ALPRAZOLAM

Alprazolam extended-releasetablets USP contain alprazolam which is a triazolo analog of the 1,4 benzodiazepine class of central nervous system-active compounds. The chemical name of alprazolam is 8-chloro-1-methyl-6-phenyl-4 H - s -triazolo [4,3-α] [1,4] benzodiazepine. The molecular formula is C 17 H 13 ClN 4 which corresponds to a molecular weight of 308.76. The structural formula is represented below: Alprazolam USP is a white to off-white, crystalline powder, which is soluble in methanol or ethanol but which has no appreciable solubility in water at physiological pH. Each alprazolam extended-release tablet USP, for oral administration, contains 0.5 mg, 1 mg, 2 mg, or 3 mg of alprazolam. The inactive ingredients are colloidal silicon dioxide, hypromellose, lactose monohydrate, and magnesium stearate. In addition, the 1 mg and 3 mg tablets contain D&C Yellow No. 10 aluminum lake and the 2 mg and 3 mg tablets contain FD&C Blue No. 2 lake. Meets USP Dissolution Test 4. Chemical Structure

Alprazolam extended-release tablets USP are indicated for the treatment of panic disorder, with or without agoraphobia. This claim is supported on the basis of two positive studies with alprazolam extended-release tablets USP conducted in patients whose diagnoses corresponded closely to the DSM-III-R/IV criteria for panic disorder (see CLINICAL EFFICACY TRIALS ). Panic disorder (DSM-IV) is characterized by recurrent unexpected panic attacks, i.e., a discrete period of intense fear or discomfort in which four (or more) of the following symptoms develop abruptly and reach a peak within 10 minutes: (1) palpitations, pounding heart, or accelerated heart rate; (2) sweating; (3) trembling or shaking; (4) sensations of shortness of breath or smothering; (5) feeling of choking; (6) chest pain or discomfort; (7) nausea or abdominal distress; (8) feeling dizzy, unsteady, lightheaded, or faint; (9) derealization (feelings of unreality) or depersonalization (being detached from oneself); (10) fear of losing control; (11) fear of dying; (12) paresthesias (numbness or tingling sensations); (13) chills or hot flushes. The longer-term efficacy of alprazolam extended-release tablets USP has not been systematically evaluated. Thus, the physician who elects to use this drug for periods longer than 8 weeks should periodically reassess the usefulness of the drug for the individual patient.

Alprazolam extended-release tablets may be administered once daily, preferably in the morning. The tablets should be taken intact; they should not be chewed, crushed, or broken. The suggested total daily dose ranges between 3 to 6 mg/day. Dosage should be individualized for maximum beneficial effect. While the suggested total daily dosages given will meet the needs of most patients, there will be some patients who require doses greater than 6 mg/day. In such cases, dosage should be increased cautiously to avoid adverse effects. Dosing in Special Populations In elderly patients, in patients with advanced liver disease, or in patients with debilitating disease, the usual starting dose of alprazolam extended-release tablets is 0.5 mg once daily. This may be gradually increased if needed and tolerated (see Dose Titration ). The elderly may be especially sensitive to the effects of benzodiazepines. Dose Titration Treatment with alprazolam extended-release tablets may be initiated with a dose of 0.5 mg to 1 mg once daily. Depending on the response, the dose may be increased at intervals of 3 to 4 days in increments of no more than 1 mg/day. Slower titration to the dose levels may be advisable to allow full expression of the pharmacodynamic effect of alprazolam extended-release tablets. Generally, therapy should be initiated at a low dose to minimize the risk of adverse responses in patients especially sensitive to the drug. Dose should be advanced until an acceptable therapeutic response (i.e., a substantial reduction in or total elimination of panic attacks) is achieved, intolerance occurs, or the maximum recommended dose is attained. Dose Maintenance In controlled trials conducted to establish the efficacy of alprazolam extended-release tablets in panic disorder, doses in the range of 1 to 10 mg/day were used. Most patients showed efficacy in the dose range of 3 to 6 mg/day. Occasional patients required as much as 10 mg/day to achieve a successful response. The necessary duration of treatment for panic disorder patients responding to alprazolam extended-release tablets is unknown. However, periodic reassessment is advised. After a period of extended freedom from attacks, a carefully supervised tapered discontinuation may be attempted, but there is evidence that this may often be difficult to accomplish without recurrence of symptoms and/or the manifestation of withdrawal phenomena. Dose Reduction Because of the danger of withdrawal, abrupt discontinuation