Venlafaxina

Venlafaxina Uses, Dosage, Side Effects, Food Interaction and all others data.

The exact mechanism of action of venlafaxine is unknown, but appears to be associated with the its potentiation of neurotransmitter activity in the CNS. Venlafaxina and its active metabolite, O-desmethylvenlafaxine (ODV), inhibit the reuptake of both serotonin and norepinephrine with a potency greater for the 5-HT than for the NE reuptake process. Both venlafaxine and the ODV metabolite have weak inhibitory effects on the reuptake of dopamine but, unlike the tricyclics and similar to SSRIs, they are not active at histaminergic, muscarinic, or alpha(1)-adrenergic receptors.

The mechanism of venlafaxine's (and its metabolite, O-desmethylvenlafaxine (ODV)) antidepressant effect is believed to be due to their potentiation of neurotransmitter activity in the central nervous system through the inhibition of the reuptake of serotonin and norepinephrine from within the synapse. Venlafaxina has also been shown to weakly inhibit dopamine reuptake. Neither venlafaxine nor ODV bind to muscarinic, histaminergic, or alpha-1 adrenergic receptors; pharmacologic activity at these receptors is hypothesized to be associated with the various anticholinergic, sedative, and cardiovascular effects seen with other psychotropic drugs. Hyponatremia has also been shown to occur as a result of treatment with SNRIs, and is associated with the development of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) . Venlafaxina also demonstrates a clinically significant and dose-related effect on blood pressure, likely due to its potentiation of norepinephrine .

Trade Name Venlafaxina
Availability Prescription only
Generic Venlafaxine
Venlafaxine Other Names Venlafaxina, Venlafaxine, Venlafaxinum
Related Drugs Rexulti, sertraline, trazodone, escitalopram, fluoxetine, alprazolam, duloxetine, Lexapro, amitriptyline, Zoloft
Type
Formula C17H27NO2
Weight Average: 277.4018
Monoisotopic: 277.204179113
Protein binding

The degree of binding of venlafaxine to human plasma is 27% ± 2% at concentrations ranging from 2.5 to 2215 ng/mL. The degree of ODV binding to human plasma is 30% ± 12% at concentrations ranging from 100 to 500 ng/mL. Protein-binding-induced drug interactions with venlafaxine are not expected.

Groups Approved
Therapeutic Class Serotonin-norepinephrine reuptake inhibitor (SNRI)
Manufacturer
Available Country
Last Updated: September 19, 2023 at 7:00 am
Venlafaxina
Venlafaxina

Uses

Venlafaxina tablets is used for the treatment of major depressive disorder.

The efficacy of venlafaxine tablets, in the treatment of major depressive disorder was established in 6 week controlled trials of adult outpatients whose diagnoses corresponded most closely to the DSM-III or DSM-III-R category of major depression and in a 4 week controlled trial of inpatients meeting diagnostic criteria for major depression with melancholia

A major depressive episode implies a prominent and relatively persistent depressed or dysphoric mood that usually interferes with daily functioning (nearly every day for at least 2 weeks); it should include at least 4 of the following 8 symptoms: change in appetite, change in sleep, psychomotor agitation or retardation, loss of interest in usual activities or decrease in sexual drive, increased fatigue, feelings of guilt or worthlessness, slowed thinking or impaired concentration, and a suicide attempt or suicidal ideation.

The efficacy of venlafaxine hydrochloride extended-release capsules in maintaining an antidepressant response for up to 26 weeks following 8 weeks of acute treatment was demonstrated in a placebocontrolled trial. The efficacy of venlafaxine tablets in maintaining an antidepressant response in patients with recurrent depression who had responded and continued to be improved during an initial 26 weeks of treatment and were then followed for a period of up to 52 weeks was demonstrated in a second placebo-controlled trial (see Clinical Trials). Nevertheless, the physician who elects to use venlafaxine tablets / extended-release capsules for extended periods should periodically re-evaluate the long-term usefulness of the drug for the individual patient.

