A breath-monitoring device has en developed by experts at the University of Florida and Xhale Inc. which could be useful in checking medication adherence in HIV/AIDS patients.
The inventors of the device say that it may help prevent the emergence of drug-resistant strains of HIV by monitoring medication adherence in high-risk individuals.
"For HIV, it's been shown that if you don't take a very high percentage of your medication, you may as well not take medication at all," said Dr. Richard Melker, a professor of anaesthesiology at the UF College of Medicine and chief technology officer for Xhale.
Patients who take some but not all of their medication increase the likelihood the virus will mutate into a deadlier, drug-resistant form.
While experts have tried several ways to monitor drug adherence ranging from daily log books to blister packs that record the time each pill is dispensed, Melker said only one works well: directly observed therapy (DOT).
"If you have a disease that is deemed to be a public health risk, authorities can put you into a program where you have to come to the clinic every day and be observed putting the pill into your mouth and swallowing it," Melker said.
However, patients find that process inconvenient. Even clinic personnel find it difficult to track patients down when they fail to show up.
Melker says that tests with the new device suggest that it may help solve these problems.
"The machine sits in your home and when it's time for you to take your medication, it makes a beeping noise. If you don't hit a button after about five minutes, it's going to beep louder and louder until you come. If you don't come after a certain amount of time, the machine can call the clinical trial coordinator and indicate that subject or patient didn't take the medication as prescribed," Melker said.
The device is slightly smaller than a shoebox, and has been programmed to record the results of each breath test.
Melker said that this would allow patients to bring a memory card or USB key to the clinic once a month, and receive a printout of their results.
He envisions that the size of the detection device will one day be reduced to such an extent that it would be ready to be fit into a mobile phone.
He, however, insists that the current device also works satisfactorily.
"The doctor can see how often you took it and exactly what time. If it made the patient really sick or dizzy and they didn't take it, they can find out why. It's not just a question of did I or didn't I take it, but when you took it or why you didn't take it," Melker said.
The makers of the device say that it may also be used to monitor medication adherence in patients with other communicable diseases, like tuberculosis.
"If we had a good way of doing DOT that's realistic, instead of having someone come to your house or you going to clinic every day of your life, then we would know whether these people stopped taking their medication and why. Right now, nobody knows any of that." Melker said.
"The implications of being able to understand what normal human behaviour is in a clinical trial and, of course, in the real world, are huge," he added.