venlafaxine hydrochloride, extended release
Brand names: venlafaxine hydrochloride, extended release
Boxed warning
BOXED WARNING WARNING: Suicidality and antidepressant drugs Antidepressants increased the risk compared to placebo of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults in short-term studies of Major Depressive Disorder (MDD) and other psychiatric disorders. Anyone considering the use of Venlafaxine Hydrochloride Extended-Release Tablets or any other antidepressant in a child, adolescent, or young adult must balance this risk with the clinical need. Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24; there was a reduction in risk with antidepressants compared to placebo in adults aged 65 and older. Depression and certain other psychiatric disorders are themselves associated with increases in the risk of suicide. Patients of all ages who are started on antidepressant therapy should be monitored appropriately and observed closely for clinical worsening, suicidality, or unusual changes in behavior. Families and caregivers should be advised of the need for close observation and communication with the prescriber. Venlafaxine Hydrochloride Extended-Release Tablets are not approved for use in pediatric patients. [See Warnings and Precautions ( 5.1 ) and Patient Counseling Information ( 17.1 )] WARNING: Suicidality and Antidepressants See full prescribing information for complete boxed warning. Increased risk of suicidal thinking and behavior in children, adolescents and young adults taking antidepressants for major depressive disorder (MDD) and other psychiatric disorders. Venlafaxine Hydrochloride Extended-Release Tablets are not approved for use in pediatric patients. ( 5.1 )
Warnings
Contraindications
4 CONTRAINDICATIONS Serotonin Syndrome and MAOIs: Do not use MAOIs intended to treat psychiatric disorders with venlafaxine hydrochloride extended-release tablets or within 7 days of stopping treatment with Venlafaxine Hydrochloride Extended-Release Tablets. Do not use venlafaxine hydrochloride extended-release tablets within 14 days of stopping an MAOI intended to treat psychiatric disorders. In addition, do not start venlafaxine hydrochloride extended-release tablets in a patient who is being treated with linezolid or intravenous methylene blue ( 4.1 ). 4.1 Monoamine Oxidase Inhibitors (MAOIs) The use of MAOIs intended to treat psychiatric disorders with Venlafaxine Hydrochloride Extended-Release Tablets or within 7 days of stopping treatment with Venlafaxine Hydrochloride Extended-Release Tablets is contraindicated because of an increased risk of serotonin syndrome. The use of Venlafaxine Hydrochloride Extended-Release Tablets within 14 days of stopping, an MAOI intended to treat psychiatric disorders is also contraindicated [ see Dosage and Administration ( 2.6 ), and Warnings and Precautions ( 5.2 )] . Starting Venlafaxine Hydrochloride Extended-Release Tablets in a patient who is being treated with MAOIs such as linezolid or intravenous methylene blue is also contraindicated because of an increased risk of serotonin syndrome [ see Dosage and Administration ( 2.7 ) and Warnings and Precautions ( 5.2 )] .
Overdose
10 OVERDOSAGE 10.1 Human Experience Among the patients included in the premarketing evaluation of venlafaxine hydrochloride extended-release capsules, there were 2 reports of acute overdosage with venlafaxine hydrochloride extended-release capsules in major depressive disorder trials, either alone or in combination with other drugs. One patient took a combination of 6 g of venlafaxine hydrochloride extended-release capsules and 2.5 mg of lorazepam. This patient was hospitalized, treated symptomatically, and recovered without any untoward effects. The other patient took 2.85 g of venlafaxine hydrochloride extended-release capsules. This patient reported paresthesia of all four limbs but recovered without sequelae. There were no reports of acute overdose with venlafaxine hydrochloride extended-release capsules in Social Anxiety Disorder trials. Among the patients included in the premarketing evaluation with venlafaxine hydrochloride immediate-release tablets, there were 14 reports of acute overdose with venlafaxine, either alone or in combination with other drugs and/or alcohol. The majority of the reports involved ingestion in which the total dose of venlafaxine taken was estimated to be no more than several-fold higher