Quetiapine Fumarate Er

Schizophrenia Quetiapine extended-release tablets are indicated for the treatment of schizophrenia. The efficacy of quetiapine extended-release tablets in schizophrenia was established in one 6-week and one maintenance trial in adults with schizophrenia. Efficacy was supported by three 6-week trials in adults with schizophrenia and one 6-week trial in adolescents with schizophrenia (13 to 17 years) treated with quetiapine tablets [see CLINICAL STUDIES (14.1)]. 1.2 Bipolar Disorder Quetiapine extended-release tablets are indicated for the acute treatment of manic or mixed episodes associated with bipolar I disorder, both as monotherapy and as an adjunct to lithium or divalproex. The efficacy of quetiapine extended-release tablets in manic or mixed episodes of bipolar I disorder was established in one 3-week trial in adults with manic or mixed episodes associated with bipolar I disorder. Efficacy was supported by two 12-week monotherapy trials and one 3-week adjunctive trial in adults with manic episodes associated with bipolar I disorder as well as one 3-week monotherapy trial in children and adolescents (10 to 17 years) with manic episodes associated with bipolar I disorder treated with quetiapine tablets [see CLINICAL STUDIES (14.2)]. Quetiapine extended-release tablets are indicated for the acute treatment of depressive episodes associated with bipolar disorder. The efficacy of quetiapine extended-release tablets was established in one 8-week trial in adults with bipolar I or II disorder and supported by two 8-week trials in adults with bipolar I or II disorder treated with quetiapine tablets [see CLINICAL STUDIES (14.2)]. Quetiapine extended-release tablets are indicated for the maintenance treatment of bipolar I disorder, as an adjunct to lithium or divalproex. Efficacy was extrapolated from two maintenance trials in adults with bipolar I disorder treated with quetiapine tablets. The effectiveness of monotherapy for the maintenance treatment of bipolar I disorder has not been systematically evaluated in controlled clinical trials [see CLINICAL STUDIES (14.2)]. 1.3 Adjunctive Treatment of Major Depressive Disorder (MDD) Quetiapine extended-release tablets are indicated for use as adjunctive therapy to antidepressants for the treatment of MDD. The efficacy of quetiapine extended-release tablets as adjunctive therapy to antidepressants in MDD was established in two 6-week trials in adults with MDD who had an inadequate response to antidepressant treatment [see CLINICAL STUDIES (14.3)]. 1.4 Special Considerations in Treating Pediatric Schizophrenia and Bipolar I Disorder Pediatric schizophrenia and bipolar I disorder are serious mental disorders, however, diagnosis can be challenging. For pediatric schizophrenia, symptom profiles can be variable, and for bipolar I disorder, patients may have variable patterns of periodicity of manic or mixed symptoms. It is recommended that medication therapy for pediatric schizophrenia and bipolar I disorder be initiated only after a thorough diagnostic evaluation has been performed and careful consideration given to the risks associated with medication treatment. Medication treatment for both pediatric schizophrenia and bipolar I disorder is indicated as part of a total treatment program that often includes psychological, educational and social interventions.

