Medications are best taken with water because beverages such as milk, mineral water and juice can sometimes alter their effects, warned Ursula Sellerberg, spokeswoman for the Federal Union of German Associations of Pharmacists.
“Milk contains the mineral calcium, which can bind with medications and prevent them from entering the bloodstream,” she said.
For this reason, milk and dairy products reduce the effectiveness of certain active pharmaceutical ingredients, for example in thyroid hormones, medications for osteoporosis and a number of antibiotics.
“A dash of milk in a cup of coffee can be enough to interfere with a medication’s effectiveness,” Sellerberg noted. A similar effect is also possible from calcium-fortified juices and calcium-rich mineral water. There is no problem, however, when one or two hours separate the intake of calcium from the intake of a medication.
Grapefruit juice, on the other hand, can intensify both the effects and side effects of various medications. “The juice inhibits enzymes in the body responsible for breaking down many medicines,” Sellerberg said.
The medicines affected are frequently for hypertension, heart diseases, lipid metabolic disorders and other chronic illnesses. No comparable interactions have been observed to date with orange or apple juice.
Medications should not be washed down with alcoholic beverages either because they, too, can interact with certain active pharmaceutical ingredients.