THE PILLS DON’T WORK

WHY your pills might not be effective. This week: Painkillers OPIOID painkillers including codeine and tramadol can help with severe pain from conditions such as arthritis, but they won’t work for around six million Britons.

That’s because up to 20 per cent of us don’t produce enough of an enzyme called CYP2D6, which helps break down these drugs to produce the pain-relieving effect, says Dr Roger Knaggs, a senior lecturer in clinical pharmacy at Nottingham University. As a result, the drug will simply pass out of the body without being used. However, people of Middle Eastern and Asian origin have the opposite problem — too high levels of CYP2D6 — so they may experience a rapid hit, with the effects wearing off very quickly.

CYP2D6 enzymes also break down the antidepressant Prozac, some beta-blockers for angina and the cancer drug tamoxifen.