Important Administration Instructions Quetiapine extended-release tablets should be swallowed whole and not split, chewed, or crushed. It is recommended that quetiapine extended-release tablets be taken without food or with a light meal (approximately 300 calories) [see Clinical Pharmacology (12.3)]. Quetiapine extended-release tablets should be administered once daily, preferably in the evening. 2.2 Recommended Dosing The recommended initial dose, titration, dose range and maximum quetiapine extended-release tablets dose for each approved indication is displayed in Table 1 below. After initial dosing, adjustments can be made upwards or downwards, if necessary, depending upon the clinical response and tolerability of the patient [see Clinical Studies ( 14.1,14.2 and 14.3)]. Table 1: Recommended Dosing for Quetiapine Extended-Release Tablets Indication Initial Dose and Titration Recommended Dose Maximum Dose Schizophrenia -Adults Day 1: 300 mg/day Dose increases can be made at intervals as short as 1 day and in increments of up to 300 mg/day 400 to 800 mg/day 800 mg/day Schizophrenia -Adolescents (13 to 17 years) Day 1: 50 mg/day Day 2: 100 mg/day Day 3: 200 mg/day Day 4: 300 mg/day Day 5: 400 mg/day 400 to 800 mg/day 800 mg/day Schizophrenia Maintenance - Monotherapy - Adults Not applicable 400 to 800 mg/day 800 mg/day Bipolar I Disorder manic or mixed - Acute monotherapy or adjunct to lithium or divalproex - Adults Day 1: 300 mg/day Day 2: 600 mg/day Day 3: between 400 and 800 mg/day 400 to 800 mg/day 800 mg/day Bipolar I Disorder, manic Acute monotherapy Children and Adolescents (10 to 17 years) Day 1: 50 mg/day Day 2: 100 mg/day Day 3: 200 mg/day Day 4: 300 mg/day Day 5: 400 mg/day 400 to 600 mg/day 600 mg/day Bipolar Disorder, Depressive Episodes - Adults Day 1: 50 mg/day Day 2: 100 mg/day Day 3: 200 mg/day Day 4: 300 mg/day 300 mg/day 300 mg/day Bipolar I Disorder Maintenance - Adjunct to lithium or divalproex - Adults Not applicable 400 to 800 mg/day 800 mg/day Major Depressive Disorder - Adjunctive Therapy with Antidepressants-Adults Day 1: 50 mg/day Day 2: 50 mg/day Day 3: 150 mg/day 150 to 300 mg/day 300 mg/day Maintenance Treatment for Schizophrenia and Bipolar I Disorder Maintenance Treatment-Patients should be periodically reassessed to determine the need for maintenance treatment and the appropriate dose for such treatment [see Clinical Studies (14.1, 14.2)]. 2.3 Dose Modifications in Elderly Patients Consideration should be given to a slower rate of dose titration and a lower target dose in the elderly and in patients who are debilitated or who have a predisposition to hypotensive reactions [see Use in Specific Populations (8.5,8.7), and Clinical Pharmacology (12.3)]. When indicated, dose escalation should be performed with caution in these patients. Elderly patients should be started on quetiapine extended-release tablets 50 mg/day and the dose can be increased in increments of 50 mg/day depending on the clinical response and tolerability of the individual patient. 2.4 Dose Modifications in Hepatically Impaired Patients Patients with hepatic impairment should be started on quetiapine extended-release tablets 50 mg/day. The dose can be increased daily in increments of 50 mg/day to an effective dose, depending on the clinical response and tolerability of the patient. 2.5 Dose Modifications when used with CYP3A4 Inhibitors Quetiapine extended-release tablets dose should be reduced to one-sixth of original dose when co-medicated with a potent CYP3A4 inhibitor (e.g., ketoconazole, itraconazole, indinavir, ritonavir, nefazodone, etc.). When the CYP3A4 inhibitor is discontinued, the dose of quetiapine extended-release tablets should be increased by 6-fold [see Clinical Pharmacology (12.3) and Drug Interactions (7.1)]. 2.6 Dose Modifications when used with CYP3A4 Inducers Quetiapine extended-release tablets dose should be increased up to 5-fold of the original dose when used in combination with a chronic treatment (e.g., greater than 7 to 14 days) of a potent CYP3A4 inducer (e.g., phenytoin, carbamazepine, rifampin, avasimibe, St. John’s wort etc.). The dose should be titrated based on the clinical response and tolerance of the individual patient. When the CYP3A4 inducer is discontinued, the dose of quetiapine extended-release tablets should be reduced to the original level within 7 to 14 days [see Clinical Pharmacology (12.3) and Drug Interactions (7.1)]. 2.7 Re-initiation of Treatment in Patients Previously Discontinued Although there are no data to specifically address re-initiation of treatment, it is recommended that when restarting therapy of patients who have been off quetiapine extended-release tablets for more than one-week, the initial dosing schedule should be followed. When restarting patients who have been off quetiapine extended-release tablets for less than one-week, gradual dose escalation may not be required and the maintenance dose may be re-initiated. 2.8 Switching Patients from Quetiapine Tablets to Quetiapine Extended-Release Tablets Patients who are currently being treated with quetiapine (immediate release formulation) may be switched to quetiapine extended-release tablets at the equivalent total daily dose taken once daily. Individual dosage adjustments may be necessary. 2.9 Switching from Antipsychotics There are no systematically collected data to specifically address switching patients from other antipsychotics to quetiapine extended-release tablets, or concerning concomitant administration with other antipsychotics. While immediate discontinuation of the previous antipsychotic treatment may be acceptable for some patients, more gradual discontinuation may be most appropriate for others. In all cases, the period of overlapping antipsychotic administration should be minimized. When switching patients from depot antipsychotics, if medically appropriate, initiate quetiapine extended-release tablets therapy in place of the next scheduled injection. The need for continuing existing extrapyramidal syndrome medication should be re-evaluated periodically.

