Haloperidol Subcutaneous Dosing
For subcutaneous administration of haloperidol in delirium, use the same dose as oral administration: 0.5-1 mg as required, which can be given every 2 hours, with a maximum of 10 mg daily (or 5 mg daily in elderly patients). 1
Standard Subcutaneous Dosing Protocol
Initial Dosing
- Start with 0.5-1 mg subcutaneously every 2 hours as needed for delirium 1
- The subcutaneous dose is equivalent to the oral dose - no conversion factor needed 1
Dose Titration
- Increase in 0.5-1 mg increments as required based on response 1
- For severely distressed patients or those causing immediate danger, consider starting with 1.5-3 mg 1
Maximum Daily Doses
- General adult population: 10 mg per 24 hours maximum 1
- Elderly patients: 5 mg per 24 hours maximum 1, 2
Continuous Subcutaneous Infusion Option
For patients requiring frequent dosing (more than twice daily), consider continuous subcutaneous infusion via syringe driver starting at 2.5-10 mg over 24 hours. 1
- This approach reduces the need for repeated bolus injections 1
- Particularly useful in palliative care settings where oral route is unavailable 1
Special Population: Elderly Patients
Critical Dosing Adjustments
- Initial dose: 0.25-0.5 mg subcutaneously (lower than general adult dose) 2
- Can be repeated every 1-2 hours as needed 2
- Strict maximum: 5 mg daily (half the general adult maximum) 1, 2
Important Safety Considerations
- Elderly patients have higher risk of extrapyramidal symptoms with typical antipsychotics like haloperidol 2
- Monitor closely for movement disorders, dystonia, and rigidity 2
- Consider atypical antipsychotics (risperidone 0.25-0.5 mg or quetiapine 25 mg) as alternatives with lower extrapyramidal risk 2
Clinical Context and Caveats
When to Use Subcutaneous Route
- Patient unable to swallow oral medications 1
- Managing delirium in palliative care or end-of-life settings 1
- Need for reliable absorption when oral route compromised 1
Combination Therapy
If agitation persists despite haloperidol, add a benzodiazepine (lorazepam or midazolam) rather than exceeding maximum haloperidol doses 1
Non-Pharmacological Measures First
Before administering haloperidol, attempt to address reversible causes: 1, 2
- Treat hypoxia, urinary retention, constipation
- Ensure adequate lighting and orientation
- Provide effective communication and reassurance
Common Pitfall to Avoid
Do not confuse subcutaneous haloperidol dosing with intramuscular depot formulations - the concentrated depot formulations (50-100 mg/mL) are for long-term maintenance therapy and can cause significant injection site reactions 3. The subcutaneous route discussed here uses standard haloperidol solution for acute symptom management.