Four drugs used to treat insomnia - zolpidem (Ambien and Ambien CR), eszopiclone (Lunesta), ramelteon (Rozerem), and zaleplon (Sonata) - have been widely promoted to both doctors and consumers.

While effective, these medicines are not necessarily better than older, less expensive drugs for many people who need a sleep aid for a night or two. For example, non-prescription drugs containing antihistamines (Benadryl, Nytol, Tylenol PM, and Sominex) and older prescription sedatives called benzodiazepines may work just as well. Among the benzodiazepines approved as sleep aids are estazolam (ProSom), flurazepam (Dalmane), and temazepam (Restoril).  However, we recommend that both the older and newer sleeping pills be taken more judiciously and less often than appears to be the current pattern of use by millions of people in the U.S. There are two main reasons for that advice:

• People with only mild insomnia problems may be relying too heavily on pills and not trying to address their sleep problems with non-drug measures.
• All insomnia medicines have side effects, can cause dependency, and even worsen your sleeping problems when abused, misused, or are taken too often. The possible side effects include daytime sleepiness, cognitive impairment, dizziness, unsteadiness, and rebound insomnia. Sleep-walking, sleep-driving, memory lapses, and hallucinations have also been reported.

People with persistent, chronic insomnia - three or more nights a week for months on end - do need treatment. We advise behavioral therapy that improves sleep habits, possibly combined with cautious use of sleeping pills.

For the average person seeking short-term help - for a few nights - we suggest trying an over-the-counter sleep aid first. If that's doesn't work, our comparison of the newer drugs led us to choose zolpidem as a Best Buy. This is the less expensive generic version of the drug Ambien. Fifteen pills cost $10 to $35, depending on dose and where you buy it.

(1) Recommended use is one pill at bedtime. The prices given are based on per pill costs. Prices reflect nationwide retail average for January 2008, rounded to the nearest dollar. Prices are derived by Consumer Reports Best Buy Drugs from data provided by Wolters Kluwer Health, Pharmaceutical Audit Suite. Wolters Kluwer is not involved in our analysis or recommendations.

(2) Those approved by the FDA for treating insomnia. Other benzodiazepines that act in the same way are also available but their makers have not sought approval for use in the treatment of insomnia. These other benzodiazepines may be prescribed off-label for that purpose by some doctors.