Increased Mortality in Elderly Patients with Dementia-Related Psychosis Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Analysis of 17 placebo-controlled trials (modal duration of 10 weeks), largely in patients taking atypical antipsychotic drugs, revealed a risk of death in drug-treated patients of between 1.6 to 1.7 times the risk of death in placebo-treated patients. Over the course of a typical 10-week controlled trial, the rate of death in drug-treated patients was about 4.5%, compared to a rate of about 2.6% in the placebo group. Although the causes of death were varied, most of the deaths appeared to be either cardiovascular (e.g., heart failure, sudden death) or infectious (e.g., pneumonia) in nature. Observational studies suggest that, similar to atypical antipsychotic drugs, treatment with conventional antipsychotic drugs may increase mortality. The extent to which the findings of increased mortality in observational studies may be attributed to the antipsychotic drug as opposed to some characteristic(s) of the patients is not clear. Quetiapine extended-release tablets are not approved for the treatment of patients with dementia-related psychosis [see BOXED WARNING]. 5.2 Suicidal Thoughts and Behaviors in 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 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 4,400 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 1,000 patients treated) are provided in Table 2. Table 2: Drug-Placebo Difference in Number of Cases of Suicidality per 1,000 Patients Treated Age Range Drug-Placebo Difference in Number of Cases of Suicidality per 1,000 Patients Treated 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 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 non-psychiatric, 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 quetiapine 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. 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, including quetiapine extended-release tablets, 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. 5.3 Cerebrovascular Adverse Reactions, Including Stroke, in Elderly Patients with Dementia-Related Psychosis In placebo-controlled trials with risperidone, aripiprazole, and olanzapine in elderly subjects with dementia, there was a higher incidence of cerebrovascular adverse reactions (cerebrovascular accidents and transient ischemic attacks), including fatalities, compared to placebo-treated subjects. Quetiapine extended-release tablets are not approved for the treatment of patients with dementia-related psychosis [see BOXED WARNING and WARNINGS AND PRECAUTIONS (5.1)]. 5.4 Neuroleptic Malignant Syndrome (NMS) A potentially fatal symptom complex sometimes referred to as Neuroleptic Malignant Syndrome (NMS) has been reported in association wi

Hypersensitivity to quetiapine or to any excipients in the quetiapine extended-release tablets formulation. Anaphylactic reactions have been reported in patients treated with quetiapine extended-release tablets.

Effect of Other Drugs on Quetiapine The risks of using quetiapine extended-release tablets in combination with other drugs have not been extensively evaluated in systematic studies. Given the primary CNS effects of quetiapine extended-release tablets, caution should be used when it is taken in combination with other centrally acting drugs. Quetiapine potentiated the cognitive and motor effects of alcohol in a clinical trial in subjects with selected psychotic disorders, and alcoholic beverages should be limited while taking quetiapine. Quetiapine exposure is increased by the prototype CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, indinavir, ritonavir, nefazodone, etc.) and decreased by the prototype of CYP3A4 inducers (e.g., phenytoin, carbamazepine, rifampin, avasimibe, St. John's wort etc.). Dose adjustment of quetiapine will be necessary if it is co-administered with potent CYP3A4 inducers or inhibitors. CYP3A4 inhibitors: Coadministration of ketoconazole, a potent inhibitor of cytochrome CYP3A4, resulted in significant increase in quetiapine exposure. The dose should be reduced to one-sixth of the original dose in patients coadministered with a strong CYP3A4 inhibitor [see Dosage and Administration (2.5) and Clinical Pharmacology (12.3)]. CYP3A4 inducers: Coadministration of quetiapine and phenytoin, a CYP3A4 inducer increased the mean oral clearance of quetiapine by 5-fold. Increased doses of quetiapine extended-release tablets up to 5 - fold may be required to maintain control of symptoms of schizophrenia in patients receiving quetiapine and phenytoin, or other known potent CYP3A4 inducers [see Dosage and Administration (2.6) and Clinical Pharmacology (12.3)].When the CYP3A4 inducer is discontinued, the dose of quetiapine extended-release tablets should be reduced to the original level within 7 to 14 days [see Dosage and Administration (2.6)]. Anticholinergic Drugs: Concomitant treatment with quetiapine and other drugs with anticholinergic activity can increase the risk for severe gastrointestinal adverse reactions related to hypomotility. Quetiapine extended-release tablets should be used with caution in patients receiving medications having anticholinergic (antimuscarinic) effects [see Warnings and Precautions (5.20)]. The potential effects of several concomitant medications on quetiapine pharmacokinetics were studied [see Clinical Pharmacology (12.3)]. 7.2 Effect of Quetiapine on Other Drugs Because of its potential for inducing hypotension, quetiapine extended-release tablets may enhance the effects of certain antihypertensive agents. Quetiapine extended-release tablets may antagonize the effects of levodopa and dopamine agonists. There are no clinically relevant pharmacokinetic interactions of quetiapine on other drugs based on the CYP pathway. Quetiapine and its metabolites are non-inhibitors of major metabolizing CYP's (1A2, 2C9, 2C19, 2D6, and 3A4).

