In today’s world, several forms of administering drug routes are readily available. Injections are just one example of the preferred methods of drug administration due to its accessibility and easy administration.

With the advancements in modern day mediation, drug administration can be done in a number of different routes including intramuscularly and subcutaneously.

Today we’ll be exploring these routes and weighing the pros and cons of both and the types of medication that are suitable with these routes1.

Why is intramuscular injections a good option?Intramuscular injections is a drug administration route that goes deeply into the muscle. This benefits patients as the medication is absorbed quickly into the bloodstream as there are more blood vessels inside the muscle allowing rapid effect and longer action to occur, in comparison to other routes1.

Because of the easy accessible nature of intramuscular injections, anyone can administer injections. There is no need for other medical devices or professionals to find the appropriate injection location. Therefore a decreased dependency on health professionals can be met as well as an increased responsibility to administer a patient’s own drugs.

Why is subcutaneous injections another good option?Subcutaneous injections uses a shorter needle to administer medication into the tissue between muscle and skin. This is beneficial for drugs like insulin with small dosages to be administered easily and quickly2. This has allowed insulin-dependent patients like Type 1 diabetics to inject themselves with insulin, making it more convenient for the patient.

As this route of administration aims for the drug to be injected into the layer in between the tissue and skin, they are rarely painful as this layer has little nerve. Making it a suitable option for patients not wanting to feel any pain.

What are the downside for both types of drug administration?The downside for intramuscular injections is that for multiple-dosage patients, the injections sites will have to constantly change due to the long needle used. If the same injection site is constantly used, short and long time symptoms can occur3.

The downside for subcutaneous injections is because of the fewer blood vessels inside subcutaneous tissue allowing a slower rate of absorption to occur in comparison to intramuscular injection that have high rates of absorption2.

The downside for both types is the use of the needle itself may scare patients away

from getting medication either from phobias or the side effects that could occur e.g. discomfort, swelling and bleeding.

Example 1 – EpinephrineEpinephrine also known as adrenaline, can be described as both a medication and hormone. Epinephrine can be administered in the form of an autoinjector (known as EpiPen®) that are intramuscularly administered into the thigh muscle by anyone who knows how to administer the medication.

Used as the first-response medication for anaphylaxis, it is the most preferred method of administering epinephrine due to its fast action allowing quick onset and reaction to occur4. Through delivering a set amount into a spring-loaded needle, this allows a patient’s fight-or-flight response5 to be stressed quickly therefore decreasing anaphylaxis symptoms.

Example 2 – Benzathine benzylpencillinBenzathine benzylpencillin, a long-acting antibiotic that assists in treating bacterial infections and can be intramuscularly administered through the buttock or upper thigh by a health care professional.

Used by patients with rheumatic fever or pharyngitis, it works through slowly stopping the growth of infection-causing bacteria, therefore stabilising the body. Also by having a slow onset, the single dose can last up to 7 days when absorbed into the blood stream.

Belonging to the penicillin group, benzathine benzylpencillin is on the World Health Organisation’s ‘Model List of Essential Medicines’6 henceforth showing

the safeness and efficiency of this medication.

•

•

4 H2O