Nefazodone for Depression

INDICATIONS AND USAGE Nefazodone hydrochloride tablets are indicated for the treatment of depression. When deciding among the alternative treatments available for this condition, the prescriber should consider the risk of hepatic failure associated with nefazodone hydrochloride treatment (see WARNINGS ). In many cases, this would lead to the conclusion that other drugs should be tried first. The efficacy of nefazodone in the treatment of depression was established in 6 to 8 week controlled trials of outpatients and in a 6 week controlled trial of depressed inpatients whose diagnoses corresponded most closely to the DSM-III or DSM-IIIR category of major depressive disorder (see CLINICAL PHARMACOLOGY ). 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 must include either depressed mood or loss of interest or pleasure and at least five of the following nine symptoms: depressed mood, loss of interest 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. The efficacy of nefazodone in reducing relapse in patients with major depression who were judged to have had a satisfactory clinical response to 16 weeks of open-label nefazodone treatment for an acute depressive episode has been demonstrated in a randomized placebo-controlled trial (see CLINICAL PHARMACOLOGY ). Although remitted patients were followed for as long as 36 weeks in the study cited (i.e., 52 weeks total), the physician who elects to use nefazodone for extended periods should periodically reevaluate the long-term usefulness of the drug for the individual patient.

DOSAGE AND ADMINISTRATION When deciding among the alternative treatments available for depression, the prescriber should consider the risk of hepatic failure associated with nefazodone hydrochloride treatment (see WARNINGS ). Initial Treatment The recommended starting dose for nefazodone hydrochloride tablets USP is 200 mg/day, administered in two divided doses (BID). In the controlled clinical trials establishing the antidepressant efficacy of nefazodone, the effective dose range was generally 300 to 600 mg/day. Consequently, most patients, depending on tolerability and the need for further clinical effect, should have their dose increased. Dose increases should occur in increments of 100 mg/day to 200 mg/day, again on a BID schedule, at intervals of no less than 1 week. As with all antidepressants, several weeks on treatment may be required to obtain a full antidepressant response. Dosage for Elderly or Debilitated Patients The recommended initial dose for elderly or debilitated patients is 100 mg/day, administered in two divided doses (BID). These patients often have reduced nefazodone clearance and/or increased sensitivity to the side effects of CNS-active drugs. It may also be appropriate to modify the rate of subsequent dose titration. As steady-state plasma levels do not change with age, the final target dose based on a careful assessment of the patient’s clinical response may be similar in healthy younger and older patients. Maintenance/Continuation/Extended Treatment There is no body of evidence available from controlled trials to indicate how long the depressed patient should be treated with nefazodone. It is generally agreed, however, that pharmacological treatment for acute episodes of depression should continue for up to 6 months or longer. Whether the dose of antidepressant needed to induce remission is identical to the dose needed to maintain euthymia is unknown. Systematic evaluation of the efficacy of nefazodone has shown that efficacy is maintained for periods of up to 36 weeks following 16 weeks of open-label acute treatment (treated for 52 weeks total) at dosages that averaged 438 mg/day. For most patients, their maintenance dose was that associated with response during acute treatment (see CLINICAL PHARMACOLOGY ). The safety of nefazodone in long-term use is supported by data from both double-blind and open-label trials involving more than 250 patients treated for at least one year. Switching Patients to or From a Monoamine Oxidase Inhibitor At least 14 days should elapse between discontinuation of an MAOI and initiation of therapy with nefazodone. In addition, at least 7 days should be allowed after stopping nefazodone before starting an MAOI.

