"May 17, 2011 -- An antidepressant that modifies sleep-wake cycles proved effective for treating major depression while also improving the sleep quality of patients in key studies, according to a newly published study.
Suicidal Thoughts And Behaviors In Children, Adolescents, And Young Adults
Patients with major depressive disorder (MDD), both adult and pediatric, may experience worsening of their depression and/or the emergence of suicidal ideation and behavior (suicidality) or unusual changes in behavior, whether or not they are taking antidepressant medications, and this risk may persist until significant remission occurs. Suicide is a known risk of depression and certain other psychiatric disorders, and these disorders themselves are the strongest predictors of suicide. There has been a long-standing concern, however, that antidepressants may have a role in inducing worsening of depression and the emergence of suicidality in certain patients during the early phases of treatment. Pooled analyses of short-term placebo-controlled studies of antidepressant drugs (SSRIs and others) showed that these drugs increase the risk of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults (ages 18-24) with MDD and other psychiatric disorders. 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 with antidepressants compared to placebo in adults aged 65 and older.
The pooled analyses of placebo-controlled studies in children and adolescents with MDD, Obsessive Compulsive Disorder (OCD), or other psychiatric disorders included a total of 24 short-term studies of 9 antidepressant drugs in over 4,400 patients. The pooled analyses of placebo-controlled studies in adults with MDD or other psychiatric disorders included a total of 295 short-term studies (median duration of 2 months) of 11 antidepressant drugs in over 77,000 patients. There was considerable variation in risk of suicidality among drugs, but a tendency toward an increase in the younger patients for almost all drugs studied. There were differences in absolute risk of suicidality across the different indications, with the highest incidence in MDD. The risk differences (drug versus placebo), however, were relatively stable within age strata and across indications. These risk differences (drug-placebo difference in the number of cases of suicidality per 1,000 patients treated) are provided in Table 1.
Table 1: Difference in the Number of Cases of Suicidality
per 1,000 Patients Treated versus Placebo
|Age Range||Increases Compared to Placebo|
|< 18||14 additional cases|
|18-24||5 additional cases|
|Decreases Compared to Placebo|
|25-64||1 fewer case|
|≥ 65||6 fewer cases|
No suicides occurred in any of the pediatric studies. There were suicides in the adult studies, but the number was not sufficient to reach any conclusion about drug effect on suicide.
It is unknown whether the suicidality risk extends to longer term use, i.e., beyond several months. However, there is substantial evidence from placebo-controlled maintenance studies in adults with depression that the use of antidepressants can delay the recurrence of depression.
All patients being treated with antidepressants for any indication should be monitored appropriately and observed closely for clinical worsening, suicidality, and unusual changes in behavior, especially during the initial few months of a course of drug therapy, or at times of dose changes, either increases or decreases.
The following symptoms, anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania, and mania, have been reported in adult and pediatric patients being treated with antidepressants for MDD, as well as for other indications, both psychiatric and nonpsychiatric. Although a causal link between the emergence of such symptoms and either the worsening of depression and/or the emergence of suicidal impulses has not been established, there is concern that such symptoms may represent precursors to emerging suicidality.
Consideration should be given to changing the therapeutic regimen, including possibly discontinuing the medication, in patients whose depression is persistently worse, or who are experiencing emergent suicidality or symptoms that might be precursors to worsening depression or suicidality, especially if these symptoms are severe, abrupt in onset, or were not part of the patient's presenting symptoms.
If the decision has been made to discontinue treatment, medication should be tapered, as rapidly as is feasible, but with recognition that abrupt discontinuation can be associated with certain symptoms [see Discontinuation Syndrome and DOSAGE AND ADMINISTRATION].
Families and caregivers of patients being treated with antidepressants for MDD or other indications, both psychiatric and nonpsychiatric, should be alerted about the need to monitor patients for the emergence of agitation, irritability, unusual changes in behavior, and the other symptoms described above, as well as the emergence of suicidality, and to report such symptoms immediately to healthcare providers. Such monitoring should include daily observation by families and caregivers. Prescriptions for Effexor XR should be written for the smallest quantity of capsules consistent with good patient management, in order to reduce the risk of overdose.
