Hesperian Health Guides
How to Give an Injection
Every day 20,000 people visit the HealthWiki for lifesaving health information. A gift of just $5 helps make this possible!
Make a gift to support this essential health information people depend on.
Injections are not needed often. Many medicines sometimes given by injection are safer when given by mouth. But it can be necessary to give an injection:
- when the medicine does not come in a form that can be given by mouth.
- when the person cannot swallow or keep medicine down without vomiting.
- in some emergencies, such as bleeding or infections after childbirth or abortion.
It is important to give injections properly. They can be dangerous when given in the wrong place, in the wrong way, or without properly cleaning the syringe, hands, and injection site. Carefully follow all of the instructions on ‘How to inject’.
- 1 Preventing infection
- 2 Where to give an injection
- 3 How to prepare a syringe for injection
- 4 How to inject into the muscle (intramuscular, or IM)
- 5 How to give an injection under the skin (subcutaneous injection)
- 6 Be prepared to treat allergic reaction and allergic shock
Needles and syringes that are not cleaned and disinfected properly can pass a disease like HIV or liver disease (hepatitis) to another person. They can also cause a serious infection at the injection site or in the blood.
- Never use the same needle and syringe to inject more than one person without cleaning and disinfecting the needle and syringe first. Follow the steps described earlier in this chapter.
- After the needle has boiled, do not touch it with anything that has not been disinfected.
- If needles are for one-time use only, see how to dispose of them safely.
Where to give an injection
There are 2 basic kinds of injections:
- injections that go into a muscle (intramuscular or IM)
- injections that go into the fatty layer under the skin (subcutaneous).
Where you choose to inject depends on how much medicine you need to inject, the size of the person receiving the injection, and what kind of medicine you are using. For information on how to give both kinds of injections, see 'How to inject into the muscle,' and 'How to give an injection under the skin'.
Most of the medicines in this book that need to be injected should go into the muscle. IM injections can be given in a large muscle in the buttock, upper arm, or thigh. It is best to use the buttock or thigh instead of the arm if:
- the amount to inject is more than 2 ml (2 cc). (But you should never inject more than 3 ml (3 cc) in a single dose. Use 2 injections instead.)
- the medicine is likely to cause pain when injected.
- the person being given the injection is very small or poorly nourished.
How to give an injection under the skin (subcutaneous injection)
- Grab the fatty part on the underside of the upper arm. Hold the skin like this:
- Put the needle under the skin at this angle. Make sure the needle does not go into the muscle. Use the same instructions for injection under the skin of the thigh or other part of the body.
Be prepared to treat allergic reaction and allergic shock
Some medicines, especially antibiotics like penicillin and ampicillin, can produce an allergic reaction, usually within 30 minutes after an injection. An allergic reaction can progress to allergic shock, which is an emergency. To prevent allergic reaction and allergic shock, before giving an injection ask the person: “Have you ever had a reaction to this medicine—like hives, itching, swelling, or trouble breathing?” If the answer is yes, do not use that medicine in any form, or any medicine from the same family of medicines. Whenever you inject medicines, watch for signs of allergic reaction and
allergic shock and have medicines for treating them nearby.
Mild allergic reaction
- hives or rash
Give 25 mg diphenhydramine by mouth 3 times a day until the signs disappear.
Pregnant or breastfeeding women may find the discomfort of a mild allergic reaction better than the risks of taking an antihistamine.
Moderate to severe allergic reaction
- swollen mouth and tongue
- difficulty breathing
- Inject 0.5 mg of epinephrine in the muscle of the outer thigh or just under the skin. See the drawing above. Give 25 mg diphenhydramine or promethazine by mouth or by injection into a muscle. Repeat in 8 hours or less if the signs do not get better.
- Watch the person for at least 4 hours to make sure the reaction does not progress to allergic shock.
- itching or hives
- swollen mouth and tongue
- weak, rapid pulse or heartbeat (more than 100 beats per minute for an adult)
- sudden paleness or cool, moist skin (cold sweats)
- difficulty breathing
- loss of consciousness
- Inject 0.5 mg of epinephrine immediately under the skin. See the drawing above. Give a second injection in 20 minutes if the signs do not get better. Inject 50 mg diphenhydramine or promethazine into muscle. Repeat in 8 hours or less if the signs do not get better.
- Inject 500 mg hydrocor tisone (cor tisol) into muscle and repeat in 4 hours if needed. Or inject 20 mg dexamethasone into muscle and repeat in 6 hours if needed.
- Watch the person for 8 to 12 hours to make sure the signs do not come back. Leave her with steroid medicines to take by mouth if her signs return. She should take 500 to 1000 mg of hydrocortisone and repeat after 4 hours if needed. Or she can take 20 mg of dexamethasone and repeat after 6 hours if needed.