Quazepam

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Tablet, Oral:

Doral: 15 mg [scored; contains corn starch, fd&c yellow #6 aluminum lake]

Generic: 15 mg

Pharmacology

Mechanism of Action

Binds to stereospecific benzodiazepine receptors on the postsynaptic GABA neuron at several sites within the central nervous system, including the limbic system, reticular formation. Enhancement of the inhibitory effect of GABA on neuronal excitability results by increased neuronal membrane permeability to chloride ions. This shift in chloride ions results in hyperpolarization (a less excitable state) and stabilization. Benzodiazepine receptors and effects appear to be linked to the GABA-A receptors. Benzodiazepines do not bind to GABA-B receptors (Vinkers 2012).

Pharmacokinetics/Pharmacodynamics

Absorption

Rapid

Distribution

V_c/F: 5 to 8.6 L/kg (Ankier 1988)

Metabolism

Hepatic via CYP3A4, CYP2C9, and CYP2C19 (Fukasawa, 2004; Kato, 2003); forms metabolites (active) 2-oxoquazepam and N-desalkyl-2-oxoquazepam

Excretion

Urine (31%, only trace amounts as unchanged drug); feces (23%)

Time to Peak

~2 hours

Half-Life Elimination

Serum: Quazepam, 2-oxoquazepam: 39 hours; N-desalkyl-2-oxoquazepam: 73 hours

Protein Binding

>95%

Use in Specific Populations

Special Populations: Elderly

Elimination half-life of N-desalkyl-2-oxoquazepam is increased 2-fold compared with younger adults.

Use: Labeled Indications

Insomnia: For the treatment of insomnia characterized by difficulty in falling asleep, frequent nocturnal awakenings, and/or early morning

Contraindications

Hypersensitivity to quazepam, other benzodiazepines, or any component of the formulation; established or suspected sleep apnea; pulmonary insufficiency

Dosage and Administration

Dosing: Adult

Hypnotic: Oral: Initial: 7.5 mg at bedtime; in some patients, the dose may be increased to 15 mg if necessary for efficacy.

Dosing: Geriatric

Dosing should be cautious; begin at lower end of dosing range (ie, 7.5 mg)

Storage

Store at 20°C to 25°C (68°F to 77°F).

Drug Interactions

Alcohol (Ethyl): CNS Depressants may enhance the CNS depressant effect of Alcohol (Ethyl). Monitor therapy

Alizapride: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Azelastine (Nasal): CNS Depressants may enhance the CNS depressant effect of Azelastine (Nasal). Avoid combination

Blonanserin: CNS Depressants may enhance the CNS depressant effect of Blonanserin. Consider therapy modification

Brexanolone: CNS Depressants may enhance the CNS depressant effect of Brexanolone. Monitor therapy

Brimonidine (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Bromopride: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Bromperidol: May enhance the CNS depressant effect of CNS Depressants. Avoid combination

Buprenorphine: CNS Depressants may enhance the CNS depressant effect of Buprenorphine. Management: Consider reduced doses of other CNS depressants, and avoiding such drugs in patients at high risk of buprenorphine overuse/self-injection. Initiate buprenorphine at lower doses in patients already receiving CNS depressants. Consider therapy modification

Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Cannabis: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Chlormethiazole: May enhance the CNS depressant effect of CNS Depressants. Management: Monitor closely for evidence of excessive CNS depression. The chlormethiazole labeling states that an appropriately reduced dose should be used if such a combination must be used. Consider therapy modification

Chlorphenesin Carbamate: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy

CloZAPine: Benzodiazepines may enhance the adverse/toxic effect of CloZAPine. Management: Consider decreasing the dose of (or possibly discontinuing) benzodiazepines prior to initiating clozapine. Consider therapy modification

CNS Depressants: May enhance the adverse/toxic effect of other CNS Depressants. Monitor therapy

Dimethindene (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Doxylamine: May enhance the CNS depressant effect of CNS Depressants. Management: The manufacturer of Diclegis (doxylamine/pyridoxine), intended for use in pregnancy, specifically states that use with other CNS depressants is not recommended. Monitor therapy

Dronabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Droperidol: May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (eg, opioids, barbiturates) with concomitant use. Exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Consider therapy modification

Esketamine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Flunitrazepam: CNS Depressants may enhance the CNS depressant effect of Flunitrazepam. Consider therapy modification

Fosphenytoin: Benzodiazepines may increase the serum concentration of Fosphenytoin. Short-term exposure to benzodiazepines may not present as much risk as chronic therapy. Monitor therapy

HYDROcodone: CNS Depressants may enhance the CNS depressant effect of HYDROcodone. Management: Avoid concomitant use of hydrocodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

HydrOXYzine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Kava Kava: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy

Lemborexant: May enhance the CNS depressant effect of CNS Depressants. Management: Dosage adjustments of lemborexant and of concomitant CNS depressants may be necessary when administered together because of potentially additive CNS depressant effects. Close monitoring for CNS depressant effects is necessary. Consider therapy modification

