Bentyl (Dicyclomine) Contraindications
Bentyl is absolutely contraindicated in infants under 6 months, nursing mothers, patients with myasthenia gravis, glaucoma, obstructive uropathy, obstructive gastrointestinal disease, severe ulcerative colitis, reflux esophagitis, unstable cardiovascular status in acute hemorrhage, and should be used with extreme caution in patients with hepatic or renal impairment. 1
Absolute Contraindications
The FDA label explicitly lists the following as absolute contraindications 1:
- Infants less than 6 months of age - dicyclomine is strictly prohibited in this population 1
- Nursing mothers - the drug is contraindicated during breastfeeding 1
- Unstable cardiovascular status in acute hemorrhage - anticholinergic effects can worsen hemodynamic instability 1
- Myasthenia gravis - dicyclomine can produce curare-like neuromuscular blockade leading to muscular weakness and possible paralysis 1
- Glaucoma - anticholinergic-induced mydriasis and cycloplegia increase intraocular pressure 1
- Obstructive uropathy - anticholinergic effects reduce bladder tone and can precipitate urinary retention 1
- Obstructive disease of the gastrointestinal tract - diarrhea may be an early symptom of incomplete intestinal obstruction, and dicyclomine would be harmful by suppressing this warning sign 1
- Severe ulcerative colitis - large doses may suppress intestinal motility and precipitate toxic megacolon 1
- Reflux esophagitis - anticholinergic effects reduce lower esophageal sphincter tone 1
Major Precautions Requiring Extreme Caution
Hepatic and Renal Impairment
Dicyclomine must be used with extreme caution in patients with known hepatic or renal disease 1. The anticholinergic effects and drug metabolism are significantly altered in these populations, though specific dosing adjustments are not provided in the labeling 1.
Prostatic Hypertrophy
Use with caution in patients with known or suspected prostatic enlargement, as this may lead to urinary retention due to the anticholinergic effects on bladder function 1. Monitor closely for difficulty with micturition 1.
Autonomic Neuropathy
Exercise caution in patients with autonomic neuropathy due to the inhibitory effect on muscarinic receptors within the autonomic nervous system 1.
Elderly Patients
The geriatric population is more susceptible to adverse anticholinergic effects and requires cautious dosing 1. Elderly patients are particularly vulnerable to CNS effects including confusional state, disorientation, hallucinations, and psychosis 1.
High Environmental Temperature
In the presence of high environmental temperature, heat prostration can occur (fever and heat stroke due to decreased sweating from anticholinergic inhibition of sweat glands) 1. The drug should be discontinued if symptoms occur 1. Similarly, use cautiously in patients with fever 1.
Ulcerative Colitis (Non-Severe)
Caution is required in patients with ulcerative colitis that is not severe, as large doses may suppress intestinal motility to the point of producing paralytic ileus and may precipitate toxic megacolon 1.
Salmonella Dysentery
Toxic dilatation of intestine and intestinal perforation is possible when anticholinergic agents are administered in patients with Salmonella dysentery 1.
Common Pitfalls to Avoid
- Do not ignore early warning signs of intestinal obstruction - diarrhea may be the first symptom of incomplete obstruction, especially in patients with ileostomy or colostomy, and dicyclomine would mask this critical finding 1
- Do not prescribe for activities requiring mental alertness - dicyclomine produces drowsiness, dizziness, and blurred vision; patients must be warned not to operate motor vehicles or machinery 1
- Do not overlook CNS effects in sensitive individuals - psychosis and delirium can occur, particularly in elderly patients or those with mental illness, though these typically resolve within 12-24 hours of discontinuation 1
- Do not use in myasthenia gravis except for one specific indication - the only exception is to reduce adverse muscarinic effects of an anticholinesterase agent 1