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Medication Administration: Intramuscular Injections (Ambulatory) - CE


Follow instructions for SARS-COV2 vaccine administration provided on Elsevier’s Vaccination Hub undefinedhttps://elsevier.health/en-US/preview/sars-cov2-vaccine" target="_blank" title="TRANSFORM HOW YOU USE DRUG INFORMATION">https://elsevier.health/en-US/preview/sars-cov2-vaccine or Clinical Key for Nursing https://www.clinicalkey.com/nursing/#!/content/drug_monograph/6-s2.0-5295.

Intramuscular (IM) injections have been associated with adverse effects and pain, and this route of medication injection should be used as a last resort. Consider contacting the practitioner for an alternative, preferred route of medication administration.

Take extra care with a patient who takes medications that increase the risk for bleeding.5

Take steps to eliminate interruptions and distractions during medication preparation.


The IM injection route deposits medication into deep muscle tissue, which has a rich blood supply, allowing medication to be absorbed faster than it would be by the subcutaneous route. This rich blood supply, however, increases the risk for injecting drugs directly into blood vessels. Any factor that interferes with local tissue blood flow affects the rate and extent of drug absorption.

An IM injection may require a longer and larger-gauge needle to penetrate deep muscle tissue. The needle is inserted at a 90-degree angle; this varies from the angle used for subcutaneous and intradermal injections (Figure 1)Figure 1.2,6 The appropriate needle length is determined by the patient’s age and weight, injection site, and the amount of adipose tissue in the chosen injection site (Table 1)Table 1.2,7 The needle must be long enough to reach the muscle tissue but not too long to present the risk of hitting underlying neurovascular structures or bone.2

IM injections should be administered with the needle perpendicular to the patient’s body or as close to a 90-degree angle as possible.2,6 IM injection sites should be rotated to decrease the risk for hypertrophy. When possible, IM injections should not be administered in muscles that are emaciated or atrophied because they absorb medication poorly.6

Aspiration before injection and slow injection of the medication are not required for vaccine administration.2 The vastus lateralis and deltoid muscle are the only two sites recommended for vaccine administration because they do not contain large vessels that are within reach of the needle.2 For all other medications there is no evidence to support abandoning the practice of aspiration before administration. More research is needed to investigate the practice of aspiration before administering an IM injection with medications other than vaccines.9,10 The recommended route and site for each vaccine is included in the manufacturer’s instructions for use.2

Muscle tissue is less sensitive to irritating and viscous medications than subcutaneous tissue. Smaller muscles absorb smaller volumes. For a well-developed adult, no more than 4 to 5 ml of medication should be administered in a single IM injection because the muscle tissue does not absorb it well.8 For “deep” IM injections, the recommended volume ranges from 2 to 5 ml.8 If the patient’s available muscle tissue is limited and the dorsogluteal muscle must be used, volumes of up to 4 ml can be administered into this site.8 The ventrogluteal muscle can accommodate up to 2.5 ml, with a maximum volume of 3 ml.8 The rectus femoris and vastus lateralis remain the recommended sites for volumes up to 5 ml in adults.8 A maximum of 2 ml is recommended for older adults and thin patients.8

The Z-track method (pulling the skin laterally before injection) can be used if the overlying tissue can be displaced. This technique prevents medication leakage into subcutaneous tissue, seals medication in the muscle, and minimizes irritation.6 To use the Z-track method in an adult, the appropriate-size needle is attached to the syringe, and an IM site is selected. The overlying skin and subcutaneous tissues are pulled to the side with the ulnar side of the nondominant hand. The skin is held in this position until the injection has been administered. After the site is cleansed, the needle is injected deep into the muscle, and the medication is injected slowly. After the needle is withdrawn, the skin is released. The displacement of the skin and muscle layer closes off the needle track when the skin is released (Figure 2)Figure 2. The Z-track method should not be used with infant vaccinations where skin is compressed.

