Possible association of QTc interval prolongation with co-administration of quetiapine and lovastatin.
BACKGROUND
QTc interval prolongation can occur as a result of treatment with both conventional and novel antipsychotic medications and is of clinical concern because of its association with the potentially fatal ventricular arrhythmia, torsade de pointes.


METHODS
One case is described in which a patient with schizophrenia, who was being treated for dyslipidemia, developed a prolonged QTc interval while taking quetiapine and lovastatin.


RESULTS
QTc returned to baseline when the lovastatin dose was reduced.


CONCLUSIONS
QTc prolongation associated with antipsychotic medication occurs in a dose-dependent manner. We therefore hypothesize that the addition of lovastatin caused an increase in plasma quetiapine levels through competitive inhibition of the cytochrome P(450) (CYP) isoenzyme 3A4. Our case highlights the potential for a drug interaction between quetiapine and lovastatin leading to QTc prolongation during the management of dysipidemia in patients with schizophrenia.
Furst
Benjamin A
BA
Department of Psychiatry and Biobehavioral Sciences, University of California at Los Angeles School of Medicine, Los Angeles, California, USA.
Champion
Katherine M
KM
Pierre
Joseph M
JM
Wirshing
Donna A
DA
Wirshing
William C
WC
D000924:Anticholesteremic Agents / Q000378:metabolism*; D014150:Antipsychotic Agents / Q000009:adverse effects*; D051544:Cytochrome P-450 CYP3A; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D003987:Dibenzothiazepines / Q000009:adverse effects*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000150:complications / Q000188:drug therapy*; D008133:Long QT Syndrome / Q000139:chemically induced* / Q000175:diagnosis; D008148:Lovastatin / Q000378:metabolism* / Q000627:therapeutic use; D008875:Middle Aged; D006899:Mixed Function Oxygenases / Q000037:antagonists & inhibitors; D000069348:Quetiapine Fumarate; D012559:Schizophrenia / Q000150:complications / Q000188:drug therapy*; D013997:Time Factors; D014280:Triglycerides / Q000097:blood
D000924:Anticholesteremic Agents; D014150:Antipsychotic Agents; D065607:Cytochrome P-450 Enzyme Inhibitors; D003987:Dibenzothiazepines; D014280:Triglycerides; D000069348:Quetiapine Fumarate; D003577:Cytochrome P-450 Enzyme System; D008148:Lovastatin; D006899:Mixed Function Oxygenases; C104464:CYP3A protein, human; D051544:Cytochrome P-450 CYP3A