What medications cause constipation?
Last updated September 3, 2026.
The NHS names opioid painkillers as the classic constipating medicine, with iron supplements, calcium or aluminum antacids, anticholinergics, some antidepressants, and some blood pressure drugs behind them. The fix is rarely stopping: the NHS says speak to your GP before stopping any prescribed medicine, since adjusting dose or family usually solves it. Fluids, fiber, and movement matter even more when a drug is the cause, and regular opioid use deserves a laxative plan from day one. Constipation paired with sudden bowel changes, pain, or tiredness is a get-checked combination.
What to do
- Tell the prescriber; do not just stop the medicine.
- Double down on fluids, fiber, and movement.
- Ask for a laxative plan with any regular opioid prescription.
- Get checked for sudden changes with pain or tiredness.
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