Aripiprazoleinteractions

Dosage adjustment due to drug interactions: Factors Dosage Adjustments for ABILIFY Known CYP2D6 Poor Metabolizers Administer half of usual dose Known CYP2D6 Poor Metabolizers and strong CYP3A4 inhibitors Administer a quarter of usual dose Strong CYP2D6 or CYP3A4 inhibitors Administer half of usual dose Strong CYP2D6 and CYP3A4 inhibitors Administer a quarter of usual dose Strong CYP3A4 inducers Double usual dose over 1 to 2 weeks

7.1 Drugs Having

Clinically Important Interactions with ABILIFY Table 22: Clinically Important Drug Interactions with ABILIFY: Concomitant Drug Name or Drug Class Clinical Rationale Clinical Recommendation Strong CYP3A4 Inhibitors (e.g., itraconazole, clarithromycin) or strong CYP2D6 inhibitors (e.g., quinidine, fluoxetine, paroxetine) Concomitant use of ABILIFY with strong CYP3A4 or CYP2D6 inhibitors increased the exposure of aripiprazole compared to the use of ABILIFY alone. Reduce the ABILIFY dosage when administered concomitantly with a strong CYP3A4 inhibitor or a strong CYP2D6 inhibitor. Strong CYP3A4 Inducers (e.g., carbamazepine, rifampin) Concomitant use of ABILIFY and carbamazepine decreased the exposure of aripiprazole compared to the use of ABILIFY alone. Increase the ABILIFY dosage when administered concomitantly with a strong CYP3A4 inducer. Antihypertensive Drugs Due to its alpha 1 -adrenergic antagonism, aripiprazole has the potential to enhance the effect of certain antihypertensive agents. Monitor blood pressure and adjust dose accordingly. Benzodiazepines (e.g., lorazepam) The intensity of sedation was greater with the combination of oral aripiprazole and lorazepam as compared to that observed with aripiprazole alone. The orthostatic hypotension observed was greater with the combination as compared to that observed with lorazepam alone. Monitor sedation and blood pressure. Adjust dose accordingly.

7.2 Drugs Having

No Clinically Important Interactions with ABILIFY Based on pharmacokinetic studies, no dosage adjustment of ABILIFY is required when administered concomitantly with famotidine, valproate, lithium, and lorazepam. In addition, no dosage adjustment is necessary for substrates of CYP2D6 (e.g., dextromethorphan, fluoxetine, paroxetine, or venlafaxine), CYP2C9 (e.g., warfarin), CYP2C19 (e.g., omeprazole, warfarin, escitalopram), or CYP3A4 (e.g., dextromethorphan) when coadministered with ABILIFY. Additionally, no dosage adjustment is necessary for valproate, lithium, lamotrigine, lorazepam, or sertraline when coadministered with ABILIFY.