Risperidone parenteral

Risperidone, parenteral (Risperdal Constra) Thioridazine (Mellaril) Thiothixene (Navane) Trifluoperazine (Stelazine)... 

Haloperidol, phenothiazines, thioxanthenes, clozapine, olanzapine, quetiapine, and risperidone 0 Parenteral agents may have a higher incidence... 

A parenteral, depot antipsychotic is one that can be administered in such a way that, after a single dose, a therapeutically efficient tissue concentration of at least 1 week s duration is achieved (251,252). Slow release of the active drug is produced by combining the base antipsychotic with a fatty acid (decanoic acid). The alcohol group of the antipsychotic is esterified by the acid, producing a lipophilic compound whose solubility in oil is increased. An oil, usually sesame, is then used as a vehicle for intramuscular injection, where the ester, which is not pharmacologically active, is hydrolyzed by tissue esterases, slowly releasing the active compound. An alternative technique is the use of microspheres (e.g., risperidone). 

Long-acting, parenteral, antipsychotic administration remains an important option in various clinical situations. Presently, only neuroleptics are available in this formulation, but it is anticipated that depot formulations of novel antipsychotics (e.g., risperidone, olanzapine) may soon be approved. The advent of such agents should significantly improve the efficacy and safety of this strategy. 

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