Venlafaxina is also used to associated treatment for these conditions: Generalized Anxiety Disorder (GAD), Major Depressive Disorder (MDD), Migraine, Neuropathic Pain, Panic Disorder, Social Anxiety Disorder (SAD), Vasomotor Symptoms Associated With Menopause

How Venlafaxina works

The exact mechanism of action of venlafaxine is unknown, but appears to be associated with the potentiation of neurotransmitter activity in the CNS. Venlafaxina and its active metabolite, O-desmethylvenlafaxine (ODV), inhibit the reuptake of both serotonin and norepinephrine with a potency greater for the 5-HT than for the NE reuptake process . Both venlafaxine and the ODV metabolite have weak inhibitory effects on the reuptake of dopamine but, unlike the tricyclics and similar to SSRIs, they are not active at histaminergic, muscarinic, or alpha(1)-adrenergic receptors.

Dosage

Venlafaxina dosage

Initial Treatment: The recommended starting dose for venlafaxine tablets is 75 mg/day, administered in two or three divided doses, taken with food. Depending on tolerability and the need for further clinical effect, the dose may be increased to 150 mg/day. If needed, the dose should be further increased up to 225 mg/day. When increasing the dose, increments of up to 75 mg/day should be made at intervals of no less than 4 days. Inoutpatientsettings there was no evidence of usefulness of doses greater than 225 mg/day for moderately depressed patients, but more severely depressed inpatients responded to a mean dose of 350 mg/day. Certain patients, including more severely depressed patients, may therefore respond more to higher doses, up to a maximum of 375 mg/day, generally in three divided doses

Dosage For Elderly Patients: No dose adjustment is recommended for elderly patients on the basis of age. As with any antidepressant, however, caution should be exercised in treating the elderly. When individualizing the dosage, extra care should be taken when increasing the dose.

Maintenance Treatment: It is generally agreed that acute episodes of major depressive disorder require several months or longer of sustained pharmacological therapy beyond response to the acute episode. In one study, in which patients responding during 8 weeks of acute treatment with venlafaxine hydrochloride extendedrelease capsules were assignedrandomlyto placebo or to the same dose of venlafaxine hydrochloride extended-release capsules (75, 150, or 225 mg/day, qAM) during 26 weeks of maintenance treatment as they had received during the acute stabilization phase, longer-term efficacy was demonstrated. A second longer-term study has demonstrated the efficacy of venlafaxine tablets in maintaining an antidepressant response in patients with recurrent depression who had responded and continued to be improved during an initial 26 weeks of treatment and were then randomly assigned to placebo or venlafaxine tablets for periods of up to 52 weeks on the same dose (100 to 200 mg/day, on ab.i.d.schedule) (seeClinical Trials). Based on these limited data, it is not known whether or not the dose of venlafaxine tablets / extended-release capsules needed for maintenance treatment is identical to the dose needed to achieve an initial response. Patients should be periodically reassessed to determine the need for maintenance treatment and the appropriate dose for such treatment.

Discontinuing Venlafaxina Tablet: Symptoms associated with discontinuation of venlafaxine tablets, other SNRIs, and SSRIs, have been reported. Patients should be monitored for these symptoms when discontinuing treatment. A gradual reduction in the dose rather than abrupt cessation is recommended whenever possible. If intolerable symptoms occur following a decrease in the dose or upon discontinuation of treatment, then resuming the previously prescribed dose may be considered. Subsequently, the physician may continue decreasing the dose but at a more gradual rate.

Side Effects

Changes in behaviour, suicidal ideation, agitation, tremor, nervousness, anxiety, insomnia, confusions, abnormal dreams, HTN, nausea, headache, asthenia, somnolence, dizziness, dry mouth, vomiting, constipation, diarrhoea, dyspepsia, abdominal pain, anorexia, sexual dysfunction, urinary frequency, visual disturbances, mydriasis, vasodilatation, paraesthesia, hypertonia, chills or fever, palpitations, wt gain or loss, arthralgia, myalgia, tinnitus, pruritus, dyspnoea, yawning, rashes, sweating, increased serum cholesterol, may impair platelet aggregation.