of treatment should be avoided (see WARNINGS , PRECAUTIONS , and DRUG ABUSE AND DEPENDENCE ). In all patients, dosage should be reduced gradually when discontinuing therapy or when decreasing the daily dosage. Although there are no systematically collected data to support a specific discontinuation schedule, it is suggested that the daily dosage be decreased by no more than 0.5 mg every three days. Some patients may require an even slower dosage reduction. In any case, reduction of dose must be undertaken under close supervision and must be gradual. If significant withdrawal symptoms develop, the previous dosing schedule should be reinstituted and, only after stabilization, should a less rapid schedule of discontinuation be attempted. In a controlled postmarketing discontinuation study of panic disorder patients which compared this recommended taper schedule with a slower taper schedule, no difference was observed between the groups in the proportion of patients who tapered to zero dose; however, the slower schedule was associated with a reduction in symptoms associated with a withdrawal syndrome. It is suggested that the dose be reduced by no more than 0.5 mg every three days, with the understanding that some patients may benefit from an even more gradual discontinuation. Some patients may prove resistant to all discontinuation regimens. Switch from Alprazolam (Immediate-Release) Tablets to Alprazolam Extended-Release Tablets Patients who are currently being treated with divided doses of alprazolam (immediate-release) tablets, for example 3 to 4 times a day, may be switched to alprazolam extended-release tablets at the same total daily dose taken once daily. If the therapeutic response after switching is inadequate, the dosage may be titrated as outlined above.

Alprazolam extended-release tablets are contraindicated in patients with known sensitivity to this drug or other benzodiazepines. Alprazolam extended-release tablets may be used in patients with open angle glaucoma who are receiving appropriate therapy, but is contraindicated in patients with acute narrow angle glaucoma. Alprazolam extended-release tablets are contraindicated with ketoconazole and itraconazole, since these medications significantly impair the oxidative metabolism mediated by cytochrome P450 3A (CYP3A) (see CLINICAL PHARMACOLOGY , WARNINGS and PRECAUTIONS–Drug Interactions ).

The information included in the subsection on Adverse Events Observed in Short-Term, Placebo-Controlled Trials with alprazolam extended-release tablets is based on pooled data of five 6- and 8-week placebo-controlled clinical studies in panic disorder. Adverse event reports were elicited either by general inquiry or by checklist, and were recorded by clinical investigators using terminology of their own choosing. The stated frequencies of adverse events represent the proportion of individuals who experienced, at least once, a treatment-emergent adverse event of the type listed. An event was considered treatment emergent if it occurred for the first time or worsened during therapy following baseline evaluation. In the tables and tabulations that follow, standard MedDRA terminology (version 4.0) was used to classify reported adverse events. Adverse Events Observed in Short-Term, Placebo-Controlled Trials of Alprazolam Extended-Release Adverse Events Reported as Reasons for Discontinuation of Treatment in Placebo-Controlled Trials Approximately 17% of the 531 patients who received alprazolam extended-release in placebo-controlled clinical trials for panic disorder had at least one adverse event that led to discontinuation compared to 8% of 349 placebo-treated patients. The most common events leading to discontinuation and considered to be drug-related (i.e., leading to discontinuation in at least 1% of the patients treated with alprazolam extended-release at a rate at least twice that of placebo) are shown in the following table. Common Adverse Events Leading to Discontinuation of Treatment in Placebo-Controlled Trials System Organ Class/ Adverse Event Percentage of Patients Discontinuing Due to Adverse Events Alprazolam Extended-Release (n=531) Placebo (n=349) Nervous system disorders Sedation Somnolence Dysarthria Coordination abnormal Memory impairment 7.5 3.2 2.1 1.9 1.5 0.6 0.3 0 0.3 0.3 General disorders/administration site conditions Fatigue 1.7 0.6 Psychiatric disorders Depression 2.5 1.2 Adverse Events Occurring at an Incidence of 1% or More Among Patients Treated with Alprazolam Extended-Release The prescriber should be aware that adverse event incidence cannot be used to predict the incidence of adverse events 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 event incidence obtained from other clinical investigations involving different treatments, uses, and investigators. The cited values, however, do provide the prescribing physician with