Lomotil (Diphenoxylate-Atropine) Dosage for Diarrhea Treatment
The recommended initial dosage of Lomotil (diphenoxylate-atropine) for adults with diarrhea is two tablets (5 mg diphenoxylate) four times daily (20 mg total per day) until initial control is achieved, after which the dosage may be reduced to as little as two tablets (5 mg) daily for maintenance therapy. 1
Adult Dosing Regimen
- Initial treatment: Two tablets four times daily (20 mg diphenoxylate per day) 1
- Maintenance therapy: Dosage may be reduced to meet individual requirements, often as little as two tablets (5 mg) daily 1
- Clinical improvement is usually observed within 48 hours of treatment initiation 1
- If no improvement is seen after 10 days of maximum dosage (20 mg daily), symptoms are unlikely to be controlled with further administration 1
Important Considerations and Contraindications
- Diphenoxylate-atropine requires a prescription and is generally less effective than loperamide for acute diarrhea 2
- Lomotil is not recommended for children under 2 years of age due to risk of serious adverse effects 1, 3
- For children under 13 years, only the oral solution formulation should be used, not tablets 1
- Diphenoxylate with atropine has more central effects and peripheral side effects compared to loperamide 2, 4
Comparative Efficacy
- Studies show that loperamide and codeine phosphate are superior to diphenoxylate in treating chronic diarrhea 4
- Diphenoxylate was significantly less effective in producing solid stool compared to loperamide and codeine in clinical trials 4
- Side effects, particularly central nervous system effects, were greatest with diphenoxylate and least with loperamide 4
- In critically ill patients with acute noninfectious diarrhea, both loperamide and diphenoxylate/atropine are conditionally recommended 5
Monitoring and Safety
- Do not exceed the recommended dosage due to risk of toxicity 1
- Monitor for side effects including central nervous system effects, which are more common with diphenoxylate than with newer agents like loperamide 2, 4
- Intestinal transit is more prolonged by both diphenoxylate and atropine than by loperamide 2
- In cases of toxicity, symptoms can be reversed with naloxone 3
Alternative Treatment Options
- Loperamide is often preferred over Lomotil for acute diarrhea with an initial dose of 4 mg followed by 2 mg every 2-4 hours or after every unformed stool (maximum 16 mg daily) 2
- Other opioids such as tincture of opium, morphine, or codeine can be used when loperamide or diphenoxylate are ineffective 2
- For cancer patients with therapy-associated diarrhea, octreotide at 500 μg three times daily subcutaneously may be considered if loperamide fails 2
Treatment Duration
- For acute diarrhea, clinical improvement is usually observed within 48 hours 1
- For chronic diarrhea, treatment may need to be continued longer, but if no improvement is seen after 10 days at maximum dosage, further administration is unlikely to be beneficial 1
Remember that while Lomotil is effective for many patients, newer agents like loperamide generally have better efficacy and safety profiles for most cases of acute diarrhea 2, 4.