Grapefruit alert to slimmers GrapefruitEating fruits like grapefruit helps to maintain good health. However, experts warn of the possibility of grapefruit interfering with other drugs, when people take lots of it as a means of controlling their weights. Sade Oguntola reports The case of a woman in Washington who went on an intense grapefruit-based diet and developed a blood clot in her leg was publicised by experts because of the need to create awareness on unpredictable consequences of medicines in the human body. The unusual case, written in the Lancet Medical Journal, medics said, may put the woman at risk of losing her limb. They concluded that grapefruit had affected the way the 42-year-old’s body processed her contraceptive pills. The woman was generally in good health, but was slightly overweight and had decided to diet. Three days before falling ill, she had begun a crash diet, which included eating 225g of grapefruit each morning, after rarely eating the fruit in the past. When doctors examined her, an ultrasound scan confirmed the woman had a large blood clot within the veins of her left leg, which stretched from her hip down to her calf, and she was deemed to be at risk of losing her leg because of gangrene. Even though there a collection of factors could have potentiated the problem, such as an inherited blood disorder, travelling a very long day previously, obesity and hormonal contraceptive, they suggested that the fruit may have blocked the action of a key enzyme that normally breaks down the form of oestrogen in her contraceptive. The unusual case is one of the many consequences of the intake of grapefruit which people trying this out for weight control should be mindful of, especially if they daily take contraceptive pills, especially because of the possibility of the chemicals in the fruit interacting with common drugs like the pill, causing blood clots that could trigger heart attacks, strokes or gangrene. This is particularly important in those that substitute meals for the fruit, which is known for its fat-burning properties. But it can also block the production of an enzyme that breaks down drugs. Grapefruit and its juice are already banned for users of some anti-cholesterol drugs after studies showed its efficiency can be inhibited. Grapefruit juice can directly or indirectly interact in important ways with a number of medications. This is why people taking some medicines for some psychiatric ailments, impotence drugs like viagra and blood pressure control drugs are also advised to take them with water rather than things like grapefruit juice. The negative effect of grapefruit juice on the effectiveness of some malaria medicines formed a part of the postgraduate dissertation of Dr. Yetunde Kolade of the Department of Pharmaceutical Chemistry, University of Ibadan. She pointed out that such a malaria medicine like halofantrine with grapefruit juice should be dissuaded, as its content hinders the absorption of the drug by the body, thus indirectly depriving the body of this essential drug in its fight against malaria. Professor Adewale Sule-Odu, a consultant obstetrician and gynaecologist at the Olabisi Onabanjo University Teaching Hospital, (OOUTH), Sagamu, Ogun State, said grapefruit is a rich source of vitamin C and other antioxidants, and cannot outrightly be said to be responsible for the woman’s problem, given the fact that she was obese and had traveled a very long distance prior to the problem. According to him, for a woman above the age of 40 years that is on contraceptive pills, since she had made a long distance trip prior to the incident, the large blood clot within the veins of her left leg, which stretched from her hip down to her calf, could have arisen because of poor blood circulation during her trip. “The large blood clot could alone be as a result of her trip. When people travel long distances and they are on an airplane, they are told to exercise their legs and feet every 30 minutes. They are told to walk up and down the aisle, move their toes, and so on, because traveling over a long period, especially for women, predisposes them to having blood clots formed in their veins. While describing the grapefruit as very rich in vitamin C and other antioxidants, and as a fruit which many people eat whole to increase the fibre content of their meal and replace meals when trying to loss weight, he said there is the possibility of blood clot occurring in men too. Mrs. Modupe Oderinde, Deputy Director and Head of Department of Pharmacy, University College Hospital (UCH), Ibadan Oyo State, said a basic fact with every drug is that they are all chemical substances that can affect the functions of the body either negatively or positively. She explained that it is important realize the importance of this and the fact that adverse drug reactions sometimes occur with some medicines. “There is no drug that anyone cannot react to because we have individual idiosyncrasies, too. There are different drug reactions that are possible. They can come as systemic manifesta-tions, in which case the whole body system is affected. There could be problems with urination, there could be skin manifestations such as skin rashes and, at the worst, the person might go into temporary coma, which can eventually lead to death. She explained that different people react to different medicines after taking some food items, just as some react to some food flavoured drugs like those flavoured with lobster. Mr. Oyekunle Amusan, Chairman, Pharmaceutical Society of Nigeria, Oyo State, said there are some drugs that showed not be taken together, just as there are some that are not supposed to be taken with some particular food items. “Unless you see your pharmacist for proper education on drug interactions, you would not know how best to use your drug for maximum efficacy and safety,”he said. Amazingly, this remarkable food-drug interaction was discovered completely by accident over a decade ago. This was when researchers were investigating whether alcohol could interact with a particular medicine used in the treatment of hypertension and used a solution of alcohol with grapefruit juice to mask the taste of alcohol for the study. Research about the interaction of grapefruit juice with drugs suggests that compounds in grapefruit juice, called furanocoumarins, may be responsible for the effects of grapefruit juice. Researchers believe that furanocoumarins block the enzymes in the intestines that normally break down many drugs. One glass of grapefruit juice could elicit the maximum blocking effect, and the effect may persist for longer than 24 hours. Since the effects can last for such a prolonged period of time, grapefruit juice does not have to be taken at the same time as the medication in order for the interaction to occur. Therefore, unlike similar interactions, where the interaction can be avoided by separating the administration of the two interacting agents by a couple of hours, the administration of grapefruit juice with susceptible drugs should be separated by 24 or more hours to avoid the interaction. Since this is not practical for individuals who are taking a medication daily, they should not consume grapefruit juice when taking medications that are affected by grapefruit juice. • Check whether your medicine interacts adversely with any food. Grapefruit juice, for instance, can increase the blood levels of some drugs, such as sedatives; calcium in dairy products impairs the absorption of tetracycline and ciprofloxacin, widely used antibiotics. • Before leaving the hospital, make sure you read your prescription. If you can’t, your pharmacist might not be able to, either. • Also, ask your doctor or nurse what the medicine is for, how often you should take it, how it should be taken and for how long, whether you should take it on an empty or full stomach, whether you should avoid certain foods, drinks or activities while taking it. Very importantly, ask what are the potential side-effects and what you should do if these side-effects do occur