Can drug side effects sometimes be beneficial?

While drug side effects are typically perceived as bad, certain medications have demonstrated unexpected positive effects, according to an article by Dr Robert H Shmerling, published on 31 May 2024, by Harvard Health Publishing.  

"Many people avoid taking medications because they fear possible side effects. That's understandable. But not taking a medication can mean missing out on its benefits. And anticipation or expectation of side effects can increase the chances you'll have them," Dr Shmerling noted.  

Though severe side effects, such as life-threatening allergic reactions, require immediate attention, less harmful effects often subside as the body adjusts to the medication. Interestingly, some side effects can even turn out to be advantageous.  

Examples of beneficial side effects  

Dr Shmerling highlighted several medications that have shifted their primary use due to unexpected benefits:  

Minoxidil (Rogaine, Gainextra, others): Initially developed for high blood pressure in the 1970s, it was found to promote hair growth in patients. Today, it is widely used as a topical treatment for hair loss.  

Diphenhydramine (Benadryl): While commonly prescribed for allergies, this medication's sedative side effect can assist adults who struggle with both allergies and insomnia. However, Dr Shmerling cautioned against long-term use due to potential links to dementia.  

Sildenafil (Viagra): Originally intended to treat high blood pressure and angina, the drug became notable for its ability to cause erections within an hour. Approved in 1998, it is now primarily used to address erectile dysfunction.  

Semaglutide (Ozempic, Wegovy): Designed for diabetes treatment, the drug's appetite-suppressing properties and associated weight loss have led to its approval for obesity management in addition to diabetes care.  

Repurposing medications through side effect profiles  

While serendipitous discoveries often drive the repurposing of medications, researchers are increasingly using side effect data to find new uses.  

For instance, medications that reduce sweating as a side effect might be effective for treating hyperhidrosis, while drugs associated with lowering blood pressure can be repurposed to manage hypertension. Advances in analyzing large side effect registries have streamlined these efforts.  

The nocebo effect  

Not all side effects are positive. "Medication side effects are a common reason people give for not taking prescribed drugs regularly," Dr Shmerling said, citing a study that links adverse reactions to up to 8% of hospital admissions.  

Adding to the complexity is the nocebo effect, where expecting side effects can make them more likely to occur. This contrasts with the placebo effect, which can lead to benefits from inactive treatments.  

A balanced perspective  

Dr Shmerling encouraged patients to weigh the risks and benefits carefully: "While it's important to be aware of the most common side effects caused by the medicines you take, it's also important not to overestimate your chances of experiencing them. And remember: there's always a chance you'll have a side effect you actually welcome."  

Ultimately, while the fear of side effects is valid, the potential benefits of taking prescribed medications, including the possibility of unexpected positive outcomes, should not be overlooked.