Drivers taking Ambien should follow proper regimen.

MIAMI BEACH -- A medical literature review and a news database search indicate that zolpidem is safe when a proper dosing regimen is followed--despite recent media reports suggesting an association between the agent and driving impairment.

"We decided to look at zolpidem--Ambien--because of some of these cases in the news [associated with driving], such as that of Patrick Kennedy. It seemed to be the one in the headlines," J. Jason Buck-land, D.O., said in an interview.

Dr. Buckland and his associate, Dr. Bradley Freeman, identified 10 studies using a PubMed search for key words zolpidem, Ambien, driving impairment, and cognition. "We tried to include the studies that used natural driving tests, but there were some with driving simulators, also," Dr. Buckland said.

The studies suggest that if zolpidem is taken correctly and at bedtime, "there are no residual impairments the next morning, 5 or 6 hours later."

Function tests the next morning were equivalent with zolpidem, compared with patients not taking any hypnotics. Dr. Buck-land and Dr. Freeman presented their findings in a poster during the annual meeting of the American Academy of Psychiatry and the Law. Neither of the authors had a disclosure statement regarding zolpidem.

The literature supports practitioners who prescribe zolpidem for short-term treatment of insomnia when appropriate informed consent is provided, they said.

It is still important to emphasize the proper dosing regimen and advise patients not to drive for 5-6 hours after taking the hypnotic. Also, closely monitor patients during initiation and any dosage changes, Dr. Buckland and Dr. Freeman advised.

In contrast to zolpidem, some of the comparison medications researchers assessed produced a "hangover effect," suggesting that the ability to drive a motor vehicle safely the next day could be impaired, said Dr. Buckland, a general psychiatry resident in the department of neuropsychiatry and behavioral medicine at Palmetto Health/University of South Carolina, Columbia.

Zolpidem is indicated for short-term treatment of insomnia. The drug's active ingredient is imidazopyridine, a nonbenzodiazepine agonist of GABA-A1. The drug has a half-life of approximately 2.5 hours.

Daytime drowsiness, dizziness, and diarrhea are commonly reported side effects. Asthenia, hiccup, and diplopia also have been reported.

Dr. Freeman, child psychiatry fellow at the same institution, said he and Dr. Buck-land also did a search using LexisNexis. They searched for legal cases using the key words Ambien and driving.

"In the cases where Ambien was used as a defense, there were other factors, such as drugs or alcohol, or they took two to three times the dose," Dr. Buckland said. "There has not been a successful defense yet."

There are reports of other behaviors with Ambien--such as someone cooking in the middle of the night but not remembering it the next day, Dr. Buckland said.

Dr. Freeman said, "There was also a report of a man driving naked after taking Ambien."

The authors concluded that the published literature demonstrates that zolpidem is a safe and effective treatment for insomnia when taken as prescribed.

"The highly publicized negative outcomes appear to be rare and often in the setting of medication misuse or concurrent use of other substances. As with many treatments, there is a risk of serious side effects even when used appropriately. However, given the severe risks of untreated insomnia, the benefits of a medication such as zolpidem will likely outweigh its risks," the authors wrote.

BY DAMIAN MCNAMARA

Miami Bureau