What to do if an antipsychotic dose is missed?

Management of Missed Antipsychotic Doses

If an antipsychotic dose is missed, it should be taken as soon as it is remembered, but doses should not be doubled to make up for missed doses. 1

Immediate Actions After Missing a Dose

• For oral antipsychotics:

  • If remembered within a few hours: Take the missed dose immediately
  • If close to next scheduled dose (within 2-4 hours): Skip the missed dose and resume regular schedule
  • Never double up on doses to compensate for a missed dose 1

• For long-acting injectable (LAI) antipsychotics:

  • Contact healthcare provider immediately
  • Reschedule the injection as soon as possible
  • If an LAI dose is missed, this provides immediate awareness to the clinical team that intervention is necessary 2

Clinical Considerations

Risk Assessment

After a missed dose, evaluate:

• Duration since last dose taken
• Patient's current symptom status
• History of rapid decompensation with missed doses
• Risk factors for relapse (substance use, high family expressed emotion) 3

Medication-Specific Considerations

1. Clozapine: Missing doses for >48 hours may require dose re-titration to avoid adverse effects
2. Antipsychotics with short half-lives: More urgent to resume dosing
3. Depot/LAI formulations: Provide more buffer time if a dose is missed 2

Prevention Strategies

For Patients with Adherence Difficulties

• Consider switching to long-acting injectable antipsychotics, especially for:
  • Patients with documented chronic psychotic symptoms
  • History of poor medication compliance 2
  • Substance misuse (which strongly predicts non-adherence) 2

Monitoring and Support

• Maintain frequent physician contact (at least monthly) to monitor symptoms, side effects, and compliance 2
• For patients with medication changes or periods of instability, consider weekly visits 3
• Educate patients and families about warning signs requiring immediate attention 3

Important Caveats

• Relapse risk: Medication non-adherence is the strongest predictor of relapse, with relapse rates five times higher among those who discontinue medication 2
• Monitoring: If a patient misses multiple doses, closer monitoring is essential as this may indicate the beginning of non-adherence that could lead to relapse 2
• Family involvement: Include families in adherence strategies as they often face the initial burden associated with psychotic relapse 2

Pitfalls to Avoid

• Assuming a single missed dose is inconsequential: Even short periods of non-adherence can initiate the relapse process in vulnerable patients
• Overestimating adherence: Both patients and clinicians tend to overestimate medication adherence 2
• Delayed intervention: If a patient misses doses, prompt intervention is necessary before a crisis develops 2
• Abrupt discontinuation: Antipsychotics should never be stopped abruptly as withdrawal syndromes, relapse and rebound can occur 4

Remember that maintaining antipsychotic treatment is crucial for preventing relapse, with approximately 65% of patients receiving placebo experiencing relapse within one year compared to 30% receiving antipsychotics 2.