WARNINGS Clinical Worsening and Suicide Risk 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 trials 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 to 24) with major depressive disorder (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 trials in children and adolescents with MDD, obsessive compulsive disorder (OCD), or other psychiatric disorders included a total of 24 short-term trials of 9 antidepressant drugs in over 4400 patients. The pooled analyses of placebo-controlled trials in adults with MDD or other psychiatric disorders included a total of 295 short-term trials (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 vs 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 1000 patients treated) are provided in Table 1 . Table 1 Age Range Drug-Placebo Difference in Number of Cases of Suicidality per 1000 Patients Treated Increases Compared to Placebo < 18 14 additional cases 18 to 24 5 additional cases Decreases Compared to Placebo 25 to 64 1 fewer case ≥ 65 6 fewer cases No suicides occurred in any of the pediatric trials. There were suicides in the adult trials, 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 trials 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 major depressive disorder 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. Families and caregivers of patients being treated with antidepressants for major depressive disorder 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 health care providers. Such monitoring should include daily observation by families and caregivers. Prescriptions for nefazodone hydrochloride tablets should be written for the smallest quantity of tablets 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 trials) 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 nefazodone hydrochloride tablets are not approved for use in treating bipolar depression. Angle-Closure Glaucoma The pupillary dilation that occurs following use of many antidepressant drugs including nefazodone hydrochloride tablets may trigger an angle closure attack in a patient with anatomically narrow angles who does not have a patent iridectomy. Hepatotoxicity (See BOXED WARNING .) Cases of life-threatening hepatic failure have been reported in patients treated with nefazodone hydrochloride tablets. The reported rate in the United States is about 1 case of liver failure resulting in death or transplant per 250,000 to 300,000 patient-years of nefazodone treatment. This represents a rate of about 3 to 4 times the estimated background rate of liver failure. This rate is an underestimate because of under reporting, and the true risk could be considerably greater than this. A large cohort study of antidepressant users found no cases of liver failure leading to death or transplant among nefazodone users in about 30,000 patient-years of exposure. The spontaneous report data and the cohort study results provide estimates of the upper and lower limits of the risk of liver failure in nefazodone-treated patients, but are not capable of providing a precise risk estimate. The time to liver injury for the reported liver failure cases resulting in death or transplant generally ranged from 2 weeks to 6 months on nefazodone therapy. Although some reports described dark urine and nonspecific prodromal symptoms (e.g., anorexia, malaise, and gastrointestinal symptoms), other reports did not describe the onset of clear prodromal symptoms prior to the onset of jaundice. The physician may consider the value of liver function testing. Periodic serum transaminase testing has not been proven to prevent serious injury but it is generally believed that early detection of drug-induced hepatic injury along with immediate withdrawal of the suspect drug enhances the likelihood for recovery. Patients should be advised to be alert for signs and symptoms of liver dysfunction (jaundice, anorexia, gastrointestinal complaints, malaise, etc.)

Drug Interactions Drugs Highly Bound to Plasma Protein Because nefazodone is highly bound to plasma protein (see CLINICAL PHARMACOLOGY , Pharmacokinetics ), administration of nefazodone to a patient taking another drug that is highly protein bound may cause increased free concentrations of the other drug, potentially resulting in adverse events. Conversely, adverse effects could result from displacement of nefazodone by other highly bound drugs. Warfarin – There were no effects on the prothrombin or bleeding times or upon the pharmacokinetics of R-warfarin when nefazodone (200 mg BID) was administered for 1 week to subjects who had been pretreated for 2 weeks with warfarin. Although the coadministration of nefazodone did decrease the subjects’ exposure to S-warfarin by 12%, the lack of effects on the prothrombin and bleeding times indicates this modest change is not clinically significant. Although these results suggest no adjustments in warfarin dosage are required when nefazodone is administered to patients stabilized on warfarin, such