Cinacalcet drug interactions

Drug-Drug and Drug-Food Interactions. Since cinacalcet is metabolized by multiple hepatic enzymes there is potential for drug interactions. Cinacalcet is also a potent inhibitor of the enzyme CYP2D6. As a result, dose adjustments of concomitant medications that are predominantly metabolized by this enzyme and have a narrow therapeutic index such as flecainide, thioridazine, vinblastine, and most tricyclic antidepressants (i.e., amitriptyline) may be required. ... 

CINACALCET BUPROPION T plasma concentrations of these substrates, with risk of toxic effects Bupropion and its metabolite hydroxybupropion inhibit CYP2D6 Initiate therapy of these drugs, particularly those with a narrow therapeutic index, at the lowest effective dose. Interaction is likely to be important with substrates for which CYP2D6 is considered the only metabolic pathway (e.g. hydrocodone, oxycodone, desipramine, paroxetine, chlorpheniramine, mesoridazine, alprenolol, amphetamines, atomoxetine)... 

The recommended starting dose of cinacalcet for secondary hyperparathyroidism is 30 mg once daily, with a maximum of 180 mg/day. For the treatment of parathyroid carcinoma, a starting dose of 30 mg twice daily is recommended, with a maximum dose of 90 mg four times daily. The dose is titrated upward every 2-4 weeks to maintain the serum PTH level between 150 and 300 pg/mL (secondary hyperparathyroidism) or to normalize the serum calcium (parathyroid carcinoma). Cinacalcet likely will interact with other drugs that are metabolized by hepatic CYPs. 

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