Table 1.

Some examples on interactions among ChEIs, memantine and other drugs via CYP450

Cytochrome	Substrates	Inhibitors	Inductors
CYP3A4	Antipsychotics: haloperidol, clozapine, risperidone, ziprasidone, sertindole, quetiapine, aripiprazole Antidepressants: tricyclicics, venlafaxine, citalopram, mirtazapine Benzodiazepines: diazepam, bromazepam Nonbenzodiazepine anxiolytics: buspirone Anticonvulsants: carbamazepine, felbamate, tiagabine Calcium antagonists: nifedipine, diltiazem, verapamil Other drugs: macrolides (erythromycin, clarithromycin), terfenadine, astemizole, tamoxifen, cyclosporine, amiodarone, quinidine AChEIs: donepezil, galantaminea	Antifungal drugs (ketoconazole, fluconazole, itraconazole) Erythromycin Fluvoxamine Nefazodone Grapefruit juice (at least 250 ml)	Barbiturates Phenytoin Rifampicin Carbamazepine Hypericum Topiramateb Oxcarbazepineb Felbamateb
CYP2D6	Antipsychotics: haloperidol, thioridazine, perphenazine, fluphenazine, zuclopentixol, risperidone, clozapine, olanzapine, aripiprazole Antidepressants: tricyclicics, fluvoxamine, fluoxetine, paroxetine, citalopram, mianserine, venlafaxine, mirtazapine Opiates: codeine, tramadole, dextrometorphan β-Blockers: metoprolol, propranolol, pindolol, timolol Antiarrythmics: propaphenon, flecainide, encainide Other drugs: debrisoquine, spartein, phenformin AChEIs: donepezil, galantaminea	Fluoxetine Paroxetine Quinidine Propaphenon Thioridazine Perphenazine	No known agent

^aNeither the AChEI rivastigmine nor the NMDA receptor antagonist memantine present hepatic metabolism. Protein binding is 96 % for donepezil, 40 % for rivastigmine, 18 % for galantamine and 145 % for memantine

^bWeak enzymatic inductor