What are the step‑by‑step instructions for safely administering the prescribed injection to the patient?

Subcutaneous Injection Patient Teaching

For subcutaneous injections, use a 4-mm needle inserted at 90 degrees into clean skin at least 2 inches away from the umbilicus, rotating sites systematically by at least 1 cm between injections, and count to 10 after depressing the plunger before withdrawing the needle. 1, 2

Pre-Injection Preparation

Hand Hygiene and Site Inspection

• Wash hands thoroughly before handling injection equipment 1
• Inspect the injection site visually for any abnormalities before proceeding 1, 2
• Never inject into areas with lumps (lipohypertrophy), redness, swelling, infection, bruising, scars, or wounds 1, 2

Medication Preparation

• Remove medication from refrigerator 30-60 minutes before injection to allow it to reach room temperature, which reduces pain 1, 3
• For cloudy insulins (NPH or premixed), roll the pen horizontally between palms 10 times, then tip up and down 10 times until all crystals dissolve—avoid vigorous shaking 2
• Check the medication label and expiration date to prevent errors 1, 2

Needle Selection

• Use 4-mm pen needles for all adults and children regardless of body size 1, 2
• Use a new, sterile needle for every injection—never reuse needles 1, 2

Site Selection and Rotation

Approved Injection Sites

• Abdomen (preferred): Inject at least 2 adult fingerbreadths (approximately 2 inches or 5 cm) away from the umbilicus in all directions, staying above the pubic bone and below the lowest rib 4, 2, 3
• Thighs: Use the upper third anterior-lateral aspect of both thighs 2, 3
• Buttocks: Use the posterior-lateral upper buttocks and flanks 2, 3
• Upper arms: Use the middle third posterior aspect (may require assistance) 2, 3

Systematic Rotation Strategy

• Divide each injection area into quadrants or halves 2, 3
• Rotate within one quadrant before moving to another area 2
• Space each new injection at least 1 cm (one finger width) from the previous site 1, 2, 3
• Follow a consistent directional pattern (e.g., clockwise) to track rotation 2
• Critical: Failure to rotate causes lumpy tissue that prevents proper medication absorption 1, 2

Site Cleaning

• Clean hands are usually sufficient for home injections 1
• If using an alcohol swab, apply in circular motion from center outward and allow the site to dry completely before injecting 1, 2

Injection Technique

For Pen Injectors

Needle Insertion:

• Hold the pen perpendicular to the skin at a 90-degree angle 1, 2
• For very thin adults, young children (≤6 years), or pregnant individuals, gently lift a skinfold with thumb and index finger without squeezing hard enough to cause blanching 1, 2
• Rest the injection arm on a firm, well-lit surface 1

Priming the Pen:

• Prime the pen before every injection by dialing 2 units and pressing the button until at least one drop appears at the needle tip 1, 2

Delivering the Dose:

• Insert the needle through the skin in one smooth motion—not too slow or too fast 1
• Do not touch the thumb button until the needle is fully inserted 1, 2
• Press the thumb button straight down along the pen's axis, not at an angle 1
• Inject slowly and steadily 1
• After the button is fully depressed, count to 10 slowly while keeping pressure on the button and the needle in the skin 1, 2
• This ensures the complete dose is delivered 1, 2

Needle Removal:

• Withdraw the needle straight out without pressing on the area 1
• Remove and immediately discard the needle in a puncture-resistant sharps container without recapping 1, 2
• Never leave needles attached to pens between injections—this allows air contamination and medication leakage 1, 2

For Syringes

• Use a ¼ to ½-inch, 27-gauge (or finer) needle 1
• Fill the syringe with exactly the prescribed dose immediately before injection 1
• Follow the same insertion, injection, and removal steps as pen injectors 1
• Dispose immediately in a sharps container without recapping 1

Post-Injection Care

Immediate Site Care

• If a small amount of blood or fluid appears, blot lightly with gauze—do not rub 1
• Do not apply pressure or bandages to the injection site 1
• Occasional bleeding or bruising does not affect medication absorption 1

Site Monitoring

• A small raised bump (wheal) may appear and is normal 1
• Avoid touching, scratching, or applying lotions to the site for several hours 1
• You may gently wash with soap and water after 1 hour without applying pressure 1

Critical Safety Points

What to Avoid

• Never share pens, cartridges, or needles between patients—this transmits blood-borne infections even with new needles 1, 2
• Never inject into the same spot repeatedly—this creates lumpy tissue that prevents medication from working properly 1, 2, 3
• Never inject through clothing—you must see the skin directly 3
• Never reuse needles—they are no longer sterile and become damaged 1, 2

When to Seek Help

• If you experience sharp, persistent pain during injection, the needle may have touched a nerve—this is random and causes no damage, but report ongoing pain to your provider 1
• If lumps, firmness, or enlarged areas develop at injection sites, show these to your healthcare provider immediately 1, 2
• If you consistently see large bruises or blood collections (hematomas), have your technique observed 1

Documentation and Follow-Up

• Keep a log of injection sites and dates to ensure proper rotation 1
• Bring your injection device and demonstrate your technique at every clinic visit 1
• Healthcare providers should inspect all injection sites at least annually 2, 3