Screening Patients for Bipolar Disorder
A major depressive episode may be the initial presentation of bipolar disorder. It is generally believed (though not established in controlled studies) that treating such an episode with an antidepressant alone may increase the likelihood of precipitation of a mixed/manic episode in patients at risk for bipolar disorder. Whether any of the symptoms described above represent such a conversion is unknown. However, prior to initiating treatment with an antidepressant, patients with depressive symptoms should be adequately screened to determine if they are at risk for bipolar disorder; such screening should include a detailed psychiatric history, including a family history of suicide, bipolar disorder, and depression. It should be noted that Effexor XR is not approved for use in treating bipolar depression.
The development of a potentially life-threatening serotonin syndrome has been reported with SNRIs and SSRIs, including Effexor XR alone, but particularly with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, buspirone, and St. John's wort) and with drugs that impair metabolism of serotonin in particular, MAOIs, both those intended to treat psychiatric disorders and others, such as linezolid or intravenous methylene blue). Serotonin syndrome symptoms may include mental status changes (e.g., agitation, hallucinations, delirium, coma) autonomic instability (e.g., tachycardia, labile blood pressure, hyperthermia, diaphoresis, flushing, and dizziness), neuromuscular symptoms (e.g., tremor, rigidity, myoclonus, hyperreflexia, incoordination); seizures and gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea). Patients should be monitored for the emergence of serotonin syndrome.
The concomitant use of Effexor XR with MAOIs (intended to treat psychiatric disorders) is contraindicated. Effexor XR should also not be started in a patient who is being treated with MAOIs such as linezolid or intravenous methylene blue. All reports with methylene blue that provided information on the route of administration involved intravenous administration in the dose range of 1 mg/kg to 8 mg/kg. No reports involved the administration of methylene blue by other routes (such as oral tablets or local tissue injection) or at lower doses. There may be circumstances when it is necessary to initiate treatment with a MAOI such as linezolid or intravenous methylene blue in a patient taking Effexor XR. Effexor XR should be discontinued before initiating treatment with the MAOI [see CONTRAINDICATIONS, DOSAGE AND ADMINISTRATION, and DRUG INTERACTIONS].
If concomitant use of Effexor XR with other serotonergic drugs (e.g., triptans, tricyclic antidepressants, mirtazapine, fentanyl, lithium, tramadol, buspirone, tryptophan, or St. John's wort) is clinically warranted, careful observation of the patient is advised, particularly during treatment initiation and dose increases [see DRUG INTERACTIONS]. Patients should be made aware of the potential risk of serotonin syndrome. Treatment with Effexor XR and any concomitant serotonergic agents should be discontinued immediately if the above events occur, and supportive symptomatic treatment should be initiated.
Elevations In Blood Pressure
Monitor blood pressure before initiating treatment with Effexor XR and regularly during treatment. Control pre-existing hypertension before initiating treatment with Effexor XR. Use caution in treating patients with pre-existing hypertension or cardiovascular or cerebrovascular conditions that might be compromised by increases in blood pressure. Sustained blood pressure elevation can lead to adverse outcomes. Cases of elevated blood pressure requiring immediate treatment have been reported with Effexor XR. Consider dose reduction or discontinuation of treatment for patients who experience a sustained increase in blood pressure.
