Akathisia is an inner sense of restlessness that can compel patients to move about as they are unable to tolerate sitting still. This side effect commonly occurs early during treatment but can occur at any point, particularly if the dose is changed. It can be so distressing that it has been linked to suicides. If akathisia is not recognized, pacing in a patient on antipsychotics can be falsely attributed to psychotic agitation. In this clinical scenario, increasing the antipsychotic would worsen akathisia and the patient’s distress. Tardive akathisia is a poorly understood phenomenon where akathisia may persist even after antipsychotics were discontinued.
- Dose reduction or switching to another LAI may be an appropriate long-term strategy, but in the short run one must treat akathisia to minimize the psychic distress which accompanies this adverse effect.
- Akathisia responds best to propranolol, clonazepam and mirtazapine, although the literature does not strongly support any one option.
- The advantage of mirtazapine is that it does not require titration, is better tolerated than propranolol, and does not have the risk of benzodiazepine misuse or mortality concern for the antipsychotic-benzodiazepine combination. The most common mirtazapine dose studied is 15 mg qhs. Its main side effects are sedation and weight gain.
- Benztropine for akathisia alone (i.e., without Parkinsonism) has limited utility.