The following adverse reactions are discussed in more detail in other sections of the labeling: Increased mortality in elderly patients with dementia-related psychosis [see WARNINGS AND PRECAUTIONS (5.1)] Suicidal thoughts and behaviors in adolescents and young adults [see WARNINGS AND PRECAUTIONS (5.2)] Cerebrovascular adverse reactions, including stroke in elderly patients with dementia-related psychosis [see WARNINGS AND PRECAUTIONS (5.3)] Neuroleptic Malignant Syndrome (NMS) [see WARNINGS AND PRECAUTIONS (5.4)] Metabolic changes (hyperglycemia, dyslipidemia, weight gain) [see WARNINGS AND PRECAUTIONS (5.5)] Tardive dyskinesia [see WARNINGS AND PRECAUTIONS (5.6)] Hypotension [see WARNINGS AND PRECAUTIONS (5.7)] Falls [see WARNINGS AND PRECAUTIONS (5.8)] Increases in blood pressure (children and adolescents) [see WARNINGS AND PRECAUTIONS (5.9)] Leukopenia, neutropenia and agranulocytosis [see WARNINGS AND PRECAUTIONS (5.10)] Cataracts [see WARNINGS AND PRECAUTIONS (5.11)] QT Prolongation [see WARNINGS AND PRECAUTIONS (5.12)] Seizures [see WARNINGS AND PRECAUTIONS (5.13)] Hypothyroidism [see WARNINGS AND PRECAUTIONS (5.14)] Hyperprolactinemia [see WARNINGS AND PRECAUTIONS (5.15)] Potential for cognitive and motor impairment [see WARNINGS AND PRECAUTIONS (5.16)] Body temperature regulation [see WARNINGS AND PRECAUTIONS (5.17)] Dysphagia [see WARNINGS AND PRECAUTIONS (5.18)] Discontinuation Syndrome [see WARNINGS AND PRECAUTIONS (5.19)] Anticholinergic (antimuscarinic) Effects [see WARNINGS AND PRECAUTIONS (5.20)] 6.1 Clinical Studies Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. Adults The information below is derived from a clinical trial database for quetiapine extended-release tablets consisting of approximately 3400 patients exposed to quetiapine extended-release tablets for the treatment of Schizophrenia, Bipolar Disorder, and Major Depressive Disorder in placebo-controlled trials. This experience corresponds to approximately 1020.1 patient-years. Adverse reactions were assessed by collecting adverse reactions, results of physical examinations, vital signs, body weights, laboratory analyses and ECG results. The stated frequencies of adverse reactions represent the proportion of individuals who experienced, at least once, an adverse reaction of the type listed. Adverse Reactions Associated with Discontinuation of Treatment in Short-Term, Placebo-Controlled Trials: Schizophrenia: There were no adverse reactions leading to discontinuation that occurred at an incidence of ≥ 2% for quetiapine extended-release tablets in schizophrenia trials. Bipolar I Disorder, Manic or Mixed Episodes: There were no adverse reactions leading to discontinuation that occurred at an incidence of ≥ 2% for quetiapine extended-release tablets in the bipolar mania trial. Bipolar Disorder, Depressive Episode: In a single clinical trial in patients with bipolar depression, 14% (19/137) of patients on quetiapine extended-release tablets discontinued due to an adverse reaction compared to 4% (5/140) on placebo. Somnolence 1 was the only adverse reaction leading to discontinuation that occurred at an incidence of ≥ 2% in quetiapine extended-release tablets in the bipolar depression trial. MDD, Adjunctive Therapy: In adjunctive therapy clinical trials in patients with MDD, 12.1% (76/627) of patients on quetiapine extended-release tablets discontinued due to adverse reaction compared to 1.9% (6/309) on placebo. Somnolence 1 was the only adverse reaction leading to discontinuation that occurred at an incidence of ≥ 2% in quetiapine extended-release tablets in MDD trials. Commonly Observed Adverse Reactions in Short-Term, Placebo-Controlled Trials: In short-term placebo-controlled studies for schizophrenia the most commonly observed adverse reactions associated with the use of quetiapine extended-release tablets (incidence of 5% or greater) and observed at a rate on quetiapine extended-release