Xhale Inc. is working to develop a small mechanism similar to an alcohol breathalyzer to monitor med adherence. “You blow into it,” Xhale's Elena Casson told POZ, “and it tells you whether you have taken the drugs.”

Casson says the adherence breathalyzer, which will send an electonic nudge if you've missed a dose, might be produced in about two years. One hurdle: If HIV meds aren't breath detectable, drug companies may need to add special markers to enable drugs to register in the breath. Casson says researchers have found two drugs—acetaminophen (Tylenol) and valproic acid (Depakote, for epilepsy and bipolar disorder)—that are naturally detectable in breath; they haven't tested others.

Xhale is also developing a breathalyzer for therapeutic drug monitoring—measuring blood levels of HIV meds to see whether your combo delivers enough (or too much) of each drug. “For this, we'll need to correlate the levels of drugs in the breath with those in the blood,” Casson says. Until then, we'll hold our breath.