Injection Sites

For IM injections, the nurse selects a site that is free of pain, infection, necrosis, bruising, and abrasions. The location of underlying bones, nerves, and blood vessels and the volume of medication to be administered are also considered. Because of the sciatic nerve location, the dorsogluteal muscle is not recommended as an injection site. If a needle hits the sciatic nerve, the patient may experience partial or permanent paralysis of the leg.8

Ventrogluteal Site

The ventrogluteal site involves the gluteus medius and minimus muscles and is a safe injection site for adults, children, and infants.6 This site provides the greatest thickness of gluteal muscle that is free of penetrating nerves and blood vessels and it has a narrower layer of fat.8

The dorsogluteal site is closer to neurovascular structures than the ventrogluteal site and is not a recommended site for injection. However, the thickness of the muscle in the dorsogluteal region is greater than muscle in the ventrogluteal region. Selected site for IM injections is based on clinical assessment of the patient.3

To locate the ventrogluteal site, the heel of the hand is placed over the greater trochanter of the patient’s hip with the wrist almost perpendicular to the femur. The right hand is used for the left hip, and the left hand is used for the right hip. The thumb is pointed toward the patient’s groin, with the index finger pointing to the anterior superior iliac spine, and the middle finger is extended back along the iliac crest toward the patient’s buttock. The index finger, the middle finger, and the iliac crest form a V-shaped triangle, with the injection site at the center of it (Figure 3)Figure 3. To relax this muscle site, the patient should lie flat and supine and flex the knee and hip, or the patient may lie on the side.

Vastus Lateralis Site

The vastus lateralis muscle is another injection site used in adults, children, and infants.6 The muscle is thick and well developed, and it is located on the anterior lateral aspect of the thigh. In an adult, the vastus lateralis extends from just above the knee to just below the greater trochanter of the femur (Figure 4)Figure 4. The middle third of the muscle is used for the IM injection site. To help relax this muscle site, the patient should lie flat, supine, flex the knee slightly, and externally rotate the foot, or the patient may assume a sitting position.

Deltoid Site

The deltoid site is easily accessible in many adults, but the muscle tends to be underdeveloped, which causes a potential for injury because the axillary, radial, brachial, and ulnar nerves and the brachial artery lie within the upper arm (Figure 5)Figure 5. This site can be used for small medication volumes (2 ml or less)8 and for administration of routine immunizations in children older than 3 years2,6 and adults with acceptable muscle mass and development, and when other sites are inaccessible because of dressings or casts.2

The deltoid muscle is located by fully exposing the patient’s upper arm and shoulder and asking the patient to relax the arm at the side or by supporting the patient’s arm and flexing the elbow. The lower edge of the acromion process, which forms the base of a triangle in line with the midpoint of the lateral aspect of the upper arm, is palpated, and the injection site is found in the center of the triangle (Figure 5)Figure 5.

Rarely, an adverse reaction occurs after immunizations. Reactions may include anaphylaxis, anaphylactic shock, and neurologic deficits.1 Vaccine adverse event reporting is monitored by the Centers for Disease Control and Prevention.

If the patient expresses concern regarding the accuracy of a medication, the medication should not be given. The patient’s concern should be explored, the practitioner notified, and the order verified.


  • Provide developmentally and culturally appropriate education based on the desire for knowledge, readiness to learn, and overall neurologic and psychosocial state.
  • Explain the procedure for an IM injection, including the purpose of the injection and the reason for using the IM route.
  • Explain the risks related to the procedure, including hematoma formation, nerve injury, and allergic reaction to the medication.
  • Instruct the patient regarding the potential side effects of the medication.
  • If the patient requires regular injections, instruct the patient on injection techniques and the importance of rotating sites to decrease the risk for hypertrophy.6
  • If regular injections are required, have the patient return demonstrate medication preparation to validate learning.
  • Instruct the patient to observe the injection site for complications and instruct on the appropriate action to take if complications are observed.
  • Instruct the patient to observe for effectiveness of the medication and adverse reactions.
  • Instruct the patient to bring an up-to-date list of medications (over-the-counter [OTC], supplements, and prescriptions) to every practitioner visit.6
  • Encourage questions and answer them as they arise.


