Can Nystatin Be Given to a Patient with Small Bowel Obstruction?
Yes, nystatin can be safely administered to patients with small bowel obstruction because it is not absorbed from the gastrointestinal tract and does not stimulate bowel motility, making it fundamentally different from contraindicated medications like prokinetics or enemas. 1
Pharmacologic Rationale
The key distinction lies in nystatin's pharmacokinetic profile:
- Nystatin has insignificant gastrointestinal absorption and is passed unchanged in the stool, meaning it acts only topically within the bowel lumen without systemic effects or impact on bowel motility 1
- This contrasts sharply with medications that are explicitly contraindicated in bowel obstruction, such as metoclopramide (a prokinetic that increases bowel motility and can worsen obstruction or cause perforation) 2, 3
- Enemas and suppositories are contraindicated because they stimulate peristalsis and increase intraluminal pressure, which nystatin does not do 3
Mechanism of Action Context
- Nystatin works by binding to sterols in fungal cell membranes, causing leakage of intracellular components—this is a local antifungal effect with no motor activity on the bowel wall 1
- It exhibits no appreciable activity on bacteria, protozoa, or viruses, and does not interact with intestinal smooth muscle 1
Clinical Considerations
While nystatin itself is safe in bowel obstruction, the clinical context matters:
- Ensure the patient can safely receive oral medications without risk of aspiration—if there is significant vomiting or gastric distension, nasogastric decompression should be established first 2
- In patients with complete obstruction and severe vomiting, consider delaying oral nystatin until adequate decompression is achieved 4
- Monitor for renal insufficiency: in patients with renal dysfunction receiving oral nystatin, significant plasma concentrations may occasionally occur, though this is rare 1
Common Pitfall to Avoid
Do not confuse nystatin with prokinetic antiemetics or rectal therapies—the contraindication in bowel obstruction applies to medications that stimulate motility (metoclopramide) or increase intraluminal pressure (enemas, suppositories), not to topically-acting, non-absorbed antifungals 2, 3, 1