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 |