Lorazepam

INDICATIONS AND USAGE Status Epilepticus Lorazepam Injection, is indicated for the treatment of the status epilepticus. Preanesthetic Lorazepam Injection, is indicated in adult patients for preanesthetic medication, producing sedation (sleepiness or drowsiness), relief of anxiety, and a decreased ability to recall events related to the day of surgery. It is most useful in those patients who are anxious about their surgical procedure and who would prefer to have diminished recall of the events of the day of surgery (see PRECAUTIONS, Information for Patients ).

DOSAGE AND ADMINISTRATION NOTE: CONTAINS BENZYL ALCOHOL (see WARNINGS and PRECAUTIONS, Pediatric Use ). Lorazepam Injection must never be used without individualization of dosage particularly when used with other medications capable of producing central-nervous-system depression. EQUIPMENT NECESSARY TO MAINTAIN A PATENT AIRWAY SHOULD BE IMMEDIATELY AVAILABLE PRIOR TO INTRAVENOUS ADMINISTRATION OF LORAZEPAM (see WARNINGS ). Status Epilepticus GENERAL ADVICE Status epilepticus is a potentially life-threatening condition associated with a high risk of permanent neurological impairment, if inadequately treated. The treatment of status, however, requires far more than the administration of an anticonvulsant agent. It involves observation and management of all parameters critical to maintaining vital function and the capacity to provide support of those functions as required. Ventilatory support must be readily available. The use of benzodiazepines, like Lorazepam Injection, is ordinarily only an initial step of a complex and sustained intervention which may require additional interventions, (e.g., concomitant intravenous administration of phenytoin). Because status epilepticus may result from a correctable acute cause such as hypoglycemia, hyponatremia, or other metabolic or toxic derangement, such an abnormality must be immediately sought and corrected. Furthermore, patients who are susceptible to further seizure episodes should receive adequate maintenance antiepileptic therapy. Any healthcare professional who intends to treat a patient with status epilepticus should be familiar with this package insert and the pertinent medical literature concerning current concepts for the treatment of status epilepticus. A comprehensive review of the considerations critical to the informed and prudent management of status epilepticus cannot be provided in drug product labeling. The archival medical literature contains many informative references on the management of status epilepticus, among them the report of the working group on status epilepticus of the Epilepsy Foundation of America “Treatment of Convulsive Status Epilepticus” (JAMA 1993; 270:854-859). As noted in the report just cited, it may be useful to consult with a neurologist if a patient fails to respond (e.g., fails to regain consciousness). INTRAVENOUS INJECTION For the treatment of status epilepticus, the usual recommended dose of Lorazepam Injection is 4 mg given slowly (2 mg/min) for patients 18 years and older. If seizures cease, no additional Lorazepam Injection is required. If seizures continue or recur after a 10- to 15-minute observation period, an additional 4 mg intravenous dose may be slowly administered. Experience with further doses of Lorazepam Injection is very limited. The usual precautions in treating status epilepticus should be employed. An intravenous infusion should be started, vital signs should be monitored, an unobstructed airway should be maintained, and artificial ventilation equipment should be available. INTRAMUSCULAR INJECTION Intramuscular Lorazepam Injection is not preferred in the treatment of status epilepticus because therapeutic lorazepam levels may not be reached as quickly as with intravenous administration. However, when an intravenous port is not available, the intramuscular route may prove useful (see CLINICAL PHARMACOLOGY, Pharmacokinetics and Metabolism ). PEDIATRIC The safety of Lorazepam Injection in pediatric patients has not been established. Preanesthetic INTRAMUSCULAR INJECTION For the designated indications as a premedicant, the usual recommended dose of lorazepam for intramuscular injection is 0.05 mg/kg up to a maximum of 4 mg. As with all premedicant drugs, the dose should be individualized (see CLINICAL PHARMACOLOGY , WARNINGS , PRECAUTIONS, and ADVERSE REACTIONS ). Doses of other central-nervous-system-depressant drugs ordinarily should be reduced (see PRECAUTIONS ). For optimum effect, measured as lack of recall, intramuscula …

CONTRAINDICATIONS Lorazepam Injection is contraindicated in patients with a known sensitivity to benzodiazepines or its vehicle (polyethylene glycol, propylene glycol and benzyl alcohol), in patients with acute narrow-angle glaucoma, or in patients with sleep apnea syndrome. It is also contraindicated in patients with severe respiratory insufficiency, except in those patients requiring relief of anxiety and/or diminished recall of events while being mechanically ventilated. The use of Lorazepam Injection intra-arterially is contraindicated because, as with other injectable benzodiazepines, inadvertent intra-arterial injection may produce arteriospasm resulting in gangrene which may require amputation (see WARNINGS ). Lorazepam Injection is contraindicated for use in premature infants because the formulation contains benzyl alcohol. (See WARNINGS and PRECAUTIONS - Pediatric Use ).