Toxicity

Overdose of venlafaxine is typically associated with mild symptoms. However, severe toxicity is reported with the most common symptoms being CNS depression, serotonin toxicity, seizure, or cardiac conduction abnormalities. Venlafaxina's toxicity appears to be higher than other SSRIs, with a fatal toxic dose closer to that of the tricyclic antidepressants than the SSRIs. Doses of 900 mg or more are likely to cause moderate toxicity. Deaths have been reported following large doses.

Precaution

History of MI or unstable cardiac disease, seizure; hypomania or mania, increased intraocular pressure or at risk of acute narrow-angle galaucoma, at risk of bleeding. Renal and hepatic impairment. Gradual dose reduction is recommended rather than abrupt withdrawal. Pregnancy and lactation. Patient Counselling May impair ability to drive or operate machinery.

Interaction

Increased risk of serotonin syndrome with TCA, SSRI, SNRI, lithium, sibutramine, tramadol. May increase serum levels with CYP3A4 inhibitors (e.g. ketoconazole, atazanavir, clarithromycin). May increase serum levels of haloperidol. May decrease serum levels of indinavir. May increase bleeding risk with aspirin, NSAIDs, warfarin and other anticoagulants.

Food Interaction

  • Avoid alcohol. Prescribing information recommends the avoidance of alcohol during therapy.
  • Avoid St. John's Wort. Co-administration of St. John's Wort may lead to additive serotonergic activity and an increased risk of serotonin syndrome.
  • Take with food. Co-administration with food helps to alleviate/mitigate GI upset.

[Moderate] GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents.

Use in combination may result in additive central nervous system depression and
MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol.

Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

Venlafaxina Hypertension interaction

[Moderate] Selective serotonin and norepinephrine reuptake inhibitor antidepressants (SNRIs) have been associated with sustained increases in blood pressure.

Therapy with SNRI antidepressants should be administered cautiously in patients with preexisting hypertension.

Blood pressure should be assessed prior to initiating treatment and monitored regularly.

The dose should be reduced or discontinued if necessary.

Volume of Distribution

  • 7.5 ± 3.7 L/kg venlafaxine
  • 5.7 ± 1.8 L/kg O-desmethylvenlafaxine(active metabolite)

Elimination Route

Venlafaxina is well absorbed, with at least 92% of a single dose absorbed on the basis of mass balance studies . Food does not affect the absorption of venlafaxine or its subsequent metabolism into ODV. Bioavailability is 45% following oral administration. Time to steady state = 3 days.

Half Life

5 hours

Clearance

Steady state plasma clearance, venlafaxine = 1.3 ± 0.6 L/h/kg; Steady state plasma clearance, ODV = 0.4 ± 0.2 L/h/kg.

Elimination Route

Renal elimination of venlafaxine and its metabolites is the primary route of excretion. Approximately 87% of a venlafaxine dose is recovered in the urine within 48 hours as either unchanged venlafaxine (5%), unconjugated ODV (29%), conjugated ODV (26%), or other minor inactive metabolites (27%).

Pregnancy & Breastfeeding use

Treatment Of Pregnant Women During The Third TrimesterNeonates exposed to venlafaxine tablets, USP, other SNRIs, or SSRIs, late in the third trimester have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding. When treating pregnant women with venlafaxine tablets during the third trimester, the physician should carefully consider the potential risks and benefits of treatment.

Contraindication

Concomitant use with MAOIs or within 14 days of discontinuing the MAOI. Use with linezolid or IV methylene blue.

Special Warning

Dosage For Patients With Hepatic Impairment: Given the decrease in clearance and increase in elimination half-life for both venlafaxine and ODV that is observed in patients with hepatic cirrhosis and mild and moderate hepatic impairment compared to normal subjects, it is recommended that the total daily dose be reduced by 50% in patients with mild to moderate hepatic impairment. Since there was much individual variability in clearance between subjects with cirrhosis, it may be necessary to reduce the dose even more than 50%, and individualization of dosing may be desirable in some patients.

Dosage For Patients With Renal Impairment: Given the decrease in clearance for venlafaxine and the increase in elimination half-life for both venlafaxine and ODV that is observed in patients with renal impairment (GFR = 10 to 70 mL/min) compared to normals, it is recommended that the total daily dose be reduced by 25% in patients with mild to moderate renal impairment. It is recommended that the total daily dose be reduced by 50% in patients undergoing hemodialysis. Since there was much individual variability in clearance between patients with renal impairment, individualization of dosing may be desirable in some patients.

