The Z-track method of I.M. injection prevents leakage of irritating and discoloring medications (such as iron dextran) into the subcutaneous tissue. It may also be used in elderly patients who have decreased muscle mass. Lateral displacement of the skin during the injection helps to seal the drug in the muscle. The ventrogluteal site is the most common location for a Z-track injection.
Patient's medication record and chart 
two 20G ¼'' to 2'' needles prescribed medication gloves 3- or 5-mL syringe two alcohol pads.
Verify the order on the patient's medication record by checking it against the doctor's order and perform hand hygiene. Check for allergies to the medication.
Measure up
Make sure the needle you're using is long enough to reach the muscle. As a rule of thumb, a 200-lb (91 kg) patient requires a 2'' needle; a 100-lb (45 kg) patient, a 1¼'' to 1½'' needle.
Attach one needle to the syringe and draw up the prescribed medication. Then draw 0.2 to 0.5 cc of air (depending on your facility's policy) into the syringe. Remove the first needle and attach the second to prevent tracking the medication through the subcutaneous tissue as the needle is inserted.
Confirm the patient's identity using two patient identifiers, explain the procedure, and provide privacy.
Place the patient in the lateral position, exposing the gluteal muscle to be used as the injection site. The patient may also be placed in the prone position.
Clean an area on the upper outer quadrant of the patient's buttock with an alcohol pad.
Put on gloves and displace the skin laterally by pulling it away from the injection site. (See Displacing the skin for Z-track injection.)
Follow with air
Insert the needle into the muscle at a 90-degree angle and aspirate for blood return. If none appears, inject the drug slowly.
Wait 10 seconds, withdraw the needle slowly, and release the displaced skin and subcutaneous tissue to seal the needle track. Don't massage or allow the patient to wear a tight-fitting garment over the site because it could force the medication into subcutaneous tissue. Encourage the patient to walk or move about in bed to facilitate absorption of the drug from the injection site.
Discard the needles and syringe in an appropriate sharps container. Don't recap needles to avoid needlestick injuries.
Remove and discard your gloves. Perform hand hygiene.
Never inject more than 5 mL of solution into a single site using the Z-track method. Alternate gluteal sites for repeat injections.
I.M. injections can cause elevated serum enzyme levels. If measuring enzyme levels is important, suggest that the doctor switch to I.V. administration and adjust dosages accordingly. (See Documenting Z-track injection.)
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