Why can't you take lomotil and imodium (loperamide) together?

Synergy: Both Lomotil & Imodium (loperamide) contain a mu opioid receptor agonist that acts in the meyenteric plexis in the GI tract. You run the risk of potential synergism whereby the effects of one increases the others potency leading to supra therapeutic effects or even a complication ileus (paralysed bowel). That said, you should follow the guidance of the physician that is managing your GI disease in this matter.

Lomotil + Imodium (loperamide): Imodium (loperamide) have similar mechanisms of action. I have seen dosages of Imodium (loperamide) and Lomotil alternated as often as every 3 hours. Do not exceed 8 tablets of either drug within a 24 hour period without first consulting your physician.