Even in less severe cases, the risks are high. Rachel was told by a doctor that her frequent OTC use “should be” fine. However, she was also warned not to take co-codamol for more than 10 days a month because one of the possible side effects of regular use is hyperalgesia, which is increased sensitivity to pain — the very thing people take the medication to reduce. “Over time, opioids can alter how your nervous system processes pain signals. Instead of dulling pain, excessive use can increase pain sensitivity by amplifying pain pathways in the brain and spinal cord,” says Dr Babak Ashrafi from Superdrug Online Doctor, an online GP. This explains why many people say co-codamol no longer works after a while. Deborah Grayson, pharmacist and founder of Practice With Confidence, says this is a physiological response. “Codeine is an opioid, and the more the body’s opiate receptors are stimulated, the more receptors it makes, so you need more medication to take away pain,” she says. She calls this a “codeine ladder”. Grayson says many people climbing this ladder end up getting “opiate headaches”, which isn’t widely known. “The only way to get around that is to remove the opiate and let the body reset.” On top of this, because of the paracetamol in the tablet, overdosing increases a person’s risk of paracetamol poisoning. This can damage the liver and kidneys, and can even be fatal.