For many of us, coffee is a daily essential, providing that much-needed boost to start our day. In moderate amounts, it’s generally safe for most people.

However, recent research highlights that coffee, when combined with certain prescription or over-the-counter medications, can cause some serious side effects.

These medications are known as contraindicated drugs, meaning their compounds should not be mixed. Before you prepare your next cup of coffee, make sure you’re not on any of these medications:

1. Ephedrine

Ephedrine is a stimulant often used to stimulate the nervous system for quicker responses. It’s also commonly used as a decongestant and bronchodilator for people with asthma, bronchitis, or other respiratory issues.

Beyond that, it’s used to treat narcolepsy, low blood pressure, and menstrual problems. When combined with caffeine, it can lead to what’s known as hyperstimulation.

The combined effect of both can overwhelm the central nervous system, potentially leading to heart attacks, high blood pressure, or strokes.

A range of antibacterial drugs, many obtainable over the counter, can also be affected if taken with coffee.

For some individuals, coffee consumption might raise blood sugar levels temporarily, which can counteract the benefits of antibacterial drugs.

2. Theophylline

Theophylline is prescribed to patients with emphysema, bronchitis, or asthma—conditions known for causing shortness of breath or wheezing due to heavy mucus obstruction and tracheal constriction.

Theophylline helps by relaxing and smoothing out the muscles, providing immediate relief.

Coffee has a similar effect on the body by causing vasodilation, meaning it opens blood vessels and helps relax muscles.

Combining these two can be dangerous, potentially causing low blood pressure or heart palpitations.

If you or someone you know has asthma, make sure they avoid excessive caffeine consumption.

Additionally, various contraceptives and antidepressants, especially tricyclic antidepressants, can result in adverse symptoms when mixed with coffee.

Always consult your doctor before consuming anything, especially if it contains caffeine!