Interaction between Ursodeoxycholic acid and Aluminum hydroxide
Minor Absorption

ID DDInter1906 and DDInter58
Interaction Aluminum-containing antacids may reduce the absorption of ursodiol. The clinical significance is unknown. Monitoring for altered efficacy may be advisable.
Management -
References
Alternative for Ursodeoxycholic acid A05A
Obeticholic acid
Alternative for Aluminum hydroxide A02A
Calcium carbonate
Magnesium carbonate
Magnesium hydroxide
Magnesium oxide

Potential Metabolism Interactions

Substrate-Substrate Interaction：If more than one drug is metabolized by the same CYP, it is possible that its metabolism is inhibited because of the competition between the drugs. That means, it can be useful to lower the dosage of the drugs in the drug-cocktail because they remain longer in the organism than in monotherapy.
Inhibitor-Inhibitor Interaction：Combining two or more inhibitors of one CYP, should be compensated by lowering the dosage of these drugs because the metabolism is reduced and the drugs remain longer in the organism than in monotherapy. Not adapting the dosage bears the risk of even more side effects.
Inhibitor-Substrate Interaction：Combining drugs that have inhibitory effect and are substrates of one particular CYP, should be compensated by lowering the dosage. They rest longer in the organism than in monotherapy. Not adapting the dosage bears the risk of even more side effects.