What is the potential interaction between the patient's current medications, including Aripiprazole (Abilify) (Aripiprazole), Atorvastatin (Lipitor) (Atorvastatin), Buspirone (Buspar) (Buspirone), Desvenlafaxine (Pristiq) (Desvenlafaxine), Dextroamphetamine-Amphetamine (Adderall) (Dextroamphetamine-Amphetamine), Haloperidol (Haldol) (Haloperidol), Lamotrigine (Lamictal) (Lamotrigine), Lisinopril (Prinivil, Zestril) (Lisinopril), Metformin (Glucophage) (Metformin), Omeprazole (Prilosec) (Omeprazole), Ondansetron (Zofran) (Ondansetron), Potassium Chloride (K-Dur, Klor-Con) (Potassium Chloride), and Sumatriptan (Imitrex) (Sumatriptan)?

From the Guidelines

The patient's medication regimen should be reviewed and adjusted to minimize the risk of potential drug interactions, particularly the combination of desvenlafaxine (Pristiq) with buspirone (Buspar) and sumatriptan, which could increase the risk of serotonin syndrome 1. The patient is taking multiple medications that may interact with each other, including:

• Dextroamphetamine-amphetamine (Adderall XR) and haloperidol (Haldol), which have opposing mechanisms of action
• Buspirone (Buspar) and desvenlafaxine (Pristiq), which could increase the risk of serotonin syndrome when combined
• Sumatriptan and desvenlafaxine, which could also increase the risk of serotonin syndrome
• Multiple psychiatric medications (aripiprazole, buspirone, desvenlafaxine, haloperidol, and lamotrigine) that may have additive central nervous system effects The patient's medication regimen should be simplified and alternatives considered to reduce the complexity of this regimen, which includes 16 different medication orders. Some key considerations for adjusting the patient's medication regimen include:
• Starting with a subtherapeutic dose as a “test” dose for new medications, especially SSRIs, to monitor for symptoms and potential interactions 1
• Gradually increasing the dose of medications, such as SSRIs, to minimize the risk of adverse effects and interactions 1
• Monitoring for potential interactions with other medications, such as statins, and adjusting the dose or timing of administration as needed 1
• Considering alternative medications or dosing regimens to minimize the risk of interactions and adverse effects, such as using a different SSRI or adjusting the dose of atorvastatin 1

From the FDA Drug Label

7.1 Drugs Having Clinically Important Interactions with Aripiprazole Table 25: Clinically Important Drug Interactions with Aripiprazole: 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) The concomitant use of aripiprazole with strong CYP 3A4 or CYP2D6 inhibitors increased the exposure of aripiprazole compared to the use of aripiprazole alone [seeClinicalPharmacology ( 12.3)]. With concomitant use of aripiprazole with a strong CYP3A4 inhibitor or CYP2D6 inhibitor, reduce the aripiprazole dosage [see Dosageand Administration( 2. 7)]. Antihypertensive Drugs Due to its alpha adrenergic antagonism, aripiprazole has the potential to enhance the effect of certain antihypertensive agents. Monitor blood pressure and adjust dose accordingly [seeWarnings and Precautions( 5.8)]. 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 [seeWarningsandPrecautions ( 5.8)]. Monitor sedation and blood pressure. Adjust dose accordingly.

The provided medication list includes atorvastatin, buspirone, desvenlafaxine, dextroamphetamine-amphetamine, haloperidol, lamotrigine, lisinopril, metformin, omeprazole, ondansetron, potassium chloride, and sumatriptan. Based on the provided drug labels, the following interactions are relevant:

• Aripiprazole and strong CYP3A4 inhibitors or strong CYP2D6 inhibitors: reduce aripiprazole dosage.
• Aripiprazole and antihypertensive drugs: monitor blood pressure and adjust dose accordingly.
• Aripiprazole and benzodiazepines: monitor sedation and blood pressure, adjust dose accordingly.
• Buspirone and haloperidol: increased serum haloperidol concentrations, clinical significance not clear.
• Buspirone and inhibitors or inducers of CYP3A4: may require dose adjustment of buspirone. There is no direct information in the provided drug labels about interactions between aripiprazole and the other medications listed, except for the general warnings about antihypertensive drugs and benzodiazepines. Therefore, no conclusion can be drawn about the interactions between aripiprazole and the other medications listed, except for the general warnings. It is recommended to consult the drug labels and medical professionals for more information on potential interactions. 2 3

From the Research

Medication Regimen Review

The provided medication list includes various prescription drugs with specific dosing instructions. To ensure patient safety, it is essential to review the medication regimen regularly, as suggested by 4. This review should involve examining all medications, noting history of adverse effects, need for the drug, duplication in therapy, inappropriate dose, route, or schedule, current adverse effects, drug-drug interactions, and drug-disease interactions.

Potential Drug Interactions

The list of medications includes drugs that may interact with each other, such as:

• Aripiprazole (ABILIFY) and haloperidol (HALDOL), which may increase the risk of extrapyramidal symptoms
• Atorvastatin (LIPITOR) and metFORMIN (GLUCOPHAGE), which may increase the risk of lactic acidosis
• BusPIRone (BUSPAR) and desvenlafaxine succinate (PRISTIQ), which may increase the risk of serotonin syndrome As noted by 5, identifying clinically relevant drug interactions is crucial to patient safety, and strategies such as minimizing the number of drugs prescribed and monitoring for signs and symptoms of toxicity or effectiveness can help reduce the risk of adverse interactions.

Medication Adherence

Medication adherence is critical to ensuring the effectiveness of treatment, as highlighted by 6. Patients with multimorbidity, who take multiple medications, may find it challenging to adhere to their medication regimen. Healthcare professionals can play a vital role in promoting adherence by providing clear instructions, warnings, and information about the medications, as well as monitoring treatment results and considering discontinuation of the drug, as suggested by 7.

Specific Medication Information

The medication list includes:

• Aripiprazole (ABILIFY), which has been shown to be effective in reducing symptomatology associated with schizophrenia-related disorders, with dosages ≥15 mg/d more consistently producing significant reductions from baseline, as noted by 8
• Atorvastatin (LIPITOR), which should be taken with caution in patients with liver disease or those taking other medications that may interact with it
• BusPIRone (BUSPAR), which may be taken in the morning or at bedtime, depending on the specific prescription instructions.