Information about quetiapine extended release tablets, from the National Prescribing Service RADAR
“There is no evidence that extended-release tablets improve efficacy, tolerability or adherence
Once-daily dosing with quetiapine extended-release tablets is equivalent to twice-daily dosing with quetiapine immediate-release tablets, e.g. quetiapine extended release 600 mg once daily is equivalent to quetiapine immediate release 300 mg twice daily. Comparative trials have found no difference in efficacy or tolerability between the 2 formulations, and have not assessed the relationship between dosing frequency and adherence.
Some people may prefer once-daily dosing with the extended-release tablets, but immediate-release tablets give greater flexibility in dosing and in timing with respect to meals.
When switching is appropriate, patients can switch directly from twice-daily immediate-release tablets to an equivalent total daily dose of the extended-release tablets, taken once daily.3 Some people may need dose adjustment.
The Pharmaceutical Benefits Advisory Committee (PBAC) found that the extended-release tablets were as effective as quetiapine immediate-release tablets (Seroquel) for no greater cost.
Quetiapine extended-release tablets are taken once daily
People may prefer evening dosing to minimise any daytime sleepiness. Extended-release tablets should not be chewed, crushed or split.
Extended-release quetiapine should not be taken with food. In one study using this formulation, a high-fat meal increased the peak blood levels of quetiapine and overall absorption.3 Raised blood levels of quetiapine may increase the risk of adverse effects.”