Medication Administration: Subcutaneous Injections (Home Health Care) - CE/NCPD

The content in Clinical Skills is evidence based and intended to be a guide to clinical practice. Always follow your organization’s practice.

ALERT

Do not administer the medication into the injection site if the skin is damaged, burned, bruised, hard, inflamed, or swollen.

Some syringe plungers and rubber stoppers on vials contain latex; read the package insert to determine if the equipment contains latex.

Do not pull back on the syringe (i.e., aspirate) after injecting heparin or insulin.

Take steps to avoid interruptions and distractions when getting medications ready.

OVERVIEW

Subcutaneous tissue is not as richly supplied with blood vessels as are muscles; therefore, medications are absorbed more slowly via subcutaneous injections than with intramuscular (IM) injections. If there is a deviation in the correct route (e.g., IM instead of subcutaneous or subcutaneous instead of IM), the medication may be absorbed too quickly and cause adverse reactions related to the injection medication. Any condition that impairs blood flow is a contraindication for subcutaneous injection.^{undefined#ref5">5}

The best sites for subcutaneous injection in adults include the outer aspect of the upper arms, the abdomen from below the costal margins to the iliac crests, the anterior aspects of the thighs, and the buttocks (Figure 1). These areas are easily accessible and are large enough to permit rotating multiple injections. For subcutaneous vaccinations in adults, only the upper outer triceps of the arm is used.⁶

The patient’s body weight and amount of adipose tissue indicate the depth of the subcutaneous layer. Therefore, the needle length and angle of needle insertion should be based on the patient’s weight and an estimate of the depth of the subcutaneous tissue (Figure 2). Typically, a 22- to 25-G, ⅝-inch needle is used for vaccinations.⁶

Nurses administering subcutaneous injections must use safety syringe devices and know how to activate the safety mechanism.

If the patient is obese, pinching the tissue and using a needle long enough to insert through the fatty tissue at the base of the skinfold is effective. The skin being pinched should include only subcutaneous tissue. Thin patients may have insufficient tissue for injections; the upper abdomen is the best injection site for patients with little peripheral subcutaneous tissue.

Using the no-pinch method reduces bilateral exposures to nurses. With this technique, the skin remains flat, and a shorter needle is inserted at a 90-degree angle.^1,4

A bilateral exposure occurs when the nurse pinches up the patient’s skin before injection and accidentally inserts the needle through the patient’s skin and into the finger. The second part of the exposure occurs when the needle must be withdrawn from the nurse’s finger and back through the patient’s skin and out. The patient has been exposed to the nurse’s blood and the nurse has been exposed to the patient’s blood (Figure 3).

To ensure that a subcutaneous medication reaches subcutaneous tissue, these rules should be used to determine the angle of injection:

• For patients with significant fatty tissue, the needle should be inserted at a 90-degree angle across pinched skin.⁶
• For patients with minimal fatty tissue, the needle should be inserted at a 45-degree angle across the pinched skin.^1,4
• For average-size patients, the needle should be inserted at a 90-degree angle across the pinched skin.⁵ When using the no-pinch method, the skin remains flat, and a ½- to ⅝-inch needle is injected at a 90-degree angle.⁵

An injection pen allows the patient to self-administer medications (e.g., insulin) subcutaneously. This offers a convenient delivery method using prefilled, disposable cartridges. The patient inserts the needle and injects a predetermined medication dose. Teaching is essential to ensure that the patient uses the correct injection technique and delivers the correct dose of medication.

Insulin pen use is increasing. These medication administration devices have been associated with increased patient compliance and decreased hypoglycemia when compared to the vial and syringe method. Furthermore, insulin pens have been shown to increase patients’ satisfaction levels and improve safety without increasing cost. Insulin pens contain a cartridge filled with medication and sometimes a removable needle tip (Figure 4). The needle is changed after each dose. Injection supplies and devices should never be used for more than one person. Some pens have a spring-loaded needle within the pen that automatically retracts after the medication has been injected (Figure 5).

A jet injection system may be used for the administration of subcutaneous medication (Figure 6). Jet injection is a needleless system that injects fluid through the skin. A subcutaneous device is available that allows medication to be delivered into a cannula placed into the tissue (Figure 7). The cannula remains in the subcutaneous tissue for several days.

Special Considerations for Insulin Administration

Injection site rotation has changed because newer human insulins carry a lower risk for hypertrophy. The patient chooses one anatomic area (e.g., abdomen) and systematically rotates sites within that region to maintain consistent insulin absorption from day to day. Insulin absorption occurs most quickly in the abdomen, followed by the arms, thighs, and buttocks.