some basis for estimating the relative contribution of drug and non-drug factors to the adverse event incidence rate in the population studied. The following table shows the incidence of treatment-emergent adverse events that occurred during 6- to 8-week placebo-controlled trials in 1% or more of patients treated with alprazolam extended-release where the incidence in patients treated with alprazolam extended-release was greater than the incidence in placebo-treated patients. The most commonly observed adverse events in panic disorder patients treated with alprazolam extended-release (incidence of 5% or greater and at least twice the incidence in placebo patients) were: sedation, somnolence, memory impairment, dysarthria, coordination abnormal, ataxia, libido decreased (see table). Treatment-Emergent Adverse Events: Incidence in Short-Term, Placebo-Controlled Clinical Trials with Alprazolam Extended-Release System Organ Class/Adverse Event Percentage of Patients Reporting Adverse Event Alprazolam Extended Release (n=531) Placebo (n=349) Nervous system disorders Sedation Somnolence Memory impairment Dysarthria Coordination abnormal Mental impairment Ataxia Disturbance in attention Balance impaired Paresthesia Dyskinesia Hypoesthesia Hypersomnia 45.2 23 15.4 10.9 9.4 7.2 7.2 3.2 3.2 2.4 1.7 1.3 1.3 22.6 6 6.9 2.6 0.9 5.7 3.2 0.6 0.6 1.7 1.4 0.3 0 General disorders/administration site conditions Fatigue Lethargy 13.9 1.7 9.2 0.6 Infections and infestations Influenza Upper respiratory tract infections 2.4 1.9 2.3 1.7 Psychiatric disorders Depression Libido decreased Disorientation Confusion Depressed mood Anxiety 12.1 6 1.5 1.5 1.3 1.1 9.2 2.3 0 0.9 0.3 0.6 Metabolism and nutrition disorders Appetite decreased Appetite increased Anorexia 7.3 7 1.5 7.2 6 0 Gastrointestinal disorders Dry mouth Constipation Nausea Pharyngolaryngeal pain 10.2 8.1 6 3.2 9.7 4.3 3.2 2.6 Investigations Weight increased Weight decreased 5.1 4.3 4.3 3.7 Injury, poisoning, and procedural complications Road traffic accident 1.5 0 Reproductive system and breast disorders Dysmenorrhea Sexual dysfunction Premenstrual syndrome 3.6 2.4 1.7 2.9 1.1 0.6 Musculoskeletal and connective tissue disorders Arthralgia Myalgia Pain in limb 2.4 1.5 1.1 0.6 1.1 0.3 Vascular disorders Hot flushes 1.5 1.4 Respiratory, thoracic, and mediastinal disorders Dyspnea Rhinitis allergic 1.5 1.1 0.3 0.6 Skin and subcutaneous tissue disorders Pruritus 1.1 0.9 Other Adverse Events Observed During the Premarketing Evaluation of Alprazolam Extended-Release Tablets Following is a list of MedDRA terms that reflect treatment-emergent adverse events reported by 531 patients with panic disorder treated with alprazolam extended-release. All potentially important reported events are included except those already listed in the above table or elsewhere in labeling, those events for which a drug cause was remote, those event terms that were so general as to be uninformative, and those events that occurred at rates similar to background rates in the general population. It is important to emphasize that, although the events reported occurred during treatment with alprazolam extended-release, they were not necessarily caused by the drug. Events are further categorized by body system and listed in order of decreasing frequency according to the following definitions: frequent adverse events are those occurring on 1 or more occasions in at least l/l00 patients; infrequent adverse events are those occurring in less than l/100 patients but at least l/1000 patients; rare events are those occurring in fewer than l/1000 patients. Cardiac disorders: Frequent: palpitation; Infrequent: sinus tachycardia Ear and Labyrinth disorders: Frequent: Vertigo; Infrequent: tinnitus, ear pain Eye disorders: Frequent: blurred vision; Infrequent: mydriasis, photophobia Gastrointestinal disorders: Frequent: diarrhea, vomiting, dyspepsia, abdominal pain; Infrequent: dysphagia, salivary hypersecretion General disorders and administration site conditions: Frequent: malaise, weakness, chest pains; Infrequent: fall, pyrexia, thirst, feeling hot and cold, edema, feeling jittery, sluggishness, asthenia, feeling drunk, chest tightness, increased energy, feeling of relaxation, hangover, loss of control of legs, rigors Musculoskeletal and connective tissue disorders: Frequent: back pain, muscle cramps, muscle twitching Nervous system disorders: Frequent: headache, dizziness, tremor; Infrequent: amnesia, clumsiness, syncope, hypotonia, seizures, depressed level of consciousness, sleep apnea syndrome, sleep talking, stupor Psychiatric system disorders: Frequent: irritability, insomnia, nervousness, derealization, libido increased, restlessness, agitation, depersonalization, nightmare; Infrequent: abnormal dreams, apathy, aggression, anger, bradyphrenia, euphoric mood, logorrhea, mood swings, dysphonia, hallucination, homicidal