Across all clinical studies with Effexor, 1.4% of patients in the Effexor XR treated groups experienced a ≥ 15 mm Hg increase in supine diastolic blood pressure (SDBP ) ≥ 105 mm Hg, compared to 0.9% of patients in the placebo groups. Similarly, 1% of patients in the Effexor XR treated groups experienced a ≥ 20 mm Hg increase in supine systolic blood pressure (SSBP) with blood pressure ≥ 180 mm Hg, compared to 0.3% of patients in the placebo groups [see Table 10 in ADVERSE REACTIONS]. Effexor XR treatment was associated with sustained hypertension (defined as treatment-emergent SDBP ≥ 90 mm Hg and ≥ 10 mm Hg above baseline for three consecutive on-therapy visits [see Table 11 in ADVERSE REACTIONS]. An insufficient number of patients received mean doses of Effexor XR over 300 mg per day in clinical studies to fully evaluate the incidence of sustained increases in blood pressure at these higher doses.
SSRIs and SNRIs, including Effexor XR, may increase the risk of bleeding events, ranging from ecchymoses, hematomas, epistaxis, petechiae, and gastrointestinal hemorrhage to life-threatening hemorrhage. Concomitant use of aspirin, Nonsteroidal Anti-Inflammatory Drugs (NSAIDs), warfarin, and other anti-coagulants or other drugs known to affect platelet function may add to this risk. Case reports and epidemiological studies (case-control and cohort design) have demonstrated an association between use of drugs that interfere with serotonin reuptake and the occurrence of gastrointestinal bleeding. Caution patients about the risk of bleeding associated with the concomitant use of Effexor XR and NSAIDs, aspirin, or other drugs that affect coagulation.
The pupillary dilation that occurs following use of many antidepressant drugs including Effexor XR may trigger an angle closure attack in a patient with anatomically narrow angles who does not have a patent iridectomy.
Activation Of Mania/Hypomania
Mania or hypomania was reported in Effexor XR treated patients in the premarketing studies in MDD, SAD, and PD (see Table 2). Mania/hypomania has also been reported in a small proportion of patients with mood disorders who were treated with other marketed drugs to treat MDD. Effexor XR should be used cautiously in patients with a history of mania or hypomania.
Table 2: Incidence (%) of Mania or Hypomania Reported
in Effexor XR Treated Patients in the Premarketing Studies
Discontinuation symptoms have been systematically evaluated in patients taking venlafaxine, including prospective analyses of clinical studies in GAD and retrospective surveys of studies in MDD and SAD. Abrupt discontinuation or dose reduction of venlafaxine at various doses has been found to be associated with the appearance of new symptoms, the frequency of which increased with increased dose level and with longer duration of treatment. Reported symptoms include agitation, anorexia, anxiety, confusion, impaired coordination and balance, diarrhea, dizziness, dry mouth, dysphoric mood, fasciculation, fatigue, flu-like symptoms, headaches, hypomania, insomnia, nausea, nervousness, nightmares, sensory disturbances (including shock-like electrical sensations), somnolence, sweating, tremor, vertigo, and vomiting.
During marketing of Effexor XR, other SNRIs, and SSRIs, there have been spontaneous reports of adverse events occurring upon discontinuation of these drugs, particularly when abrupt, including the following: dysphoric mood, irritability, agitation, dizziness, sensory disturbances (e.g., paresthesia, such as electric shock sensations), anxiety, confusion, headache, lethargy, emotional lability, insomnia, hypomania, tinnitus, and seizures. While these events are generally self-limiting, there have been reports of serious discontinuation symptoms.
Patients should be monitored for these symptoms when discontinuing treatment with Effexor XR. 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 [see DOSAGE AND ADMINISTRATION].
Seizures have occurred with venlafaxine therapy. Effexor XR, like many antidepressants, should be used cautiously in patients with a history of seizures and should be discontinued in any patient who develops seizures. [Must mitigate the risk: Risk factors, concomitant meds that lower the seizure threshold.]
Hyponatremia can occur as a result of treatment with SSRIs and SNRIs, including Effexor XR. In many cases, the hyponatremia appears to be the result of the Syndrome of Inappropriate Antidiuretic Hormone (SIADH) secretion. Cases with serum sodium lower than 110 mmol/L have been reported. Elderly patients may be at greater risk of developing hyponatremia with SSRIs and SNRIs [see Use In Specific Populations]. Also, patients taking diuretics, or those who are otherwise volume-depleted, may be at greater risk. Consider discontinuation of Effexor XR in patients with symptomatic hyponatremia, and institute appropriate medical intervention.
