81 - Aripiprazole 2 monthly8,9

Aripiprazole 2-monthly8,9

Schizophrenia and related psychoses CHAPTER 1 Aripiprazole 2-­monthly8,9 Two-­monthly ALAI (Aripiprazole 2-­Month Ready-­to-­Use 960mg [Ari2MRTU]) is ­indicated for maintenance treatment of schizophrenia (in the USA it is also licensed for maintenance monotherapy treatment of bipolar-­1 disorder9). It is available as 720mg and 960mg formulations and should only be administered into the gluteal muscle. The 960mg dose is equivalent to 10–20mg daily of oral aripiprazole. The initiation regimen is shown in Table 1.12. The maintenance dose of Ari 2MRTU should be administered into the gluteal muscle every 56 days (this seems to be the manufacturer’s definition of ‘2-­monthly’). It may be given up to 2 weeks before or 2 weeks after the scheduled injection due date.8 Table 1.13 gives recommendations in the event of a missed or delayed maintenance dose of Ari 2MRTU. In the event of an adverse reaction, reduce the maintenance dose to 720mg every 2 months. For patients on concomitant treatment with CYP2D6 or CYP3A4 inhibitors or those who are confirmed CYP2D6 poor metabolisers, the 720mg dose is considered more appropriate.9 Ari 2MRTU 960 is generally well tolerated, with safety, tolerability, efficacy and pharmacokinetic profiles similar to those of the 1-­monthly ALAI (400mg).10–13 Table 1.12  Aripiprazole 2-­month ready-­to-­use initiation regimen.8 Switching from Initiation regimen Oral antipsychotics Establish tolerability with aripiprazole before initiating ALAI treatment One-injection start Administer one 960mg injection + give 10–20mg oral aripiprazole for 14 consecutive days Two-injection start Administer one 960mg injection and one 400mg injection at two different injection sites + give one 20mg dose of oral aripiprazole 400mg ALAI Initiate 960mg no sooner than 26 days after the last 400mg ALAI Table 1.13  Recommendations for delayed maintenance dose of Ari 2MRTU. Missed maintenance dose8 Recommendations

8weeks and <14 weeks since last injection Administer 960mg or 720mg as soon as possible 14 weeks since last injection Administer 960mg or 720mg + oral aripiprazole for 14 days or Maintenance dose 960mg: Administer 960mg + 400mg + one dose of 20mg oral aripiprazole Maintenance dose 720mg: Administer 720mg + 300mg + one dose of 20mg oral aripiprazole Resume 2-­monthly dosing schedule