  1. Perform hand hygiene. Don appropriate personal protective equipment (PPE) based on the patient’s need for isolation precautions or the risk of exposure to bodily fluids.
  2. Introduce yourself to the patient.
  3. Verify the correct patient using two identifiers.
  4. Explain the procedure to the patient and ensure that the patient agrees to treatment.
  5. Ensure that evaluation findings are communicated to the clinical team leader per the organization’s practice.
  6. Assess the patient for specific contraindications to receiving an IM injection and advise the practitioner accordingly. Evaluate for factors such as muscle atrophy, reduced blood flow, compromised skin condition, and circulatory shock.
  7. Determine the patient’s current symptoms (if applicable) before initiating medication therapy to evaluate medication effectiveness after administration.
  8. Determine the patient’s knowledge regarding the medication to be received.
  9. Ask the patient about a history of allergies, including any drug allergies, type of allergens, and normal allergic reaction.
  10. Review the patient’s previous verbal and nonverbal responses to injections.
  11. Obtain the patient’s actual weight in kilograms. Stated, estimated, or historical weight should not be used.4
  12. Check accuracy and completeness of the practitioner’s original order.
  13. Obtain the medication and verify the expiration date.
  14. Inspect the medication for particulates, discoloration, or other loss of integrity.
    Do not use any medication that is cloudy or precipitated unless such is indicated by its manufacturer as being safe; otherwise, this may lead to harmful reactions.
  15. Understand drug reference information pertinent to the medication’s action, purpose, onset of action and peak action, normal dose, and common side effects.
  16. Ensure the six rights of medication safety: right medication, right dose, right time, right route, right patient, and right documentation.
  17. Label all medications, medication containers, and other solutions. The only exceptions are medications that are still in their original container or medications that are administered immediately by the person who prepared them.5
    Medications or other solutions in unlabeled containers are unidentifiable. Errors, sometimes tragic, have resulted from medications and other solutions removed from their original containers and placed into unlabeled containers. This unsafe practice neglects basic principles of medication management safety, yet has been routine in many organizations.5
  18. Assemble the appropriate-size needles, syringes, and other administration supplies, as needed.
  19. Perform hand hygiene and don gloves. Don additional PPE based on the patient’s need for isolation precautions or the risk of exposure to bodily fluids.
  20. Select the appropriate site for injection based on the patient’s age, weight, muscle tissue mass, and medication volume and viscosity.
  21. Assist the patient to a comfortable position that is appropriate for the chosen injection site (e.g., sitting, or lying flat, on side, or prone).
    Rationale: A comfortable position reduces strain on the muscle and minimizes injection discomfort.
  22. Ensure that the patient’s injection site is accessible. If necessary, assist the patient with removing clothing.
    1. Inspect the skin surface over sites for bruises, inflammation, or edema.
      Rationale: Injection sites should be free of abnormalities that interfere with drug absorption (e.g., bruising, signs associated with infection).
    2. Note the integrity and size of the muscle. Palpate for tenderness or hardness and avoid hardened areas. If the patient receives frequent injections, rotate sites.
      Rationale: Sites used repeatedly become hardened from lipohypertrophy (increased growth in fatty tissue).
  23. Locate the injection site again using anatomic landmarks. The ventrogluteal site is a safe injection site for adults and children receiving irritating or viscous solutions and is the site of choice for administering IM injections to adults.8 In addition, this site provides the greatest thickness of gluteal muscle, is free of penetrating nerves and blood vessels, and has a narrower layer of fat.8
    Rationale: Injection into the correct anatomic site prevents injury to nerves, bone, and blood vessels.
  24. Cleanse the site with alcohol or an antiseptic swab, per the organization’s practice. Allow the skin to dry completely. Optional: Use a vapocoolant spray (e.g., ethyl chloride) for pain relief just before injection.
    Rationale: A vapocoolant spray decreases pain at injection site.
  25. Hold a clean swab or dry gauze between the third and fourth fingers of the nondominant hand.
    Rationale: The swab or gauze remains readily accessible for use when withdrawing the needle.
  26. Remove the needle cap by pulling it straight off.
    Rationale: Pulling the cap straight off prevents the needle from touching the sides of the cap, thus preventing contamination.
  27. Hold the syringe between the thumb and forefinger of the dominant hand as if holding a dart, palm down.
    Rationale: A quick, smooth injection requires proper manipulation of the syringe parts.
  28. Administer the injection using the Z-track method.
    1. Position the ulnar side of the nondominant hand just below the site and pull the skin laterally. Hold this position until the medication is injected.
    2. With the dominant hand, inject the needle quickly into the muscle at a 90-degree angle using a steady and smooth motion.2
      Rationale: The Z-track technique creates a zigzag path through tissues that seals the needle track to avoid tracking medication. A quick, dart-like injection reduces discomfort. Z-track injections may be used for all IM injections.6,8
    3. After the needle pierces the skin, use the thumb and forefinger of the nondominant hand to hold the syringe barrel while still pulling on the skin. Move the dominant hand to the end of the plunger. Avoid moving the syringe.
      Rationale: Smooth manipulation of the syringe reduces discomfort from needle movement. Skin remains pulled until after medication is injected to ensure Z-track administration.
    4. Optional: If the patient’s muscle mass is small, grasp the body of muscle between the thumb and forefingers of the nondominant hand while still pulling the skin laterally.
      Rationale: Grasping the muscle body helps ensure that the medication reaches the muscle mass.
    5. Pull back on the plunger. If no blood appears, inject the medication. If blood appears in the syringe, remove the needle, discard the medication, obtain a new syringe, and try again.
      Rationale: Aspiration of blood into the syringe indicates possible placement into a vein.
    6. Smoothly, quickly, and steadily withdraw the needle and release the skin. Apply a dry cotton ball or gauze with light pressure for several seconds over the site.
  29. Apply gentle pressure to the site; do not massage. Evaluate the site and apply a bandage if needed.
    Rationale: Massage damages underlying tissue.
  30. Replace the patient’s clothing and assist the patient to a comfortable position.
  31. Discard the uncapped needle (or needle enclosed in the safety shield) and attached syringe into a puncture-proof and leakproof receptacle.
    Rationale: Discarding the uncapped needle helps prevent injury to the patient and health care team members. Recapping needles increases the risk for a needlestick injury.7
  32. Monitor the patient for adverse and allergic reactions to the medication. Recognize and immediately treat respiratory distress and circulatory collapse, which are signs of a severe anaphylactic reaction. Follow the organization’s practice for emergency response.
  33. Discard supplies, remove PPE, and perform hand hygiene.
  34. Document the procedure in the patient’s record.


