Drugs can be injected intramuscularly (IM) into the muscle fascia, which has a robust blood supply and allows for a higher absorption rate through muscle fibres than through the subcutaneous route. For drugs that need a quick absorption rate but also a somewhat lengthy action, the IM intramuscular site is used. A variety of drugs, including sedatives, anti-emetics, hormone treatments, analgesics, and vaccines, can be delivered intramuscularly in the community and acute care setting because IM injection sites have a robust blood supply that allows them to absorb higher volumes of solution. Muscle tissue is also less susceptible to irritants, concentrated drugs, and viscous substances than subcutaneous tissue is.
