Urine test can spot who's not taking their pills

A simple urine test for people with high blood pressure could help doctors determine if patients aren't taking their medication as directed or whether their body isn't responding to treatment, a new study suggests.

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Using this test, British researchers found one-quarter of more than 200 patients weren't following medication orders. The urine screening could help prevent unnecessary tests and procedures for high blood pressure that appears resistant to treatment but really isn't, the study said.

The study was published online in the journal Heart.

Apparent unresponsiveness

"A majority of these patients in any secondary/tertiary care centre would routinely undergo many additional tests and procedures in search of the explanation for their apparent unresponsiveness to standard therapy prescribed in primary care," the researchers wrote in a journal news release.

The study involved 208 patients with high blood pressure treated at a specialist clinic. Of these patients, 125 were newly referred by their primary care doctor and 66 were follow-up patients who had poor control of their condition. The remaining patients had resistant high blood pressure that did not seem to respond to medication.

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The researchers analysed the participants' urine for commonly prescribed high blood pressure drugs. They found that one-quarter of the patients were not taking medications as prescribed by their doctor. Of these patients, 10 percent did not adhere to their treatment at all and 15 percent only took their medication sometimes.

The study also showed the average number of drugs detected in the urine samples was lower than the number of medications prescribed. The patients with the lowest blood pressure were among those taking all of their medications, the researchers said.

No traces of drugs in urine

Meanwhile, the patients least likely to follow their drug regimen were those diagnosed with resistant high blood pressure that did not respond to treatment. The researchers said almost one in four of these patients had no traces of any high blood pressure drugs in their urine.

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Although the study was small, the study's authors said their findings suggest a large number of patients are not taking their medication as directed by their doctor. They added that analyzing patients' urine could avoid this unnecessary testing in one in five cases of high blood pressure.

Morris Brown, of the clinical pharmacology unit at the University of Cambridge in England, wrote in an accompanying journal editorial that the technique could "solve at a stroke the problem of monitoring adherence, and should rapidly transform practice".

Image: Urine samplefrom Shutterstock