Long-Acting Injectable Antipsychotics (LAIs)

Primer

Long-Acting Injectable (LAI) Antipsychotics are antipsychotics delivered via intramuscular injection that can provide medication coverage from a period of weeks to months. Once stabilized on an LAI, patients rarely will need oral antipsychotic supplementation.

Advantages

Advantages of LAI include increased medication adherence compared to oral antipsychotics, and a reduced risk of re-hospitalization.[1][2]

Formulations

First-Generation

First Generation Long-Acting Injectable Antipsychotics

Name Initiation Maintenance
Haloperidol decanoate 50mg 50 to 200mg, q3 to 4 weeks
Fluphenazine decanoate 12.5mg 12.5 to 50mg, q2 to 3 weeks
Flupenthixol decanoate 20mg 50 to 300mg, q2 to 4 weeks
Zuclopenthixol decanoate 100mg 200 to 500mg, q1 to 4 weeks

Second Generation

Second Generation Long-Acting Injectable Antipsychotics

Name Tradename Formulations Method of Delivery Dosing Interval Notes
Aripiprazole monohydrate Abilify Maintenna 300mg, 400mg Vial, prefilled syringes qmonthly Requires a period of 2 weeks of oral dosing (“oral bridge”) with oral aripiprazole. Can be given via deep intramuscular (IM) deltoid or gluteal injection.
Aripiprazole lauroxil Aristada 441mg, 662mg, 882 mg Prefilled syringes qmonthly (441–882 mg), or q6 weeks (882 mg) The 882 mg dose can be administered every 6 weeks. Requires a period of 3 weeks of overlap with oral aripiprazole. Can be given via deep intramuscular (IM) deltoid or gluteal injection.
Olanzapine pamoate Zyprexa Relprevv 210mg, 300mg, 405mg Vial 150 to 300 mg q2 weeks, or 300 to 405 mg qmonthly. Requires monitoring post-injection (3 hours). For deep intramuscular gluteal injection only and not approved for deltoid injections.
Paliperidone palmitate Invega Sustenna, Xeplion 39mg, 78mg, 117mg, 156mg, 234 mg Prefilled syringes qmonthly Oral supplementation not necessary (as per drug monograph), though is still done in practice. Can be given via deep intramuscular (IM) deltoid or gluteal injection.
Paliperidone palmitate Invega Trinza 273mg, 410mg, 546mg, 819 mg Prefilled syringes q3 months Use in patients already treated with Invega Sustenna. Can be given via deep intramuscular (IM) deltoid or gluteal injection.
Risperidone microspheres Risperdal Consta 12.5mg, 25mg, 37.5mg, 50 mg Vial q2 weeks Requires a period of 3 weeks of overlap with oral risperidone. Can be given via deep intramuscular (IM) deltoid or gluteal injection.

Missed Doses

If an LAI is missed, the following schedule can be followed without restarting a titration:

  • q1w (or every 8-13 days): May administer up to 1 day before and up to 7 days after the scheduled due date
  • q2w: May administer up to 3 days before and up to 14 days after the scheduled due date.
  • q3w: May administer up to 3 days before and up to 21 days after the scheduled due date.
  • q4w: May administer up to 3 days before and up to 28 days after the scheduled due date.
  • q5w: May administer up to 3 days before and up to 28 days after the scheduled due date.
  • q6w: May administer up to 3 days before and up to 28 days after the scheduled due date.
  • q12 weeks: May administer up to 3 days before and up to 28 days after the scheduled due date

References

1) Kim, H. O., Seo, G. H., & Lee, B. C. (2020). Real-world effectiveness of long-acting injections for reducing recurrent hospitalizations in patients with schizophrenia. Annals of General Psychiatry, 19(1), 1-7.
2) Remington, G., Addington, D., Honer, W., Ismail, Z., Raedler, T., & Teehan, M. (2017). Guidelines for the pharmacotherapy of schizophrenia in adults. The Canadian Journal of Psychiatry, 62(9), 604-616.