ADVERSE REACTIONS Status Epilepticus The most important adverse clinical event caused by the use of Lorazepam Injection is respiratory depression (see WARNINGS ). The adverse clinical events most commonly observed with the use of Lorazepam Injection in clinical trials evaluating its use in status epilepticus were hypotension, somnolence, and respiratory failure. INCIDENCE IN CONTROLLED CLINICAL TRIALS All adverse events were recorded during the trials by the clinical investigators using terminology of their own choosing. Similar types of events were grouped into standardized categories using modified COSTART dictionary terminology. These categories are used in the table and listings below with the frequencies representing the proportion of individuals exposed to Lorazepam Injection or to comparative therapy. The prescriber should be aware that these figures cannot be used to predict the frequency of adverse events in the course of usual medical practice where patient characteristics and other factors may differ from those prevailing during clinical studies. Similarly, the cited frequencies cannot be directly compared with figures obtained from other clinical investigators involving different treatment, uses, or investigators. An inspection of these frequencies, however, does provide the prescribing physician with one basis to estimate the relative contribution of drug and nondrug factors to the adverse event incidences in the population studied. COMMONLY OBSERVED ADVERSE EVENTS IN A CONTROLLED DOSE-COMPARISON CLINICAL TRIAL Table 1 lists the treatment-emergent adverse events that occurred in the patients treated with Lorazepam Injection in a dose-comparison trial of lorazepam 1 mg, 2 mg, and 4 mg. TABLE 1. NUMBER (%) OF STUDY EVENTS IN A DOSE COMPARISON CLINICAL TRIAL Body System Event Lorazepam Injection (n=130) One hundred and thirty (130) patients received Lorazepam Injection. Any Study Event (1 or more) Totals are not necessarily the sum of the individual study events because a patient may report two or more different study events in the same body system. 16 (12.3%) Body as a whole Infection 1 ( <1%) Cardiovascular system Hypotension 2 (1.5%) Digestive system Liver function tests abnormal 1 ( <1%) Nausea 1 ( <1%) Vomiting 1 ( <1%) Metabolic and Nutritional Acidosis 1 ( <1%) Nervous system Brain edema 1 ( <1%) Coma 1 ( <1%) Convulsion 1 ( <1%) Somnolence 2 (1.5%) Thinking abnormal 1 ( <1%) Respiratory system Hyperventilation 1 ( <1%) Hypoventilation 1 ( <1%) Respiratory failure 2 (1.5%) Terms not classifiable Injection site reaction 1 ( <1%) Urogenital system Cystitis 1 ( <1%) COMMONLY OBSERVED ADVERSE EVENTS IN ACTIVE-CONTROLLED CLINICAL TRIALS In two studies, patients who completed the course of treatment for status epilepticus were permitted to be reenrolled and to receive treatment for a second status episode, given that there was a sufficient interval between the two episodes. Safety was determined from all treatment episodes for all intent-to-treat patients, i.e., from all “patient-episodes.” Table 2 lists the treatment-emergent adverse events that occurred in at least 1% of the patient-episodes in which Lorazepam Injection or diazepam was given. The table represents the pooling of results from the two controlled trials. TABLE 2. NUMBER (%) OF STUDY EVENTS IN ACTIVE CONTROLLED CLINICAL TRIAL Body System Event Lorazepam Injection (n=85) The number indicates the number of “patient-episodes.” Patient-episodes were used rather than “patients” because a total of 7 patients were reenrolled for the treatment of a second episode of status: 5 patients received Lorazepam Injection on two occasions that were far enough apart to establish the diagnosis of status epilepticus for each episode, and, using the same time criterion, 2 patients received diazepam on two occasions. Diazepam (n=80) Any Study Event (1 or more) Totals are not necessarily the sum of the individual study events because a patient may report two or more differen …

