Anti-seizure medication must be tailored for individual patients, as the difference between a therapeutic dose and a toxic one is quite small. Now, researchers at the University of Basel in Switzerland have developed a breath test that can rapidly provide information on the optimal drug treatment approach for epilepsy patients. Their test provides information on drug levels in the body, as well as drug metabolites and other metabolic hallmarks, that can help clinicians to predict whether someone is responding appropriately to a medication or whether they need a modified dose. Epilepsy patients who take anti-seizure medication must tread a fine line. “Slightly too little and it isn’t effective. Slightly too much and it becomes toxic,” said Pablo Sinues, a researcher involved in the project, in a press release. To make matters more complicated, patients respond to therapy differently, depending on how they metabolize the drug molecules in their body, meaning that clinicians need to tailor the dose for each patient. In the case of children, who experience changing metabolism as they grow, this may require regular monitoring and dose adjustment. At present, blood tests are used to identify how much of a drug compound is present in the blood, but this doesn’t show the whole picture. Moreover, children are not big fans of needles. The philosophy behind this new technology is breath before blood, and it consists of a highly sensitive secondary electrospray ionization–high-resolution mass spectrometry system that can measure breath metabolites in real time. The results are instant, and do not require laboratory analysis, providing an indication of the metabolites present on someone’s breath in tiny quantities. “You can think of it as being like the alcohol test that police use when they stop drivers,” said Sinues. “Because alcohol is present at high concentrations in breath, one only needs a small device. But we’re searching for a droplet in 20 swimming pools.” The technique not only offers an indication of drug levels in the body of the user, but also provides information on how they are responding to the therapy. For instance, the study found that certain amino acid metabolic pathways are active in patients who suffer drug side-effects, and also identified a metabolic signature for patients who don’t achieve a good therapeutic effect from the drug. The technology is not yet suited for general use, but the researchers are working to develop it further so that it can become clinically available. Source