than the usual therapeutic dose. The 3 patients who took the highest doses were estimated to have ingested approximately 6.75 g, 2.75 g, and 2.5 g. The resultant peak plasma levels of venlafaxine for the latter 2 patients were 6.24 and 2.35 μg/mL, respectively, and the peak plasma levels of O‑desmethylvenlafaxine were 3.37 and 1.30 μg/mL, respectively. Plasma venlafaxine levels were not obtained for the patient who ingested 6.75 g of venlafaxine. All 14 patients recovered without sequelae. Most patients reported no symptoms. Among the remaining patients, somnolence was the most commonly reported symptom. The patient who ingested 2.75 g of venlafaxine was observed to have 2 generalized convulsions and a prolongation of QTc to 500 msec, compared with 405 msec at baseline. Mild sinus tachycardia was reported in 2 of the other patients. In postmarketing experience, overdose with venlafaxine has occurred predominantly in combination with alcohol and/or other drugs. The most commonly reported reactions in overdosage include tachycardia, changes in level of consciousness (ranging from somnolence to coma), mydriasis, seizures, and vomiting. Electrocardiogram changes (e.g., prolongation of QT interval, bundle branch block, QRS prolongation), ventricular tachycardia, bradycardia, hypotension, rhabdomyolysis, vertigo, liver necrosis, serotonin syndrome, and death have been reported. Published retrospective studies report that venlafaxine overdosage may be associated with an increased risk of fatal outcomes compared to that observed with SSRI antidepressant products, but lower than that for tricyclic antidepressants. Epidemiological studies have shown that venlafaxine-treated patients have a higher pre-existing burden of suicide risk factors than SSRI-treated patients. The extent to which the finding of an increased risk of fatal outcomes can be attributed to the toxicity of venlafaxine in overdosage as opposed to some characteristic(s) of venlafaxine-treated patients is not clear. Prescriptions for Venlafaxine Hydrochloride Extended-Release Tablets should be written for the smallest quantity of tablets consistent with good patient management, in order to reduce the risk of overdose. 10.2 Management of Overdosage Treatment should consist of those general measures employed in the management of overdosage with any antidepressant. Ensure an adequate airway, oxygenation, and ventilation. Monitor cardiac rhythm and vital signs. General supportive and symptomatic measures are also recommended. Induction of emesis is not recommended. Gastric lavage with a large bore orogastric tube with appropriate airway protection, if needed, may be indicated if performed soon after ingestion or in symptomatic patients. Activated charcoal should be administered. Due to the large volume of distribution of this drug, forced diuresis, dialysis, hemoperfusion, and exchange transfusion are unlikely to be of benefit. No specific antidotes for venlafaxine are known. In managing overdosage, consider the possibility of multiple drug involvement. The physician should consider contacting a poison control center for additional information on the treatment of any overdose. Telephone numbers for certified poison control centers are listed in the Physicians' Desk Reference ® (PDR) .
Drug interactions
7 DRUG INTERACTIONS MAOIs: concomitant use contraindicated. ( 4 ) Avoid MAOIs 14 days before starting venlafaxine and 7 days after stopping venlafaxine. ( 5.2 ) Cimetidine: Caution in patients with pre-existing hypertension, in elderly patients and patients with hepatic dysfunction. ( 7.2 ) Haloperidol: Increase in haloperidol AUC and C max . ( 7.4 ) Ketoconazole: Increase in venlafaxine and O-desmethylvenlafaxine AUC and C max . Caution when using venlafaxine with substances that inhibit both CYP2D6 and CYP3A4. ( 7.7 ) Metoprolol: Possibly reduced blood pressure lowering effect despite increased metoprolol plasma levels. Caution should be exercised with co-administration of venlafaxine and metoprolol. ( 7.8 ) CNS-active drugs: Caution when using venlafaxine with such drugs. ( 7.10 ) Serotonergic drugs (e.g., triptans, SSRIs, other SNRIs, linezolid, lithium, tramadol, or St. John's Wort): Potential for serotonin syndrome. Careful patient observation advised. ( 7.10 ) Tryptophan supplements: Concomitant use not recommended. ( 7.10 ) 7.1 Alcohol A single dose of ethanol (0.5 g/kg) had no effect on the pharmacokinetics of venlafaxine or O‑desmethylvenlafaxine (ODV) when venlafaxine was administered at 150 mg/day in 15 healthy male subjects. Additionally, administration of venlafaxine in a stable regimen did not exaggerate the psychomotor and psychometric effects induced by ethanol in these same subjects when they were not receiving venlafaxine. 