Pain during insulin injections may be decreased by allowing alcohol skin preparation to dry before injecting insulin, relaxing muscles around the injection site, injecting room temperature insulin, and inserting the needle quickly. Needle length may also affect pain during insulin injections. Patients with diabetes experience significantly less pain when a shorter, straight insulin needle is used, rather than a long, tapered needle.

Insulin administration should be coordinated around mealtimes to ensure timely blood glucose monitoring and the prevention of hyperglycemia and hypoglycemia.

Special Considerations for Heparin Administration

Patients receiving heparin are at risk for bleeding, including bleeding gums, hematemesis, hematuria, and melena. Results from coagulation blood tests (e.g., activated partial thromboplastin time) allow the nurse to monitor the desired therapeutic range for heparin therapy.

Before administering heparin, the nurse should assess for preexisting conditions that contraindicate the use of heparin, as well as for conditions in which increased risk for hemorrhage are present. The patient’s current medication regimen, including use of over-the-counter and herbal medications (e.g., garlic, ginger, ginkgo, horse chestnut, feverfew) and possible prescription medication (e.g., aspirin, nonsteroidal antiinflammatory drugs, cephalosporins, antithyroid agents, probenecid, and thrombolytics) should also be assessed for possible interactions with heparin.

When heparin is administered subcutaneously, it should be injected at a 90-degree angle and administered over a 30-second period.⁵

To minimize the pain and bruising associated with low-molecular-weight heparin (LMWH), the medication is given subcutaneously on the right or left side of the abdomen, at least 5 cm (2 inches) away from the umbilicus.^4,5 LMWH requires no dietary monitoring, and it has fewer hemorrhagic complications than natural (or unfractionated) heparin.

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

SUPPLIES

See Supplies tab at the top of the page.

EDUCATION

• Give developmentally and culturally appropriate education based on the desire for knowledge, readiness to learn, preferred learning style, and overall neurologic and psychosocial state.
• Instruct the patient to wear a medical identification bracelet, indicating important medical information, including bleeding tendencies, illnesses (e.g., diabetes), and allergies.
• Teach the patient the techniques for self-administration. Begin this teaching as early as possible and teach injection techniques to the caregivers as well.
• Explain to the patient, family, and caregivers the purpose of the medication, why this route is preferred, and why site rotation is important.
• Give the patient written information on the medication the patient should be taking.³
• Give the patient, family, and caregivers the brand and generic names of all prescribed medications.
• Teach the patient regarding the potential side effects and adverse reactions to the medication.
• For vaccinations, provide the corresponding vaccination information sheets (VIS).
• Teach the patient, family, and caregivers that sharing medications with other people is dangerous.
• Explain to the patient, family, and caregivers that medications should be taken as prescribed until the practitioner directs otherwise.
• Explain to the patient, family, and caregivers the importance of managing medication information to identify and resolve discrepancies.³
• Teach the patient, family, and caregivers to keep all medications out of the reach of children, cognitively impaired adults, and pets.
• Allow the patient to discuss any unresolved concerns about the medication.
• Encourage questions and answer them as they arise.

PROCEDURE

1. Clean hands and don appropriate personal protective equipment (PPE) based on the risk of exposure to bodily fluids or infection precautions.
2. Determine if the patient has health literacy needs or requires tools or assistance to effectively communicate. Be sure these needs can be met without compromising safety.
3. Review the patient’s previous experience and knowledge of subcutaneous injection and understanding of the care to be provided.
4. Verify the practitioner’s order and assess the patient for pain.
5. Get, update, and compare information about the medications the patient is currently taking with those ordered to identify and resolve discrepancies.³
6. Assess the patient’s health and medication history.
7. Determine if the patient has specific contraindications to receiving the medication and notify the practitioner as needed.
8. Assess the patient for drug, food, component, and latex allergies.

   Some syringe plungers and rubber stoppers on vials contain latex; read the package insert to determine if the equipment contains latex.

9. If a decision is made to proceed with administration despite allergies, follow the organization’s practice for administering a first dose of medication. The dose may need to be given in a controlled environment, and an order may need to be obtained for an anaphylaxis kit and the kit obtained before administration.
10. Assess for factors such as circulatory shock or reduced local tissue perfusion.
11. Assess the patient’s symptoms before initiating medication therapy.
12. Assess the patient for adequate adipose tissue.
13. Assess the patient’s knowledge regarding the medication to be received.
14. Weigh the patient in kilograms.² Do not use stated, estimated, or last documented weight.²
15. Get the medication, check against the practitioner’s order, verify the expiration date, and check that the medication and container are clean and intact.
16. Check the rights of medication safety.
17. Inform the patient that the injection may cause a slight burning or stinging. Answer any questions.
18. Prepare an area in a clean, convenient location and assemble the necessary supplies.
19. Assist the patient into a comfortable position. Instruct the patient to relax the arm, leg, or abdomen, depending on site selection.