Acute Overdose

Symptoms: Sweating, dizziness, somnolence, mydriasis, convulsions, vomiting, ECG changes, cardiac arrhythmias and seizures.

Management: Symptomatic and supportive treatment. Ensure adequate airway, oxygenation and ventilation. Initiate gastric lavage immediately after ingestion. Admin activated charcoal to reduce absorption. Monitor cardiac rhythm and vital signs.

Storage Condition

Store between 20-25° C.

Innovators Monograph

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FAQ

What is the Venlafaxina used for?

Venlafaxina is used to treat depression, anxiety, panic attacks, and social anxiety disorder (social phobia). It may improve your mood and energy level and may help restore your interest in daily living.

How safe Venlafaxina is?

Venlafaxina is safe to take for a long time. A few people may get sexual side effects, such as problems getting an erection or a lower sex drive. In some cases these can continue even after stopping the medicine.

What are the common side effect of Venlafaxina?

Common side effects

  • feeling sick.
  • headaches.
  • sweating.
  • dry mouth.
  • trouble sleeping.
  • feeling dizzy.
  • feeling sleepy.
  • constipation.


Is Venlafaxina safe during pregnancy?

Use of the Venlafaxina during early pregnancy may be linked to several birth defects, including heart defects, defects of the brain and spine, cleft lip and cleft palate, hypospadias, and gastroschisis.

Can I still take Venlafaxina while pregnant?

Venlafaxina has been linked to a very small increased risk of problems for your unborn baby. If your depression is not treated during pregnancy this can also increase the chance of problems. You may need to take Venlafaxina during pregnancy if you need it to remain well.

Is Venlafaxina safe during breastfeeding?

If your baby is healthy, Venlafaxina can be used during breastfeeding. It has been used in breastfeeding mothers usually without any problems.Venlafaxina passes into breast milk in small amounts. It has been linked with side-effects in very few breastfed babies.

What happens if I drink while taking Venlafaxina?

Alcohol can increase the nervous system side effects of Venlafaxina such as dizziness, drowsiness, and difficulty concentrating. Some people may also experience impairment in thinking and judgment. You should avoid or limit the use of alcohol while being treated with Venlafaxina.

Why is Venlafaxina bad for me?

Venlafaxina can also increase your heart rate. If you have hyperthyroidism and take Venlafaxina, your heart rate may increase to a dangerous level.

Can Venlafaxina cause weight gain?

A large proportion of patients treated with Venlafaxina, gain a significant amount of weight.

Does Venlafaxina affect memory?

Venlafaxina with buspirone are both of these medicines are reported to cause memory problems.

What does Venlafaxina do to the brain?

Venlafaxina works by increasing serotonin levels, norepinephrine, and dopamine in the brain by blocking transport proteins and stopping its reuptake at the presynaptic terminal.

Can Venlafaxina cause hair loss?

there has been only 1 report of hair loss associated with venlafaxine therapy,5 and ours is the first report of hair loss with both fluoxetine and Venlafaxina.

Can Venlafaxina cause nightmares?

Even antidepressants such as duloxetine and Venlafaxina can cause nightmares.

Does Venlafaxina affect your eyes?

Venlafaxina may cause some people to become drowsy or have blurred vision.

Can I drive after taking Venlafaxina?

Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert or able to see clearly.

Does Venlafaxina affect sleep?

Venlafaxina increased both wake time and sleep stage.

When should I take Venlafaxina ?

The tablet is usually taken two or three times a day with food. It's best to take it in the morning.Venlafaxina also can choose to take them at any time as long as you stick to the same time every day.

What happens when you stop Venlafaxina?

Stopping Venlafaxina abruptly may result in one or more of the following withdrawal symptoms: irritability, nausea, feeling dizzy, vomiting, nightmares, headache, and/or paresthesias (prickling, tingling sensation on the skin). Depression is also a part of bipolar illness.

*** Taking medicines without doctor's advice can cause long-term problems.
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