7.2 Cimetidine Concomitant administration of cimetidine and venlafaxine in a steady-state study for both drugs resulted in inhibition of first-pass metabolism of venlafaxine in 18 healthy subjects. The oral clearance of venlafaxine was reduced by about 43%, and the exposure (AUC) and maximum concentration (C max ) of the drug were increased by about 60%. However, coadministration of cimetidine had no apparent effect on the pharmacokinetics of ODV, which is present in much greater quantity in the circulation than venlafaxine. The overall pharmacological activity of venlafaxine plus ODV is expected to increase only slightly, and no dosage adjustment should be necessary for most normal adults. However, for patients with pre-existing hypertension, and for elderly patients or patients with hepatic dysfunction, the interaction associated with the concomitant use of venlafaxine and cimetidine is not known and potentially could be more pronounced. Therefore, caution is advised with such patients. 7.3 Diazepam Under steady-state conditions for venlafaxine administered at 150 mg/day, a single 10 mg dose of diazepam did not appear to affect the pharmacokinetics of either venlafaxine or ODV in 18 healthy male subjects. Venlafaxine also did not have any effect on the pharmacokinetics of diazepam or its active metabolite, desmethyldiazepam, or affect the psychomotor and psychometric effects induced by diazepam. 7.4 Haloperidol Venlafaxine administered under steady-state conditions at 150 mg/day in 24 healthy subjects decreased total oral-dose clearance (Cl/F) of a single 2 mg dose of haloperidol by 42%, which resulted in a 70% increase in haloperidol AUC. In addition, the haloperidol C max increased 88% when coadministered with venlafaxine, but the haloperidol elimination half-life (t 1/2 ) was unchanged. The mechanism explaining this finding is unknown. 7.5 Lithium The steady-state pharmacokinetics of venlafaxine administered at 150 mg/day were not affected when a single 600 mg oral dose of lithium was administered to 12 healthy male subjects. ODV also was unaffected. Venlafaxine had no effect on the pharmacokinetics of lithium (see also CNS-Active Drugs, below). 7.6 Drugs Highly Bound to Plasma Proteins Venlafaxine is not highly bound to plasma proteins; therefore, administration of Venlafaxine Hydrochloride Extended-Release Tablets to a patient taking another drug that is highly protein bound should not cause increased free concentrations of the other drug. 7.7 Drugs that Inhibit Cytochrome P450 Isoenzymes CYP2D6 Inhibitors: In vitro and in vivo studies indicate that venlafaxine is metabolized to its active metabolite, ODV, by CYP2D6, the isoenzyme that is responsible for the genetic polymorphism seen in the metabolism of many antidepressants. Therefore, the potential exists for a drug interaction between drugs that inhibit CYP2D6-mediated metabolism of venlafaxine, reducing the metabolism of venlafaxine to ODV, resulting in increased plasma concentrations of venlafaxine and decreased concentrations of the active metabolite. CYP2D6 inhibitors such as quinidine would be expected to do this, but the effect would be similar to what is seen in patients who are genetically CYP2D6 poor metabolizers [ see Clinical Pharmacology ( 12.3 )] . Therefore, no dosage adjustment is required when venlafaxine is coadministered with a CYP2D6 inhibitor. Ketoconazole: A pharmacokinetic study with ketoconazole 100 mg b.i.d. with a single dose of venlafaxine 50 mg in extensive metabolizers (EM; n=14) and 25 mg in poor metabolizers (PM; n=6) of CYP2D6 resulted in higher plasma concentrations of both venlafaxine and O-desmethylvenlafaxine (ODV) in most subjects following administration of ketoconazole. Venlafaxine C max increased by 26% in EM subjects and 48% in PM subjects. C max values for ODV increased by 14% and 29% in EM and PM subjects, respectively. Venlafaxine AUC increased by 21% in EM subjects and 70% in PM subjects (range in PM subjects: -2% to 206%), and AUC values for ODV increased by 23% and 33% in EM and PM (range in PM subjects: - 38% to 105%) subjects, respectively. Combined AUCs of venlafaxine and ODV increased on average by approximately 23% in EM subjects and 53% in PM subjects (range in PM subjects: 4% to 134%). Concomitant use of CYP3A4 inhibitors and venlafaxine may increase levels of venlafaxine and ODV. Therefore, caution is advised if a patient’s therapy includes a CYP3A4 inhibitor and venlafaxine concomitantly. 