The Unwanted Side Effects Of Medication

Why do different medications have so many undesirable side effects?

Dr Joel Yong, PhD
Feb 10 · 4 min read
Photo by Sharon McCutcheon on Unsplash

odern medicine has a whole array of drugs at its disposal to quell various symptoms that one’s body is experiencing as a result of a cascade of biochemical signals gone wrong.

Let’s look at the manufacturing assembly process in the making of a car. A car has many different parts — but let’s assume, in a simplified scenario, that only the doors and the wheels have to be fitted onto the car, and one team handles the fitting of the doors, while another team handles the fitting of the wheels sequentially after the doors have been put on.

When the door fitting team is running behind schedule, the wheel fitting team cannot finish as many cars as they would like to — the door fitting team is holding them up.

The door fitting team’s problem has now become the wheel fitting team’s problem in this sequential cascade.

But what we do see at the end of the production line is the symptom that the wheel fitting team ain’t doing the job effectively enough. Sure, they can be sent for extra training and productivity courses… but ultimately, the problem will remain if the door fitting team does not pull its weight.

In our body…

The cascade problem also exists. Our body contains multiple cell lines — one cell synthesises a biochemical based on its active DNA structure that signals another cell to sequentially synthesise another protein.

The next cell then synthesises a protein that signals yet another cell, which creates the cascade effect.

The problem, then, lies when one cell isn’t synthesising sufficient biochemicals to signal the next cell. Or if it is synthesising too much of the necessary biochemical.

If we were to look at each signal as a lock and key mechanism, where a unique signal binds on to a specific cell receptor to signal that cell to do something, then too little of that signal may cause the cell to not respond sufficiently, while too much of that signal may cause an overreactivity.

Because the question then lies, with regards to our health:

Which cell line isn’t pulling its weight in the entire biochemical signalling cascade?

The methodology of modern medicine

Modern medicine looks at the various different symptoms of a disease and looks at developing drugs or chemical analogues that can stimulate an underreactive cell receptor or calm down an overreactive receptor.

In Unlocking The Lock And Key Mechanism That Governs Our Body’s Cellular Functions, I touch on the use of antihistamine drugs to block histamine molecules (which our body’s cells synthesise) by binding preferentially onto the histamine receptors but not allowing them to unlock their function of secreting mucus.

Unfortunately, these antihistamines can end up binding to other different receptors and causing them to signal other cells to behave differently, which then results in the symptoms of other side effects occurring.

We can look at the structures of different chemicals and receptors to understand how a chemical can bind to a receptor.

Can one key unlock different locks? It’s highly possible, isn’t it? Especially if the shapes of the locks are different?

The ability of the key to fit may be questionable, but what if it fits just enough to trigger a response from a cell?

And that’s the problem with different medications

They can be designed to block or stimulate a specific symptom.

However, while they may be great for their intended use…

There’s always the question of “where else will they affect”?

Antihistamines, for example, will interfere with the activity of histamine — that we do know. Some of them are also able to interfere the activity of acetylcholine in the brain, which can result in tangible side effects, including those of:

sedation, drowsiness, fatigue and impaired concentration and memory causing detrimental effects on learning.

And there we have it.

Different medications were designed with specific purposes in mind and specific symptoms to block.

However, they are able to cause undesirable side effects elsewhere because they may have parallel abilities in unlocking or blocking other receptors, which then results in the development of those side effects.

That’s also why hydroxychloroquine, which was designed to counteract the effects of malaria, was also being investigated if it could be repurposed into a drug that could aid in halting the replication of the COVID-19 coronavirus!

Ideally, a drug would just be used for a singular purpose.

However, the human body is extremely complex. There are so many different types of cells and cell receptors in the body, and a drug may inadvertently unlock or block another receptor to cause the side effect to appear!

The complexity of the different cells in our body and how they function just cannot allow for a simplistic, linear understanding of what effects a drug can have on different cell functions in our body. There is much more than that to be analysed.

Joel Yong, PhD, is a biochemical engineer/scientist, an educator and a writer. He has authored 5 ebooks (available on in Kindle format) and co-authored 6 journal articles in internationally peer-reviewed scientific journals. His main focus is on finding out the fundamentals of biochemical mechanisms in the body that the doctors don’t educate the lay people about, and will then proceed to deconstruct them for your understanding — as an educator should.

Do feel free to subscribe to my mailing list for more exclusive content!

You may also want to visit Digging Deeper Into Doctoral Diagnoses to check out relevant questions or answers to questions that have eluded you for quite a fair bit.

Medical Myths and Models

Insights to help you live a healthier life

Dr Joel Yong, PhD

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Deconstructing the interconnectedness between health and business. Join my mailing list at

Medical Myths and Models

Probing medical paradigms to improve our understanding of health and disease

Dr Joel Yong, PhD

Written by

Deconstructing the interconnectedness between health and business. Join my mailing list at

Medical Myths and Models

Probing medical paradigms to improve our understanding of health and disease

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