Pedal edema associated with atypical antipsychotics

Area of Science:

• Psychiatry
• Pharmacology

Background:

• Bipolar affective disorder requires long-term antipsychotic treatment.
• Atypical antipsychotics like risperidone and quetiapine are commonly prescribed.
• Monitoring for adverse drug reactions is crucial in psychiatric pharmacotherapy.

Observation:

• A patient with bipolar disorder developed pedal edema after starting risperidone and quetiapine.
• Edema persisted after risperidone withdrawal but improved upon quetiapine dose reduction and discontinuation.
• Hematological and biochemical tests were within normal limits.

Findings:

• Quetiapine was identified as the probable cause of drug-induced pedal edema.
• The Naranjo scale indicated a probable adverse drug reaction (score of 7).
• Complete resolution of edema occurred after quetiapine dechallenge.

Implications:

• Clinicians should consider quetiapine as a potential cause of pedal edema in patients with bipolar disorder.
• Careful dose titration and monitoring are essential when prescribing quetiapine.
• This case highlights the importance of dechallenge in diagnosing drug-induced adverse events.