  • Medication administered according to the six rights of medication safety
  • Desired effect of medication with no adverse reactions, signs of allergies, or undesired effects
  • Acceptable level of comfort after injection
  • Patient able to explain purpose, dose, and effects of medication


  • Medication not administered according to the six rights of medication safety
  • Patient complaints of localized pain, bleeding, or continued burning at injection site, indicating potential injury to nerve or vessels
  • Blood aspiration during injection
  • Medication administration in subcutaneous tissue
  • Adverse reaction to the medication, with signs of urticaria, eczema, pruritus, wheezing, or dyspnea
  • Other adverse effects: hematoma or abscess; infection; fibrosis of the muscle, tissue damage because of patient movement during injection; glass particles injected into muscle as a result of not using a filter needle; permanent damage to sciatic nerve resulting in paralysis, fibrosis, or abscess
  • Unmanaged pain


  • Medication name, dose, route, site, time, and date of administration
  • Patient’s response to medication, including any adverse reactions
  • Unexpected outcomes and related interventions
  • Education
  • Patient’s comfort and interventions performed
  • Patient’s weight in kilograms per the organization’s practice
  • Evaluation findings communicated to the clinical team leader per the organization’s practice


  • Children can be very anxious or fearful of needles. Assistance is sometimes necessary to hold and properly position the child. Distraction, such as blowing bubbles and applying pressure at the injection site before administering the injection, may help alleviate the child’s anxiety.
  • If possible, a topical analgesic should be applied to the injection site with sufficient time allowed for peak action before the IM injection. A vapocoolant spray (e.g., ethyl chloride) may also be used just before the injection to decrease pain.
  • The vastus lateralis muscle is the preferred site for administration of immunizations to newborns, infants, and children up to 3 years old.2 The deltoid muscle is the acceptable site for administration of routine immunizations in children 3 to 18 years old who have acceptable muscle mass and development.2
  • A colorful adhesive bandage or sticker to the injection site should be considered.


  • Older adult patients may have decreased muscle mass, which reduces drug absorption from IM injections.
  • Older adult patients may have loss of muscle tone and strength that impairs mobility, placing them at high risk for falls as a result of guarding an injection site.
  • Older adult patients who require frequent injections should be instructed to apply a topical analgesic to the injection site before administration.


