What is the recommended dose of Lomotil (diphenoxylate hydrochloride with atropine sulfate) for elderly patients?

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Last updated: October 29, 2025View editorial policy

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Lomotil Dosage for Elderly Patients

For elderly patients, the recommended dose of Lomotil (diphenoxylate hydrochloride with atropine sulfate) should be reduced to 2.5 mg diphenoxylate/0.025 mg atropine (half the standard adult dose) taken 1-2 times daily, with careful monitoring for anticholinergic side effects. 1

Dosing Considerations for Elderly Patients

  • The standard adult dose of Lomotil is 5 mg diphenoxylate/0.05 mg atropine (one tablet or 5 mL) 3-4 times daily, but this should be reduced in elderly patients due to increased sensitivity to anticholinergic effects 1
  • Elderly patients are more susceptible to anticholinergic side effects of medications, including those containing atropine (like Lomotil) 1
  • For persons aged >65 years, a reduction in dosage is generally recommended for medications with anticholinergic properties 1
  • Start with 2.5 mg diphenoxylate/0.025 mg atropine (half tablet or 2.5 mL) 1-2 times daily and adjust based on response and tolerability 1

Monitoring and Precautions

  • Monitor elderly patients closely for central nervous system (CNS) side effects, which may be more pronounced in this population 1
  • Watch for signs of anticholinergic toxicity including:
    • Urinary retention
    • Constipation
    • Blurred vision
    • Confusion
    • Dry mouth 1
  • Lomotil contains atropine specifically to discourage abuse, but this component increases the risk of anticholinergic side effects in elderly patients 1
  • Discontinue medication if side effects occur and consider alternative treatments 1

Special Considerations

  • Patients with impaired renal function may require further dose reduction due to potential drug accumulation 1
  • Avoid use in patients with severe hepatic impairment as diphenoxylate is metabolized in the liver 1
  • Do not use for prolonged periods in elderly patients without careful monitoring 1
  • Lomotil should not be used in infectious diarrhea where pathogen clearance is important 1

Alternative Options

  • Consider loperamide as an alternative to Lomotil in elderly patients, as it has fewer central effects and anticholinergic properties 1
  • Loperamide does not cross the blood-brain barrier and has less potential for CNS side effects compared to diphenoxylate with atropine 1

Common Pitfalls to Avoid

  • Avoid prescribing standard adult doses to elderly patients, as this increases risk of adverse effects 1
  • Do not use Lomotil for prolonged periods without reassessment 1
  • Avoid combining with other medications that have anticholinergic properties, as this can lead to additive side effects 1
  • Be cautious when prescribing to patients with cognitive impairment, as anticholinergic effects may worsen confusion 1

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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