Zolpidem is sold commercially under the names Ambien and Intermezzo and has been available in generic form for several years. You might see Zolpidem called a "non-benzodiazepine sleep aid" although putting it into the drug class imidazopyridines is more precise. You might also see it called a GABA-A receptor modulator or a Z-drug.
The technical name is N,N-dimethyl-2-(6-dimethyl-2-p-tolyl imidazo[1,2-a]pyridin-3-yl)acetamide and the formula is C19H21N3O.
Zolpidem comes as a tablet or pill, although it is sometimes sold as a spray that is applied to the tongue/mouth. The drug is taken directly before bed as it works quickly.
This drug is "labeled" (approved by the FDA) for only a short period of usage. Doctors are allowed to prescribe it for as long as they feel necessary, but as a patient you need to do your part and follow your doctor's instructions.
Side effects that people often feel, especially when they start the medicine, include lightheadedness, difficulty keeping balance, and a feeling of being drugged up. More worrying side effects include rash, itching, and in a small minority of patients chest pain, shortness of breath, and blurred vision. Contact your doctor if you have any of these side effects.
Amnesia is a particularly worrisome side effect for some Ambien users. It is a temporary amnesia that blocks out memories from a certain time period. Look around the web and you can find anecdotes of people worried about their amnesia. It is not clear how common amnesia from zolipidem is. There has been some scientific work showing zolpidem may reduce the ability of the brain to turn short-term memories into long term memories. New research in that area shows people taking Ambien may be more likely to remember negative events. This disturbing news implies that the drug can actually make post-traumatic stress disorder worse.
Studies in rats found Zolpidem caused weight gain around the abdomen (visceral fat) and to move around less. Interestingly, the rats seemed to show more axiety when on the drug. When the drug was taken away the rats lost weight and became less anxious. These were high doses of zolipedem, higher than humans would take, after adjusting for body weight.
Sleeping pills tend to have abuse potential. A Harvard Medical School study concluded zolipdem "may possess moderate abuse potential that limits its clinical utility." Different people have different reactions to drug, including the tendency to form dependence. You should always be careful when taking medicines that affect the sleep cycle.
A small study at the Henry Ford Hospital found that "chronic hypnotic use by primary insomniacs does not lead to dose escalation." even when people had been taking the drug for a year. It was a small sample size and the FDA still labels the drug for only short-term use.
Zolpidem has long been thought to help people fall asleep but not to stay asleep. In other words, it works better for sleep-onset insomnia than sleep maintenance insomnia.
This would tend to indicate a short half-life in the body (which is indeed true) and few problems with morning grogginess. However, a recent study found the drug resulted in "clinically significant balance and cognitive impairments upon awakening from sleep". The sleep inertia threat is such a problem that the researchers concluded that the use of drug was more dangerous than previously thought.
Along similar lines, a French study found zolipdem use results in slightly impaired driving ability the following day. A Chinese study found long-term zolipidem users had an increased risk for injury.
Intermezzo is a preparation of zolpidem specifically tailored for patients to take when they wake in the middle of the night. Purdue Pharma L.P. and Transcept Pharmaceuticals are marketing this formulation, which is the first drug every approved by the FDA for sleep maintenance insomnia.
Previously, Transcept Pharmaceuticals tried to get the FDA to approve a preparation of zolpidem for mid-night ingestion. The FDA said "no" citing fears of excessive sleep inertia come morning.
Another study suggests zolpidem can enhance memory formation. If true, this contradicts other observations about amnesia.