Quazepam

Overdose

Contact a poison control center for up-to-date information on the management of benzodiazepine overdose.

Manifestations of Quazepam overdose include somnolence, confusion, and coma. General supportive measures should be employed, along with immediate gastric lavage. Dialysis is of limited value. Flumazenil may be useful, but can contribute to the appearance of neurological symptoms including convulsions. Hypotension may be treated by appropriate medical intervention. Animal experiments suggest that forced diuresis or hemodialysis are of little value in treating Quazepam overdose. As with the management of intentional overdose with any drug, the possibility of multiple drug ingestion should be considered.

Contraindications

Quazepam is contraindicated in patients with known hypersensitivity to quazepam or other benzodiazepines. Rare cases of angioedema involving the tongue, glottis or larynx have been reported in patients after taking the first or subsequent doses of Quazepam. Some patients have had additional symptoms such as dyspnea, throat closing, or nausea and vomiting that suggest anaphylaxis. Patients who develop such reactions should not be rechallenged with Quazepam.

Contraindicated in patients with established or suspected sleep apnea, or with pulmonary insufficiency.

Pharmaceutical form

Undesirable effects

The following serious adverse reactions are discussed in greater detail in other sections of the label:

• CNS-depressant effects and next-day impairment
• Benzodiazepine withdrawal syndrome
• Abnormal thinking and behavior changes, and complex behaviors
• Worsening of depression

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.

The table shows adverse reactions occurring at an incidence of 1% or greater in relatively short-duration, placebo-controlled clinical trials of Quazepam. 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 actual practice.

A double-blind, controlled sleep laboratory study (N=30) in elderly patients compared the effects of quazepam 7.5 mg and 15 mg to that of placebo over a period of 7 days. Both the 7.5 mg and 15 mg doses appeared to be well tolerated. Caution must be used in interpreting this data due to the small size of the study.

Therapeutic indications

Quazepam® (quazepam) is indicated for the treatment of insomnia characterized by difficulty in falling asleep, frequent nocturnal awakenings, and/or early morning awakenings. The effectiveness of Quazepam has been established in placebo-controlled clinical studies of 5 nights duration in acute and chronic insomnia. The sustained effectiveness of Quazepam has been established in chronic insomnia in a sleep lab (polysomnographic) study of 28 nights duration. Because insomnia is often transient and intermittent, the prolonged administration of Quazepam Tablets is generally not necessary or recommended. Since insomnia may be a symptom of several other disorders, the possibility that the complaint may be related to a condition for which there is a more specific treatment should be considered.

Pharmacokinetic properties

Quazepam is rapidly (absorption half-life of about 30 minutes) and well absorbed from the gastrointestinal tract. The peak plasma concentration of quazepam is approximately 20 ng/mL after a 15 mg dose and occurs at about 2 hours.

Quazepam, the active parent compound, is extensively metabolized in the liver; two of the plasma metabolites are 2-oxoquazepam and N-desalkyl-2-oxoquazepam. All three compounds show CNS depressant activity.

The degree of plasma protein binding for quazepam and its two major metabolites is greater than 95%.

Following administration of 14C-quazepam, 31% of the dose appeared in the urine and 23% in the feces over five days; only trace amounts of unchanged drug were present in the urine.

The mean elimination half-life of quazepam and 2-oxoquazepam is 39 hours and that of Ndesalkyl-2-oxoquazepam is 73 hours. Steady-state levels of quazepam and 2-oxoquazepam are attained by the seventh daily dose and that of N-desalkyl-2-oxoquazepam by the thirteenth daily dose.

Name of the medicinal product

Qualitative and quantitative composition

Special warnings and precautions for use

Included as part of the PRECAUTIONS section.

Quazepam is a central nervous system (CNS) depressant and can impair daytime function in some patients even when used as prescribed. Prescribers should monitor for excess depressant effects, but impairment can occur in the absence of subjective symptoms, and may not be reliably detected by ordinary clinical exam (i.e. less than formal psychomotor testing). While pharmacodynamic tolerance or adaptation to some adverse depressant effects of Quazepam may develop, patients using Quazepam should be cautioned against driving or engaging in other hazardous activities or activities requiring complete mental alertness.

