(RxWiki News) Just because a painkiller can be bought over-the-counter doesn’t mean that it can't hurt the body. Marathon runners that take preventive painkillers may be at risk for bad reactions.
A recent study surveyed a group of marathon runners about the use of painkillers during training and before the race.
The results showed that nearly half of runners took some type of painkiller and one in six reported heart, stomach or kidney trouble.
"Discuss OTC painkillers with your pharmacist."
Michael Küster, MD, from the Pain Management Center DGS in Bonn, Germany, led a team of fellow researchers to investigate the effects of painkillers on the body before a person runs a marathon.
The research team asked 7,048 runners who participated in the 2010 Bonn Marathon/Half Marathon to fill out a survey about their use of prescription and over-the-counter (OTC) painkillers before the marathon. Only 3,913 of the runners filled out the surveys.
The results showed that 49 percent of responders said they took painkillers before running in the marathon/half marathon. Among the group that said they took OTC painkillers before the race, 20 percent of them said they also used OTC painkillers while they were training for the marathon.
Most, 54 percent, of the painkillers were OTC. More women, 61 percent, took painkillers than men, 42 percent.
The most common painkiller used was diclofenac (brand name Aclonac), which was taken by 47 percent of the runners who took painkillers. Diclofenac is only available by prescription in the US, but can be purchased OTC in other countries including Germany.
Many, 11 percent, of the runners who took diclofenac said they took more than the OTC recommended dose of 100 mg. Ibuprofen was the second most commonly used painkiller and 43 percent of those taking ibuprofen reported taking 800 mg or more, which is double the OTC dose.
Nearly all, 93 percent, of the runners said they had not been told about the risks associated with using these types of painkillers with endurance sports.
The surveys asked each of the runners about any symptoms of a bad reaction to the painkillers that may be associated with heart, stomach or kidney trouble.
Symptoms included heart palpitations, stomach cramps, muscle cramps and blood in the urine, stool or vomiting.
A total of 18 percent of the full marathon runners taking painkillers reported at least one symptom compared to 7 percent of half marathon runners. Stomach cramps were the most common side effect from painkillers, which was experienced by 14 percent of the group.
Heart palpitations were the second most common side effect, which was experienced by 9 percent of the group.
The risk for having a symptom was five times higher in runners who took painkillers compared to those who did not take anything.
Runners who took more than the recommended dose of a painkiller had three times higher risk for a side effect than those who took the recommended dosage.
At high doses, 10 percent of diclofenac, 52 percent of ibuprofen users and 87 percent of aspirin users reported symptoms. Nearly half, 49 percent, of runners who took high doses of aspirin reported stomach or kidney bleeding.
Overall, nine people went to the hospital after the race, all of which had taken painkillers. None of the responders who had not taken painkillers reported blood in their urine, compared to 4 percent of runners who had taken painkillers.
The authors said that the use of painkillers before the race did not prevent post-exercise pain.
The authors concluded that the use of painkillers before and during endurance sports might cause serious health problems. The authors recommended efforts to increase awareness of the health problems associated with painkiller use in endurance athletes.
This study was published in April in BMJ Open. The Hertie Foundation helped support funding for this project. No conflicts of interest were reported.