Potential drug–drug interactions in Alzheimer patients with behavioral symptoms

Figures & data

Table 1 List of important drugs that are substrates or inhibitors of cytochromes CYP2D6 and CYP3A4

Substance name	CYP2D6		Substance name	CYP3A4
	Substrates	Inhibitors		Substrates	Inhibitors
Amiodarone		+	Albuterol	+
Aripiprazole	+	+	Alprazolam	+
Bupropion	+	+	Amiodarone	+	+
Cimetidine	+	+	Aripiprazole	+
Citalopram	+		Atorvastatin	+	+
Donepezil		+	Betamethasone	+
Duloxetine	+		Buspirone	+
Fluoxetine	+	+	Carbamazepine	+
Galantamine	+		Chlordiazepoxide	+
Haloperidol	+	+	Citalopram	+
Levomepromazine	+	+	Cortisol	+
Melperone		+	Diazepam	+
Metoclopramide		+	Diltiazem	+	+
Moclobemide		+	Donepezil	±
Norfluoxetine	+	+	Enalapril	+
Paroxetine		+	Erythromycin	+	+
Pergolide		+	Escitalopram	+
Perphenazine		+	Estrogens	+
Propafenone		+	Etoricoxib	+
Propranolol	+	+	Finasteride	+
Sertraline	+		Fluconazole		+
Thioridazine	+		Fluvoxamine	±	+
Trazodone	+	+	Galantamine	+
Tricyclic antidepressants	+		Grapefruit juice*	+
Venlafaxine	+		Haloperidol	+	+
Fluphenazine	+		Isosorbide	+
Risperidone	+		Itraconazole	+	+
			Itraconazole	+	+
			Ketoconazole	+	+
			Lansoprazole	+
			Mirtazapine	+	±
			Nefazodone	+	+
			Nifedipine	+	+
			Quetiapine	+
			Raloxifene	+	+
			Sertraline	±	+
			Simvastatin	+	+
			Trazodone	+	±
			Triazolam	+
			Tricyclic antidepressants	+	+
			Zolpidem	+

Note: Data from Hiemke,⁶⁸ Bressler,⁹⁶ Ingelman-Sundberg,⁹⁷ Zhou et al.⁹⁸ ±, Weak inhibitory or inducing effect; +, significant inhibitory or inducing effect.

Table 2 Principal CYP3A4 inducer drugs

Drug name
Carbamazepine
Efavirenz
Dexamethasone
Lovastatin
Oxybutynin
Rifabutin
Rifampicin
Phenobarbital
Phenytoin
Primidone

Note: Data from Spina et al,⁵⁷ Hiemke,⁶⁸ Ingelman-Sundberg,⁹⁷ Zhou et al.⁹⁸

Figure 1 Pharmacodynamic drug–drug interaction in a cholinergic synapse: acetylcholinesterase inhibitor (AChEI) and anti-muscarinic drug.

Notes: The concomitant administration of AChEIs (green triangles) and anticholinergic drugs may result in a pharmacodynamic interaction in the synapse where the beneficial increment of acetylcholine (blue circle), related to AChE (blue triangles) inhibition, is at least partially reversed by anti-muscarinic drugs (red ellipse) at receptor levels (blue bars).

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