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Aripiprazole (ABILIFY) Drug Interactions

Worst Pills, Best Pills Newsletter article April, 2010

Users of the antipsychotic drug aripiprazole (ABILIFY) should be aware of the drug’s potential interactions with 53 other drugs.

Aripiprazole is an antipsychotic agent widely used to treat schizophrenia and bipolar disorder. It can also serve as an adjunct to antidepressants in treating major depression.

Like many drugs, aripiprazole is metabolized by two important enzymes: CYP2D6 and CYP3A4. When aripiprazole is taken with other drugs that decrease or increase the activity of...

Users of the antipsychotic drug aripiprazole (ABILIFY) should be aware of the drug’s potential interactions with 53 other drugs.

Aripiprazole is an antipsychotic agent widely used to treat schizophrenia and bipolar disorder. It can also serve as an adjunct to antidepressants in treating major depression.

Like many drugs, aripiprazole is metabolized by two important enzymes: CYP2D6 and CYP3A4. When aripiprazole is taken with other drugs that decrease or increase the activity of these enzymes, the speed at which aripiprazole is metabolized can be affected.

If the enzyme metabolizes aripiprazole too slowly, there is a risk that the blood levels of aripiprazole will become too high (leading to toxicity). Signals of aripiprazole toxicity include nausea, vomiting, constipation, headache, dizziness, akathisia (inability to to sit or keep still), anxiety, insomnia and restlessness.

Similarly, if the enzyme metabolizes aripiprazole too quickly, the blood levels of the drug will become too low (reducing aripiprazole’s efficacy).

Drugs that increase aripiprazole levels

Drugs that inhibit CYP3A4 are likely to increase aripiprazole blood levels. For example, the antifungal drug ketoconazole (NIZORAL) is an especially potent inhibitor of CYP3A4. This drug increases the blood levels of aripiprazole and its active metabolite by as much as 70 percent.

Drugs that inhibit CYP2D6 will also increase aripiprazole blood levels. For example, the cardiac drug quinidine (DURAQUIN, QUINAGLUTE DURA-TABS, QUINIDEX) is a particularly potent inhibitor of CYP2D6, and, on average, it more than doubles aripiprazole blood levels.

See Table 1 for a list of drugs that inhibit CYP3A4 or CYP2D6 and increase the risk of aripiprazole toxicity. Because the extent of CYP3A4 inhibition by the various drugs in this list varies, the magnitude of the interactions with aripiprazole may vary depending on which drug is used as well as the dose and duration of the drug.

Drugs that decrease aripiprazole levels

Drugs that cause CYP3A4 and CYP2D6 to metabolize drugs more rapidly ("enzyme inducers") also cause aripiprazole to be metabolized too quickly, decreasing the effectiveness of the aripiprazole.

Several studies have shown that the enzyme inducer carbamazepine markedly reduces aripiprazole blood levels, and it may inhibit the effect of aripiprazole.

See Table 2 for a list of drugs that decrease the blood levels and effectiveness of aripiprazole.

Other drugs that can interact with aripiprazole

If you are taking drugs for diabetes, high blood pressure or seizures, it is possible that aripiprazole therapy may affect your dosage requirements. Notify your prescriber if you have any of these diseases and are taking aripiprazole.

What You Can Do

Because many drugs affect the activity of the enzymes that metabolize aripiprazole, find out from your prescriber if your new drugs will interact with your aripiprazole treatment.

If you are taking aripiprazole and begin or end treatment with a drug that can either increase or decrease aripiprazole blood levels, speak with your prescriber. He or she likely will need to adjust your aripiprazole dosage.

Table 1. Drugs That Inhibit CYP3A4 or CYP2D6 and Increase Risk of Aripiprazole Toxicity

 

Generic Name

BRAND NAME

amiodarone

CORDARONE, PACERONE***

amprenavir

AGENERASE

aprepitant

EMEND

atazanavir

REYATAZ

bupropion

WELLBUTRIN**

chloroquine

ARALEN

chlorpheniramine

ALERMINE, CHLOR-TRIMETON

chlorpromazine

THORAZINE**

cinacalcet

SENSIPAR

clarithromycin

BIAXIN**

cyclosporine

NEORAL, SANDIMMUNE

darunavir

PREZISTA

delavirdine

RESCRIPTOR

diltiazem

CARDIZEM, CARDIZEM CD, DILACOR XR, TIAZAC**

diphenhydramine

BENADRYL, DYTAN SUSPENSION, DYTAN-D SUSPENSION, SOMINEX FORMULA

duloxetine

CYMBALTA

erythromycin

E-MYCIN, EES, ERYTHROCIN

fluconazole

DIFLUCAN

fluoxetine

PROZAC, SERAFEM**

fluvoxamine

LUVOX**

halofantrine

HALFAN

haloperidol

HALDOL**

imatinib

GLEEVEC

indinavir

CRIXIVAN

itraconazole

SPORANOX*

ketoconazole

NIZORAL

paroxetine

PAXIL, PEXEVA**

perphenazine

TRILAFON

posaconazole

NOXAFIL

propafenone

RYTHMOL

propoxyphene

DARVOCET, DARVON*

quinidine

DURAQUIN, QUINAGLUTE DURA-TABS, QUINIDEX**

quinupristin

SYNERCID

ritonavir

KALETRA, NORVIR

saquinavir

FORTOVASE, INVIRASE

tamoxifen

NOLVADEX**

telithromycin

KETEK*

terbinafine

LAMISIL*

thioridazine

MELLARIL*

verapamil

CALAN, CALAN SR, COVERA-HS, ISOPTIN, ISOPTIN SR, VERELAN

voriconazole

VFEND

* Do Not Use on WorstPills.org
** Limited Use on WorstPills.org
*** Last Choice Drug on WorstPills.org

Table 2. Drugs That Decrease Aripiprazole’s Blood Levels and Effectiveness

 

Generic Name

BRAND NAME

carbamazepine

CARBATROL, TEGRETOL

efavirenz

SUSTIVA

nafcillin

UNIPEN

nevirapine

VIRAMUNE

oxcarbazepine

TRILEPTAL

phenobarbital

LUMINAL, SOLFOTON**

phenytoin

DILANTIN

primidone

MYSOLINE

rifabutin

MYCOBUTIN

rifampin

RIFADIN, RIMACTANE

rifapentine

PRIFTIN

St. John’s wort*

* Do Not Use on WorstPills.org
** Limited Use on WorstPills.org