This grapefruit-medication interaction is harmful because the chemicals in the fruit interfere with the enzymes that metabolize the medication in our digestive system. This may result in medication staying in the body for too long or too short time. If the medication stays in the body for too long, its concentration will increase exponentially causing serious side-effects whereas if the medication is metabolized too quickly, then the action of medication won’t be effective.
A clinical pharmacologist at the Lawson Health Research Institute in London, Ont., David Bailey, discovered this grapefruit-medication interaction around twenty years ago. According to him, the number of drugs with the ability to interact with grapefruit has increased manifold since then. Bailey also said that taking one tablet with a glass of grapefruit juice is like taking 20 tablets with a glass of water. Thus we are unintentionally becoming victims of over-dosage. Also, due to increased concentration of the medication, the medication turns toxic instead of being therapeutic.
The number of medications that can interact with grapefruit is large. They mostly include commonly prescribed medicines to fight with infections, treat high blood pressure and heart problems, reduce cholesterol, etc. Others include the medications to fight cancer or those prescribed to people who received organ transplants.
According to researchers, people above 45 years of age are more vulnerable to this deadly interaction as people belonging to this age group often buy these prescription drugs that interact with grapefruit. Also this age group is unable to tolerate the higher concentration of medication in their body as compared to young people. The researchers also added that apart from grapefruit, other citrus fruits like limes, pomelos, marmalade (Seville oranges) can also lead to drug interactions.