Z drug

Zolpidem.svg

Z drugs are a class of nonbenzodiazepine medications primarily used for the treatment of insomnia. They are known for their sedative and hypnotic effects, which help patients fall asleep more quickly and stay asleep longer. The term "Z drugs" is derived from the names of the first three drugs in this class: Zolpidem, Zaleplon, and Eszopiclone.

Pharmacology

Z drugs work by modulating the gamma-aminobutyric acid (GABA) receptor, specifically the GABA_A receptor. This receptor is a major inhibitory neurotransmitter in the central nervous system. By enhancing the effects of GABA, Z drugs promote sedation and sleep.

Mechanism of Action

Z drugs bind to the benzodiazepine site on the GABA_A receptor, but they are chemically distinct from benzodiazepines. This binding increases the frequency of chloride channel opening, leading to hyperpolarization of the neuron and a decrease in neuronal excitability.

Pharmacokinetics

The pharmacokinetic profiles of Z drugs vary:

• Zolpidem has a rapid onset of action and a short half-life, making it suitable for sleep initiation.
• Zaleplon has an even shorter half-life, which is beneficial for patients who have difficulty falling asleep but do not have issues with sleep maintenance.
• Eszopiclone has a longer half-life, which can help with both sleep initiation and maintenance.

Clinical Use

Z drugs are primarily prescribed for short-term management of insomnia. They are often preferred over benzodiazepines due to their lower risk of dependence and fewer residual effects the next day.

Side Effects

Common side effects of Z drugs include:

• Drowsiness
• Dizziness
• Headache
• Gastrointestinal disturbances

Rare but serious side effects can include complex sleep-related behaviors such as sleepwalking, sleep-driving, and engaging in other activities while not fully awake.

Contraindications

Z drugs should be used with caution in patients with a history of substance abuse, respiratory depression, or severe liver impairment.

Regulatory Status

Z drugs are classified as Schedule IV controlled substances in the United States, indicating a potential for abuse and dependence.

Also see

• Benzodiazepine
• Insomnia
• GABA receptor
• Sedative
• Hypnotic

External links

• FDA website on sleep medications
• NHS guide to insomnia