given simultaneously with triptans, other selective serotonin reuptake inhibitors and lithium drugs.
special instructions
When depression increases the risk of suicidal thoughts and suicidal attempts.This risk persists until the onset of persistent remission. Because improvement may not occur within the first few weeks of treatment or more, patients should be kept under constant medical supervision throughout this entire period until the onset of sustained improvement. The risk of suicidal attempts is highest immediately after starting the drug, but also increases again in the early stages of recovery. Velafax should not be used in the treatment of children and adolescents under 18 years of age. In patients with a history of suicidal behavior, or a tendency to the occurrence of suicidal thoughts before treatment, as well as in young adult patients, the risk of suicidal thoughts or attempts at suicide is highest. In placebo-controlled clinical trials of antidepressants in adult patients with mental disorders, an increased likelihood of suicidal behavior (suicide attempt and suicidal thoughts) in people under 25 years of age who receive antidepressants, including venlafaxine, is shown. Patients and people caring for patients should be warned about the need to monitor the occurrence of suicidal thoughts and immediately seek medical attention in the event of the occurrence of relevant symptoms. As with the treatment of other Heimi antidepressants, an abrupt cessation of venlafaxine therapy — especially after high doses of the drug — can cause symptoms of withdrawal syndrome, and therefore it is recommended to gradually reduce the dose of the drug before discontinuing the drug. The risk of withdrawal symptoms depends on the size of the dose, the duration of therapy, and the individual sensitivity of the patient. Patients with affective disorders in the treatment of antidepressants (including venlafaxine) may experience hypomania or mania. Velafax (as well as other antidepressants) should be prescribed with caution to patients with a history of mania (such patients need medical supervision). As with other antidepressants, venlafaxine should be administered with caution to patients with epileptic seizures in history. Treatment with venlafaxine should be interrupted when epileptic seizures occur.The drug should not be prescribed to patients with uncontrolled epilepsy, and patients with controlled epilepsy need careful observation. The use of venlafaxine may be associated with the development of psychomotor anxiety, which is clinically reminiscent of akathisia and is characterized by subjectively unpleasant and distressing anxiety with the need to move, often combined with disability sit or stand still. This condition is most often observed during the first few weeks of treatment. If such symptoms occur, increasing the dose may have an adverse effect and consider the appropriateness of continuing to take venlafaxine. Patients should be warned about the need to immediately consult a doctor if a rash, urticaria or other allergic reactions occur. A dose-dependent increase in blood pressure has been noted in some patients while receiving venlafaxine. therefore, regular blood pressure monitoring is recommended, especially during the selection or increase of the dose. heart rate, especially while taking high doses. Care should be taken when using the drug in patients with a tendency to tachycardia. Patients, especially the elderly, should be warned about the possibility of dizziness and an imbalance (balance orthostatic hypotension). Patients taking venlafaxine rarely observed changes in ECG parameters (prolongation of the PR interval, expansion of the QRS complex, prolongation of the QT interval. With caution, venlafaxine should be prescribed to patients who have recently had a myocardial infarction and with unstable angina, ecause the safety of the drug in this category of patients is not izuchena.Kak and other serotonin reuptake inhibitors, venlafaxine may increase the risk of bleeding into the skin and mucous membranes. When treating patients prone to such conditions, caution is needed. While taking venlafaxine, especially in conditions of dehydration or a decrease in circulating blood volume (including in elderly patients and patients taking diuretics), hyponatremia and / or inadequate syndrome may occur. secretion of antidiuretic hormone. Mydriasis can be observed while taking the drug, and therefore it is recommended to control intraocular pressure in patients prone to elevation or with angle-closure glaucoma. Not recommended It is planned to combine venlafaxine with weight-reducing agents (incl.phentermine), due to the lack of data on efficacy and safety. Clinical studies carried out to date have not revealed tolerance to venlafaxine or dependence on it. Despite this, the physician must establish careful monitoring of patients to identify signs of drug abuse (as with other drugs acting on the central nervous system). Patients with a history of indications of drug dependence need special monitoring. When using venlafaxine for a long period of time, it is necessary to control the level of serum cholesterol. With caution, the drug should be prescribed for abnormal liver function or kidney function. Sometimes it may be necessary to reduce the dose. On the background of venlafaxine intake, special care should be taken when conducting electroconvulsive therapy, since there is no experience with venlafaxine in these conditions. During treatment, alcohol is not recommended. Influence on the ability to drive vehicles and control mechanisms Venlafaxine has virtually no effect on psychomotor and cognitive functions. However, given the possibility of significant side effects from the CNS, during the period of treatment with venlafaxine, care must be taken when driving vehicles and engaging in potentially hazardous activities that require increased concentration and psychomotor speed.