indication

For the short-term treatment of insomnia.

pharmacology

Zolpidem is a sedative or hypnotic agent with a chemical structure unrelated to benzodiazepines, barbiturates, or other drugs with known hypnotic properties. It interacts with a GABA-BZ receptor complex and shares some of the pharmacological properties of the benzodiazepines. In contrast to the benzodiazepines, which non-selectively bind to and activate all three alpha receptor subtypes, zolpidem in vitro binds the (alpha1) receptor preferentially. The (alpha1) receptor is found primarily on the Lamina IV of the sensorimotor cortical regions, substantia nigra (pars reticulata), cerebellum molecular layer, olfactory bulb, ventral thalamic complex, pons, inferior colliculus, and globus pallidus.

mechanism of action

Zolpidem modulates the alpha-subunit, known as the benzodiazepine receptor, within the GABA_A receptor chloride channel macromolecular complex. Unlike the benzodiazepines, which non-selectively interact with all three alpha-receptor subtypes, Zolpidem preferentially binds to the alpha-1 receptor.

toxicity

Oral (male rat) LD₅₀ = 695 mg/kg. Symptoms of overdose include impairment of consciousness ranging from somnolence to light coma.

biotransformation

Zolpidem is converted to inactive metabolites in the liver.

absorption

Zolpidem is rapidly absorbed from the GI tract.

half life

2.6 hours

route of elimination

Zolpidem tartrate tablets are converted to inactive metabolites that are eliminated primarily by renal excretion.

drug interactions

Amprenavir: Amprenavir, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if amprenavir is initiated, discontinued or dose changed.

Atazanavir: Atazanavir, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if atazanavir is initiated, discontinued or dose changed.

Clarithromycin: Clarithromycin, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if clarithromycin is initiated, discontinued or dose changed.

Conivaptan: Conivaptan, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if conivaptan is initiated, discontinued or dose changed.

Darunavir: Darunavir, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if darunavir is initiated, discontinued or dose changed.

Delavirdine: Delavirdine, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if delavirdine is initiated, discontinued or dose changed.

Fluconazole: Fluconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if fluconazole is initiated, discontinued or dose changed.

Fosamprenavir: Fosamprenavir, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if fosamprenavir is initiated, discontinued or dose changed.

Indinavir: Indinavir, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if indinavir is initiated, discontinued or dose changed.

Isoniazid: Isoniazid, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if isoniazid is initiated, discontinued or dose changed.

Itraconazole: Itraconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if itraconazole is initiated, discontinued or dose changed.

Ketoconazole: Ketoconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if ketoconazole is initiated, discontinued or dose changed.

Lopinavir: Lopinavir, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if lopinavir is initiated, discontinued or dose changed.

Methotrimeprazine: Additive CNS depressant effects. Reduce zolpidem dose by half upon initiation of methotrimeprazine. Zolpidem dose may be adjusted once methotrimeprazine dose has been established. Monitor for increased CNS depression.

Nefazodone: Nefazodone, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if nefazodone is initiated, discontinued or dose changed.

Nelfinavir: Nelfinavir, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if nelfinavir is initiated, discontinued or dose changed.

Nicardipine: Nicardipine, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if nicardipine is initiated, discontinued or dose changed.

Posaconazole: Posaconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if posaconazole is initiated, discontinued or dose changed.

Quinidine: Quinidine, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if quinidine is initiated, discontinued or dose changed.

Ritonavir: Ritonavir, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if ritonavir is initiated, discontinued or dose changed.

Saquinavir: Saquinavir, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if saquinavir is initiated, discontinued or dose changed.

Telithromycin: Telithromycin, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if telithromycin is initiated, discontinued or dose changed.

Triprolidine: The CNS depressants, Triprolidine and Zolpidem, may increase adverse/toxic effects due to additivity. Monitor for increased CNS depressant effects during concomitant therapy.

Voriconazole: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of zolpidem by decreasing its metabolism. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of zolpidem if voriconazole is initiated, discontinued or dose changed.