7.8 Drugs Metabolized by Cytochrome P450 Isoenzymes CYP2D6 In vitro studies indicate that venlafaxine is a relatively weak inhibitor of CYP2D6. These findings have been confirmed in a clinical drug interaction study comparing the effect of venlafaxine with that of fluoxetine on the CYP2D6-mediated metabolism of dextromethorphan to dextrorphan. Imipramine - Venlafaxine did not affect the pharmacokinetics of imipramine and 2-OH-imipramine. However, desipramine AUC, C max , and C min increased by about 35% in the presence of venlafaxine. The 2-OH-desipramine AUCs increased by at least 2.5 fold (with venlafaxine 37.5 mg q12h) and by 4.5 fold (with venlafaxine 75 mg q12h). Imipramine did not affect the pharmacokinetics of venlafaxine and ODV. The clinical significance of elevated 2-OH-desipramine levels is unknown. Metoprolol - Concomitant administration of venlafaxine (50 mg every 8 hours for 5 days) and metoprolol (100 mg every 24 hours for 5 days) to 18 healthy male subjects in a pharmacokinetic interaction study for both drugs resulted in an increase of plasma concentrations of metoprolol by approximately 30-40% without altering the plasma concentrations of its active metabolite, α‑hydroxymetoprolol. Metoprolol did not alter the pharmacokinetic profile of venlafaxine or its active metabolite, O-desmethylvenlafaxine. Venlafaxine appeared to reduce the blood pressure lowering effect of metoprolol in this study. The clinical relevance of this finding for hypertensive patients is unknown. Caution should be exercised with co-administration of venlafaxine and metoprolol. Venlafaxine treatment has been associated with dose-related increases in blood pressure in some patients. It is recommended that patients receiving Venlafaxine Hydrochloride Extended-Release Tablets have regular monitoring of blood pressure [ see Warnings and Precautions (5.3)] . Risperidone - Venlafaxine administered under steady-state conditions at 150 mg/day slightly inhibited the CYP2D6-mediated metabolism of risperidone (administered as a single 1 mg oral dose) to its active metabolite, 9-hydroxyrisperidone, resulting in an approximate 32% increase in risperidone AUC. However, venlafaxine coadministration did not significantly alter the pharmacokinetic profile of the total active moiety (risperidone plus 9-hydroxyrisperidone). CYP3A4 Venlafaxine did not inhibit CYP3A4 in vitro . This finding was confirmed in vivo by clinical drug interaction studies in which venlafaxine did not inhibit the metabolism of several CYP3A4 substrates, including alprazolam, diazepam, and terfenadine. Indinavir - In a study of 9 healthy volunteers, venlafaxine administered under steady-state conditions at 150 mg/day resulted in a 28% decrease in the AUC of a single 800 mg oral dose of indinavir and a 36% decrease in indinavir C max . Indinavir did not affect the pharmacokinetics of venlafaxine and ODV. The clinical significance of this finding is unknown. CYP1A2 Venlafaxine did not inhibit CYP1A2 in vitro . This finding was confirmed in vivo by a clinical drug interaction study in which venlafaxine did not inhibit the metabolism of caffeine, a CYP1A2 substrate. CYP2C9 Venlafaxine did not inhibit CYP2C9 in vitro . In vivo , venlafaxine 75 mg by mouth every 12 hours did not alter the pharmacokinetics of a single 500 mg dose of tolbutamide or the CYP2C9 mediated formation of 4-hydroxy-tolbutamide. CYP2C19 Venlafaxine did not inhibit the metabolism of diazepam, which is partially metabolized by CYP2C19 (see Diazepam above). 7.9 Monoamine Oxidase Inhibitors (MAOIs) [ See Dosage and Administration ( 2.6 and 2.7 ), Contraindications ( 4.1 ), and Warnings and Precautions ( 5.2 ).] 7.10 Other Serotonergic Drugs The concomitant use of serotonergic drugs (including other SNRIs, SSRIs, triptans, tricyclic antidepressants, opioids, lithium, buspirone, amphetamines, tryptophan, and St. John’s Wort) with venlafaxine hydrochloride extended-release tablets increases the risk of serotonin syndrome. Monitor patients for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increases. If serotonin syndrome occurs, consider discontinuation of venlafaxine hydrochloride extended-release tablets and/or concomitant serotonergic drugs [ see Warnings and Precautions (5.2) ]. 