Next Dose: 117 mg (75 mg eq.) Invega Palmitate Monthly Maintenance
After completing the standard two-dose initiation regimen (234 mg on Day 1, followed by 156 mg on Day 8), the next dose should be 117 mg (75 mg equivalent paliperidone) administered approximately one month (±7 days) after the Day 8 injection. 1
Dosing Schedule
The FDA-approved initiation regimen you've completed consists of:
- Day 1: 234 mg (150 mg eq.) deltoid injection
- Day 8: 156 mg (100 mg eq.) deltoid injection
- Day 36 (±7 days): Begin monthly maintenance dosing 1, 2
Maintenance Dose Selection
The recommended monthly maintenance dose is 117 mg (75 mg eq.), though the approved range is 39-234 mg based on individual response 1, 3. This 117 mg dose represents the standard maintenance dose that balances efficacy and tolerability for most patients.
Key considerations for dose adjustment:
- If symptoms remain inadequately controlled after clinical reassessment, increase by 39 mg increments (maximum 234 mg monthly) 1
- Dose increases should occur at intervals >4 days apart 1
- Higher doses (156-234 mg) showed lower numbers-needed-to-treat in clinical trials but with dose-related adverse effects 4
Administration Details
Injection site options for maintenance:
- Deltoid: Use 1-inch 23-gauge needle if <90 kg; 1.5-inch 22-gauge if ≥90 kg
- Gluteal: Use 1.5-inch 22-gauge needle (any weight) 1, 2
Timing flexibility: Monthly doses can be given ±7 days from the scheduled date without clinically significant impact on plasma concentrations 2, 3
Pharmacokinetic Rationale
The two-dose initiation achieves therapeutic plasma levels rapidly without oral supplementation 2, 5. Deltoid administration on Days 1 and 8 provides approximately 28% higher peak concentrations than gluteal injection, establishing steady-state within 4-5 days 1. The terminal half-life of approximately 23 hours with sustained release allows monthly dosing 1.
Clinical efficacy timeline:
- Significant PANSS improvement vs. placebo observed by Day 8 (p=0.037) 5
- Continued improvement at Day 22 (p≤0.007) and Day 36 (p<0.001) 5
Special Population Adjustments
Renal impairment (if applicable):
- Mild (CrCl 50-80 mL/min): Reduce maintenance to maximum 78 mg monthly 1
- Moderate-severe (CrCl 10-50 mL/min): Maximum 39 mg monthly 1
Elderly patients: Use same dosing as younger adults unless renal function is impaired 1
Monitoring
No oral antipsychotic supplementation is required with this regimen 1, 2. Monitor for injection site reactions (4-10% incidence), extrapyramidal symptoms, weight gain, and prolactin elevation, though these are generally dose-dependent and well-tolerated at standard maintenance doses 4.