Drug Interactions INTERACTION WITH BENZODIAZEPINES AND OTHER CNS DEPRESSANTS The concomitant use of benzodiazepines and opioids increases the risk of respiratory depression because of actions at different receptor sites in the CNS that control respiration. Benzodiazepines interact at GABAA sites and opioids interact primarily at mu receptors. When benzodiazepines and opioids are combined, the potential for benzodiazepines to significantly worsen opioid-related respiratory depression exists. Monitor patients closely for respiratory depression and sedation. Lorazepam Injection, like other injectable benzodiazepines, produces additive depression of the central nervous system when administered with other CNS depressants such as ethyl alcohol, phenothiazines, barbiturates, MAO inhibitors, and other antidepressants. When scopolamine is used concomitantly with injectable lorazepam, an increased incidence of sedation, hallucinations and irrational behavior has been observed. There have been rare reports of significant respiratory depression, stupor and/or hypotension with the concomitant use of loxapine and lorazepam. Marked sedation, excessive salivation, ataxia, and, rarely, death have been reported with the concomitant use of clozapine and lorazepam. Apnea, coma, bradycardia, arrhythmia, heart arrest, and death have been reported with the concomitant use of haloperidol and lorazepam. The risk of using lorazepam in combination with scopolamine, loxapine, clozapine, haloperidol, or other CNS-depressant drugs has not been systematically evaluated. Therefore, caution is advised if the concomitant administration of lorazepam and these drugs is required. Concurrent administration of any of the following drugs with lorazepam had no effect on the pharmacokinetics of lorazepam: metoprolol, cimetidine, ranitidine, disulfiram, propranolol, metronidazole, and propoxyphene. No change in Lorazepam Injection dosage is necessary when concomitantly given with any of these drugs. LORAZEPAM-VALPROATE INTERACTION Concurrent administration of lorazepam (2 mg intravenously) with valproate (250 mg twice daily orally for 3 days) to 6 healthy male subjects resulted in decreased total clearance of lorazepam by 40% and decreased formation rate of lorazepam glucuronide by 55%, as compared with lorazepam administered alone. Accordingly, lorazepam plasma concentrations were about two-fold higher for at least 12 hours post-dose administration during valproate treatment. Lorazepam dosage should be reduced to 50% of the normal adult dose when this drug combination is prescribed in patients (see DOSAGE AND ADMINISTRATION ). LORAZEPAM-ORAL CONTRACEPTIVE STEROIDS INTERACTION Coadministration of lorazepam (2 mg intravenously) with oral contraceptive steroids (norethindrone acetate, 1 mg, and ethinyl estradiol, 50 μg, for at least 6 months) to healthy females (n=7) was associated with a 55% decrease in half-life, a 50% increase in the volume of distribution, thereby resulting in an almost 3.7-fold increase in total clearance of lorazepam as compared with control healthy females (n=8). It may be necessary to increase the dose of Lorazepam Injection in female patients who are concomitantly taking oral contraceptives (see DOSAGE AND ADMINISTRATION ). LORAZEPAM-PROBENECID INTERACTION Concurrent administration of lorazepam (2 mg intravenously) with probenecid (500 mg orally every 6 hours) to 9 healthy volunteers resulted in a prolongation of lorazepam half-life by 130% and a decrease in its total clearance by 45%. No change in volume of distribution was noted during probenecid co-treatment. Lorazepam Injection dosage needs to be reduced by 50% when coadministered with probenecid (see DOSAGE AND ADMINISTRATION ).

Special Populations EFFECT OF AGE Pediatrics NEONATES (BIRTH TO 1 MONTH) Following a single 0.05 mg/kg (n=4) or 0.1 mg/kg (n=6) intravenous dose of lorazepam, mean total clearance normalized to body weight was reduced by 80% compared to normal adults , terminal half-life was prolonged 3-fold, and volume of distribution was decreased by 40% in neonates with asphyxia neonatorum compared to normal adults. All neonates were of ≥37 weeks of gestational age. INFANTS (1 MONTH UP TO 2 YEARS) There is no information on the pharmacokinetic profile of lorazepam in infants in the age range of 1 month to 2 years. CHILDREN (2 YEARS TO 12 YEARS) Total (bound and unbound) lorazepam had a 50% higher mean volume of distribution (normalized to body-weight) and a 30% longer mean half-life in children with acute lymphocytic leukemia in complete remission (2 to 12 years, n=37) compared to normal adults (n=10). Unbound lorazepam clearance normalized to body-weight was comparable in children and adults. ADOLESCENTS (12 YEARS TO 18 YEARS) Total (bound and unbound) lorazepam had a 50% higher mean volume of distribution (normalized to body-weight) and a mean half-life that was two fold greater in adolescents with acute lymphocytic leukemia in complete remission (12 to 18 years, n=13) compared to normal adults (n=10). Unbound lorazepam clearance normalized to body-weight was comparable in adolescents and adults. Elderly Following single intravenous doses of 1.5 to 3 mg of Lorazepam Injection, mean total body clearance of lorazepam decreased by 20% in 15 elderly subjects of 60 to 84 years of age compared to that in 15 younger subjects of 19 to 38 years of age. Consequently, no dosage adjustment appears to be necessary in elderly subjects based solely on their age. EFFECT OF GENDER Gender has no effect on the pharmacokinetics of lorazepam. EFFECT OF RACE Young Americans (n=15) and Japanese subjects (n=7) had very comparable mean total clearance value of 1.0 mL/min/kg. However, elderly Japanese subjects had a 20% lower mean total clearance than elderly Americans, 0.59 mL/min/kg vs 0.77 mL/min/kg, respectively. PATIENTS WITH RENAL INSUFFICIENCY Because the kidney is the primary route of elimination of lorazepam glucuronide, renal impairment would be expected to compromise its clearance. This should have no direct effect on the glucuronidation (and inactivation) of lorazepam. There is a possibility that the enterohepatic circulation of lorazepam glucuronide leads to a reduced efficiency of the net clearance of lorazepam in this population. Six normal subjects, six patients with renal impairment (Cl cr of 22±9 mL/min), and four patients on chronic maintenance hemodialysis were given single 1.5 to 3.0 mg intravenous doses of lorazepam. Mean volume of distribution and terminal half-life values of lorazepam were 40% and 25% higher, respectively, in renally impaired patients than in normal subjects. Both parameters were 75% higher in patients undergoing hemodialysis than in normal subjects. Overall, though, in this group of subjects the mean total clearance of lorazepam did not change. About 8% of the administered intravenous dose was removed as intact lorazepam during the 6-hour dialysis session. The kinetics of lorazepam glucuronide were markedly affected by renal dysfunction.The mean terminal half-life was prolonged by 55% and 125% in renally impaired patients and patients under hemodialysis, respectively, as compared to normal subjects. The mean metabolic clearance decreased by 75% and 90% in renally impaired patients and patients under hemodialysis, respectively, as compared with normal subjects. About 40% of the administered lorazepam intravenous dose was removed as glucuronide conjugate during the 6-hour dialysis session. HEPATIC DISEASE Because cytochrome oxidation is not involved with the metabolism of lorazepam, liver disease would not be expected to have an effect on metabolic clearance. This prediction is supported by the observation that following a s …