7.11 Drugs that Interfere with Hemostasis (e.g., NSAIDs, Aspirin, and Warfarin) Serotonin release by platelets plays an important role in hemostasis. Epidemiological studies of the case-control and cohort design that have demonstrated an association between use of psychotropic drugs that interfere with serotonin reuptake and the occurrence of upper gastrointestinal bleeding. These studies have also shown that concurrent use of an NSAID or aspirin may potentiate this risk of bleeding. Altered anticoagulant effects, including increased bleeding, have been reported when SSRIs and SNRIs are coadministered with warfarin. Patients receiving warfarin therapy should be carefully monitored when Venlafaxine Hydrochloride Extended-Release Tablets are initiated or discontinued [ see Warnings and Precautions ( 5.13 )] . 7.12 Electroconvulsive Therapy There are no clinical data establishing the benefit of electroconvulsive therapy combined with Venlafaxine Hydrochloride Extended-Release Tablets treatment. 7.13 Postmarketing Spontaneous Drug Interaction Reports There have been reports of elevated clozapine levels that were temporally associated with adverse reactions, including seizures, following the addition of venlafaxine. There have been reports of increases in prothrombin time, partial thromboplastin time, or INR when venlafaxine was given to patients receiving warfarin therapy. 7.14 Drug-Laboratory Test Interactions False-positive urine immunoassay screening tests for phencyclidine (PCP) and amphetamine have been reported in patients taking venlafaxine. This is due to lack of specificity of the screening tests. False positive test results may be expected for several days following discontinuation of venlafaxine therapy. Confirmatory tests, such as gas chromatography/mass spectrometry, will distinguish venlafaxine from PCP and amphetamine.
Uses
1 INDICATIONS AND USAGE Venlafaxine Hydrochloride Extended-Release Tablets are a selective serotonin and norepinephrine reuptake inhibitor (SNRI) indicated for: Major Depressive Disorder (MDD) ( 1.1 ) Social Anxiety Disorder (SAD) ( 1.2 ) 1.1 Major Depressive Disorder Venlafaxine Hydrochloride Extended-Release Tablets are indicated for the treatment of major depressive disorder (MDD). Efficacy of venlafaxine in MDD was shown in both short-term trials and a longer-term trial in MDD [see Clinical Studies ( 14.1 )] . A major depressive episode (DSM-IV) implies a prominent and relatively persistent (nearly every day for at least 2 weeks) depressed mood or the loss of interest or pleasure in nearly all activities, representing a change from previous functioning, and includes the presence of at least five of the following nine symptoms during the same two-week period: depressed mood, markedly diminished interest or pleasure in usual activities, significant change in weight and/or appetite, insomnia or hypersomnia, psychomotor agitation or retardation, increased fatigue, feelings of guilt or worthlessness, slowed thinking or impaired concentration, a suicide attempt or suicidal ideation. 1.2 Social Anxiety Disorder Venlafaxine Hydrochloride Extended-Release Tablets are indicated for the treatment of Social Anxiety Disorder (SAD), also known as Social Phobia, as defined in DSM-IV. Social Anxiety Disorder (DSM-IV) is characterized by a marked and persistent fear of 1 or more social or performance situations in which the person is exposed to unfamiliar people or to possible scrutiny by others. Exposure to the feared situation almost invariably provokes anxiety, which may approach the intensity of a panic attack. The feared situations are avoided or endured with intense anxiety or distress. The avoidance, anxious anticipation, or distress in the feared situation(s) interferes significantly with the person's normal routine, occupational or academic functioning, or social activities or relationships, or there is a marked distress about having the phobias. Lesser degrees of performance anxiety or shyness generally do not require psychopharmacological treatment. Efficacy of venlafaxine extended release in the treatment of SAD was established in short-term SAD trials [ see Clinical Studies ( 14.2 )] .