patients should be monitored as required by standard medical practices. CNS-Active Drugs Monoamine Oxidase Inhibitors – See WARNINGS . Haloperidol – When a single oral 5 mg dose of haloperidol was coadministered with nefazodone (200 mg BID) at steady state, haloperidol apparent clearance decreased by 35% with no significant increase in peak haloperidol plasma concentrations or time of peak. This change is of unknown clinical significance. Pharmacodynamic effects of haloperidol were generally not altered significantly. There were no changes in the pharmacokinetic parameters for nefazodone. Dosage adjustment of haloperidol may be necessary when coadministered with nefazodone. Lorazepam – When lorazepam (2 mg BID) and nefazodone (200 mg BID) were coadministered to steady state, there was no change in any pharmacokinetic parameter for either drug compared to each drug administered alone. Therefore, dosage adjustment is not necessary for either drug when coadministered. Triazolam/Alprazolam – See CONTRAINDICATIONS and WARNINGS . Alcohol – Although nefazodone did not potentiate the cognitive and psychomotor effects of alcohol in experiments with normal subjects, the concomitant use of nefazodone and alcohol in depressed patients is not advised. Buspirone – In a study of steady-state pharmacokinetics in healthy volunteers, coadministration of buspirone (2.5 or 5 mg BID) with nefazodone (250 mg BID) resulted in marked increases in plasma buspirone concentrations (increases up to 20 fold in C max and up to 50 fold in AUC) and statistically significant decreases (about 50%) in plasma concentrations of the buspirone metabolite 1-pyrimidinylpiperazine. With 5 mg BID doses of buspirone, slight increases in AUC were observed for nefazodone (23%) and its metabolites hydroxynefazodone (17%) and mCPP (9%). Subjects receiving nefazodone 250 mg BID and buspirone 5 mg BID experienced lightheadedness, asthenia, dizziness, and somnolence, adverse events also observed with either drug alone. If the two drugs are to be used in combination, a low dose of buspirone (e.g., 2.5 mg QD) is recommended. Subsequent dose adjustment of either drug should be based on clinical assessment. Pimozide – See CONTRAINDICATIONS , WARNINGS , and PRECAUTIONS , Pharmacokinetics of Nefazodone in ‘Poor Metabolizers’ and Potential Interaction With Drugs That Inhibit and/or Are Metabolized by Cytochrome P450 Isozymes. Fluoxetine – When fluoxetine (20 mg QD) and nefazodone (200 mg BID) were administered at steady state there were no changes in the pharmacokinetic parameters for fluoxetine or its metabolite, norfluoxetine. Similarly, there were no changes in the pharmacokinetic parameters of nefazodone or HO-NEF; however, the mean AUC levels of the nefazodone metabolites mCPP and triazole-dione increased by 3 to 6 fold and 1.3 fold, respectively. When a 200 mg dose of nefazodone was administered to subjects who had been receiving fluoxetine for 1 week, there was an increased incidence of transient adverse events such as headache, lightheadedness, nausea, or paresthesia, possibly due to the elevated mCPP levels. Patients who are switched from fluoxetine to nefazodone without an adequate washout period may experience similar transient adverse events. The possibility of this happening can be minimized by allowing a washout period before initiating nefazodone therapy and by reducing the initial dose of nefazodone. Because of the long half-life of fluoxetine and its metabolites, this washout period may range from one to several weeks depending on the dose of fluoxetine and other individual patient variables. Phenytoin – Pretreatment for 7 days with 200 mg BID of nefazodone had no effect on the pharmacokinetics of a single 300 mg oral dose of phenytoin. However, due to the nonlinear pharmacokinetics of phenytoin, the failure to observe a significant effect on the single-dose pharmacokinetics of phenytoin does not preclude the possibility of a clinically significant interaction with nefazodone when phenytoin is dosed chronically. However, no change in the initial dosage of phenytoin is considered necessary and any subsequent adjustment of phenytoin dosage should be guided by usual clinical practices. Desipramine – When nefazodone (150 mg BID) and desipramine (75 mg QD) were administered together there were no changes in the pharmacokinetics of desipramine or its metabolite, 2-hydroxy desipramine. There were also no changes in the pharmacokinetics of nefazodone or its triazole-dione metabolite, but the AUC and C max of mCPP increased by 44% and 48%, respectively, while the AUC of HO-NEF decreased by 19%. No changes in doses of either nefazodone or desipramine are necessary when the two drugs are given concomitantly. Subsequent dose adjustments should be made on the basis of clinical response. Lithium – In 13 healthy subjects the coadministration of nefazodone (200 mg BID) with lithium (500 mg BID) for 5 days (steady-state conditions) was found to