Breath Analyzer Monitors Drug Compliance

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Drug adherence is not just important for combating infectious diseases. People with mental illness might skip pills because of unwanted side effects, like impotence. Those with chronic illness might stop treatment if they're feeling better. Others, suffering from "drug fatigue," simply get tired of taking medicine after many years and stop, says Hirsch. And of course, some people just forget.

Xhale intends for the monitoring device to be customizable, pairing it with, for example, an alert system that would beep, flash, or vibrate as a reminder when it's time to take medication. Additionally, the company plans to shrink the device to make it portable, and bring down its cost from $1,000 to less than $200, according to Melker.

The team has tested the device on six healthy people and found that if the pill and test were taken after fasting, the device worked 100 percent of the time. When the test was performed after eating fatty foods, however, the accuracy of the device dropped markedly: it only worked 20 out of 30 times. But Melker says that the team has made the sensor 10 times more sensitive since those tests were performed. He adds that the company is planning to set up a double-blind trial within the next two to three months, and that it hopes to have a commercial product in 18 months. The company also plans to compare the device with programs in which caregivers watch the patients take their pills, which is widely accepted as the best method to get people to take medicine.

The Action Point Adherence Program at the Housing and Urban Health Clinic in San Francisco strives to help the people who have the most difficulty taking HIV medicine correctly: those who are homeless, severely mentally ill, or addicted to drugs. Patients meet with an adherence nurse every day or once a week, and the center occasionally reviews pharmaceutical records or counts pills to evaluate compliance. According to director Joseph Pace, the program has tried technologies such as watches and pagers to issue alerts when it is time for a patient to take medication, but it found that direct patient-doctor contact works best. "We're not policing people," he says, and adds that caregivers at the clinic have learned to live with a certain amount of ambiguity.

Pace is doubtful that a breath-analyzer device for compliance would be useful in this kind of program. Even if it were coupled with a reminder device, it might be hard for some patients to remember to both take the pill and breathe in the tube, says Pace. He points out that not all people would be willing to exhibit an obvious reminder of their condition in public. Moreover, asking patients to use the device implies that the medical staff believes that the patient won't tell the truth, Pace notes, which could hurt the doctor-patient relationship. Building a strong relationship with patients, he says, is what will "engender the truth."