Several common drug classes are known to slow the digestive tract or otherwise make regular bowel movements more difficult, says Dr. Benson.
Opioid Pain Relievers
Opioids are prescription pain relievers used for moderate to severe pain. Examples include oxycodone, hydrocodone, morphine, and fentanyl. “Opioids are probably the most common prescription medications that cause constipation,” says Benson.
Blood Pressure Medications
Calcium channel blockers are used to lower blood pressure. Verapamil is one that can be particularly constipating, says Benson.
“Calcium channel blockers decrease calcium entry into some of the smooth muscle cells of the GI tract, and as a result, they decrease colonic motility,” he says. In other words, they can slow the contractions that push stool through the colon.
Antidepressants
Anticholinergics for Overactive Bladder and Other Problems
Anticholinergic drugs treat conditions including overactive bladder and some neurologic or gastrointestinal problems.
“These medications block a chemical called acetylcholine, and acetylcholine helps with gut motility. If you block that, it decreases gut motility, which leads to constipation,” says Benson.
Oxybutynin, a medication for overactive bladder, is one example of an anticholinergic that can cause constipation, says Sarah Rhodes, PharmD, an assistant professor of clinical science in High Point University’s Fred Wilson School of Pharmacy in North Carolina.
Ondansetron (Zofran) for Nausea and Vomiting
“If it’s prescribed frequently, it can lead to constipation because it decreases motility,” Benson says.
