You have been coughing for days.

No fever. No catarrh. No sore throat.

You take something for the cough, but it just doesn't seem to go away.

What if the problem isn't a cold at all?

Sometimes, a blood pressure medicine can be responsible.

Let's talk about ACE inhibitors.

🩸 First, what does ACE have to do with blood pressure?

ACE stands for angiotensin-converting enzyme.

It is an enzyme in the body that helps produce a substance called angiotensin II.

Angiotensin II is one of the substances that can raise blood pressure.

It does this mainly in two ways.

• First, it causes the blood vessels to tighten. 

This is called vasoconstriction. Think of a blood vessel like a flexible tube carrying blood. When the tube becomes narrower, the pressure inside it can increase.

• Second, angiotensin II tells the adrenal glands to release a hormone called aldosterone.

Aldosterone tells the kidneys to hold on to more sodium and water. When more sodium and water are retained, the amount of fluid circulating in the blood can increase, which can also contribute to higher blood pressure.

So, in simple terms:

Angiotensin II can raise blood pressure by tightening blood vessels and encouraging the body to retain sodium and water.

💊 So where do ACE inhibitors come in?

ACE inhibitors are medicines that block the ACE enzyme.

Examples include:

• Lisinopril

• Enalapril

• Captopril

• Ramipril

• Moexipril

When ACE is blocked, less angiotensin II is produced.

As a result, the blood vessels are less strongly stimulated to tighten, so they can relax more easily.

There is also less stimulation of aldosterone, meaning the body is less encouraged to retain sodium and water.

Together, these effects help lower blood pressure.

That is one of the main reasons ACE inhibitors are used to treat hypertension.

😮‍💨 But then… where does the cough come from?

Here's the interesting part.

ACE has another job.

It also helps break down a substance called bradykinin.

Bradykinin is a substance involved in several processes in the body, including effects on blood vessels and the airways.

When an ACE inhibitor blocks ACE, ACE cannot break down bradykinin as effectively.

So bradykinin can build up.

In some people, this increased bradykinin is associated with a persistent, dry cough.

And that's why someone taking an ACE inhibitor may develop a cough that seems to have appeared out of nowhere.

🤔 So is the cough necessarily a cold?

Not always.

If someone taking an ACE inhibitor develops a persistent dry cough, the medication itself can be one possible explanation.

The important point is that not every cough in someone taking an ACE inhibitor is automatically caused by the medicine. Other causes still need to be considered.

🧠 The simple takeaway

ACE inhibitors are designed to block ACE because this helps reduce the production and effects of angiotensin II, ultimately helping to lower blood pressure.

But blocking ACE also reduces the breakdown of bradykinin.

For some people, that increased bradykinin is associated with the characteristic dry cough.

So sometimes, the medicine helping to control your blood pressure may also be behind that stubborn cough.

Pharmacology is full of connections like this. 💊

One enzyme can be involved in different processes, so blocking that enzyme can produce both the effect we want and an unwanted effect.

Taking an ACE inhibitor and experiencing a persistent cough? Don't stop your medication on your own. Speak with a qualified healthcare professional about it.

If you enjoy learning the “why” behind medicines and everyday health experiences, follow PharmaGuide for more simple pharmacology explained without the unnecessary big-big grammar. 😂💊

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