    Rationale: Relaxing the skin and muscles at the site helps minimize discomfort.

20. Select an appropriate site for injection based on subcutaneous tissue mass, medication volume, and desired absorption rate. Inspect the skin surface over sites for bruises, inflammation, and edema.
    1. When administering heparin, use abdominal injection sites.

       Rationale: Anticoagulant causes local bleeding and bruising when injected into areas such as arms and legs.

    2. When administering LMWH, choose a site on the right or left side of the abdomen at least 5 cm (2 inches) away from the umbilicus.^4,5

       Rationale: Injecting LMWH on the side of the abdomen helps decrease pain and bruising at the injection site.

    3. When administering insulin, systematically rotate the injection site within the same anatomic area (e.g., abdomen) (Box 1).

       Rationale: Rotating insulin sites within the same anatomic area helps maintain consistency in insulin absorption from day to day because different anatomic areas provide different absorption rates.⁴

21. Palpate for masses or tenderness.
22. Prepare the skin by swabbing the injection site with a clean, single-use swab, starting at the center and moving in a circular motion outward (Figure 8). Allow the skin to dry completely.
23. Make sure that the needle is the correct size.
    1. Pinch method: Grasp the skinfold at site with thumb and forefinger. Measure the fold from top to bottom and ensure that the needle is half the length of the fold.

       Rationale: Subcutaneous injections can be given into the muscle inadvertently, especially in the abdomen and thigh sites. Appropriate needle size and angle of insertion helps ensure that medication is injected into the subcutaneous tissue without harm to underlying muscle mass, nerves, or bone.⁶

    2. No-pinch method: Use a ½- to ⅝-inch needle.⁵
24. Hold gauze between the third and fourth fingers of the nondominant hand.

    Rationale: Holding the gauze in this manner keeps it readily accessible when withdrawing the needle.

25. Remove the needle cap from the needle by pulling it straight off.

    Rationale: Preventing the needle from touching the sides of the cap prevents contamination.

26. Hold the syringe between the thumb and forefinger of the dominant hand like a dart (Figure 9).
27. Locate the injection site using anatomic landmarks.

    Rationale: Injection into the correct anatomic site prevents injury to nerves, bone, and blood vessels.

28. Insert the needle quickly, and inject the medication slowly using one of these methods:

    Rationale: A quick, smooth injection requires proper manipulation of syringe parts.

    1. Pinch method: Ensure that the area is clearly illuminated to prevent a bilateral exposure.
       1. For an average-size patient, pinch the skin with the nondominant hand using the thumb and index finger. Insert the needle quickly and firmly at a 90-degree angle.⁵ Release the skin. Option: When using an injection pen or giving heparin, continue to pinch the skin while injecting the medication.

          Rationale: Pinching the skin elevates subcutaneous tissue and desensitizes the area. Quick, firm insertion minimizes discomfort. Inserting at the correct angle prevents accidental injection into muscle.

       2. For a patient with obesity or one with significant fatty tissue, pinch the skin at the site and insert the needle at a 90-degree angle below the tissue fold.⁵

          Rationale: Patients who are obese have a fatty layer of tissue above the subcutaneous layer.

       3. For a thin patient or a patient lacking subcutaneous tissue, use extra caution because manually elevating (pinching) the injection site can increase the likelihood of bilateral exposure injuries. Consider using the upper abdomen; it may be the most appropriate site for thin patients.
       4. After the needle enters the site, grasp the lower end of the syringe barrel with the nondominant hand to stabilize it. Move the dominant hand to the end of the plunger and slowly inject the medication. Avoid moving the syringe. Option: While continuing to pinch the skin, use the dominant hand to inject the medicine and release the skin after injection.

          Rationale: Syringe movement may displace the needle and cause discomfort. Injecting the medication slowly minimizes discomfort.

    2. No-pinch method: Insert the needle quickly and firmly at a 90-degree angle.⁵ Use the dominant hand to inject the medication and release the skin after injection.
29. Keep the needle in the skin after injection for 5 seconds to prevent the medication from leaking out.^1,4 When using an insulin pen, keep the pen against the skin after injection for 10 seconds to prevent the medication from leaking out.^1,4
30. Withdraw the needle quickly and smoothly, and gently place gauze over the site.