Signs and symptoms of hyponatremia include headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness, which may lead to falls. Signs and symptoms associated with more severe and/or acute cases have included hallucination, syncope, seizure, coma, respiratory arrest, and death.
Weight and Height Changes In Pediatric Patients
The average change in body weight and incidence of weight loss (percentage of patients who lost 3.5% or more) in the placebo-controlled pediatric studies in MDD, GAD, and SAD are shown in Tables 3 and 4.
Table 3: Average Change in Body Weight (kg) From
Beginning of Treatment in Pediatric Patients in Double-blind,
Placebo-controlled Studies of Effexor XR
|Indication (Duration)||Effexor XR||Placebo|
|MDD and GAD (4 pooled studies, 8 weeks)||-0.45 (n = 333)||+0.77 (n = 333)|
|SAD (16 weeks)||-0.75 (n = 137)||+0.76 (n = 148)|
Table 4: Incidence (%) of
Pediatric Patients Experiencing Weight Loss (3.5% or more) in Double-blind,
Placebo-controlled Studies of Effexor XR
|MDD and GAD (4 pooled studies, 8 weeks)||18a (n = 333)||3.6 (n = 333)|
|SAD (16 weeks)||47a (n = 137)||14 (n = 148)|
|ap < 0.001 versus placebo|
Weight loss was not limited to patients with treatment-emergent anorexia [see Appetite Changes in Pediatric Patients].
The risks associated with longer term Effexor XR use were assessed in an open-label MDD study of children and adolescents who received Effexor XR for up to six months. The children and adolescents in the study had increases in weight that were less than expected, based on data from age-and sex-matched peers. The difference between observed weight gain and expected weight gain was larger for children ( < 12 years old) than for adolescents ( ≥ 12 years old).
Table 5 shows the average height increase in pediatric patients in the short-term, placebo-controlled MDD, GAD, and SAD studies. The differences in height increases in GAD and MDD studies were most notable in patients younger than twelve.
Table 5: Average Height
Increases (cm) in Pediatric Patients in Placebo-controlled Studies of Effexor
|Indication (Duration)||Effexor XR||Placebo|
|MDD (8 weeks)||0.8 (n = 146)||0.7 (n = 147)|
|GAD (8 weeks)||0.3a (n = 122)||1.0 (n = 132)|
|SAD (16 weeks)||1.0 (n = 109)||1.0 (n = 112)|
|ap = 0.041|
In the six-month, open-label MDD study, children and adolescents had height increases that were less than expected, based on data from age-and sex-matched peers. The difference between observed and expected growth rates was larger for children ( < 12 years old) than for adolescents ( ≥ 12 years old).
Appetite Changes In Pediatric Patients
Decreased appetite (reported as treatment-emergent anorexia) was more commonly observed in Effexor XR treated patients versus placebo-treated patients in the premarketing evaluation of Effexor XR for MDD, GAD, and SAD (see Table 6).
Table 6: Incidence (%) of Decreased Appetite and
Associated Discontinuation Ratesa (%) in Pediatric Patients in
Placebo-controlled Studies of Effexor XR
|Indication (Duration)||Effexor XR Incidence||Discontinuation||Placebo Incidence||Discontinuation|
|MDD and GAD (pooled, 8 weeks)||10||0.0||3||--|
|SAD (16 weeks)||22||0.7||3||0.0|
|aThe discontinuation rates for weight loss were 0.7% for patients receiving either Effexor XR or placebo.|
Interstitial Lung Disease And Eosinophilic Pneumonia
Interstitial lung disease and eosinophilic pneumonia associated with venlafaxine therapy have been rarely reported. The possibility of these adverse events should be considered in venlafaxine-treated patients who present with progressive dyspnea, cough or chest discomfort. Such patients should undergo a prompt medical evaluation, and discontinuation of venlafaxine therapy should be considered.