Additive effects occur with concomitant use of other CNS depressants (e.g., other benzodiazepines, opioids, tricyclic antidepressants, alcohol), including daytime use. Downward dose adjustment of Quazepam and concomitant CNS depressants should be considered. The potential for adverse drug interactions continues for several days following discontinuation of Quazepam, until serum levels of both active parent drug and psychoactive metabolites decline.

Use of Quazepam with other sedative-hypnotics is not recommended. Alcohol generally should not be used during treatment with Quazepam. The risk of next-day psychomotor impairment is increased if Quazepam is taken with less than a full night of sleep remaining (7- to 8 hours); if higher than the recommended dose is taken; if co-administered with other CNS depressants.

A withdrawal syndrome similar to that from alcohol (e.g., convulsions, tremor, abdominal and muscle cramps, vomiting, and sweating) can occur following abrupt discontinuation of Quazepam. The more severe withdrawal effects are usually limited to patients taking higher than recommended doses over an extended time. Abrupt discontinuation should be avoided in such patients, and the dose gradually tapered. Prescribers should monitor patients for tolerance, abuse, and dependence.

Milder withdrawal symptoms (e.g., dysphoria and insomnia) can occur following abrupt discontinuation of benzodiazepines taken at therapeutic levels for short periods.

Because sleep disturbances may be the presenting manifestation of a physical and/or psychiatric disorder, symptomatic treatment of insomnia should be initiated only after a careful evaluation of the patient. The failure of insomnia to remit after 7 to 10 days of treatment may indicate the presence of a primary psychiatric and/or medical illness that should be evaluated. Worsening of insomnia or the emergence of new thinking or behavior abnormalities may be the consequence of an unrecognized psychiatric or physical disorder. Such findings have emerged during the course of treatment with sedative-hypnotic drugs.

Rare cases of angioedema involving the tongue, glottis or larynx have been reported in patients after taking the first or subsequent doses of sedative-hypnotics, including Quazepam. Some patients have had additional symptoms such as dyspnea, throat closing, or nausea and vomiting that suggest anaphylaxis.

Some patients have required medical therapy in the emergency department. If angioedema involves the tongue, glottis or larynx, airway obstruction may occur and be fatal. Patients who develop angioedema after treatment with Quazepam should not be rechallenged with the drug.

Abnormal thinking and behavior changes have been reported in patients treated with sedative-hypnotics including Quazepam. Some of these changes include decreased inhibition (e.g., aggressiveness and extroversion that seemed out of character), bizarre behavior, and depersonalization. Visual and auditory hallucinations have also been reported. Amnesia, and other neuro-psychiatric symptoms may occur.

Paradoxical reactions such as stimulation, agitation, increased muscle spasticity, and sleep disturbances may occur unpredictably.

Complex behaviors such as “sleep-driving” (i.e., driving while not fully awake, with amnesia for the event) have been reported with use of sedative-hypnotics. These behaviors can occur with initial treatment or in patients previously tolerant of Quazepam or other sedative-hypnotics. Although these behaviors can occur with use at therapeutic doses, risk is increased by higher doses or concomitant use of alcohol or other CNS depressants. Due to risk to the patient and community, Quazepam should be discontinued if “sleep-driving” occurs.

Other complex behaviors (e.g., preparing and eating food, making phone calls, or having sex) have been reported in patients who are not fully awake after taking a sedative-hypnotic. As with sleep-driving, patients usually do not remember these events.

Benzodiazepines may worsen depression. Consequently, appropriate precautions (e.g., limiting the total prescription size and increased monitoring for suicidal ideation) should be considered.

See FDA-approved patient labeling (Medication Guide).

Inform patients about the benefits and risks of Quazepam, stressing the importance of use as directed. Assist patients in understanding the Medication Guide and instruct them to read it with each prescription refill.

