A massive amount of people drink coffee every single day, according to a survey by Statista. It is thought that at least two thirds of all Brits (63%) consider themselves regular coffee drinkers - but this seemingly innocent habit could be interfering with certian medication or even making side effects more likely.

The culprit is caffeine, a stimulant that not only gives you that much-needed energy boost but also lingers in your system for quite some time. This can cause your favourite brew to work against you if you're on antidepressants or heart medication, for example.

Caffeine primarily stimulates the central nervous system, leading to increased alertness and focus. It can also affect your cardiovascular system, potentially raising your heart rate and blood pressure, and it acts as a diuretic, increasing urination.

Naturally found in plants like coffee beans and tea leaves, caffeine can also be added to other products such as energy drinks and certain fizzy drinks. Even cocoa beans contain caffeine, though the amount varies depending on the type of chocolate that is made from these beans.

Certain medical conditions can make individuals particularly sensitive to the effects of caffeine. For example, those suffering from irritable bowel syndrome (IBS) may find that caffeine triggers symptoms such as bloating, stomach cramps or diarrhoea, reports Surrey Live.

Which medications can caffeine interfere with?

The effects of caffeine on the body extend far beyond a simple energy surge, and it could interfere with certain medications. A report by The Conversation suggests that caffeine may pose a challenge for at least five different medicines.

• Cold and flu medicines: Pseudoephedrine, a decongestant found in cold and flu remedies, is also a stimulant like caffeine. When taken together, the effects can be amplified, potentially leading to jitters or restlessness, headaches, a fast heart rate and insomnia.
• Thyroid medication: Levothyroxine, the standard treatment for an underactive thyroid, is highly sensitive to timing, and your morning coffee can get in the way. Studies show that drinking coffee too soon after taking levothyroxine can reduce its absorption by up to 50%..
• Antidepressants/Antipsychotics: Lab studies suggest caffeine can bind to certain medications widely used to treat depression, anxiety and other psychiatric conditions in the stomach, reducing absorption and potentially making them less effective.
• Painkillers: Some over-the-counter painkillers may include added caffeine. Drinking coffee can speed up how quickly these drugs are absorbed by accelerating how fast the stomach empties. While this may help painkillers work faster, it could also raise the risk of side effects.
• Heart medication: Caffeine can temporarily raise blood pressure and heart rate, typically lasting three to four hours after consumption. For people taking blood pressure medication or drugs that control irregular heart rhythms (arrhythmias), this may counteract the intended effects of the medication.

Does this mean I have to give up coffee?

Not necessarily. If you're regularly taking medication, it doesn't mean you have to completely eliminate coffee from your diet. It simply means adjusting when and how you consume it to minimise any potential side effects.

In some instances, such as with levothyroxine or bisphosphonates, people should wait up to an hour after taking their medication before indulging in a cup of coffee or breakfast. If you're on antidepressants, antipsychotics or blood pressure medicines, it's best to discuss your caffeine consumption with your GP.

Alternatively, you could opt for a decaffeinated version of your usual brew. There are plenty of options available in supermarkets, which could help you avoid some of the side effects without disrupting your routine.

According to experts at ZOE, decaf coffee has 97% less caffeine than regular coffee, leaving up to about 7 milligrams of caffeine per cup. This is a major reduction compared to a regular cup of coffee, which has 70–140 mg of caffeine.