Patient Counseling Information
See FDA-approved patient labeling (Medication Guide).
Prescribers or other healthcare professionals should inform patients, their families, and their caregivers about the benefits and risks associated with treatment with Effexor XR and should counsel them in its appropriate use. A patient Medication Guide about “Antidepressant Medicines, Depression and Other Serious Mental Illnesses, and Suicidal Thoughts or Actions” is available for Effexor XR. The prescriber or healthcare professional should instruct patients, their families, and their caregivers to read the Medication Guide and should assist them in understanding its contents. Patients should be given the opportunity to discuss the contents of the Medication Guide and to obtain answers to any questions they may have. The complete text of the Medication Guide is reprinted at the end of this document. Patients should be advised of the following issues and should be asked to alert their prescriber if these occur while taking Effexor XR.
Suicidal Thoughts and Behaviors
Advise patients, their families and caregivers to look for the emergence of suicidality, worsening of depression, and other psychiatric symptoms (anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia, psychomotor restlessness, hypomania, mania, other unusual changes in behavior), especially early during treatment and when the dose is adjusted up or down. Such symptoms should be reported to the patient's prescriber or health professional, especially if they are severe, abrupt in onset, or were not part of the patient's presenting symptoms. Symptoms such as these may be associated with an increased risk for suicidal thinking and behavior and indicate a need for very close monitoring [see BOXED WARNING and WARNINGS AND PRECAUTIONS].
Advise patients taking Effexor XR not to use concomitantly other products containing venlafaxine or desvenlafaxine. Healthcare professionals should instruct patients not to take Effexor XR with an MAOI or within 14 days of stopping an MAOI and to allow 7 days after stopping Effexor XR before starting an MAOI [see CONTRAINDICATIONS].
Patients should be cautioned about the risk of serotonin syndrome, with the concomitant use of Effexor XR and triptans, tramadol, tryptophan supplements, with antipsychotics or other dopamine antagonists, or other serotonergic agents [see WARNINGS AND PRECAUTIONS and DRUG INTERACTIONS].
Elevated Blood Pressure
Advise patients that they should have regular monitoring of blood pressure when taking Effexor XR [see WARNINGS AND PRECAUTIONS].
Patients should be cautioned about the concomitant use of Effexor XR and NSAIDs, aspirin, warfarin, or other drugs that affect coagulation since combined use of psychotropic drugs that interfere with serotonin reuptake and these agents has been associated with an increased risk of bleeding [see WARNINGS AND PRECAUTIONS].
Angle Closure Glaucoma
Patients should be advised that taking Effexor XR can cause mild pupillary dilation, which in susceptible individuals, can lead to an episode of angle closure glaucoma. Pre-existing glaucoma is almost always open-angle glaucoma because angle closure glaucoma, when diagnosed, can be treated definitively with iridectomy. Open-angle glaucoma is not a risk factor for angle closure glaucoma. Patients may wish to be examined to determine whether they are susceptible to angle closure, and have a prophylactic procedure (e.g., iridectomy), if they are susceptible [see WARNINGS AND PRECAUTIONS].
Activation of Mania/Hypomania
Advise patients, their families and caregivers to observe for signs of activation of mania/hypomania [see WARNINGS AND PRECAUTIONS].
Serum Cholesterol and Triglyceride Elevation
Advise patients not to stop taking Effexor XR without talking first with their healthcare professional. Patients should be aware that discontinuation effects may occur when stopping Effexor XR [see WARNINGS AND PRECAUTIONS and ADVERSE REACTIONS].
Interference with Cognitive and Motor Performance
Caution patients about operating hazardous machinery, including automobiles, until they are reasonably certain that Effexor XR therapy does not adversely affect their ability to engage in such activities.
Advise patients to avoid alcohol while taking Effexor XR [see DRUG INTERACTIONS].
Advise patients to notify their physician if they develop allergic phenomena such as rash, hives, swelling, or difficulty breathing.
