Medications: Ambien^® – zolpidem

Ambien, a gamma-aminobutyric acid (GABA) A agonist, is indicated for the short-term treatment of insomnia characterized by difficulties with sleep initiation. Ambien has been shown to decrease sleep latency for up to 35 days in controlled clinical studies. (1)

DOSAGE AND ADMINISTRATION

• Use the lowest dose effective for the patient (2.1)
• Recommended initial dose is 5 mg for women and 5 or 10 mg for men, immediately before bedtime with at least 7–8 hours remaining before the planned time of awakening (2.1)
• Geriatric patients and patients with hepatic impairment: Recommended dose is 5 mg for men and women (2.2)
• Lower doses of CNS depressants may be necessary when taken concomitantly with Ambien (2.3)
• The effect of Ambien may be slowed if taken with or immediately after a meal (2.4)

• Most commonly observed adverse reactions were:
• Short-term (< 10 nights): Drowsiness, dizziness, and diarrhea
• Long-term (28 – 35 nights): Dizziness and drugged feelings (6.1)

Known hypersensitivity to zolpidem (4)

WARNINGS AND PRECAUTIONS:

• CNS depressant effects: Impairs alertness and motor coordination. Instruct patients on correct use. (5.1)
• Need to evaluate for co-morbid diagnosis: Reevaluate if insomnia persists after 7 to 10 days of use. (5.2)
• Severe anaphylactic/anaphylactoid reactions: Angioedema and anaphylaxis have been reported. Do not rechallenge if such reactions occur. (5.3)
• Sleep-driving and other complex behaviors while not fully awake. Risk increases with dose and use with other CNS depressants and alcohol. Immediately evaluate any new onset behavioral changes. (5.4)
• Depression: Worsening of depression or suicidal thinking may occur. Prescribe the least amount of tablets feasible to avoid intentional overdose. (5.5)
• Respiratory Depression: Consider this risk before prescribing in patients with compromised respiratory function (5.6)
• Withdrawal effects: Symptoms may occur with rapid dose reduction or discontinuation (5.7, 9.3)

• CNS depressants, including alcohol: Possible adverse additive CNS-depressant effects (5.1, 7.1)
• Imipramine: Decreased alertness observed (7.1)
• Chlorpromazine: Impaired alertness and psychomotor performance observed (7.1)
• Rifampin: Combination use may decrease effect (7.2)
• Ketoconazole: Combination use may increase effect (7.2)

In postmarketing experience of overdose with zolpidem tartrate alone, or in combination with CNS-depressant agents, impairment of consciousness ranging from somnolence to coma, cardiovascular and/or respiratory compromise, and fatal outcomes have been reported.

General symptomatic and supportive measures should be used along with immediate gastric lavage where appropriate. Intravenous fluids should be administered as needed. Zolpidem’s sedative hypnotic effect was shown to be reduced by flumazenil and therefore may be useful; however, flumazenil administration may contribute to the appearance of neurological symptoms (convulsions). As in all cases of drug overdose, respiration, pulse, blood pressure, and other appropriate signs should be monitored, and general supportive measures employed. Hypotension and CNS depression should be monitored and treated by appropriate medical intervention. Sedating drugs should be withheld following zolpidem overdosage, even if excitation occurs. The value of dialysis in the treatment of overdosage has not been determined, although hemodialysis studies in patients with renal failure receiving therapeutic doses have demonstrated that zolpidem is not dialyzable.

As with the management of all overdosage, the possibility of multiple drug ingestion should be considered. The physician may wish to consider contacting a poison control center for up-to-date information on the management of hypnotic drug product overdosage.