Tell patients that Quazepam can cause next-day impairment, even in the absence of symptoms. Caution patients against driving or engaging in other hazardous activities or activities requiring complete mental alertness when using Quazepam. Tell patients that daytime impairment may persist for several days following discontinuation of Quazepam.

Instruct patients to contact you before stopping or decreasing the dose of Quazepam, because withdrawal symptoms can occur.

Instruct patients that sedative hypnotics can cause abnormal thinking and behavior change, including “sleep-driving” and other complex behaviors while not being fully awake (preparing and eating food, making phone calls, or having sex). Tell patients to call you immediately if they develop any of these symptoms.

Inform patients that severe allergic reactions can occur from Quazepam. Describe the signs/symptoms of these reactions and advise patients to seek medical attention immediately if these occur.

Tell patients that Quazepam can worsen depression, and to immediately report any suicidal thoughts.

Ask patients about alcohol consumption, medicines they are taking now, and drugs they may be taking without a prescription. Advise patients that alcohol generally should not be used during treatment with Quazepam.

Instruct patients to inform you if they are nursing or pregnant, or may become pregnant while taking Quazepam.

Tell patients not to increase the dose of Quazepam on their own, and to inform you if they believe the drug “does not work”.

Quazepam showed no evidence of carcinogenicity in oral carcinogenicity studies in mice and hamsters.

Quazepam was negative in the bacterial reverse mutation (Ames) assay and equivocal in the mouse lymphoma tk assay.

Reproduction studies in mice conducted with quazepam at doses equal to 60 and 180 times the human dose of 15 mg produced slight reductions in fertility rate. Similar reductions in fertility rate have been reported in mice dosed with other benzodiazepines, and is believed to be related to the sedative effects of these drugs at high doses.

There are no adequate and well-controlled studies in pregnant women. Administration of benzodiazepines immediately prior to or during childbirth can result in a syndrome of hypothermia, hypotonia, respiratory depression, and difficulty feeding. In addition, infants born to mothers who have taken benzodiazepines during the later stages of pregnancy can development dependence, and subsequently withdrawal, during the postnatal period. Although administration of quazepam to pregnant animals did not indicate a risk for adverse effects on morphological development at clinically relevant doses, data for other benzodiazepines suggest the possibility of adverse developmental effects (long-term effects on neurobehavioral and immunological function) in animals following prenatal exposure to benzodiazepines. Quazepam should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Developmental toxicity studies of quazepam in mice at doses up to 400 times the human dose (15 mg) revealed no major drug-related malformations. Minor fetal skeletal variations that occurred were delayed ossification of the sternum, vertebrae, distal phalanges and supraoccipital bones, at doses approximately 70 and 400 times the human dose. A developmental toxicity study of quazepam in New Zealand rabbits at doses up to approximately 130 times the human dose demonstrated no effect on fetal morphology or development of offspring.

Quazepam and its metabolites are excreted in human milk. Caution should be exercised when administering Quazepam to a nursing woman.

Safety and effectiveness in pediatric patients have not been established.

Quazepam may cause confusion and over-sedation in the elderly. Elderly patients generally should be started on a low dose of Quazepam and observed closely.

Elderly and debilitated patients may be more sensitive to benzodiazepines, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

A double-blind controlled sleep laboratory study (N=30) compared the effects of quazepam 7.5 mg and 15 mg to that of placebo over a period of 7 days. Both the 7.5 mg and 15 mg doses appeared to be well tolerated. Caution must be used in interpreting this data due to the small size of the study.

Dosage (Posology) and method of administration

Use the lowest dose effective for the patient, as important adverse effects of Quazepam are dose related.

The recommended initial dose is 7.5 mg. The 7.5 mg dose can be increased to 15 mg if necessary for efficacy.

The 7.5 mg dose can be achieved by splitting the 15 mg tablet along the score line.

Elderly and debilitated patients may be more sensitive to benzodiazepines.