Lofexidine: May enhance the CNS depressant effect of CNS Depressants. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Monitor therapy

Magnesium Sulfate: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Melatonin: May enhance the sedative effect of Benzodiazepines. Monitor therapy

Methadone: Benzodiazepines may enhance the CNS depressant effect of Methadone. Management: Clinicians should generally avoid concurrent use of methadone and benzodiazepines when possible; any combined use should be undertaken with extra caution. Consider therapy modification

Methotrimeprazine: CNS Depressants may enhance the CNS depressant effect of Methotrimeprazine. Methotrimeprazine may enhance the CNS depressant effect of CNS Depressants. Management: Reduce adult dose of CNS depressant agents by 50% with initiation of concomitant methotrimeprazine therapy. Further CNS depressant dosage adjustments should be initiated only after clinically effective methotrimeprazine dose is established. Consider therapy modification

MetyroSINE: CNS Depressants may enhance the sedative effect of MetyroSINE. Monitor therapy

Minocycline (Systemic): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Nabilone: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

OLANZapine: May enhance the adverse/toxic effect of Benzodiazepines. Management: Avoid concomitant use of parenteral benzodiazepines and IM olanzapine due to risks of additive adverse events (e.g., cardiorespiratory depression). Olanzapine prescribing information provides no specific recommendations regarding oral administration. Avoid combination

Opioid Agonists: CNS Depressants may enhance the CNS depressant effect of Opioid Agonists. Management: Avoid concomitant use of opioid agonists and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Orphenadrine: CNS Depressants may enhance the CNS depressant effect of Orphenadrine. Avoid combination

Oxomemazine: May enhance the CNS depressant effect of CNS Depressants. Avoid combination

OxyCODONE: CNS Depressants may enhance the CNS depressant effect of OxyCODONE. Management: Avoid concomitant use of oxycodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Paraldehyde: CNS Depressants may enhance the CNS depressant effect of Paraldehyde. Avoid combination

Perampanel: May enhance the CNS depressant effect of CNS Depressants. Management: Patients taking perampanel with any other drug that has CNS depressant activities should avoid complex and high-risk activities, particularly those such as driving that require alertness and coordination, until they have experience using the combination. Consider therapy modification

Phenytoin: Benzodiazepines may increase the serum concentration of Phenytoin. Short-term exposure to benzodiazepines may not present as much risk as chronic therapy. Monitor therapy

Piribedil: CNS Depressants may enhance the CNS depressant effect of Piribedil. Monitor therapy

Pramipexole: CNS Depressants may enhance the sedative effect of Pramipexole. Monitor therapy

ROPINIRole: CNS Depressants may enhance the sedative effect of ROPINIRole. Monitor therapy

Rotigotine: CNS Depressants may enhance the sedative effect of Rotigotine. Monitor therapy

Rufinamide: May enhance the adverse/toxic effect of CNS Depressants. Specifically, sleepiness and dizziness may be enhanced. Monitor therapy

Selective Serotonin Reuptake Inhibitors: CNS Depressants may enhance the adverse/toxic effect of Selective Serotonin Reuptake Inhibitors. Specifically, the risk of psychomotor impairment may be enhanced. Monitor therapy

Sodium Oxybate: Benzodiazepines may enhance the CNS depressant effect of Sodium Oxybate. Avoid combination

Suvorexant: CNS Depressants may enhance the CNS depressant effect of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. Consider therapy modification

Tapentadol: May enhance the CNS depressant effect of CNS Depressants. Management: Avoid concomitant use of tapentadol and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Teduglutide: May increase the serum concentration of Benzodiazepines. Monitor therapy

Tetrahydrocannabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Tetrahydrocannabinol and Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Thalidomide: CNS Depressants may enhance the CNS depressant effect of Thalidomide. Avoid combination

Theophylline Derivatives: May diminish the therapeutic effect of Benzodiazepines. Consider therapy modification

Trimeprazine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Yohimbine: May diminish the therapeutic effect of Antianxiety Agents. Monitor therapy

Zolpidem: CNS Depressants may enhance the CNS depressant effect of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. Consider therapy modification

Adverse Reactions

>10%: Central nervous system: Daytime sedation (12%)

<10%:

Central nervous system: Headache (5%), dizziness (2%), fatigue (2%)

Gastrointestinal: Xerostomia (2%), dyspepsia (1%)

Frequency not defined.