tablets at least twice that of placebo were somnolence (25%), dry mouth (12%), dizziness (10%), and dyspepsia (5%). Adverse Reactions occurring at an Incidence of 2% or More Among quetiapine extended-release tablets Treated Patients in Short-Term, Placebo-Controlled Trials. Table 12 enumerates the incidence, rounded to the nearest percent, of adverse reactions that occurred during acute therapy of schizophrenia (up to 6 weeks) in 2% or more in patients treated with quetiapine extended-release tablets (doses ranging from 300 to 800 mg/day) where the incidence in patients treated with quetiapine extended-release tablets was greater than the incidence in placebo-treated patients. Table 12: Adverse Reactions in 6-Week Placebo-Controlled Clinical Trials for the Treatment of Schizophrenia Preferred Term Quetiapine extended-release tablets (N=951) Placebo (N=319) Somnolence 1 25% 10% Dry Mouth 12% 1% Dizziness 10% 4% Extrapyramidal Symptoms 2 8% 5% Orthostatic Hypotension 7% 5% Constipation 6% 5% Dyspepsia 5% 2% Heart Rate Increased 4% 1% Tachycardia 3% 1% Fatigue 3% 2% Hypotension 3% 1% Vision Blurred 2% 1% Toothache 2% 0% Increased Appetite 2% 0% Muscle Spasms 2% 1% Tremor 2% 1% Akathisia 2% 1% Anxiety 2% 1% Schizophrenia 2% 1% Restlessness 2% 1% 1. Somnolence combines adverse reaction terms somnolence and sedation. 2. Extrapyramidal symptoms include the terms: cogwheel rigidity, drooling, dyskinesia dystonia, extrapyramidal disorder, hypertonia, movement disorder, muscle rigidity, parkinsonism, parkinsonian gait, and tardive dyskinesia. In a 3-week, placebo-controlled study in bipolar mania the most commonly observed adverse reactions associated with the use of quetiapine extended-release tablets (incidence of 5% or greater) and observed at a rate on quetiapine extended-release tablets at least twice that of placebo were somnolence (50%), dry mouth (34%), dizziness (10%), constipation (10%), weight gain (7%), dysarthria (5%), and nasal congestion (5%). Table 13 enumerates the incidence, rounded to the nearest percent, of adverse reactions that occurred during acute therapy of bipolar mania (up to 3 weeks) in 2% or more of patients treated with quetiapine extended-release tablets (doses ranging from 400 to 800 mg/day) where the incidence in patients treated with quetiapine extended-release tablets was greater than the incidence in placebo-treated patients. Table 13: Adverse Reactions in a 3-Week Placebo-Controlled Clinical Trial for the Treatment of Bipolar Mania Preferred Term Quetiapine extended-release tablets (N=151) Placebo (N=160) Somnolence 1 50% 12% Dry Mouth 34% 7% Dizziness 10% 4% Constipation 10% 3% Dyspepsia 7% 4% Fatigue 7% 4% Weight Gain 7% 1% Extrapyramidal Symptoms 2 7% 4% Nasal Congestion 5% 1% Dysarthria 5% 0% Increased Appetite 4% 2% Back Pain 3% 2% Toothache 3% 1% Heart Rate Increased 3% 0% Abnormal Dreams 3% 0% Orthostatic Hypotension 3% 0% Tachycardia 2% 1% Vision Blurred 2% 1% Sluggishness 2% 1% Lethargy 2% 1% 1. Somnolence combines adverse reaction terms somnolence and sedation. 2. Extrapyramidal symptoms include the terms: muscle spasms, akathisia, cogwheel rigidity, dystonia, extrapyramidal disorder, restlessness and tremor. In the 8-week placebo-controlled bipolar depression study in adults, the most commonly observed adverse reactions associated with the use of quetiapine extended-release tablets (incidence of 5% or greater) and observed at a rate on quetiapine extended-release tablets at least twice that of placebo were somnolence (52%), dry mouth (37%), increased appetite (12%), weight gain (7%), dyspepsia (7%), and fatigue (6%). Table 14 enumerates the incidence, rounded to the nearest percent, of adverse reactions that occurred during acute therapy of bipolar depression (up to 8 weeks) in 2% or more of adult patients treated with q