ideation, mania, hypomania, impulse control, psychomotor retardation, suicidal ideation Renal and urinary disorders: Frequent: difficulty in micturition; Infrequent: urinary frequency, urinary incontinence Respiratory, thoracic, and mediastinal disorders: Frequent: nasal congestion, hyperventilation; Infrequent: choking sensation, epistaxis, rhinorrhea Skin and subcutaneous tissue disorders: Frequent: sweating increased; Infrequent: clamminess, rash, urticaria Vascular disorders: Infrequent: hypotension The categories of adverse events reported in the clinical development program for alprazolam tablets in the treatment of panic disorder differ somewhat from those reported for alprazolam extended-release tablets because the clinical trials with alprazolam tablets and alprazolam extended-release tablets used different standard medical nomenclature for reporting the adverse events. Nevertheless, the types of adverse events reported in the clinical trials with alprazolam tablets were generally the same as those reported in the clinical trials with alprazolam extended-release tablets. Discontinuation-Emergent Adverse Events Occurring at an Incidence of 5% or More Among Patients Treated with Alprazolam Extended-Release The following table shows the incidence of discontinuation-emergent adverse events that occurred during short-term, placebo-controlled trials in 5% or more of patients treated with alprazolam extended-release where the incidence in patients treated with alprazolam extended-release was two times greater than the incidence in placebo-treated patients. Discontinuation-Emergent Symptoms: Incidence in Short-Term, Placebo-Controlled Trials with Alprazolam Extended-Release System Organ Class/ Adverse Event Percentage of Patients Reporting Adverse Event Alprazolam Extended Release (n=422) Placebo (n=261) Nervous system disorders Tremor Headache Hypoesthesia Paresthesia 28.2 26.5 7.8 7.1 10.7 12.6 2.3 2.7 Psychiatric disorders Insomnia Nervousness Depression Derealization Anxiety Depersonalization 24.2 21.8 10.9 8 7.8 5.7 9.6 8.8 5 3.8 2.7 1.9 Gastrointestinal disorders Diarrhea 12.1 3.1 Respiratory, thoracic and mediastinal disorders Hyperventilation 8.5 2.7 Metabolism and nutrition disorders Appetite decreased 9.5 3.8 Musculoskeletal and connective tissue disorders Muscle twitching 7.4 2.7 Vascular disorders Hot flushes 5.9 2.7 There have also been reports of withdrawal seizures upon rapid decrease or abrupt discontinuation of alprazolam (see WARNINGS ). To discontinue treatment in patients taking alprazolam extended-release tablets, the dosage should be reduced slowly in keeping with good medical practice. It is suggested that the daily dosage of alprazolam extended-release tablets be decreased by no more than 0.5 mg every three days (see DOSAGE AND ADMINISTRATION ). Some patients may benefit from an even slower dosage reduction. In a controlled postmarketing discontinuation study of panic disorder patients which compared this recommended taper schedule with a slower taper schedule, no difference was observed between the groups in the proportion of patients who tapered to zero dose; however, the slower schedule was associated with a reduction in symptoms associated with a withdrawal syndrome. As with all benzodiazepines, paradoxical reactions such as stimulation, increased muscle spasticity, sleep disturbances, hallucinations, and other adverse behavioral effects such as agitation, rage, irritability, and aggressive or hostile behavior have been reported rarely. In many of the spontaneous case reports of adverse behavioral effects, patients were receiving other CNS drugs concomitantly and/or were described as having underlying psychiatric conditions. Should any of the above events occur, alprazolam should be discontinued. Isolated published reports involving small numbers of patients have suggested that patients who have borderline personality disorder, a prior history of violent or aggressive behavior, or alcohol or substance abuse may be at risk for such events. Instances of irritability, hostility, and intrusive thoughts have been reported during discontinuation of alprazolam in patients with posttraumatic stress disorder. Post Introduction Reports Various adverse drug reactions have been reported in association with the use of alprazolam tablets since market introduction. The majority of these reactions were reported through the medical event voluntary reporting system. Because of the spontaneous nature of the reporting of medical events and the lack of controls, a causal relationship to the use of alprazolam tablets cannot be readily determined. Reported events include: gastrointestinal disorder, hypomania, mania, liver enzyme elevations, hepatitis, hepatic failure, Stevens-Johnson syndrome, angioedema, peripheral edema, hyperprolactinemia, gynecomastia, and galactorrhea (see PRECAUTIONS ).

