Why should certain medicines not be taken with coffee or tea?

For many of us, starting the day without a cup of coffee or tea is unthinkable. However, in some cases, caution should be taken regarding the drink taken with the medicine. Some medicines can be taken at different times of the day, but it is also advised not to take them with things that contain caffeine.

Antonio Javier Carcas Sansovan, professor of pharmacology at the University of Madrid, said: ‘There are about 60 drugs that do not interact with caffeine. “When we take a drug, it passes through our body once it reaches the stomach or intestine into the bloodstream and is then distributed throughout the body.”

Elena Piotra Ruiz de Azua, professor of pharmacology at the University of Navarra, explained that drugs have pharmacological targets, meaning their positive effect starts when they reach specific parts of the body. These targets are a strategic point for treating a disease. Whereas proteins are useful in initiating or blocking the effect of a drug. For this, the drug has to be completely absorbed and distributed in the body.

The drug has to be metabolized i.e. excreted from the body and this is the job of the liver. It is among the organs of the body that cleanse the body, but what if coffee is added to the whole journey? It depends on the drug and its purpose.

Caffeine is a nervous system stimulant

Remember that caffeine is a central nervous system stimulant, which can cause jitters and high blood pressure. If we are talking about a drug that is intended to have a sedative effect on the brain, then mixing it with coffee or a caffeinated drink would be harmful because it would reduce the effects of the drug. Many of these drugs used in treatment belong to the ‘benzodiazepine’ family, which are used for anxiety and insomnia.

“Along with the drug, caffeine will also reach the brain, then on the one hand your nervous system will be stimulated by the caffeine and on the other hand the drug will have an effect,” says Pyotra. Taking these medications with caffeinated beverages is strongly discouraged. ‘Because the molecules you’re ingesting through coffee or cola work in the exact opposite way to drugs,’ he says.

Excessive drug accumulation in the liver

In addition, some drugs use enzymes and proteins like caffeine to be metabolized in the liver. Therefore, there is a kind of interference due to which this drug accumulates in the body in excess. The experts warn that ‘for some drugs the increase in plasma may be irrelevant because they have a greater margin of safety.’ But for other very specific drugs, such as those prescribed for schizophrenia, in which it is important to treat, co-homing can be dangerous. They are drugs that don’t matter in excess but if it goes beyond the prescribed amount, it can increase the risk.’

Carcass says caffeine can modify the effect of some medications by increasing or decreasing them. There are also drugs that inhibit the action of the enzyme responsible for the above process by blocking the metabolism of caffeine. An example of this is some antibiotics such as quinolones. ‘It may be that the drug suppresses or slows down the metabolism of caffeine and therefore increases the amount of caffeine in the body and has a greater effect,’ says the professor.

Digestive problem

It is also recommended that some medications, such as those used to treat hypothyroidism, be taken on an empty stomach. “It’s important to take thyroxine on an empty stomach, without eating or drinking coffee, and to wait a while before breakfast so that the drug is fully absorbed at the intestinal level and thus our body’s immune system,” Pyotra says. Optimum levels of hormones can be achieved in the body.

And the presence of food in the stomach and intestines can potentially interfere with the absorption of certain medications. Even if you take the recommended dose and if a part of it is not absorbed, it will not have a clinical effect.’ For other drugs, however, dosage is the best rule of thumb. Some anti-inflammatory drugs can be very harmful to the gastric mucosa. For this reason it is sometimes recommended to take it with food to reduce the harmful effect of the gastro.’

Milk factor in coffee

“Don’t be fooled by coffee with lots of milk,” says Pyotra. ‘Tetracyclines, which are a type of antibiotic, combine with milk to create a complex and prevent absorption.’ Taking some medications with dairy products doesn’t make a difference, but some antibiotics may lose their effectiveness.

If taking medications that affect the central nervous system, such as antidepressants, it’s important to follow a doctor’s instructions, Piotra says, because caffeine itself is a major stimulant of the system. It is important to take the medicines exactly as prescribed by the healthcare professionals.

‘Forget home recipes. If it’s a sachet and it has to be dissolved in water, do it that way, not in juice or other liquids because they completely change the effect of the medicine.’ They also say that there are many medications that are not a problem to take with coffee.

“You have to look at each case individually, and the best way to make sure is to ask your pharmacist or doctor about it,” says Karkaska. ‘It’s generally good to drink coffee in moderation.’