Mechanism of Action The mechanism of action of quetiapine in the listed indications is unclear. However, the efficacy of quetiapine in these indications could be mediated through a combination of dopamine type 2 (D 2) and serotonin type 2A (5HT 2A) antagonism. The active metabolite, N-desalkyl quetiapine (norquetiapine), has similar activity at D 2, but greater activity at 5HT 2A receptors, than the parent drug (quetiapine). 12.2 Pharmacodynamics Quetiapine and its metabolite norquetiapine have affinity for multiple neurotransmitter receptors with norquetiapine binding with higher affinity than quetiapine in general. The K i values for quetiapine and norquetiapine at the dopamine D 1 are 428/99.8 nM, at D 2 626/489nM, at serotonin 5HT 1A 1040/191 nM at 5HT2A 38/2.9 nM, at histamine H 1 4.4/1.1 nM, at muscarinic M 1 1086/38.3 nM, and at adrenergic α 1b 14.6/46.4 nM and, at α 2 receptors 617/1290 nM, respectively. Quetiapine and norquetiapine lack appreciable affinity to the benzodiazepine receptors. Effect on QT Interval In clinical trials quetiapine was not associated with a persistent increase in QT intervals. However, the QT effect was not systematically evaluated in a thorough QT study. In post marketing experience there were cases reported of QT prolongation in patients who overdosed on quetiapine [see OVERDOSAGE (10.1)] , in patients with concomitant illness, and in patients taking medicines known to cause electrolyte imbalance or increase QT interval. 12.3 Pharmacokinetics Adults Following multiple dosing of quetiapine up to a total daily dose of 800 mg, administered in divided doses, the plasma concentration of quetiapine and norquetiapine, the major active metabolite of quetiapine, were proportional to the total daily dose. Accumulation is predictable upon multiple dosing. Steady-state mean C max and AUC of norquetiapine are about 21 to 27% and 46 to 56%, respectively, of that observed for quetiapine. Elimination of quetiapine is mainly via hepatic metabolism. The mean-terminal half-life is approximately 7 hours for quetiapine and approximately 12 hours for norquetiapine within the clinical dose range. Steady-state concentrations are expected to be achieved within two days of dosing. Quetiapine extended-release tablets are unlikely to interfere with the metabolism of drugs metabolized by cytochrome P450 enzymes. Children and Adolescents At steady state the pharmacokinetics of the parent compound, in children and adolescents (10 to 17 years of age), were similar to adults. However, when adjusted for dose and weight, AUC and C max of the parent compound were 41% and 39% lower, respectively, in children and adolescents than in adults. For the active metabolite, norquetiapine, AUC and C max were 45% and 31% higher, respectively, in children and adolescents than in adults. When adjusted for dose and weight, the pharmacokinetics of the metabolite, norquetiapine, was similar between children and adolescents and adults [see USE IN SPECIFIC POPULATIONS (8.4)]. Absorption Quetiapine reaches peak plasma concentrations approximately 6 hours following administration. Quetiapine extended-release tablets dosed once daily at steady state has comparable bioavailability to an equivalent total daily dose of quetiapine tablets administered in divided doses, twice daily. A high-fat meal (approximately 800 to 1,000 calories) was found to produce statistically significant increases in the quetiapine extended-release tablets C max and AUC of 44% to 52% and 20% to 22%, respectively, for the 50 mg and 300 mg tablets. In comparison, a light meal (approximately 300 calories) had no significant effect on the C max or AUC of quetiapine. It is recommended that quetiapine extended-release tablets be taken without food or with a light meal [see DOSAGE AND ADMINISTRATION (2.1)]. Distribution Quetiapine is widely distributed throughout the body with an apparent volume of distribution of 10±4 L/kg. It is 83% bound to plasma proteins at therapeutic concentrations. In vitro, quetiapine did not affect the binding