Have you ever wondered where your medicine goes after you swallow it?
We swallow it, drink some water, and just hope it works and we get better as soon as possible, right?
However, more than that, once this tiny pill goes down, an incredible journey begins inside our bodies. As a pharmacist, when I learned about this process, I found it to be a fascinating and surprisingly overlooked one. I’ve seen many people rely on medicines, so now I want to take you on a journey through the body. Additionally, the path is known as pharmacokinetics and pharmacodynamics.
What are those? In brief, pharmacokinetics describes how your body reacts to the medicine, while pharmacodynamics describes how the medicine affects your body.
Let’s explore this process together, and we’ll delve into the details of what happens after you take a pill, step by step.
- Swallows go to the stomach.
When we take a pill, it travels down the throat into the stomach, where the drug begins to dissolve. Some medicines are designed to act fast, others to release slowly, or in a specific part of our gut. If it’s coated or in a capsule, it might need a bit of time to break open. Certain pills respond better with food, after a meal, or on an empty stomach. Please remember that this is not just a random rule; it depends on the specific medicine or type of pill, as it affects how and where the body absorbs the drug most effectively.
Pharmacokinetics begins here, with how your body handles the medicine. Dissolving and absorbing are part of this process.
Pharmacokinetics (PK) is defined as the study of the kinetics of the absorption, distribution, metabolism, and excretion (ADME) of drugs. So, it describes the path the drug takes inside our bodies from the moment we take it until it’s eliminated.
Absorption is the process by which the drug enters the bloodstream, distribution is the mechanism by which it spreads to different parts of the body, metabolism is the process by which the liver processes or transforms the drug, and elimination is the process by which the body eliminates it.
- Absorption in the intestine
After the drug has dissolved, the real work begins. The active ingredient is absorbed into our bloodstream, mostly through the small intestine. Let’s imagine our gut acts like a sponge, soaking up the drug so it can start circulating through our body.
This is the reason we, as pharmacists, care about timing, food, and even other drugs you might be taking. All we do is make sure you take the right amount of medicine that gets into your system.
- Distribution – The drug travels through the bloodstream
Once in the blood, the drug goes wherever it is needed. It travels to the target area, such as the brain, lungs, bladder, joints, or other specific organs. Not every drug can go anywhere; every drug has its specific target. Some medicines can cross the blood-brain barrier (BBB) while others can’t. This represents a few of the reasons why drug design is so exciting.
- Metabolism – the liver gets involved.
Before the drug exits our bodies, it must be processed. That‘s our liver’s job. The liver is the body’s processing center. It breaks down the medicine (metabolizes it) using special enzymes into forms our bodies can safely get rid of.
Some drugs become active after liver processing, while others become less effective. That’s why liver health is important; that’s also the reason medicines shouldn’t be mixed with alcohol or certain herbal remedies that affect liver enzymes.
- Elimination – time to say goodbye
After doing its fascinating job, the drug exits our bodies mostly through urine (via the kidneys) or stool (via bile). It’s our bodies’ way of cleaning up. Pharmacists often ask you to drink plenty of water when you’re on medication, because staying hydrated helps the body clear things up efficiently.
Then… what about how the drug works?
In the beginning, I’ve already mentioned what the drug does to your body, so here’s where pharmacodynamics comes in. Pharmacodynamics refers to how a drug interacts with our body to create an effect – the good (therapeutic) and the not-so-good (side effects).
Pharmacodynamics helps answer questions such as: How does my headache go away after taking a headache pill? Why do blood pressure medicines drop my blood pressure?
It shows things like how strongly the drug binds to its target (like a lock and key), what happens after it binds, and how intense or long-lasting the effect is. So, pharmacodynamics helps us understand how a drug works, how strong its effects are, and how long they last.
Why does knowing this matter?
Knowing how our body handles a drug (pharmacokinetics) and how the drug affects our body (pharmacodynamics) isn’t just for pharmacists. Still, it helps all of us become smarter and safer about how to take medications.
It helps you to understand how many times a day to take the drug and the food instructions. Not everyone responds to the same medicine in the same way, and sometimes healthcare professionals adjust safe doses for children, older adults, or people with liver or kidney problems. Even something we advise, such as drinking more water or whether to crush a certain pill, can influence how a medicine works in your body.
Final thoughts
So, next time you take a pill, please remember it’s not just putting it in your mouth and swallowing it, but more than that. Your body functions in the background, much like a well-organized pharmacy lab from absorbing, transporting, breaking down, and eliminating the pills, and using the medicine in amazing ways.
If you ever feel unsure, curious about when or how to take your pills, do not hesitate to ask your pharmacist; that’s what we’re here for. Here, you can drop a comment or share this post with someone curious, too. I’d love to hear from them.
Take your meds wisely. Thanks for reading.