Patient education: How to give an intramuscular injection (The Basics)

What is an intramuscular injection? — An intramuscular injection ("IM injection") is a way to give medicine into a muscle. "Injection" is another word for shot. An IM injection uses a longer needle than other types of shots.

Some medicines given by IM injection are absorbed very quickly. Others are released slowly into the body. Some medicines are affected by digestive juices and can only be given into a muscle, rather than taken by mouth. Other medicines are given into a muscle when you cannot take them by mouth, for example, if you have trouble swallowing.

Where do I give an IM injection? — It is easiest to give an IM injection into the muscles of the upper leg. But you can also use the muscles in your upper arm or buttock. There are 2 places in your thigh where you can give an IM injection: the front, or the side.

To give an injection into the thigh, start by finding the correct location. You want to give the shot about halfway between your groin and your knee. You can use the middle or outer thigh (figure 1).

If you need to give yourself a shot regularly, change where you give it each time. Giving shots in the same spot can cause skin changes in that area. Try to avoid areas that are close to sores, moles, or scars.

How do I give an IM injection? — Start by getting your supplies together:

●Wash and dry your hands.

●Gather the medicine, syringe, and alcohol wipes. Make sure that you are using the correct syringe and needle size for your medicine and body type. A needle that is too short can cause you to inject the medicine into the tissue right under the skin instead of into the muscle. If you are not sure what size syringe and needle you need, ask your doctor, nurse, or pharmacist.

●Check your medicine regularly to make sure that the expiration date has not passed. If your medicine has expired, call your doctor, nurse, or pharmacy to get a refill.

●If your medicine needs to be mixed, gently roll the bottle (vial) back and forth between your hands 10 times.

●Clean the rubber stopper at the top of the bottle with an alcohol pad, and let it dry.

Get the syringe ready:

●If you are using a prefilled syringe, you do not need to do anything to get it ready. If you see an air bubble in a prefilled syringe, this is OK. It helps to make sure that you get all of the medicine when you give the shot.

●If you need to fill the syringe (figure 2):

•Remove the cap from the needle.

•Pull the plunger back until the tip is at the line showing the dose of medicine you need.

•Push the needle into the rubber stopper. Then, push the plunger so that the air goes into the bottle.

•Turn the bottle with the syringe in it upside down, and hold the bottle with 1 hand. Do not let the needle bend. Make sure that the tip of the needle is in the fluid. Pull back slowly on the plunger with your other hand to let medicine into the syringe. Do this until the medicine reaches the line for the dose you need.

•Look at the medicine in the syringe. If you see any air bubbles, push the medicine back into the bottle and repeat the above step to fill the syringe. Repeat this until you do not see any air bubbles in the syringe. You can also tap on the syringe to move the air bubbles and push them back into the bottle.

•Look at the color and appearance of the medicine in the syringe. Some medicines are clear and colorless. Others are cloudy. Be sure that you know if your medicine should be clear or cloudy.

•If you see any clumps or particles, do not use the medicine.

•Check again to make sure that you have the right dose.

•Pull the needle out of the rubber stopper. Your doctor or nurse will let you know if you need to change needles before giving the shot.

•If you are not giving the shot right away, cover the needle before putting it down. Be careful not to poke yourself with the needle.

•Put your medicine away. Ask your doctor or pharmacist where you should store your medicine.

Give the shot (figure 3):

●Wash and dry your hands.

●Decide where to give the shot – Do not give the shot in the same place twice in a row. For example, if you gave your last shot in your left thigh, give the next one in your right thigh.

●If you usually have pain when giving the shot, you can hold an ice cube to your skin for a few minutes. Or your doctor might give you numbing cream to use on the area.

●Clean the skin with an alcohol wipe where you plan to give the shot. Let the skin dry fully. The alcohol helps prevent infections.

●Relax your muscles where you will give the shot. Gently stretch the skin where you will give the shot between your thumb and first finger to make it tight.

●Hold the syringe in your other hand, like you would a pencil, at a 90° angle. Quickly push the needle all of the way into the skin. Slowly press the plunger all of the way down. Wait about 10 seconds before removing the needle. This lets the medicine begin to absorb into the muscle. Children and people with less fatty tissue might need to use a shorter needle.

●Use a piece of gauze and press gently on the injection site for about 5 seconds. If you see blood or clear fluid, press the area for another few seconds. Do not rub.

●Throw the used needle and syringe away in a special container made of thick plastic. Do not throw needles away in the regular trash.

●Wash and dry your hands.

What else should I know? — You might have some bleeding, soreness, mild bruising, or redness where you gave yourself the shot. This is normal. But call your doctor if you have a lot of pain or other symptoms that worry you, or if you have trouble giving yourself the shot.

Some people find it difficult to give themselves a shot. If possible, ask a person that you trust to learn how to give you the shot so they can help you.

It is helpful to keep track of the where you gave a shot and what date and time. You can do this using a notebook or your smartphone.

When should I call the doctor? — Call for an ambulance right away (in the US and Canada, call 9-1-1) if you have any signs of an allergic reaction. These include:

●Hives or swelling of the face, eyes, or other parts of the body

●Trouble breathing or feeling like your throat is closing

●Vomiting or diarrhea

●Feeling dizzy or passing out

Call your doctor or nurse for advice if:

●You have redness, warmth, itching, or swelling that lasts more than a few hours, or drainage from where the needle went into your skin.

●You are having side effects from your medicine.

●You do not know how much medicine to give yourself.

●You are not able to afford your medicines or supplies.

More on this topic

Patient education: How to give a subcutaneous injection (The Basics)
Patient education: How to dispose of needles and other sharps (The Basics)