    Rationale: Supporting tissues around the injection site helps minimize discomfort during needle withdrawal. Dry gauze may minimize discomfort associated with alcohol on nonintact skin.

31. Apply gentle pressure to the site. If administering heparin, hold the gauze in place until clotting occurs.

    Do not massage the site.

    Rationale: Applying gentle pressure aids absorption. Massaging may damage underlying tissue.

32. Discard the uncapped needle or needle enclosed in a safety shield (Figure 10) and the attached syringe into a sharps receptacle or other approved container.
33. Assess the injection site for complications and apply an adhesive bandage if needed.
34. Assist the patient into a comfortable position.
35. Watch the patient for adverse and allergic reactions to the medication. If a reaction occurs, follow the organization’s practice for emergency response.
36. Report any adverse reactions to the medication to the patient’s practitioner and document them in the patient’s record.

EXPECTED OUTCOMES

• Patient, family, and caregivers verbalize understanding of technique for subcutaneous injections.
• Patient, family, and caregivers can teach back instructions for correct technique for subcutaneous injections.
• Skin surrounding injection site remains intact.
• Medication is administered per the rights of medication safety.
• No adverse reactions are noted.

UNEXPECTED OUTCOMES

• Medication is not administered per the rights of medication safety.
• Localized pain, bruising, bleeding, numbness, tingling, or burning occurs at injection site.
• Patient experiences an adverse reaction of the medication.
• Patient experiences anaphylaxis (difficulty breathing, sensation of lump in the throat, wheezing, pale or flushed skin, hives, itching, swelling of tongue, nausea, vomiting or diarrhea, rapid pulse, dizziness, or fainting).
• Patient experiences a delayed hypersensitivity reaction.
• Patient’s skin develops hypertrophy from repeated injections.
• Infection occurs.
• Medication is administered intradermally or intramuscularly.

DOCUMENTATION

• Comfort assessment and any interventions provided
• Medication, dose, route, site, time, and date given
• Manufacturer, lot number, expiration date, date VIS published, date VIS given to patient
• Patient, family, and caregivers teaching
• Patient’s response to medication, including any adverse reactions
• Patient’s weight in kilograms
• Treatment related to side effects or adverse reactions
• Unexpected outcomes and related interventions
• Assessment of pain, treatment if necessary, and reassessment
• Patient’s progress toward goals
• Complete list of patient’s current medications and those recently discontinued

OLDER ADULT CONSIDERATIONS

• Older adults have less elastic skin and reduced subcutaneous skinfold thickness. For the thin, older adult who has little subcutaneous tissue, use the upper abdominal site.

REFERENCES

1. Association of Diabetes Care & Education Specialists (ADCES). (2020). Insulin injection know-how: Pro tips (and tricks) for easier and better insulin injections. Retrieved August 13, 2024, from https://www.diabeteseducator.org/docs/default-source/legacy-docs/_resources/pdf/general/Insulin_Injection_How_To_AADE.pdf
2. Institute for Safe Medication Practices (ISMP). (2024). 2024-2025 Targeted medication safety best practices for hospitals. Retrieved August 13, 2024, from https://www.ismp.org/guidelines/best-practices-hospitals
3. Joint Commission, The. (2024). National Patient Safety Goals for the home care program. Retrieved August 13, 2024, from https://www.jointcommission.org/-/media/tjc/documents/standards/national-patient-safety-goals/2024/npsg_chapter_ome_jan2024.pdf
4. Lilley, L.L., Rainforth Collins, S., Snyder, J.S. (2023). Chapter 32: Antidiabetic drugs. In Pharmacology and the nursing process (10th ed., pp. 492-517). St. Louis: Elsevier.
5. Reed, A.E. (2025). Chapter 22: Parenteral medications. In A.G. Perry and others (Eds.), Clinical nursing skills & techniques (11th ed., pp. 659-716). St. Louis: Elsevier.
6. Wolicki, J., Miller, E. (2021). Chapter 6: Vaccine administration. In E. Hall and others (Eds.), Epidemiology and prevention of vaccine-preventable diseases (14th ed., pp. 69-96). Centers for Disease Control and Prevention (CDC). Washington, DC: Public Health Foundation. Retrieved August 13, 2024, from https://www.cdc.gov/pinkbook/hcp/table-of-contents/chapter-6-vaccine-administration.html?CDC_AAref_Val=https://www.cdc.gov/vaccines/pubs/pinkbook/vac-admin.html

Clinical Review: Justin J. Milici, MSN, RN, CEN, CPEN, CPN, TCRN, CCRN, FAEN

Published: September 2024