Psychopharmacology and adverse effects of antipsychotic long-acting injections: a review.
BACKGROUND
Depot antipsychotics are widely used in clinical practice. Long-acting formulations of second-generation antipsychotics are now being developed and introduced.


OBJECTIVE
To review the pharmacology, pharmacokinetics and adverse effect profiles of currently available antipsychotic long-acting injections (LAIs).


METHODS
The psychopharmacological properties of first- and second-generation antipsychotic LAIs are reviewed using data available up to October 2008.


RESULTS
First-generation antipsychotic (FGA) LAIs are associated with a high rate of acute and chronic movement disorders. Risperidone LAI is better tolerated in this respect, but is associated with hyperprolactinaemia and weight gain. Olanzapine LAI causes weight gain and other metabolic effects but appears not to be associated with an important incidence of movement disorders.


CONCLUSIONS
Dosing of LAIs is complicated by delayed release of drug, changes in plasma levels without change in dose, and by the lack of data establishing clear dose requirements. All LAIs offer the prospect of assured adherence (although patients may still default on treatment) but their use is complicated by adverse effects, complex pharmacokinetics and confusion over dose-response relationships.
Taylor
David
D
Pharmacy Department, Maudsley Hospital, Denmark Hill, London SE5 8AZ, UK. David.taylor@slam.nhs.uk
D014150:Antipsychotic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D003692:Delayed-Action Preparations / Q000494:pharmacology* / Q000627:therapeutic use; D004334:Drug Administration Schedule; D064420:Drug-Related Side Effects and Adverse Reactions; D004409:Dyskinesia, Drug-Induced / Q000209:etiology; D006801:Humans; D055118:Medication Adherence; D011618:Psychotic Disorders / Q000188:drug therapy*
D014150:Antipsychotic Agents; D003692:Delayed-Action Preparations