The dose of HALDOL Decanoate 50 or HALDOL Decanoate 100 should be expressed in terms of its haloperidol content. The starting dose of haloperidol decanoate should be based on the patient's age, clinical history, physical condition, and response to previous antipsychotic therapy. The preferred approach to determining the minimum effective dose is to begin with lower initial doses and to adjust the dose upward as needed. For patients previously maintained on low doses of antipsychotics (. up to the equivalent of 10 mg/day oral haloperidol), it is recommended that the initial dose of haloperidol decanoate be 10–15 times the previous daily dose in oral haloperidol equivalents; limited clinical experience suggests that lower initial doses may be adequate.
Following administration of fluphenazine decanoate, the amount of prodrug at the sites of injection declined exponentially (half-life days). Highest concentrations of drug and prodrug were found in iliac and hypogastric lymph nodes nearest to injection sites in which both analytes were detectable 28 days post dose. The half-life for the decline of fluphenazine from lymph nodes ( days) was similar to that from plasma ( days). Following administration of fluphenazine base, only % of the dose remained at the sites of injection after 2 days. Concentrations of drug in iliac and hypogastric lymph nodes were comparable to those in distal lymph nodes. Fluphenazine concentrations in the lymphatic tissues decreased at about the same rate as plasma concentrations.