"Ambien should only be taken when you have a window of seven to eight hours for sleep," Greenblatt said. "Your staff should know that you've taken the medication, and that you should not be involved in any decision-making during that time."
Fotinakes added that sleeping pills and other sedatives have been proven to be more potent in the elderly. In light of this, he said, "It may not be the best idea for the commander-in-chief to be under the influence when he or she may have to make a snap decision regarding national security in the middle of the night; Hillary's so-called telephone call at 3:00 a.m."
Other sedatives — such as antihistamines and alcohol — could have similar effects, he added. "Yet, most people would not turn a hair if the president had a few shots before retiring to bed."
And as long as he is cautious in his timing, McCain may have little problem with the side effects of Ambien — a widely used drug which accounted for more than 45 million prescriptions in the United States in 2005.
"The key is to use Ambien-like sleeping medications in moderation and don't mix them with other sedative drugs or alcohol," Fotinakes said. "Most importantly, avoid use in the event you have to consider escalation from Defcon 4 to Defcon 3."