A 52-year-old woman with a history of schizoaffective disorder, depressive type, is brought to the office by her husband for follow-up. The patient was hospitalized last month due to worsening auditory hallucinations that were telling her to kill herself. She responded to an increased dose of risperidone and was discharged a week later. The patient reports feeling relieved that the voices telling her to kill herself have gone away since her antipsychotic dose was increased. Her husband also reports that she is much less agitated since the voices have subsided, but he is concerned that she smiles less and seems slowed down. He is worried that she is becoming depressed. On examination the patient is alert, calm, and cooperative. She has a mild tremor and does not swing her arms when she walks. Her affect appears sad. She denies any auditory hallucinations or thoughts of wanting to die. Which of the following is the most appropriate pharmacological management for this patient's condition?
Antipsychotic extrapyramidal effects | Pharmacotherapy* | |
Acute |
|
|
Akathisia |
|
|
Parkinsonism |
|
|
Tardive |
|
|
*Management may include reducing the dose or switching to another antipsychotic, depending on the clinical scenario. | ||
This patient's development of tremor, psychomotor retardation (bradykinesia), and decreased arm swing shortly after an increase in risperidone dose is suggestive of antipsychotic-induced parkinsonism. Cogwheel rigidity, shuffling gait, and masklike facies (which can be difficult to differentiate from depressed affect) are also characteristic.
Risperidone is a second-generation antipsychotic (SGA) with dopamine receptor antagonist activity. It is less likely to cause extrapyramidal symptoms (EPS) compared to a first-generation antipsychotic (FGA). However, among SGAs, risperidone is the most likely to cause EPS, especially at higher doses. Options to manage antipsychotic-induced parkinsonism include:
The anticholinergic antiparkinsonian medication benztropine is commonly used. Amantadine, a dopaminergic medication (that usually does not worsen psychosis), can also be used.
(Choice B) Propranolol, a beta blocker, has been used to treat akathisia, another type of EPS characterized by an inability to sit still.
(Choice C) The patient has EPS, not current symptoms of a major depressive episode. By definition, patients with schizoaffective disorder may have periods with psychotic symptoms in the absence of mood episodes. Adding an antidepressant (eg, sertraline) may be needed during the course of the patient's illness, but this will not improve her current presenting symptoms and is not the most appropriate treatment at this time.
(Choice D) Due to the risk of agranulocytosis, clozapine is generally reserved for psychotic patients who do not respond to ≥2 other antipsychotics. Switching to clozapine is not necessary because drug-induced parkinsonism is reversible and will likely improve with the addition of benztropine to risperidone. In cases of tardive dyskinesia, which is a potentially progressive, debilitating, and irreversible form of EPS classically characterized by orobuccolingual and facial dyskinesia (eg, tongue protrusion, lip smacking), switching to clozapine would be an option.
(Choice E) Switching to haloperidol (a high-potency FGA) would be incorrect because it carries a higher risk of parkinsonian side effects compared to risperidone.
Educational objective:
Antipsychotics may cause drug-induced parkinsonism, a type of extrapyramidal symptom (EPS). Treatment options include antipsychotic dose reduction, treatment with benztropine or amantadine, or switching to another antipsychotic with a lower potential to cause EPS, if feasible.