A new study published in SLEEP reports the results of a new formulation of Zolpidem (Ambien) which is placed under the tongue for people who have middle of the night insomnia. This is a patented lozenge which is said to dissolve quickly and have acid-base buffers that enhance its rapid absorption into the blood stream.People were recruited who complained of trouble getting back to sleep in the middle of the night, but those with sleep disorders or depression were not allowed into the study. They were allowed to sleep for 4 hours, awakened by the researchers, took the lozenge, sat up for 30 minutes, and then tried to sleep again for 4 more hours. Each subject did this on two separate nights, once with the drug and once with placebo. Those taking the zolpidem lozenge fell asleep more quickly and had more sleep in the coming four hours. They are said to have had no morning side effects such as sleepiness or trouble doing a math task.
This study is important because people who only have insomnia in the last half of the night have few options for medication treatment. All of the older benzodiazepine medications take too long to take effect and also take too long to be eliminated by morning. The only real option is Sonata (zaleplon), which can take effect in as little as 30 minutes and be pretty much eliminated in 2 or 3 hours. It is approved by the FDA to take with four or more hours of planned sleep, but it suffers from eratic absorption (food and fat delay it), and it has not been tested extensively in the middle of the night. Similarly, taking regular zolpidem (Ambien) in the night is a problem due to the time of absorption and the longer elimination period. About 7 hours of planned sleep is suggested for oral Ambien.
I know of patients and colleagues who use a sublingual (under the tongue) method for regular zolpidem and zaleplon. For zaleplon, you have to open the capsule, and dump the powder out and for zolpidem you have to crush the pill or wait for it to dissolve. The current study used a low dose of zolpidem (about 3 to 4 mg), and the best dose to be recommended remains to be determined. These problems will be much less when further studies of the lozenge are released.
In general, I favor the shortest acting sleeping pills so that there is less chance of residual effect and less total time of the drug in the body. The sublingual form allows for very rapid absorption, so the drug can get straight to work, and the liver and kidney can immediately metabolize it. Someone should have thought of this before !