Advise patients to notify their physician if they become pregnant or intend to become pregnant during therapy [see Use in Specific Populations].
Advise patients to notify their physician if they are breast-feeding an infant [see Use in Specific Populations].
Effexor XR contains spheroids, which release the drug slowly into the digestive tract. The insoluble portion of these spheroids is eliminated, and patients may notice spheroids passing in the stool or via colostomy. Patients should be informed that the active medication has already been absorbed by the time the patient sees the spheroids.
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Tumors were not increased by venlafaxine treatment in mice or rats. Venlafaxine was given by oral gavage to mice for 18 months at doses up to 120 mg/kg per day, which was 1.7 times the maximum recommended human dose on a mg/m² basis. Venlafaxine was also given to rats by oral gavage for 24 months at doses up to 120 mg/kg per day. In rats receiving the 120 mg/kg dose, plasma concentrations of venlafaxine at necropsy were 1 times (male rats) and 6 times (female rats) the plasma concentrations of patients receiving the maximum recommended human dose. Plasma levels of the O-desmethyl metabolite (ODV) were lower in rats than in patients receiving the maximum recommended dose. Odesmethylvenlafaxine (ODV), the major human metabolite of venlafaxine, administered by oral gavage to mice and rats for 2 years did not increase the incidence of tumors in either study. Mice received ODV at dosages up to 500/300 mg/kg/day (dosage lowered after 45 weeks of dosing). The exposure at the 300 mg/kg/day dose is 9 times that of a human dose of 225 mg/day. Rats received ODV at dosages up to 300 mg/kg/day (males) or 500 mg/kg/day (females). The exposure at the highest dose is approximately 8 (males) or 11 (females) times that of a human dose of 225 mg/day.
Venlafaxine and the major human metabolite, ODV, were not mutagenic in the Ames reverse mutation assay in Salmonella bacteria or the Chinese hamster ovary/HGPRT mammalian cell forward gene mutation assay. Venlafaxine was also not mutagenic or clastogenic in the in vitro BALB/c-3T3 mouse cell transformation assay, the sister chromatid exchange assay in cultured Chinese hamster ovary cells, or in the in vivo chromosomal aberration assay in rat bone marrow. ODV was not clastogenic in the in vitro Chinese hamster ovary cell chromosomal aberration assay or in the in vivo chromosomal aberration assay in rats.
Impairment of Fertility
Reproduction and fertility studies of venlafaxine in rats showed no adverse effects of venlafaxine on male or female fertility at oral doses of up to 2 times the maximum recommended human dose of 225 mg/day on a mg/m² basis. However, reduced fertility was observed in a study in which male and female rats were treated with O-desmethylvenlafaxine (ODV), the major human metabolite of venlafaxine, prior to and during mating and gestation. This occurred at an ODV exposure (AUC) approximately 2 to 3 times that associated with a human venlafaxine dose of 225 mg/day.
Use In Specific Populations
Pregnancy Category C
Venlafaxine did not cause malformations in offspring of rats or rabbits given doses up to 2.5 times (rat) or 4 times (rabbit) the maximum recommended human daily dose on a mg/m² basis. However, in rats, there was a decrease in pup weight, an increase in stillborn pups, and an increase in pup deaths during the first 5 days of lactation, when dosing began during pregnancy and continued until weaning. The cause of these deaths is not known. These effects occurred at 2.5 times (mg/m²) the maximum human daily dose. The no effect dose for rat pup mortality was 0.25 times the human dose on a mg/m² basis. In reproductive developmental studies in rats and rabbits with O-desmethylvenlafaxine (ODV), the major human metabolite of venlafaxine, evidence of teratogenicity was not observed at exposure margins of 13 in rats and 0.3 in rabbits. There are no adequate and well-controlled studies in pregnant women. Effexor XR should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.
