Depot injections

Intravenous aqueous injections provide an excellent means of achieving a rapid therapeutic response. Parenteral product design, eg, vehicle and other excipient selection, as well as choice of route of adrninistration, can prolong therapeutic activity and increase onset times. Thus, oily solutions, suspensions, or emulsions can be adrninistered by subcutaneous or intramuscular routes to create prolonged effect, ie, depot injection (28). 

An example of such a product is Sterile Medroxyprogestrone Acetate Suspension used for its contraceptive property. Such an injection is designed to provide up to three months of contraceptive activity. Another such product is a depot injection of leuprolode acetate, an analogue of gonadatropin-releasing hormone (see Drug delivery systems). In this case, the product is a sterilized powder of microspheres to be suspended upon the addition of an appropriate diluent and intended for monthly injection. 

Oil-soluble derivatives of testosterone itself predate those of its 19-nor congener these agents too are used to administer depot injections so as to provide in effect long-term blood levels of drug. Thus, acylation of testosterone with propionyl chloride in the presence of pyridine yields testosterone propionate (76a)acylation by means of decanoic anhydride yields testosterone decanoate (76b).Finally, reaction of 75 with 3-cyclopentylpropionyl chloride affords testosterone cypionate (76c)This last undergoes hydrolysis unusually slowly because of the presence of two substituents at the 5 position (see Newman s Rule of 6). ... 

Systemic corticosteroids, administered orally or by depot injection, are considered last-resort options when all other treatments for SAR are inadequate. Systemic steroids may be used to control rhinitis symptoms in patients with severe PAR or nasal polyposis. Data comparing oral and parenteral steroid therapy are lacking however, oral therapy is preferred due to its low cost... 

Sociocultural, illness, and biological factors affect individual attitudes towards psychotropic medications. Health beliefs or explanatory models, particularly causal attributions regarding the illness and the treatment options afforded within such models, exert a profound influence on patients attitudes and behavior regarding medications (Smith, Lin Mendoza, 1993). Such effects can be subtle and can occur during the course of treatment even if there has been initial successful negotiation about the nature of the illness and treatment. In psychiatric illness little research has been leveled at the personal meaning that patients bring to treatment practices such as electro-convulsive therapy (ECT), oral medications, and depot injections, or to the transition between different administrative routes and types of medications. 

Depot injection A long-acting formulation of an antipsychotic drug given by occasional (often monthly) intramuscular injection. 

If partial or poor adherence is an issue, a long-acting or depot injectable antipsychotic should be considered (e.g., risperidone microspheres, halo-peridol decanoate, fluphenazine decanoate). 

Buprenorphine Depot (injectable, extended release form of buprenorphine)... 

Testosterone (T.) derivatives for clinical use. T. esters for im. depot injection are T. propionate and T. heptanoate (or enanthate). These are given in oily solution by deep intramuscular injection. Upon diffusion of the ester from the depot, esterases quickly split off the acyl residue, to yield free T. With increasing lipophilicity, esters will tend to remain in the depot, and the duration of action therefore lengthens. A T. ester for oral use is the undecanoate. Owing to the fatty acid nature of undecanoic acid, this ester is absorbed into the lymph, enabling it to bypass the liver and enter, via the thoracic duct, the general circulation. 17-0 Methyltestosterone is effective by the oral route due to its increased metabolic stability, but because of the hepatotoxicity of Cl 7-alkylated androgens (cholestasis, tumors) its use should be avoided. Orally active mesterolone is 1 a-methyl-dihydrotestosterone. Trans-dermal delivery systems for T. are also available. 

Insulin, whatever its source, may be formulated in a number of ways. This directly affects its activity profile upon administration to diabetic patients. Fast (short)-acting insulins are those preparations that yield an elevated blood insulin concentration relatively quickly after their administration, which is usually by s.c. or, less commonly, by i.m. injection. Slow-acting insulins, on the other hand, enter the circulation much more slowly from the depot (injection) site. This is characterized by a slower onset of action, but one of longer duration (Table 8.4). 

Depot injections Typically a sparingly soluble drug as a solid or and implants dispersed in an oil. Easier to administer in... 

Recommended dosage and monitoring requirements Sandostatin injectable solution is usually administered subcutaneously in initial doses of 50 to 100 pg two or three times daily. Upward dose titration is frequently required. Sandostatin LAR Depot injectable suspension should never be administered intravenously or subcutaneously. Patients not currently receiving octreotide acetate should begin therapy with subcutaneous injections and then can be switched to the depot injection of 20mg intragluteally at 4-week intervals for 3 months. 

Johnson DAW, Wright NF. Drug prescribing for schizophrenic outpatients on depot injections repeat surveys over 18 years. Br J Psychiatry 1990 156 827-834. 

Parenteral depot injection (Sandostatin LAR Depot) 10, 20, 30 mg powder in single-use vials to reconstitute for IM injection... 

FIGURE 11-52. Positive symptom pharmacy. First-line treatment of positive symptoms is now atypical antipsychotics (SDA), not only for schizophrenia but also for positive symptoms associated with bipolar disorder, Alzheimer s disease, childhood psychoses, and other psychotic disorders. However, conventional antipsychotics (D2) and benzodiazepines (BZ) are still useful for acute intramuscular administration (in case of emergency), and D2 for monthly depot injections for noncompliant patients, as well as for second-line use after several atypical agents fail. Clozapine (C), polypharmacy, and combinations (combos) are relegated to second- and third-line treatment for positive symptoms of psychosis. 

Fluoxetine hydrochloride Flurometholone Fluticasone propionate Fluvoxamine maleate Formestane depot injection Fortison liquid/power pepti-2000-liquid powder Fotemustine IV injection (finished formulation)... 

However, chronic administration (e.g. as a depot injection) evokes an initial agonist phase of several days to weeks, followed by a suppression of gonadotrophin secretion. The precise molecular site of action of this process is unclear, but it is thought to involve an initial loss of receptors, followed by an uncoupling of receptors from their effector systems. Chronic administration is used clinically in the treatment of sex-hormone responsive tumors such as prostate and breast cancer. 

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