Archives August 2023

Drug side effects are common, and often quite troublesome.

Major side effects, such as severe or even life-threatening allergic reactions, require immediate treatment and discontinuation of the drug. More minor symptoms may be tolerable when weighed against drug benefits. And sometimes, these go away on their own as the body gets used to the drug.

But there’s another type of side effect you hear much less about: ones that are beneficial. Though uncommon, they’re worth keeping in mind when you’re starting a new medicine.

Aren’t all side effects bad?

The term side effect is usually assumed to be a bad thing. And that’s typically true. But that leaves out the “good” side effects. Relatively little is published on this, so it’s not clear how common they are. But four notable examples include:

• Minoxidil (Rogaine, Gainextra, other brands). Developed in the 1970s for high blood pressure, this drug also increased hair growth in study subjects. What was initially considered a bothersome side effect eventually became its primary use: topical forms of this drug are commonly used to treat hair loss.
• Diphenhydramine (Benadryl or generic versions). This common treatment for allergic conditions has the side effect of drowsiness. For adults with allergy issues and trouble sleeping, the sedative effect can be helpful. Regular, long-term use of diphenhydramine is not recommended, as it may increase the risk of dementia.
• Sildenafil (Viagra or generic versions). Originally developed as a treatment for high blood pressure and angina, it didn’t take long for male users to realize the drug could trigger erections within 30 to 60 minutes. The makers of sildenafil recognized that under the right circumstances, this could be a highly beneficial side effect. In 1998 it was approved as a treatment for erectile dysfunction.
• Semaglutide (Ozempic, Wegovy, Rybelsus). This drug was developed to treat diabetes, but early users noticed reduced appetite and significant weight loss. Now, several formulations of these related drugs are approved for diabetes and/or weight loss.

In the best study I’ve read on the topic, researchers found more than 450 reports of serendipitous beneficial effects of various drugs since 1991. And that may be an underestimation, since report forms did not specifically ask for or label this type of side effect, according to the study authors.

Silver linings: Repurposing and repackaging drugs

While the discovery of helpful drugs can arise unexpectedly, drug developers are increasingly using a more intentional approach: using side effect profiles to look for new uses.

For example:

• A drug reported to cause reduced sweating as a side effect may be effective for hyperhidrosis, a condition marked by excessive sweating.
• Drugs reported to cause low blood pressure as a side effect might be effective treatments for high blood pressure (hypertension).
• New treatments for breast cancer may include older medicines that have a similar side effect profile as known anti-cancer drugs.

The availability of large side effect registries has made this method of identifying drugs for repurposing a more realistic option. So, even negative side effects can have a silver lining.

Bad side effects and the nocebo effect

While side effects can be positive, most are not. Medication side effects are a common reason people give for not taking prescribed drugs regularly. And adverse reactions to medicines prompt up to 8% of hospital admissions, according to one analysis.

To make matters worse, in some cases the expectation of side effects seems to make them more likely to occur. Called the nocebo effect, it increases the chances of experiencing a negative side effect and seems due, at least in part, to expectations. Contrast this with the placebo effect, where a sugar pill or another inactive treatment can lead to benefit.

The bottom line

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.

So, 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.

About the Author

Robert H. Shmerling, MD, Senior Faculty Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Robert H. Shmerling is the former clinical chief of the division of rheumatology at Beth Israel Deaconess Medical Center (BIDMC), and is a current member of the corresponding faculty in medicine at Harvard Medical School. … See Full Bio View all posts by Robert H. Shmerling, MD

Picture this: you’re with friends in an unfamiliar forest using only a map and a compass to guide you to an upcoming checkpoint. There are no cell phones or GPS gadgets to help, just good old brainpower fueled by a sense of adventure as you wind through leafy trees and dappled sunlight.

This is not an excursion to a campsite or a treasure hunt. It’s a navigation sport called orienteering — a fun way to get outside, exercise, and maybe even help fight cognitive decline, according to a 2023 study.

What is orienteering?

Orienteering combines map and compass reading with exercise. Competitors (“orienteers”) race against a clock to reach checkpoints in outdoor settings that can range from city parks to remote areas with mountains, lakes, rivers, or snowy fields.