Neonates exposed to Effexor XR, other SNRIs, or SSRIs, late in the third trimester have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding. Such complications can arise immediately upon delivery. Reported clinical findings have included respiratory distress, cyanosis, apnea, seizures, temperature instability, feeding difficulty, vomiting, hypoglycemia, hypotonia, hypertonia, hyperreflexia, tremor, jitteriness, irritability, and constant crying. These features are consistent with either a direct toxic effect of SSRIs and SNRIs, or possibly a drug discontinuation syndrome. It should be noted, that in some cases the clinical picture is consistent with serotonin syndrome [see WARNINGS AND PRECAUTIONS and DRUG INTERACTIONS]. When treating a pregnant woman with Effexor XR during the third trimester, the physician should carefully consider the potential risks and benefits of treatment.
Labor And Delivery
The effect of venlafaxine on labor and delivery in humans is unknown.
Venlafaxine and ODV have been reported to be excreted in human milk. Because of the potential for serious adverse reactions in nursing infants from Effexor XR, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Two placebo-controlled trials in 766 pediatric patients with MDD and two placebo-controlled trials in 793 pediatric patients with GAD have been conducted with Effexor XR, and the data were not sufficient to support a claim for use in pediatric patients.
Although no studies have been designed to primarily assess Effexor XR's impact on the growth, development, and maturation of children and adolescents, the studies that have been done suggest that Effexor XR may adversely affect weight and height (see WARNINGS AND PRECAUTIONS). Should the decision be made to treat a pediatric patient with Effexor XR, regular monitoring of weight and height is recommended during treatment, particularly if treatment is to be continued long-term [see WARNINGS AND PRECAUTIONS]. The safety of Effexor XR treatment for pediatric patients has not been systematically assessed for chronic treatment longer than six months in duration. In the studies conducted in pediatric patients (ages 6-17), the occurrence of blood pressure and cholesterol increases considered to be clinically relevant in pediatric patients was similar to that observed in adult patients. Consequently, the precautions for adults apply to pediatric patients [see WARNINGS AND PRECAUTIONS].
The percentage of patients in clinical studies for Effexor XR for MDD, GAD, SAD, and PD who were 65 years of age or older are shown in Table 15.
Table 15: Percentage (and Number of Patients Studied)
of Patients 65 Years of Age and Older by Indicationa
|aIn addition, in the premarketing assessment of Effexor (immediate release), 12% (357/2,897) of patients were ≥ 65 years of age.|
No overall differences in effectiveness or safety were observed between geriatric patients and younger patients, and other reported clinical experience generally has not identified differences in response between the elderly and younger patients. However, greater sensitivity of some older individuals cannot be ruled out. SSRIs and SNRIs, including Effexor XR, have been associated with cases of clinically significant hyponatremia in elderly patients, who may be at greater risk for this adverse event [see WARNINGS AND PRECAUTIONS].
The pharmacokinetics of venlafaxine and ODV are not substantially altered in the elderly [see CLINICAL PHARMACOLOGY and (see Figure 3)]. No dose adjustment is recommended for the elderly on the basis of age alone, although other clinical circumstances, some of which may be more common in the elderly, such as renal or hepatic impairment, may warrant a dose reduction [see DOSAGE AND ADMINISTRATION].
Age And Gender
A population pharmacokinetic analysis of 404 Effexor-treated patients from two studies involving both twice daily and three times daily regimens showed that dose-normalized trough plasma levels of either venlafaxine or ODV were unaltered by age or gender differences. Dosage adjustment based on the age or gender of a patient is generally not necessary [see DOSAGE AND ADMINISTRATION] (see Table 15).
Use In Patient Subgroups
Figure 3: Pharmacokinetics of venlafaxine and its
metabolite O-desmethylvenlafaxine (ODV) in special populations.
Abbreviations: ODV, O-desmethylvenlafaxine; AUC, area under the curve; Cmax, peak plasma concentrations; *Similar effect is expected with strong CYP2D6 inhibitors
Last reviewed on RxList: 1/12/2015
This monograph has been modified to include the generic and brand name in many instances.
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