PART 3 / CH 57
Depot Neuroleptics
Roy Perlis
A. Overview
· Decreases rate of relapse, probably improves compliance.
· Underutilized in U.S.
· Available forms:
Haldol decanoate (IM, q2-4 weeks) T1/2 = 21d
Prolixin decanoate (IM, q2 weeks) T1/2= 14d
B. Dosing principles/conversion
· Haldol dec = (daily PO dose x 30d) / 2
e.g., Haldol dec 150mg IM qmonth = Haldol 10mg PO qd
· Haldol dec 200mg IM qmonth = Prolixin dec 25mg IM q2weeks
· Injection site: Upper/outer quadrant of gluteus maximus
or mid deltoid. Use Z-track technique.
· Maximum single dosage: 200mg IM
C. Loading-dose strategy (Ereshefsky method)
| Action | Example |
|---|---|
| Stabilize patient on PO Haldol for >1 week. | Haldol 10mg PO BID |
| Loading dose = total daily dose x 20 | 20 x 20 = 400mg |
| Give in divided doses of Haldol decanoate, 100-200mg IM, 4-7 days apart. Discontinue PO Haldol. | d1: Haldol dec 200 IMx1 d4: Haldol dec 200 IMx1 |
| After 1 month, check Haldol level (goal= 5-12ng/mL) | level = 8ng/mL |
| Decrease by at least 25-30% for next IM dose | d30: Haldol dec 150 IMx1 d33: Haldol dec 150 IMx1 |
| Recheck Haldol level after next month, decrease dose by another 25% (of original) | d60: Haldol dec 200mg IM |
source: Ereshefsky L et al. (1993) A loading dose strategy for converting from oral to depot haloperidol. HCP 12.