Interaction between Ranolazine and Armodafinil
Major Metabolism

ID DDInter1570 and DDInter119
Interaction Coadministration with inducers of CYP450 3A4 may decrease the plasma concentrations of ranolazine, which is primarily metabolized by the isoenzyme.
Management The manufacturer considers the use of ranolazine to be contraindicated in patients taking potent CYP450 3A4 inducers such as carbamazepine, enzalutamide, lumacaftor, mitotane, phenobarbital, phenytoin, primidone (partially metabolized to phenobarbital), rifamycins, and St. John's wort. The extent to which other, less potent CYP450 3A4 inducers may interact with ranolazine is unknown. Caution is advised if they are used with ranolazine.
References
Alternative for Ranolazine C01E
Alternative for Armodafinil N06B

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.