( CNN ) -- Lunesta may help you doze off at night , but it 's the morning after that has officials concerned -- which is why on Thursday they halved the recommended dosage for the well-known sleep aid . The U.S. Food and Drug Administration cited data showing that a person may be less alert and do things such as driving less safely the day after taking Lunesta . In particular , the federal agency pointed to one study of 91 healthy adults between the ages of 25 and 40 , some of whom were given 3 mg of Lunesta , while the others got a placebo , or inactive pill . Men and women who took the active drug had `` severe next-morning psychomotor and memory impairment '' some 7Â½ hours later , as well as `` impairment to driving skills , memory and coordination as long as 11 hours after the drug is taken , '' according to an FDA news release . As a result , the FDA decided to decrease the recommended starting dose of Eszopiclone , as sold by Sunovion under the brand name Lunesta , from 2 mg to 1 mg . The federal agency noted that health care professionals could increase the dosage as high as 3 mg while warning of the consequences . `` To help ensure patient safety , health care professionals should prescribe , and patients should take , the lowest dose of a sleep medicine that effectively treats their insomnia , '' said Dr. Ellis Unger , a drug evaluation director at the FDA . Sunovion , the company that makes and markets Lunesta , did not immediately respond Thursday to CNN requests for comment on the recommended dosage change . According to the product 's website , Lunesta is `` the No . 1 prescribed branded sleep aid , '' with more than 31 million prescriptions for the drug written . The same site states that `` more than 30 studies '' have shown Lunesta `` to be effective in many different types of insomnia patients , '' adding that `` there are no restrictions on duration for taking Lunesta . ''
The U.S. Food and Drug Administration : The recommended starting dose for Lunesta should be next-morning , not 3 mg . It notes studies showing `` severe 1 mg psychomotor and memory impairment '' Lunesta is the `` No . 91 prescribed branded sleep aid , '' its website says .