be well tolerated. When the two drugs were coadministered, there were no changes in the steady-state pharmacokinetics of either lithium, nefazodone, or its metabolite HO-NEF; however, there were small decreases in the steady-state plasma concentrations of two nefazodone metabolites, mCPP and triazole-dione, which are considered not to be of clinical significance. Therefore, no dosage adjustment of either lithium or nefazodone is required when they are coadministered. Carbamazepine – The coadministration of nefazodone (200 mg BID) for 5 days to 12 healthy subjects on carbamazepine who had achieved steady state (200 mg BID) was found to be well tolerated. Steady-state conditions for carbamazepine, nefazodone, and several of their metabolites were achieved by day 5 of coadministration. With coadministration of the two drugs there were significant increases in the steady-state C max and AUC of carbamazepine (23% and 23%, respectively), while the steady-state C max and the AUC of the carbamazepine metabolite, 10,11 epoxycarbamazepine, decreased by 21% and 20%, respectively. The coadministration of the two drugs significantly reduced the steady-state C max and AUC of nefazodone by 86% and 93%, respectively. Similar reductions in the C max and AUC of HO-NEF were also observed (85% and 94%), while the reductions in C max and AUC of mCPP and triazole-dione were more modest (13% and 44% for the former and 28% and 57% for the latter). Due to the potential for coadministration of carbamazepine to result in insufficient plasma nefazodone and hydroxynefazodone concentrations for achieving an antidepressant effect for nefazodone, it is recommended that nefazodone not be used in combination with carbamazepine (see CONTRAINDICATIONS and WARNINGS ). General Anesthetics – Little is known about the potential for interaction between nefazodone and general anesthetics; therefore, prior to elective surgery, nefazodone hydrochloride should be discontinued

ADVERSE REACTIONS Associated with Discontinuation of Treatment Approximately 16% of the 3496 patients who received nefazodone in worldwide premarketing clinical trials discontinued treatment due to an adverse experience. The more common (≥ 1%) events in clinical trials associated with discontinuation and considered to be drug related (i.e., those events associated with dropout at a rate approximately twice or greater for nefazodone compared to placebo) included: nausea (3.5%), dizziness (1.9%), insomnia (1.5%), asthenia (1.3%), and agitation (1.2%). Incidence in Controlled Trials Commonly Observed Adverse Events in Controlled Clinical Trials The most commonly observed adverse events associated with the use of nefazodone (incidence of 5% or greater) and not seen at an equivalent incidence among placebo-treated patients (i.e., significantly higher incidence for nefazodone compared to placebo, p ≤ 0.05), derived from the table below, were: somnolence, dry mouth, nausea, dizziness, constipation, asthenia, lightheadedness, blurred vision, confusion, and abnormal vision. Adverse Events Occurring at an Incidence of 1% or More Among Nefazodone-Treated Patients The table that follows enumerates adverse events that occurred at an incidence of 1% or more, and were more frequent than in the placebo group, among nefazodone-treated patients who participated in short-term (6 to 8 week) placebo-controlled trials in which patients were dosed with nefazodone to ranges of 300 to 600 mg/day. This table shows the percentage of patients in each group who had at least one episode of an event at some time during their treatment. Reported adverse events were classified using standard COSTART-based Dictionary terminology. The prescriber should be aware that these figures cannot be used to predict the incidence of side effects in the course of usual medical practice where patient characteristics and other factors differ from those which prevailed in the clinical trials. Similarly, the cited frequencies cannot be compared with figures obtained from other clinical investigations involving different treatments, uses, and investigators. The cited figures, however, do provide the prescribing physician with some basis for estimating the relative contribution of drug and nondrug factors to the side-effect incidence rate in the population studied. Treatment-Emergent Adverse Experience Incidence in 6 to 8 Week Placebo-Controlled Clinical Trials a , Nefazodone 300 to 600 mg/day Dose Range Percent of Patients Body System Preferred Term Nefazodone (n = 393) Placebo (n = 394) Body as a Whole Headache 36 33 Asthenia 11 5 Infection 8 6 Flu syndrome 3 2 Chills 2 1 Fever 2 1 Neck rigidity 1 0 Cardiovascular Postural hypotension 4 1 Hypotension 2 1 Dermatological Pruritus 2 1 Rash 2 1 Gastrointestinal Dry mouth 25 13 Nausea 22 12 Constipation 14 8 Dyspepsia 9 7 Diarrhea 8 7 Increased appetite 5 3 Nausea & vomiting 2 1 Metabolic Peripheral edema 3 2 Thirst 1 < 1 Musculoskeletal Arthralgia 1 < 1 Nervous