(1) Buttocks. The buttocks are the preferred site for administration of the
intramuscular injection. The muscles (gluteal) of this area are thick and are utilized
frequently in daily activities, thus causing complete absorption of drugs.
(a) Using care in choosing the location for administering the injection
will minimize the possibility of hitting a bone, large blood vessel, or the sciatic nerve.
(b) To identify the injection site, draw an imaginary horizontal line
across the buttocks from hip bone to hip bone. Then divide each buttock in half with an
imaginary vertical line (see figure 2-1). The four imaginary sections of the buttock are
referred to as quadrants. The proper location for an injection is in the upper outer
quadrant of either buttock.
Figure 2-1. Intramuscular injection site in the buttocks (upper, outer quadrant).
(c) Remember, if an injection is given outside of the upper outer
quadrant, irreparable injury may be done to the sciatic nerve or the needle may
penetrate the gluteal artery and this can cause significant bleeding from the vessel.