  1. Centers for Disease Control and Prevention. (2021). Chapter 4: Vaccine safety. In J. Hamborsky, A. Kroger, C. Wolfe (Eds.), Epidemiology and prevention of vaccine-preventable diseases (13th ed., pp. 47-62). Washington, DC: Public Health Foundation. Retrieved October 21, 2021, from https://www.cdc.gov/vaccines/pubs/pinkbook/safety.html (Level VII)
  2. Centers for Disease Control and Prevention (CDC). (2021). Vaccine recommendations and guidelines of the ACIP: Vaccine administration. Retrieved October 21, 2021, from https://www.cdc.gov/vaccines/hcp/acip-recs/general-recs/administration.html (Level VII)
  3. Coskun, H., Kilic, C., Senture, C. (2016). The evaluation of dorsogluteal and ventrogluteal injection sites: A cadaver study. Journal of Clinical Nursing, 25(7-8), 1112-1119. doi:10.1111/jocn.13171 (Level V)
  4. Institute for Safe Medication Practices (ISMP). (2020). Targeted medication safety best practices for hospitals. Retrieved October 21, 2021, from https://www.ismp.org/sites/default/files/attachments/2020-02/2020-2021 TMSBP- FINAL_1.pdf (Level VII)
  5. Joint Commission, The. (2021). National Patient Safety Goals® for the ambulatory health care program. Retrieved October 21, 2021, from https://www.jointcommission.org/-/media/tjc/documents/standards/national-patient-safety-goals/2021/npsg_chapter_ahc_jan2021.pdf (Level VII)
  6. Lilley, L.L., Rainforth Collins, S., Snyder, J.S. (Eds.). (2020). Chapter 9: Photo atlas of drug administration. In Pharmacology and the nursing process (9th ed., pp. 103-134). St. Louis: Elsevier.
  7. Occupational Safety and Health Administration (OSHA). (2001). Occupational exposure to bloodborne pathogens; needlestick and other sharps injuries; final rule. Federal Register, 66, 5317-5325. Retrieved October 21, 2021, from https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=FEDERAL_REGISTER&p_id=16265 (classic reference)* (Level VII)
  8. Ogston-Tuck, S. (2014). Intramuscular injection technique: An evidence-based approach. Nursing Standard, 29(4), 52-59. doi:10.7748/ns.29.4.52.e9183 (classic reference)*
  9. Sepah, Y. and others. (2017). Aspiration in injections: Should we continue or abandon the practice? (version 3). F1000Research, 3, 157. doi:10.12688/f1000research.1113.3
  10. Sisson, H. (2015). Aspirating during the intramuscular injection procedure: A systematic review. Journal of Clinical Nursing, 24(17-18), 2368-2375. doi:10.1111/jocn.12824 (classic reference)* (Level I)


Centers for Disease Control and Prevention (CDC). (2018). Vaccine administration. Retrieved on October 21, 2021, from https://www.cdc.gov/vaccines/hcp/admin/admin-protocols.html

Kroger, A., Bahta, L., Hunter, P. (2021). General best practice guidelines for immunization: Best practices guidance of the advisory committee on immunization practices (ACIP). Retrieved on October 21, 2021, from https://www.cdc.gov/vaccines/hcp/acip-recs/general-recs/index.html

U.S. Food and Drug Administration (FDA). (2018). Safely using sharps (needles and syringes) at home, at work and on travel. Retrieved October 21, 2021, from (Level VII)

World Health Organization (WHO). (2015). Guiding principles to ensure injection device security. Retrieved on October 21, 2021, from (classic reference)*

*In these skills, a “classic” reference is a widely cited, standard work of established excellence that significantly affects current practice and may also represent the foundational research for practice.

Elsevier Skills Levels of Evidence

  • Level I - Systematic review of all relevant randomized controlled trials
  • Level II - At least one well-designed randomized controlled trial
  • Level III - Well-designed controlled trials without randomization
  • Level IV - Well-designed case-controlled or cohort studies
  • Level V - Descriptive or qualitative studies
  • Level VI - Single descriptive or qualitative study
  • Level VII - Authority opinion or expert committee reports