DESCRIPTION Lorazepam, a benzodiazepine with antianxiety, sedative, and anticonvulsant effects, is intended for the intramuscular or intravenous routes of administration. It has the chemical formula: 7-chloro-5(2-chlorophenyl)-1,3-dihydro-3-hydroxy-2 H -1, 4-benzodiazepin-2-one. The molecular weight is 321.16, and the C.A.S. No. is [846-49-1]. The structural formula is: Lorazepam is a nearly white powder almost insoluble in water. Each mL of sterile injection contains either 2.0 or 4.0 mg of lorazepam, 0.18 mL polyethylene glycol 400 in propylene glycol with 2.0% benzyl alcohol as preservative. Lorazepam Injection structural formula

OVERDOSAGE Overdosage of benzodiazepines is characterized by central nervous system depression ranging from drowsiness to coma. In mild to moderate cases, symptoms can include drowsiness, confusion, dysarthria, lethargy, hypnotic state, diminished reflexes, ataxia, and hypotonia. Rarely, paradoxical or disinhibitory reactions (including agitation, irritability, impulsivity, violent behavior, confusion, restlessness, excitement, and talkativeness) may occur. In severe overdosage cases, patients may develop respiratory depression and coma. Overdosage of benzodiazepines in combination with other CNS depressants (including alcohol and opioids) may be fatal (see WARNINGS, Abuse, Misuse, and Addiction ). Markedly abnormal (lowered or elevated) blood pressure, heart rate, or respiratory rate raise the concern that additional drugs and/or alcohol are involved in the overdosage. In managing benzodiazepine overdosage, employ general supportive measures, including intravenous fluids and airway management. Flumazenil, a specific benzodiazepine receptor antagonist indicated for the complete or partial reversal of the sedative effects of benzodiazepines in the management of benzodiazepine overdosage, can lead to withdrawal and adverse reactions, including seizures, particularly in the context of mixed overdosage with drugs that increase seizure risk (e.g., tricyclic and tetracyclic antidepressants) and in patients with long-term benzodiazepine use and physical dependency. The risk of withdrawal seizures with flumazenil use may be increased in patients with epilepsy. Flumazenil is contraindicated in patients who have received a benzodiazepine for control of a potentially life-threatening condition (e.g., status epilepticus). If the decision is made to use flumazenil, it should be used as an adjunct to, not as a substitute for, supportive management of benzodiazepine overdosage. See the flumazenil Injection Prescribing Information. Consider contacting the Poison Help line (1-800-222-1222) or a medical toxicologist for additional overdosage management recommendations.

HOW SUPPLIED Lorazepam Injection, USP is available as: Product Code Unit of Sale Strength (Concentration) Each 368302 NDC 65219-368-02 Unit of 25 2 mg/mL NDC 65219-368-01 1 mL Single-Dose Vial 368310 NDC 65219-368-10 Unit of 10 20 mg per 10 mL (2 mg/mL) NDC 65219-368-08 10 mL Multiple-Dose Vial For Intramuscular or Intravenous injection. Store in a refrigerator. PROTECT FROM LIGHT. Use carton to protect contents from light. The container closure is not made with natural rubber latex.