Zolpidem (Ambien - Sanofi-Aventis), a nonbenzodiazepine benzodiazepine receptor agonist, is the most frequently prescribed hypnotic in the US. As its patent approaches expiration, its manufacturer has received FDA approval to market an extended-release formulation of the drug, Ambien CR. The pharmacological rationale for doing so is that short-acting hypnotics like zolpidem are more effective at inducing sleep than they are at maintaining it.

Eszopiclone (Lunesta - Sepracor), a benzodiazepine-like drug, has been approved by the FDA for oral treatment of insomnia. It is the S-isomer of zopiclone (Imovane, and others in Canada), which has been available in other countries for almost 20 years. Unlike similar drugs such as zolpidem (Ambien) or zaleplon (Sonata), Lunesta is not being restricted in its labeling to short-term use. Like other hypnotics, eszopiclone is a schedule IV drug.

Ramelteon (Rozerem - Takeda), a melatonin receptor agonist, has been approved by the FDA for treatment of insomnia characterized by difficulty falling asleep. Unlike all other prescription hypnotics, which are classified as schedule IV drugs, ramelteon is not a controlled substance.

Edluar (Meda), a new sublingual tablet formulation of the benzodiazepine receptor agonist zolpidem (Ambien, and others), has been approved by the FDA for treatment of insomnia.

On January 10, 2013, the FDA issued a news release to announce that it was requiring the manufacturers of the zolpidem-containing products Ambien, Ambien CR, Edluar and Zolpimist, which are all approved for treatment of insomnia, to lower the doses for women and to recommend in their labeling consideration of a lower dose for men. No change will be required in the dose of Intermezzo, a low-dose sublingual formulation of zolpidem for middle-of-the-night awakening, which is already recommended in a lower dose for women.

The FDA has approved a new low-dose sublingual tablet formulation of the benzodiazepine receptor agonist zolpidem tartrate (Intermezzo – Transcept/Purdue) for treatment of insomnia due to middle-of-the-night awakening. Ambien and other zolpidem formulations available in the US are labeled for use only at bedtime.

The physiologic changes that occur with aging can affect the pharmacokinetics and pharmacodynamics of many prescription and over-the-counter drugs, increasing the likelihood of adverse effects.

The FDA has approved suvorexant (Belsomra – Merck), the first orexin receptor antagonist to become available in the US, for treatment of sleep-onset and/or sleep-maintenance insomnia.

Alprazolam (Xanax - Upjohn), a triazolobenzodiazepine previously available in the USA for treatment of anxiety (Medical Letter 24:41, 1982), was recently approved by the US Food and Drug Administration (FDA) for treatment of panic disorder, with or without agoraphobia. According to one report, alprazolam was the fifth most widely prescribed drug in the USA last year (American Medical News, March 4, 1991, page 4).

The FDA has approved daridorexant (Quviviq – Idorsia), an orexin receptor antagonist, for treatment of sleep-onset and/or sleep-maintenance insomnia in adults. Daridorexant is the third orexin receptor antagonist to be approved for this indication; suvorexant (Belsomra) and lemborexant (Dayvigo) were approved earlier.