Use with Other CNS Depressants If alprazolam extended-release tablets are to be combined with other psychotropic agents or anticonvulsant drugs, careful consideration should be given to the pharmacology of the agents to be employed, particularly with compounds which might potentiate the action of benzodiazepines. The benzodiazepines, including alprazolam, produce additive CNS depressant effects when coadministered with other psychotropic medications, anticonvulsants, antihistaminics, ethanol and other drugs which themselves produce CNS depression. Use with Imipramine and Desipramine The steady state plasma concentrations of imipramine and desipramine have been reported to be increased an average of 31% and 20%, respectively, by the concomitant administration of alprazolam tablets in doses up to 4 mg/day. The clinical significance of these changes is unknown. Drugs that inhibit alprazolam metabolism via cytochrome P450 3A The initial step in alprazolam metabolism is hydroxylation catalyzed by cytochrome P450 3A (CYP3A). Drugs which inhibit this metabolic pathway may have a profound effect on the clearance of alprazolam (see CONTRAINDICATIONS and WARNINGS for additional drugs of this type). Drugs demonstrated to be CYP3A inhibitors of possible clinical significance on the basis of clinical studies involving alprazolam (caution is recommended during coadministration with alprazolam) Fluoxetine — Coadministration of fluoxetine with alprazolam increased the maximum plasma concentration of alprazolam by 46%, decreased clearance by 21%, increased half-life by 17%, and decreased measured psychomotor performance. Propoxyphene — Coadministration of propoxyphene decreased the maximum plasma concentration of alprazolam by 6%, decreased clearance by 38%, and increased half-life by 58%. Oral Contraceptives — Coadministration of oral contraceptives increased the maximum plasma concentration of alprazolam by 18%, decreased clearance by 22%, and increased half-life by 29%. Drugs and other substances demonstrated to be CYP3A inhibitors on the basis of clinical studies involving benzodiazepines metabolized similarly to alprazolam or on the basis of in vitro studies with alprazolam or other benzodiazepines (caution is recommended during coadministration with alprazolam) Available data from clinical studies of benzodiazepines other than alprazolam suggest a possible drug interaction with alprazolam for the following: diltiazem, isoniazid, macrolide antibiotics such as erythromycin and clarithromycin, and grapefruit juice. Data from in vitro studies of alprazolam suggest a possible drug interaction with alprazolam for the following: sertraline and paroxetine. However, data from an in vivo drug interaction study involving a single dose of alprazolam 1 mg and steady state doses of sertraline (50 to 150 mg/day) did not reveal any clinically significant changes in the pharmacokinetics of alprazolam. Data from in vitro studies of benzodiazepines other than alprazolam suggest a possible drug interaction for the following: ergotamine, cyclosporine, amiodarone, nicardipine, and nifedipine. Caution is recommended during the coadministration of any of these with alprazolam (see WARNINGS ). Drugs demonstrated to be inducers of CYP3A Carbamazepine can increase alprazolam metabolism and therefore can decrease plasma levels of alprazolam.