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. 2016 Apr 15;9:31–45. doi: 10.2147/PGPM.S101474

Table S1.

Summary of potential drug–gene and drug–drug interactions in Case #1

Impact Action Mechanism
Drug–gene interactions
Atorvastatin calcium and CYP3A4/CYP3A5 Major Consider dose reduction CYP3A4/3A5 poor metabolizer status may lead to decreased metabolism of atorvastatin
Fluticasone/salmeterol and CYP3A4/CYP3A5 Major Monitor therapy CYP3A4/3A5 poor metabolizer status may result in decreased metabolism of fluticasone/salmeterol
Lidocaine/prilocaine and CYP3A4/CYP3A5 Major Monitor therapy Poor metabolizer status may result in decreased metabolism of CYP3A4/CYP3A5 substrates (lidocaine)
Losartan/hydrochlorothiazide and CYP3A4/CYP3A5 Moderate Monitor therapy Poor metabolizer status may result in decreased metabolism of CYP3A4/CYP3A5 substrates (losartan)
Montelukast sodium and CYP3A4/CYP3A5 Major Monitor therapy CYP3A4/3A5 poor metabolizer may cause decreased metabolism of montelukast
Prednisone and CYP3A4/CYP3A5 Moderate Monitor therapy Due to CYP3A4/3A5 poor metabolizer status, less prednisone (inactive) may be converted to prednisolone (active form)
Roflumilast and CYP3A4/CYP3A5 Moderate Monitor therapy CYP3A4/3A5 poor metabolizer status may result in increased exposure to roflumilast
Drug–drug interactions based on CYP450 metabolism
Primidone and roflumilast Major Avoid combination CYP3A4 inducers (primidone) may decrease the serum concentration of roflumilast
Atorvastatin calcium and primidone Major Consider modification CYP3A4 inducers (primidone) may increase the metabolism of CYP3A4 substrates
Losartan/hydrochlorothiazide and primidone Major Consider modification CYP3A4 inducers (primidone) may increase the metabolism of CYP3A4 substrates
Diclofenac potassium and primidone Moderate Monitor therapy CYP2C9 inducers (primidone) may decrease the serum concentration of diclofenac
Prednisone and primidone Moderate Monitor therapy CYP3A4 inducers (primidone) may decrease the serum concentration of prednisone
Non-CYP450 drug–drug interactions
Meclizine HCl and tiotropium bromide Major Avoid combination Anticholinergic agents may enhance the anticholinergic effect of tiotropium
Nortriptyline HCl and tiotropium bromide Major Avoid combination Anticholinergic agents may enhance the anticholinergic effect of tiotropium
Oxybutynin chloride and tiotropium bromide Major Avoid combination Anticholinergic agents may enhance the anticholinergic effect of tiotropium
Aspirin and diclofenac potassium Major Consider modification An increased risk of bleeding may be associated with use of this combination
Clonidine HCl and metoprolol succinate Major Consider modification Alpha2-agonists may enhance the atrioventricular-blocking effect of beta-blockers. Beta-blockers may enhance the rebound hypertensive effect of alpha2-agonists
Clonidine HCl and nortriptyline HCl Moderate Consider modification Tricyclic antidepressants may diminish the antihypertensive effect of alpha2-agonists
Diclofenac potassium and furosemide Moderate Consider modification Nonsteroidal anti-inflammatory agents may diminish the diuretic effect of loop diuretics
Metoclopramide HCl and nortriptyline HCl Major Consider modification Metoclopramide may enhance the adverse/toxic effect of tricyclic antidepressants
Prednisone and roflumilast Major Consider modification Roflumilast may enhance the immunosuppressive effect of prednisone
Meclizine HCl and oxybutynin chloride Moderate Monitor therapy Anticholinergic agents may enhance the adverse/toxic effect of other anticholinergic agents
Nortriptyline HCl and oxybutynin chloride Moderate Monitor therapy Anticholinergic agents may enhance the adverse/toxic effect of other anticholinergic agents