What happens if a patient misses an Invega (paliperidone) shot?

Management of Missed Invega (Paliperidone) Injections

If a patient misses an Invega (paliperidone palmitate) injection, they should receive their next dose as soon as possible, with specific timing and dosing requirements based on how long the dose has been missed.

Understanding Paliperidone Palmitate Administration

Paliperidone palmitate is a long-acting injectable (LAI) antipsychotic medication that requires specific administration protocols:

• The standard initiation regimen consists of 150 mg equivalent (234 mg) on day 1 followed by 100 mg equivalent (156 mg) on day 8, both administered into the deltoid muscle 1
• Monthly maintenance dosing typically ranges from 25-150 mg equivalent (39-234 mg), with a recommended dose of 75 mg equivalent (117 mg) 1
• The medication can be administered in either the deltoid or gluteal muscle after the initial loading doses 1, 2

Protocol for Missed Doses

When a patient misses their scheduled injection, the following approach should be implemented:

• For monthly maintenance doses, there is a ±7 day window without clinically significant impact on plasma concentrations 1
• If a patient misses their dose beyond this window, the re-initiation schedule depends on the duration since the last injection 1

Specific Re-initiation Guidelines:

1. If missed by less than 4 weeks from scheduled date:

   • Administer the previously stabilized dose as soon as possible 1, 2
   • Resume the monthly injection schedule from this new date 1

2. If missed by 4-6 weeks from scheduled date:

   • Administer the same dose the patient was previously receiving 1
   • Resume the regular monthly schedule 1

3. If missed by more than 6 weeks:

   • Re-initiation with the original loading dose regimen is recommended: 150 mg equivalent (234 mg) on day 1 and 100 mg equivalent (156 mg) on day 8, both in the deltoid muscle 1, 2
   • Then resume monthly maintenance dosing 1

Clinical Considerations and Monitoring

When managing missed doses, several important clinical factors should be considered:

• Monitor for potential symptom recurrence or relapse as drug levels may have decreased below therapeutic threshold 2
• Assess the patient for any signs of psychotic symptoms that may have emerged during the period without medication 2
• Consider temporary oral antipsychotic supplementation if clinically indicated by symptom recurrence 2
• Evaluate factors that led to the missed dose to improve adherence moving forward 2

Common Pitfalls to Avoid

• Avoid improper re-initiation dosing: Using maintenance doses when a full re-initiation protocol is needed can result in subtherapeutic levels 3
• Avoid overlooking injection site considerations: For re-initiation, deltoid administration is required for the loading doses 1, 2
• Avoid disregarding patient-specific factors: Consider renal function, age, and concomitant medications when determining appropriate dosing after missed injections 1
• Avoid neglecting monitoring: Patients who have missed doses require careful assessment for symptom recurrence and potential adverse effects when restarting treatment 3

Special Populations

• Patients with renal impairment: Dosage adjustments may be needed when restarting after missed doses 1
• Elderly patients: Consider age-related decline in creatinine clearance when determining re-initiation protocol 1
• Patients with history of adverse reactions: More cautious re-initiation may be warranted in patients who previously experienced significant side effects 3

Following these guidelines will help ensure appropriate management of missed Invega injections while maintaining therapeutic efficacy and patient safety.