Commonly prescribed analgesic drugs, including opiates and certain antidepressants, could be doing more harm than good, according to a study published in PLOS One this week. Not only can these addictive pain medications cause sedation, disordered breathing and accidental overdoses, but they reflect poorly on a patient’s cardiometabolic profile and increase risks of developing obesity and hypertension.

“There is increasing recognition of the metabolic impact of many prescribed analgesic medications used for the relief of chronic pain,” first author Sophie Cassidy wrote. “Certain medications have been used far more widely in recent years, in particular those for chronic non-cancer pain.” Those drugs include opioids, the alpha2-delta ligands pregabilin and gabapentin and a handful of antidepressants, most commonly amitriptyline and duloxetine.

An estimated 3 to 4 percent of the U.S. population is prescribed opioids, Cassidy and colleagues wrote, despite their well-known addictive, dependency-driven properties. In some cases, these neuropathic pain medications are prescribed alongside cardiometabolic (CM) drugs.

Cassidy et al. studied 133,401 patients enrolled in the U.K. Biobank cohort, a large-scale population-based cohort which measures a patient’s use of prescription drugs alongside several CM factors like exercise and lifestyle habits. Of the group the researchers studied, 125,978 were taking CM drugs and 7,423 were prescribed both CM drugs and an analgesic.

The team found those prescribed a combination of CM drugs and opiates showed the riskiest cardiometabolic health profile, with a 95 percent increased risk of developing obesity. Those patients also saw 82 percent increased odds for a “very high-risk” waist circumference and a 63 percent increased chance of developing hypertension. These results remained the same after Cassidy and colleagues adjusted for several lifestyle variables.

“There could be a number of possible mechanisms by which opioids might be associated with weight gain,” the authors wrote. “Sedation might decrease physical activity and therefore reduce energy expenditure. Opioids have also been shown to alter taste perception with a craving for sugar and sweet foods described.”

This is the largest study of its kind, Cassidy and co-authors wrote, but further research is needed, especially as the U.S. slips into an opioid crisis.

“The data from this study adds further support to calls for these medications to be prescribed for shorter periods and raises further questions about the safety of their use,” the researchers wrote.