lated to quetiapine’s potential for inducing orthostatic changes [see Warnings and Precautions (5.8)].
Children and Adolescents: Safety and effectiveness of SEROQUEL XR have not been established in pediatric patients. In the acute (6-week) schizophrenia trial in adolescents, potentially clinically significant increases in heart rate (> 110 bpm) occurred in 5.2% of patients receiving SEROQUEL 400 mg and 8.5% of patients receiving SEROQUEL 800 mg compared to 0% of patients receiving placebo. Mean increases in heart rate were 3.8 bpm and 11.2 bpm for SEROQUEL 400 mg and 800 mg groups, respectively, compared to a decrease of 3.3 bpm in the placebo group [see Warnings and Precautions (5.8)].
In the acute (3-week) bipolar mania trial in children and adolescents, potentially clinically significant increases in heart rate (> 110 bpm) occurred in 1.1% of patients receiving SEROQUEL 400 mg and 2.4% of patients receiving SEROQUEL 600 mg compared to 0% of patients receiving placebo. Mean increases in heart rate were 12.8 bpm and 13.4 bpm for SEROQUEL 400 mg and 600 mg groups, respectively, compared to a decrease of 1.7 bpm in the placebo group [see Warnings and Precautions (5.8)].
6.3 Post Marketing Experience
The following adverse reactions were identified during post approval use of SEROQUEL. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Adverse reactions reported since market introduction which were temporally related to SEROQUEL therapy includes anaphylactic reaction and galactorrhea.
Other adverse reactions reported since market introduction, which were temporally related to SEROQUEL therapy, but not necessarily causally related, include the following: agranulocytosis, cardiomyopathy, hyponatremia, myocarditis, rhabdomyolysis, syndrome of inappropriate antidiuretic hormone secretion (SIADH), Stevens-Johnson syndrome (SJS), and decreased platelets.
In post-marketing clinical trials, elevations in total cholesterol (predominantly LDL cholesterol) have been reported.
7 DRUG INTERACTIONS
The risks of using SEROQUEL XR in combination with other drugs have not been extensively eva luated in systematic studies. Given the primary CNS effects of SEROQUEL XR, caution should be used when it is taken in combination with other centrally acting drugs. Quetiapine potentiated the cognitive and motor effects of alcohol in a clinical trial in subjects with selected psychotic disorders, and alcoholic beverages should be limited while taking quetiapine.
Because of its potential for inducing hypotension, SEROQUEL XR may enhance the effects of certain antihypertensive agents.
SEROQUEL XR may antagonize the effects of levodopa and dopamine agonists.
7.1 The Effect of Other Drugs on Quetiapine
Phenytoin
Coadministration of quetiapine (250 mg three times/day) and phenytoin (100 mg three times/day) increased the mean oral clearance of quetiapine by 5-fold. Increased doses of SEROQUEL XR may be required to maintain control of symptoms of schizophrenia in patients receiving quetiapine and phenytoin, or other hepatic enzyme inducers (eg, carbamazepine, barbiturates, rifampin, glucocorticoids). Caution should be taken if phenytoin is withdrawn and replaced with a non-inducer (eg, valproate) [see Dosage and Administration (2)].