of warfarin or diazepam to human serum albumin. In turn, neither warfarin nor diazepam altered the binding of quetiapine. Metabolism and Elimination Following a single oral dose of 14C-quetiapine, less than 1% of the administered dose was excreted as unchanged drug, indicating that quetiapine is highly metabolized. Approximately 73% and 20% of the dose was recovered in the urine and feces, respectively. The average dose fraction of free quetiapine and its major active metabolite is <5% excreted in the urine. Quetiapine is extensively metabolized by the liver. The major metabolic pathways are sulfoxidation to the sulfoxide metabolite and oxidation to the parent acid metabolite; both metabolites are pharmacologically inactive. In vitro studies using human liver microsomes revealed that the cytochrome P450 3A4 isoenzyme is involved in the metabolism of quetiapine to its major, but inactive, sulfoxide metabolite and in the metabolism of its active metabolite norquetiapine. Age Oral clearance of quetiapine was reduced by 40% in elderly patients (≥ 65 years, n = 9) compared to young patients (n = 12), and dosing adjustment may be necessary [see DOSAGE AND ADMINISTRATION (2.3)]. Gender There is no gender effect on the pharmacokinetics of quetiapine. Race There is no race effect on the pharmacokinetics of quetiapine. Smoking Smoking has no effect on the oral clearance of quetiapine. Renal Insufficiency Patients with severe renal impairment (CLcr=10 to 30 mL/min/1.73m 2, n=8) had a 25% lower mean oral clearance than normal subjects (CL cr>80 mL/min/1.73m 2, n=8), but plasma quetiapine concentrations in the subjects with renal insufficiency were within the range of concentrations seen in normal subjects receiving the same dose. Dosage adjustment is therefore not needed in these patients [see USE IN SPECIFIC POPULATIONS (8.6)]. Hepatic Insufficiency Hepatically impaired patients (n=8) had a 30% lower mean oral clearance of quetiapine than normal subjects. In 2 of the 8 hepatically impaired patients, AUC and C max were 3 times higher than those observed typically in healthy subjects. Since quetiapine is extensively metabolized by the liver, higher plasma levels are expected in the hepatically impaired population, and dosage adjustment may be needed [see DOSAGE AND ADMINISTRATION (2.4) and USE IN SPECIFIC POPULATIONS (8.7)]. Drug-Drug Interaction Studies The in vivo assessments of effect of other drugs on the pharmacokinetics of quetiapine are summarized in Table 24 [see DOSAGE AND ADMINISTRATION (2.5, 2.6) and DRUG INTERACTIONS (7.1)]. Table 24: The Effect of Other Drugs on the Pharmacokinetics of Quetiapine Coadministered Drug Dose Schedules Effect on Quetiapine Pharmacokinetics Coadministered Drug Quetiapine Phenytoin 100 mg three times daily 250 mg three times daily 5-fold Increase in oral clearance Divalproex 500 mg twice daily 150 mg twice daily 17% increase mean max plasma concentration at steady state. No effect on absorption or mean oral clearance Thioridazine 200 mg twice daily 300 mg twice daily 65% increase in oral clearance Cimetidine 400 mg three times daily for 4 days 150 mg three times daily 20% decrease in mean oral clearance Ketoconazole (potent CYP 3A4 inhibitor) 200 mg once daily for 4 days 25 mg single dose 84% decrease in oral clearance resulting in a 6.2 fold increase in AUC of quetiapine Fluoxetine 60 mg once daily 300 mg twice daily No change in steady state PK Imipramine 75 mg twice daily 300 mg twice daily No change in steady state PK Haloperidol 7.5 mg twice daily 300 mg twice daily No change in steady state PK Risperidone 3 mg twice daily 300 mg twice daily No change in steady state PK In vitro enzyme inhibition data suggest that quetiapine and 9 of its metabolites would have little inhibitory effect on in vivo metabolism mediated by cytochromes CYP 1A2, 2C9, 2C19, 2D6 and 3A4. Quetiapine at doses of 750 mg/day did not affect the single dose pharmacokine