Long-acting injectable antipsychotics for maintenance therapy after acute mania

See Overview of pharmacotherapy for acute mania in adults and young people for the role of antipsychotics in the maintenance treatment of mania.

Long-acting injectable antipsychotics are not commonly used in bipolar disorder. However, they may be useful for maintenance therapy (either as monotherapy or combined with another drug) in patients who prefer to use them or refuse to take oral drugs after acute mania has resolved—for the advantages and disadvantages of long-acting injectable antipsychotic formulations compared to oral antipsychotic formulations, see Advantages and disadvantages of long-acting injectable antipsychotic formulations compared to oral antipsychotic formulations.

A long-acting injectable antipsychotic should be started in consultation with the patient’s psychiatrist or mental health team, and managed by a practitioner experienced in their use.

Of the antipsychotics available as a long-acting injectable formulation, aripiprazole or risperidone is preferred because there is some evidence for their use in bipolar disorder. Avoid long-acting injectable haloperidol and olanzapine because of the risk of serious adverse effects—see Antipsychotic adverse effects for more detail.

When starting a long-acting injectable antipsychotic, it is preferable to use an antipsychotic that the patient has tolerated in oral form and, ideally, has responded to and is stabilised on (ie taken for at least 2 weeks). This:

  • reduces the risk of a persistent intolerable adverse effect
  • makes switching easier and more accurate (if the patient is stabilised on the antipsychotic)
  • increases the chance the patient will respond to the long-acting injectable formulation (if they have responded to the oral antipsychotic).

If the patient takes an oral antipsychotic other than aripiprazole or risperidone, first switch to one of those drugs to establish tolerability.

When choosing between aripiprazole and risperidone, discuss antipsychotic choice with the patient and, if they consent, their family, carers or significant others using the discussion points here.

Establish baseline values of parameters that can be affected by antipsychotic therapy—see Baseline parameters potentially affected by antipsychotic therapy. Dosage should be guided by response to therapy and tolerability (regularly monitor for adverse effects). Dose titration of long-acting injectable antipsychotics should be guided by a psychiatrist.

An appropriate regimen of a long-acting antipsychotic for bipolar disorder in adults and young people is:

1 aripiprazole monohydrate 400 mg intramuscularly, every 4 weeks. Continue previous oral aripiprazole regimen (or start oral aripiprazole as for acute mania) for the first 2 weeks. If the 400 mg dose is not tolerated, reduce to 300 mg every 4 weeks bipolar disorder, acute mania (long-acting injectable) aripiprazole monohydrate aripiprazole aripiprazole

OR

1 risperidone intramuscularly, every 2 weeks at a dose equivalent to the previous oral risperidone dose (see Approximate equivalent oral and long-acting injectable dosages for some antipsychotics) or, if oral risperidone was not previously taken, 25 mg every 2 weeks. Continue previous oral risperidone regimen (or start oral risperidone as for acute mania) for the first 3 weeks. After 3 weeks, adjust the dose according to response and tolerability1; usual range 25 to 50 mg every 2 weeks. Thereafter, do not increase the dosage more often than every 4 weeks2. bipolar disorder, acute mania (long-acting injectable) risperidone risperidone risperidone

1 After intramuscular risperidone injection, the effect is not seen for at least 3 weeks; oral supplementation is always required for the first 3 weeks after increasing the dose.Return
2 The oral formulation of risperidone has not been shown to be effective in prophylaxis of bipolar disorder.Return