Nov, 21 2025
Medication-induced constipation affects up to 60% of opioid users and many on anticholinergics or diuretics. Learn why fiber often fails, which laxatives actually work, and how to prevent it before it starts.
Constipation from Drugs: Common Medications That Cause It and What to Do
When you take a medication for one problem, you don’t expect it to cause another—like constipation from drugs, a common and often overlooked side effect of many prescription and over-the-counter medicines. Also known as drug-induced constipation, this isn’t just an inconvenience—it can lead to serious discomfort, bowel obstruction, or even hospitalization if ignored. It’s not just about opioids. Blood pressure pills, antidepressants, iron supplements, and even antacids can slow your digestive tract without you realizing why.
Some of the most common culprits are opioids, painkillers like oxycodone and morphine that directly reduce gut motility. But anticholinergics, used for overactive bladder, Parkinson’s, and even allergies, also block the signals that make your intestines move. Then there’s calcium channel blockers, a class of blood pressure drugs including amlodipine and diltiazem, which relax smooth muscle—including in your colon. Even iron supplements, often prescribed for anemia, are notorious for turning bowel movements into a daily struggle. These aren’t rare side effects—they’re expected in up to half of people taking them long-term.
You might think drinking more water or eating more fiber will fix it, and sometimes that helps. But when the drug itself is the root cause, those fixes often fall short. That’s why so many people end up relying on laxatives—some daily—just to stay regular. The problem? Not all laxatives are safe for long-term use, and some can interfere with other meds you’re taking. If you’re on chlorthalidone, lithium, or SGLT2 inhibitors, your body’s already under extra stress. Adding the wrong laxative could make things worse.
What you’ll find below isn’t just a list of drugs that cause constipation. It’s a practical guide to recognizing the pattern, understanding why it happens, and knowing what steps actually work—without guessing. From real-world tips on managing opioid-induced constipation to alternatives that don’t wreck your gut, these posts give you the tools to talk to your doctor with confidence—and get real relief.