Prednisone Does Not Directly Cause Constipation
Prednisone itself is not listed as a medication that causes constipation in clinical guidelines or FDA labeling. In fact, the evidence suggests that constipation in patients taking prednisone is typically related to other factors, not the corticosteroid itself.
Evidence from Guidelines and Drug Labels
The NCCN Palliative Care guidelines 1 explicitly identify medications known to cause constipation, listing "antacids, anticholinergic drugs (antidepressants, antispasmodics, phenothiazines, and haloperidol), and antiemetics" as culprits, with opioid analgesics being the most common cause. Notably, corticosteroids like prednisone are absent from this list of constipating medications.
Similarly, a systematic review on constipation 2 identifies specific drug classes associated with constipation including:
- Antihypertensive drugs (reduce smooth muscle activity)
- Tricyclic antidepressants
- Oral iron supplements and aluminum-containing drugs
- Opiates and cannabinoids
- Bisphosphonates
Again, corticosteroids are not mentioned as causative agents.
FDA Drug Label Information
The official FDA drug label for prednisone 3 does not list constipation as an adverse effect. The gastrointestinal warnings focus on gastric irritation and peptic ulcer risk, recommending that prednisone be taken with food or milk and that antacids be administered between meals to prevent ulcers—but constipation is not mentioned as a side effect.
Clinical Context
When constipation occurs in patients receiving prednisone-containing regimens (such as CHOP chemotherapy for lymphoma), the constipation is attributable to other components of the treatment. A study of patients receiving CHOP chemotherapy 4 found that constipation management was important, but this was primarily due to vincristine (a known constipating agent) rather than the prednisolone component.
Important Caveats:
- Secondary causes matter: If a patient on prednisone develops constipation, evaluate for other medications (especially opioids, anticholinergics, iron supplements), reduced mobility, dietary changes, or underlying conditions
- Indirect effects: High-dose or prolonged prednisone therapy can cause metabolic changes (hyperglycemia, electrolyte disturbances) that might secondarily affect bowel function, but this is not a direct constipating effect
- Combination therapy: Patients on prednisone often receive multiple medications; identify the actual culprit rather than attributing constipation to the corticosteroid
In summary, prednisone is not a constipating medication based on guideline evidence, FDA labeling, and clinical literature. If constipation develops in a patient taking prednisone, look for other causes.