By Neha Kashyap 

Published on July 19, 2022

 Medically reviewed by Rochelle Collins, DO

Infusion therapy is a procedure in which medications are delivered directly into the bloodstream, usually with a needle and catheter that's inserted into a vein.

Infusion therapy is needed when a patient cannot take a drug orally. It's also a method of delivering medications in larger or more controlled amounts, such as during chemotherapy for cancer or with pain medication during childbirth.1

You can get infusion therapy in a medical setting or at home. Insulin shots are an example of home infusion therapy.2

This article explains the uses, benefits, and potential side effects of different kinds of infusion therapy.


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Types of Infusion Therapy and Their Uses

The types of infusion therapy are:

  • Intravenous (IV)

  • Epidural

  • Intramuscular

  • Subcutaneous

Intravenous (IV)

Intravenous therapy is when medications or fluids are injected directly into the bloodstream. IV therapy is commonly used for:3

  • Maintaining fluids in the body after dehydration, diarrhea, vomiting, or surgery

  • Chronic conditions, such as chemotherapy or immunotherapy for cancer

  • Antibiotic therapy

  • Administering anesthesia before surgery

  • Blood transfusions

  • Providing nutrients, like iron and B vitamins,14 when they are chronically low5


An epidural is a type of infusion therapy that is inserted around the spinal nerves in the lower back. Epidurals block pain signals from being sent from the spine to the brain. An epidural can administer the following:

  • Analgesia (pain relief)

  • Anesthesia (numbing)

  • Steroids for pain, as with acute back pain

Epidurals are best-known as a way to prevent or numb the pain of childbirth, but they can also be used to prevent pain during and after surgery. Epidurals might also help relieve acute pain.6


Intramuscular infusion therapy is when medication is inserted into muscle tissue. Uses of intramuscular infusion therapy include:7

  • Hormone therapy, such as testosterone or estrogen injections for cancer treatment

  • Antibiotics

  • Vaccines8

  • Antibodies (immunoglobulins), which are proteins made by cells to help the immune system fight bacteria, viruses, or other harmful substances9


Subcutaneous infusion therapy is when drugs are injected into fat underneath the skin. Subcutaneous injection sites include the upper arms, stomach, upper thighs, lower back and buttocks. Subcutaneous therapy includes:

  • Insulin therapy for diabetics

  • Opioids for pain relief

  • Allergy medications like epinephrine

  • Heparin, a medication used to prevent blood clots10

Benefits of Infusion Therapy

The benefits of infusion therapy include:

  • Fast-acting relief, especially in emergency situations, like after an allergic reaction or during childbirth3

  • Medication for those who cannot take pills orally

  • Administering larger and/or controlled amounts of medication

  • Intramuscular and subcutaneous injections help drugs remain in the body longer

  • High success rates for several conditions

Infusion Therapy Success Rates

Several studies have shown high success rates for infusion therapies. For example:

  • Epidurals are about 98%–99% successful in relieving pain for people giving birth.11

  • Monoclonal antibody treatments for COVID-19 reduced viral burden—the amount of virus healthcare providers can find in your body—by 90% in trial participants, and emergency room visits and infection time were cut by almost half.12 However, most of the monoclonal antibodies authorized for treating or preventing COVID-19 have been revoked due to limited effectiveness against newer variants.

  • Ketamine infusion therapy could be a fast and effective treatment for chronic depression, with about half of patients in one study responding to treatment.13

  • Some cancers respond better to chemotherapy, a type of infusion therapy that kills harmful cells, than others. For example, a recent study found prostate cancer patients were about 10% more likely to survive with chemotherapy than other cancer treatments.14 But there are other infusion therapies available to treat cancer that have fewer side effects than chemotherapy. These include hormone therapy.15 antibodies,16 vaccines,17 and immunotherapy.18

Side Effects of Infusion Therapy

Infusion therapy side effects might include:

  • Redness at the site of injection

  • Swelling

  • Injury at the injection site

  • Muscle pain

  • Allergic reactions like rash, difficulty breathing, and confusion

The following are some risks associated with each type of infusion therapy.

IV Therapy Complications

IV therapy complications may include:

  • Burning, stinging, or redness if IV solution leaks onto skin surrounding the injection site

  • Pus leaking from injection if infected

  • Pulmonary edema, or excess lung fluid: This requires quick medical attention and is marked by shortness of breath and coughing up a frothy substance.

  • Air embolism (when air enters the vein): Symptoms include shortness of breath, increased heart rate, shoulder pain, light-headedness, and confusion.3

Epidural Therapy Complications

Epidural therapy complications may include:6

  • Low blood pressure

  • Headache

  • Hot flashes

  • Damaged blood vessel

  • Damage to injection site nerves

  • Losing bladder and bowel control

Intramuscular Therapy Complications

Intramuscular therapy complications may include:19

  • Nerve damage

  • Medication leaking into surrounding tissue

  • Muscle atrophy, or when a muscle loses strength

  • Bone injury

Subcutaneous Therapy Complications

Subcutaneous therapy complications may include:

  • Blister at injection site20

  • Headache

  • Sore throat

  • Nausea

  • Kidney problems

  • Blood clots21

Who Should Not Get Infusion Therapy?

Infusion therapy isn't for everybody, including:

  • Some children under 1222

  • Some older adults23

  • In some cases, people with high blood pressure or high cholesterol

  • Those with a history of heart problems

  • People experiencing heavy bleeding, including during childbirth

  • Those who've had blood clots in the past24

  • People giving birth who are experiencing low blood pressure

Before undergoing infusion therapy, be sure to share your medical history and any concerns you have with your healthcare provider.

How to Prepare and What to Expect

To prepare for infusion therapy, you'll want to ask your practitioner about the following:

  • If you have to avoid any foods or modify your medication schedule before treatment25

  • If others are allowed to come with you to the procedure

  • If there will be pain and something to relieve that pain26

  • What will be used to treat allergic reactions if they arise

  • How many sessions are required for treatment

  • Any side effects you should monitor at home

  • How many training sessions you and your caregivers will receive for home infusion therapy

  • How to measure medications accurately for home infusion therapy

Expect the following during infusion therapy:5

  • That the injection site and needles are disinfected

  • That the injection site is covered after your treatment

  • Having a comfortable chair to sit in throughout the treatment

  • Anesthesia for some larger needles that are used during treatment

  • Being monitored throughout your therapy

  • For home fusion, that you and your caregivers receive adequate training and follow-up appointments


Infusion therapy is when a medication or nutrient is inserted directly into a person's system. Infusion therapy can be intravenous (IV), meaning through an IV needle; an epidural, which is inserted around nerves in the spinal cord; intramuscular, which is inserted in muscle tissue; or subcutaneous, inserted into body fat under the skin.