Anticholinergics and Sweating: What You Need to Know

When you take a medication that blocks acetylcholine, like anticholinergics, a class of drugs that inhibit the neurotransmitter acetylcholine to reduce muscle spasms, secretions, or overactive bladder. Also known as cholinergic blockers, these drugs are used for everything from overactive bladder to Parkinson’s and even some types of depression. But one side effect you might not expect is that they can shut down your body’s ability to sweat. That’s not just inconvenient—it can be dangerous.

Anticholinergics work by telling your body to calm down. They reduce saliva, tears, stomach acid, and yes—sweat. If you’re on a drug like oxybutynin for bladder control, diphenhydramine for allergies, or even some tricyclic antidepressants, you might notice your skin staying dry even when it’s hot. This isn’t just a nuisance. Without sweat, your body can’t cool itself. Heat exhaustion or heat stroke can sneak up fast, especially in older adults or people who exercise or work outdoors. And it’s not just sweating. Dry mouth, constipation, blurry vision, and trouble urinating are common too. These aren’t rare side effects—they’re built into how these drugs work.

Some people don’t realize their dry skin or heat sensitivity is drug-related. They think they’re just dehydrated or getting older. But if you started sweating less after beginning a new medication, that’s a red flag. It’s not something you should ignore. The anticholinergic burden, the total amount of anticholinergic activity from all medications a person takes adds up. Even low-dose drugs taken together can push you into risky territory. Older adults are especially vulnerable because their bodies process these drugs slower, and their sweat glands don’t work as well to begin with.

There’s no magic fix, but there are smart moves. Talk to your doctor about whether you really need all your anticholinergic meds. Could a non-anticholinergic alternative work? For example, mirabegron is often used instead of oxybutynin for overactive bladder. Could you lower the dose? Could you time your meds so you’re not active during the hottest part of the day? And always keep water nearby—even if you don’t feel thirsty.

What you’ll find in the posts below are real, practical guides on how these drugs affect your body—not just sweating, but also how they interact with other meds, how to spot hidden risks, and what to do if side effects start to pile up. These aren’t theoretical warnings. They’re from people who’ve been there, and from clinicians who’ve seen the fallout when these side effects are ignored.