Depot injections

A depot injection is an injection, usually subcutaneous or intramuscular, of a pharmacological agent which releases its active compound in a consistent way over a long period of time.

Depot injections are usually either solid or oil-based. Depot injections may be available as certain forms of a drug, such as decanoate salts or esters. Examples of depot injections include Depo Provera and haloperidol decanoate. Prostate cancer patients receiving hormone therapy usually get depot injections as a treatment or therapy. Zoladex is an example of a depot delivered medication for prostate cancer treatment or therapy.

The advantages of using a long-acting depot injection include increased medication compliance due to reduction in the frequency of dosing, as well as more consistent serum concentrations. A significant disadvantage is that the drug is not immediately reversible, since it is slowly released.

In psychiatry
In Psychiatric Nursing, a short acting depot, zuclopenthixol acetate (Clopixol Acuphase), which lasts in the system anything from 24 – 72 hours, is now more regularly used for rapid tranquillisation.