Somnolence 25 14 Dizziness 17 5 Insomnia 11 9 Lightheadedness 10 3 Confusion 7 2 Memory impairment 4 2 Paresthesia 4 2 Vasodilatation b 4 2 Abnormal dreams 3 2 Concentration decreased 3 1 Ataxia 2 0 Incoordination 2 1 Psychomotor retardation 2 1 Tremor 2 1 Hypertonia 1 0 Libido decreased 1 < 1 Respiratory Pharyngitis 6 5 Cough increased 3 1 Special Senses Blurred vision 9 3 Abnormal vision c 7 1 Tinnitus 2 1 Taste perversion 2 1 Visual field defect 2 0 Urogenital Urinary frequency 2 1 Urinary tract infection 2 1 Urinary retention 2 1 Vaginitis d 2 1 Breast pain d 1 < 1 Events reported by at least 1% of patients treated with nefazodone and more frequent than the placebo group are included; incidence is rounded to the nearest 1% (< 1% indicates an incidence less than 0.5%). Events for which the nefazodone incidence was equal to or less than placebo are not listed in the table, but included the following: abdominal pain, pain, back pain, accidental injury, chest pain, neck pain, palpitation, migraine, sweating, flatulence, vomiting, anorexia, tooth disorder, weight gain, edema, myalgia, cramp, agitation, anxiety, depression, hypesthesia, CNS stimulation, dysphoria, emotional lability, sinusitis, rhinitis, dysmenorrhea d , dysuria. Vasodilatation – flushing, feeling warm. Abnormal vision – scotoma, visual trails. Incidence adjusted for gender. Dose Dependency of Adverse Events The table that follows enumerates adverse events that were more frequent in the nefazodone dose range of 300 to 600 mg/day than in the nefazodone dose range of up to 300 mg/day. This table shows only those adverse events for which there was a statistically significant difference (p ≤ 0.05) in incidence between the nefazodone dose ranges as well as a difference between the high dose range and placebo. Dose Dependency of Adverse Events in Placebo-Controlled Trials a Percent of Patients Body System Preferred Term Nefazodone 300 to 600 mg/day (n = 209) Nefazodone ≤ 300 mg/day (n = 211) Placebo (n = 212) Gastrointestinal Nausea 23 14 12 Constipation 17 10 9 Nervous Somnolence 28 16 13 Dizziness 22 11 4 Confusion 8 2 1 Special Senses Abnormal Vision 10 0 2 Blurred Vision 9 3 2 Tinnitus 3 0 1 a. Events for which there was a statistically significant difference (p ≤ 0.05) between the nefazodone dose groups. Visual Disturbances In controlled clinical trials, blurred vision occurred in 9% of nefazodone-treated patients compared to 3% of placebo-treated patients. In these same trials abnormal vision, including scotomata and visual trails, occurred in 7% of nefazodone-treated patients compared to 1% of placebo-treated (see Treatment-Emergent Adverse Experience table, above). Dose-dependency was observed for these events in these trials, with none of the scotomata and visual trails at doses below 300 mg/day. However, scotomata and visual trails observed at doses below 300 mg/day have been reported in postmarketing experience with nefazodone (see PRECAUTIONS , Information for Patients ). Vital Sign Changes (See PRECAUTIONS , Postural Hypotension .) Weight Changes In a pooled analysis of placebo-controlled premarketing studies, there were no differences between nefazodone and placebo groups in the proportions of patients meeting criteria for potentially important increases or decreases in body weight (a change of ≥ 7%). Laboratory Changes Of the serum chemistry, serum hematology, and urinalysis parameters monitored during placebo-controlled premarketing studies with nefazodone, a pooled analysis revealed a statistical trend between nefazodone and placebo for hematocrit, i.e., 2.8% of nefazodone patients met criteria for a potentially important decrease in hematocrit (≤ 37% male or ≤ 32% female) compared to 1.5% of placebo patients (0.05 < p ≤ 0.10). Decreases in hematocrit, presumably dilutional, have been reported with many other drugs that block alpha 1 -adrenergic receptors. There was no apparent clinical significance of the observed changes in the few patients meeting these criteria. ECG Changes Of the ECG parameters monitored during placebo-controlled premarketing studies with nefazodone, a pooled analysis revealed a statistically significant difference between nefazodone and placebo for sinus bradycardia, i.e., 1.5% of nefazodone patients met criteria for a potentially important decrease in heart rate (≤ 50 bpm and a decrease of ≥ 15 bpm) compared to 0.4% of placebo patients (p < 0.05). There was no obvious clinical significance of the observed changes in the few patients meeting these criteria. Other Events Observed During the Premarketing Evaluation of Nefazodone During its premarketing assessment, multiple doses of nefazodone were administered to 3496 patients in clinical studies, including more than 250 patients treated for at least one year. The conditions and duration of exposure to nefazodone varied greatly, and included (in overlapping categories) open and double-blind studies, uncontrolled and controlled studies, inpatient and