Dosage forms & strengths
2 DOSAGE AND ADMINISTRATION Venlafaxine Hydrochloride Extended-Release Tablets should be administered in a single dose with food either in the morning or in the evening at approximately the same time each day. Each tablet should be swallowed whole with fluid and not divided, crushed, chewed, or placed in water. Initial Treatment ( 2.1 ) Indication Starting Dose Dose Increase Maximum Dose Major Depressive Disorder 75 mg/day (in some patients, 37.5 mg/day for 4-7 days) 75 mg/day increments at intervals of 4 days or longer 225 mg/day Social Anxiety Disorder 75 mg/day No benefit at higher doses 75 mg/day Venlafaxine Hydrochloride Extended-Release Tablets should be taken as a single daily dose with food in either the morning or evening at the same time each day. ( 2 ) Discontinuation: Gradual; individualized as necessary. ( 2.4 ) 2.1 Initial Treatment Major Depressive Disorder For most patients, the recommended starting dose for Venlafaxine Hydrochloride Extended-Release Tablets is 75 mg/day, administered in a single dose. In the clinical trials establishing the efficacy of venlafaxine hydrochloride extended-release capsules in moderately depressed outpatients, the initial dose of venlafaxine was 75 mg/day. For some patients, it may be desirable to start at 37.5 mg/day for 4 to 7 days, to allow new patients to adjust to the medication before increasing to 75 mg/day. While the relationship between dose and antidepressant response for venlafaxine hydrochloride extended-release capsules has not been adequately explored, patients not responding to the initial 75 mg/day dose may benefit from dose increases to a maximum of approximately 225 mg/day. Dose increases should be in increments of up to 75 mg/day, as needed, and should be made at intervals of not less than 4 days, since steady state plasma levels of venlafaxine and its major metabolites are achieved in most patients by day 4. In the clinical trials establishing efficacy, upward titration was permitted at intervals of 2 weeks or more; the average doses were about 140 to 180 mg/day [ see Clinical Studies ( 14 )] . It should be noted that, while the maximum recommended dose for moderately depressed outpatients is also 225 mg/day for venlafaxine hydrochloride immediate-release tablets, more severely depressed inpatients in one study of the development program for that product responded to a mean dose of 350 mg/day (range of 150 to 375 mg/day). Whether or not higher doses of Venlafaxine Hydrochloride Extended-Release Tablets are needed for more severely depressed patients is unknown; however, the experience with venlafaxine hydrochloride extended-release capsule doses higher than 225 mg/day is very limited. Social Anxiety Disorder (Social Phobia) The recommended dose is 75 mg/day, administered in a single dose. There was no evidence that higher doses confer any additional benefit. 2.2 Maintenance Treatment There is no body of evidence available from controlled trials to indicate how long patients with major depressive disorder should be treated with Venlafaxine Hydrochloride Extended-Release Tablets. 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 extended-release capsules were assigned randomly to placebo or to the same dose of venlafaxine hydrochloride extended-release capsules (75, 150, or 225 mg per 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 hydrochloride immediate-release tablets in maintaining a response in patients with recurrent major depressive disorder who had responded and continued to be improved during an initial 26 weeks of treatment and were then randomly assigned to placebo or venlafaxine hydrochloride immediate-release tablets for periods of up to 52 weeks on the same dose (100 to 200 mg/day, on a b.i.d. schedule) [ see Clinical Studies (14)] . Based on these limited data, it is not known whether or not the dose of Venlafaxine Hydrochloride Extended-Release Tablets 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. 2.3 Special Populations Treatment of Pregnant Women During the Third Trimester Neonates exposed to venlafaxine hydrochloride extended-release capsules, other SNRIs, or SSRIs late in the third trimester have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding [ see Use in Specific Populations ( 8.1 )] . When treating pregnant women with Venlafaxine Hydrochloride Extended-Release Tablets during the third trimester, the physician should carefully consider the potential risks and benefits of treatment. Patients with Hepatic Impairment Given the decrease in clearance and increase in elimination half-life for both venlafaxine and O‑desmethylvenlafaxine (ODV) that is observed in patients with hepatic cirrhosis and mild and moderate hepatic impairment compared with normal subjects [ see Use in Specific Populations ( 8.6 ) and Clinical Pharmacology ( 12.3 )] , 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 patients with cirrhosis, it may be necessary to reduce the dose even more than 50%, and individualization of dosing may be desirable in some patients. 