“You can go out in a group or on your own. You get a very detailed map and navigate your way to checkpoints that record your time electronically,” says Clinton Morse, national communications manager with Orienteering USA, the national governing body for the sport in the United States.

Because orienteers are racing the clock, they might run on trails, hike up hills, or scramble around boulders. That’s for foot-orienteering events. There are also orienteering events with courses geared for mountain biking, cross-country skiing, or canoeing.

How might orienteering affect thinking skills?

A small 2023 study published online in PLoS One found a potential link between orienteering and sharp thinking skills.

Researchers asked 158 healthy people, ages 18 to 87, about their health, activities, navigation abilities, and memory. About half of the participants had varying levels of orienteering experience. The other participants were physically active but weren’t orienteers.

Compared with study participants who didn’t engage in orienteering, those who were orienteers reported

• having better navigational processing skills (recognizing where objects were, and where participants were in relation to the objects)
• having better navigational memory skills (recalling routes and landmarks).

The study was observational — that is, not a true experiment — and thus didn’t prove that orienteering boosted people’s thinking skills. But the link might be plausible.

“Aerobic exercise releases chemicals in the brain that foster the growth of new brain cells. And when you use a map and connect it to landmarks, you stimulate growth between brain cells,” says Dr. Andrew Budson, lecturer in neurology at Harvard Medical School and chief of cognitive and behavioral neurology at VA Boston Healthcare System.

Where can you find orienteering opportunities?

There are about 70 orienteering clubs across the United States, and many more around the world (the sport is extremely popular in Europe). To find an orienteering event in your area, use the club finder tool offered by Orienteering USA.

How can you get started with orienteering?

People of all ages and athletic levels can take part, because orienteering courses vary from local parks to wilderness experiences. Costs are about $7 to $10 per person for local events, or $25 to $40 per person for national events, plus any travel and lodging expenses.

To make orienteering easy at first, Morse suggests going with a group and taking things slowly on a short novice course. “You don’t have to race,” he says. “Some people do this recreationally to enjoy the challenge of completing a course at their own pace.”

The trickiest part is learning to read the map. Morse’s advice:

• Turn the map as you change directions. Hold the map so that the direction you’re heading in is at the top of the page. For example, if the compass indicates that you’re heading south, turn the map upside down, so the south part is on top and easier to follow.
• Create a mental image of what the map is telling you. If there’s a fence along a field on the map, build a picture of it in your mind so you can recognize it when you see it, even if you haven’t been there before.

Tips for safe and enjoyable orienteering events:

• Dress appropriately. Wear comfortable clothes including long pants, good walking shoes, and a hat.
• Lather up. You’ll be outside for at least an hour, and you’ll need sunblock and possibly tick and bug spray depending on the terrain. Preventing tick bites that can lead to Lyme disease and other tick-borne illnesses is important in many locations.
• Bring some essentials. Pack water, a snack, sunblock, bug spray, and your phone. (Keep the phone turned off unless you need to call for help.)
• Use good judgment. Know that the shortest route on the map won’t always be the best, since it might take you up a hill or through thick vegetation. It might be better to go around those areas.

Once you learn the basics of orienteering, you can make it more physically challenging (and a better workout) by going faster and trying to beat your previous times, or by signing up for a more advanced course that’s longer and requires more exertion and speed.

And no matter which event you take part in, enjoy the adventure. “You’re not just following a path, you’re solving puzzles while being immersed in nature,” Morse says. “It’s a great way to experience the outdoors.”

About the Author

Heidi Godman, Executive Editor, Harvard Health Letter

Heidi Godman is the executive editor of the Harvard Health Letter. Before coming to the Health Letter, she was an award-winning television news anchor and medical reporter for 25 years. Heidi was named a journalism fellow … See Full Bio View all posts by Heidi Godman

About the Reviewer

Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing

Dr. Howard LeWine is a practicing internist at Brigham and Women’s Hospital in Boston, Chief Medical Editor at Harvard Health Publishing, and editor in chief of Harvard Men’s Health Watch. See Full Bio View all posts by Howard E. LeWine, MD