Cardiovascular: Palpitations

Central nervous system: Abnormality in thinking, agitation, amnesia, anxiety, apathy, ataxia, confusion, depression, drug dependence, euphoria, malaise, nervousness, nightmares, paranoia, speech disturbance

Dermatologic: Pruritus, skin rash

Endocrine & metabolic: Decreased libido

Gastrointestinal: Abdominal pain, anorexia, constipation, diarrhea, dysgeusia, nausea

Genitourinary: Impotence, urinary incontinence

Neuromuscular & skeletal: Hyperkinesia, hypokinesia, tremor, weakness

Ophthalmic: Cataract, visual disturbance

<1%, postmarketing, and/or case reports: Anaphylaxis, angioedema, sleep disorder (complex sleep-related behavior, eg, cooking while sleeping, eating food while sleeping, making phone calls while sleeping, sleep driving)

Warnings/Precautions

Concerns related to adverse effects:

• Anterograde amnesia: Benzodiazepines have been associated with anterograde amnesia (Nelson 1999).
• CNS depression: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks that require mental alertness (eg, operating machinery, driving).
• Hypersensitivity reactions: Postmarketing studies have indicated that the use of hypnotic/sedative agents for sleep has been associated with hypersensitivity reactions including anaphylaxis as well as angioedema. Patients that have developed angioedema should not be rechallenged with quazepam.
• Paradoxical reactions: Paradoxical reactions, including hyperactive or aggressive behavior, have been reported with benzodiazepines; risk may be increased in adolescent/pediatric patients, geriatric patients, or patients with a history of alcohol use disorder or psychiatric/personality disorders (Mancuso 2004).
• Psychomotor impairment: Increased risk of psychomotor impairment if usual dose is exceeded, used with concomitant CNS depressants, or a full night of sleep (>7 to 8 hours) is not possible.
• Sleep-related activities: Hazardous sleep-related activities such as sleep-driving, cooking and eating food, and making phone calls while asleep have been noted with benzodiazepines (Dolder 2008).

Disease-related concerns:

• Depression: Use caution in patients with depression, particularly if suicidal risk may be present.
• Drug abuse: Use with caution in patients with a history of drug abuse or acute alcoholism; potential for drug dependency exists. Psychological and physical dependence may occur with prolonged use.
• Respiratory disease: Use with caution in patients with respiratory disease.

Concurrent drug therapy issues:

• Concomitant use with opioids: [US Boxed Warning]: Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Follow patients for signs and symptoms of respiratory depression and sedation.
• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Special populations:

• Debilitated patients: Use with caution in debilitated patients.
• Elderly patients: Elderly patients may be more sensitive to benzodiazepines; quazepam may cause confusion and oversedation. Use with caution. Elderly patients may be at an increased risk of death with use; risk has been found highest within the first 4 months of use in elderly dementia patients (Jennum 2015; Saarelainen 2018).
• Fall risk: Use with extreme caution in patients who are at risk of falls; benzodiazepines have been associated with falls and traumatic injury (Nelson 1999).

Other warnings/precautions:

• Appropriate use: Should be used only after evaluation of potential causes of sleep disturbance. Failure of sleep disturbance to resolve after 7 to 10 days may indicate psychiatric or medical illness. A worsening of insomnia or the emergence of new abnormalities of thought or behavior may represent unrecognized psychiatric or medical illness and requires immediate and careful evaluation. Does not have analgesic, antidepressant, or antipsychotic properties. Use lowest effective dose; adverse reactions of quazepam are dose related.
• Tolerance: Quazepam is a long half-life benzodiazepine. Duration of action after a single dose is determined by redistribution rather than metabolism. Tolerance develops to the hypnotic effects (Vinkers 2012). Chronic use of this agent may increase the perioperative benzodiazepine dose needed to achieve desired effect.
• Withdrawal: Rebound or withdrawal symptoms, including seizures, may occur following abrupt discontinuation or large decreases in dose. Milder withdrawal symptoms may occur following abrupt discontinuation of short-term therapy. Use caution when reducing dose or withdrawing therapy; decrease slowly and monitor for withdrawal symptoms. Flumazenil may cause withdrawal in patients receiving long-term benzodiazepine therapy.

Monitoring Parameters

Respiratory and mental status (as clinically indicated); liver function (baseline, as clinically indicated)

Pregnancy

Pregnancy Considerations

Although information specific to the use of quazepam has not been located, all benzodiazepines are assumed to cross the placenta. Teratogenic effects have been observed with some benzodiazepines; hypoglycemia and respiratory problems in the neonate may occur following exposure late in pregnancy. Maternal use of quazepam later in pregnancy may also be associated with difficulty feeding, hypothermia, hypotonia, and respiratory depression in neonates. Neonatal withdrawal symptoms may occur within days to weeks after birth and “floppy infant syndrome” (which also includes withdrawal symptoms) has been reported with some benzodiazepines (Bergman 1992; Iqbal 2002; Wikner 2007).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
• Patient may experience loss of strength and energy, dry mouth, headache, dizziness, or day fatigue. Have patient report immediately to prescriber signs of depression (thoughts of suicide, anxiety, emotional instability, or illogical thinking), behavioral changes, sensing things that seem real but are not, trouble with memory, confusion, nausea, or vomiting (HCAHPS).
• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.