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 with normal subjects [ see Use in Specific Populations ( 8.7 ) and Clinical Pharmacology ( 12.3 )] , it is recommended that the total daily dose be reduced by 25% to 50%. In patients undergoing hemodialysis, it is recommended that the total daily dose be reduced by 50%. Because there was much individual variability in clearance between patients with renal impairment, individualization of dosage may be desirable in some patients. Elderly Patients No dose adjustment is recommended for elderly patients solely on the basis of age. As with any drug for the treatment of major depressive disorder or Social Anxiety Disorder, however, caution should be exercised in treating the elderly. When individualizing the dosage, extra care should be taken when increasing the dose. 2.4 Discontinuing Venlafaxine Hydrochloride Extended-Release Tablets Symptoms associated with discontinuation of venlafaxine hydrochloride extended-release capsules, other SNRIs, and SSRIs have been reported [ see Warnings and Precautions ( 5.5 )] . 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. In clinical trials with venlafaxine hydrochloride extended-release capsules, tapering was achieved by reducing the daily dose by 75 mg at 1 week intervals. Individualization of tapering may be necessary. 2.5 Switching Patients from Venlafaxine Hydrochloride Immediate-Release Tablets Depressed patients who are currently being treated at a therapeutic dose with venlafaxine hydrochloride immediate-release tablets may be switched to Venlafaxine Hydrochloride Extended-Release Tablets at the nearest equivalent dose (mg/day), e.g., 37.5 mg venlafaxine two-times-a-day to 75 mg Venlafaxine Hydrochloride Extended-Release Tablets once daily. However, individual dosage adjustments may be necessary. 2.6 Switching a Patient To or From a Monoamine Oxidase Inhibitor (MAOI) Intended to Treat Psychiatric Disorders At least 14 days should elapse between discontinuation of an MAOI intended to treat psychiatric disorders and initiation of therapy with Venlafaxine Hydrochloride Extended-Release Tablets. Conversely, at least 7 days should be allowed after stopping Venlafaxine Hydrochloride Extended-Release Tablets before starting an MAOI intended to treat psychiatric disorders [ see Contraindications ( 4.1 )] . 2.7 Use of Venlafaxine Hydrochloride Extended-Release Tablets with Other MAOIs, Such as Linezolid or Methylene Blue Do not start Venlafaxine Hydrochloride Extended-Release Tablets in a patient who is being treated with linezolid or intravenous methylene blue because there is increased risk of serotonin syndrome. In a patient who requires more urgent treatment of a psychiatric condition, other interventions, including hospitalization, should be considered [ see Contraindications ( 4.1 )] . In some cases, a patient already receiving Venlafaxine Hydrochloride Extended-Release Tablets therapy may require urgent treatment with linezolid or intravenous methylene blue. If acceptable alternatives to linezolid or intravenous methylene blue treatment are not available and the potential benefits of linezolid or intravenous methylene blue treatment are judged to outweigh the risks of serotonin syndrome in a particular patient, Venlafaxine Hydrochloride Extended-Release Tablets should be stopped promptly, and linezolid or intravenous methylene blue can be administered. The patient should be monitored for symptoms of serotonin syndrome for 7 days or until 24 hours after the last dose of linezolid or intravenous methylene blue, whichever comes first. Therapy with Venlafaxine Hydrochloride Extended-Release Tablets may be resumed 24 hours after the last dose of linezolid or intravenous methylene blue [ see Warnings and Precautions ( 5.2 )] . The risk of administering methylene blue by non-intravenous routes (such as oral tablets or by local injection) or in intravenous doses much lower than 1 mg/kg with Venlafaxine Hydrochloride Extended-Release Tablets is unclear. The clinician should, nevertheless, be aware of the possibility of emergent symptoms of serotonin syndrome with such use [ see Warnings and Precautions ( 5.2 )] .