New Delhi: Washing down pills with juice, particularly of citrus fruits, makes the medicine less effective, the Indian Medical Association (IMA) has warned.
In a recent advisory, the medical body says juices have been shown to affect the absorption of drugs, particularly those prescribed for chronic medical conditions such as hypertension or heart disease, and one should have these pills only with water.
"Orange and apple juices have been shown to lower the absorption of certain drugs, thus compromising their effectiveness. On the other hand, grapefruit juice increases the absorption of some drugs. This can turn normal doses into toxic ones," said Dr K K Aggarwal, secretary general of IMA, citing a study by the University of Western Ontario, Canada.
The US Food and Drug Administration (FDA), in its consumer health information, also details why grapefruit should not be taken with medicines.
"Some medicines, like statins prescribed to lower cholesterol, are broken down in the body (metabolized) by proteins called enzymes in our small intestine. Grapefruit juice can block the work of enzymes, increasing the amount of medicine absorbed by the body and risking an overdose," says the FDA bulletin.
It adds, "Other medicines, like Allegra (fexofenadine) used for treating allergies, are moved into the body's cells with the help of proteins called transporters. Grapefruit juice can block the work of transporters, decreasing the amount of medicine absorbed by the body and reducing the medicine's effectiveness."
According to Dr S K Sarin, director, Institute of Liver and Biliary Sciences (ILBS), fruit juices, particularly citrus ones, can affect absorption in two ways. One, by the changing the blood PH —acidity or alkalinity of blood—and, two, by breaking the coating of the pills.
"In India, there is not much research on the harmful effect of taking medicines with fruit juices. But we generally advise patients to have them with water, unless specified otherwise," he said.
Medical experts also point out how prescription rules are barely adhered to and pharmacists, a key link between the doctor and the patient, are mostly unaware about how medicines should be taken.
"In developed countries, the pharmacist guides patients on how to take medicines and whether to have a certain medication with juice or not. But in India few care about such details, leading to poor efficacy of the drug regimen," said Dr Randhir Sud, chairman, Medanta Institute of Digestive and Hepatobiliary Sciences.
In India, only about 20%-30% of doctors write out a detailed prescription, said Dr Anoop Misra, chairman Fortis C-Doc, "Time of meal, time of day and how to take medicines are important details for any prescription. Any mistake or miscommunication can lead to side-effects. For example, aspirin should be taken after meals to decrease its side effects on the stomach. Milk and calcium should not be given with iron, as its absorption will be less," he said.