Interaction between Nicotinamide and Canagliflozin
Moderate Antagonism

ID DDInter1289 and DDInter280
Interaction The efficacy of insulin and other antidiabetic agents may be diminished by certain drugs, including atypical antipsychotics, corticosteroids, diuretics, estrogens, gonadotropin-releasing hormone agonists, human growth hormone, phenothiazines, progestins, protease inhibitors, sympathomimetic amines, thyroid hormones, L-asparaginase, alpelisib, copanlisib, danazol, diazoxide, isoniazid, megestrol, omacetaxine, phenytoin, tagraxofusp, temsirolimus, as well as pharmacologic dosages of nicotinic acid and adrenocorticotropic agents. These drugs may interfere with blood glucose control because they can cause hyperglycemia, glucose intolerance, new-onset diabetes mellitus, and/or exacerbation of preexisting diabetes.
Management Close clinical monitoring of glycemic control is recommended following initiation or discontinuation of these drugs, and the dosages of concomitant antidiabetic agents adjusted as necessary. Patients should be advised to notify their physician if their blood glucose is consistently high or if they experience symptoms of severe hyperglycemia such as excessive thirst and increases in the volume or frequency of urination.
References
Alternative for Nicotinamide A11H
Alternative for Canagliflozin A10B

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.