How grapefruit can cause fatal drug interactions

Whether you eat the fruit or drink its juice, the large colourful citrus fruit grapefruit would not probably invoke many, if any, concerns amongst the majority of people. For starters, its botanical name is ‘fruits of paradise’, which would automatically hint that it is loaded with a wide range of health boosts. Indeed this is true; grapefruit is incredibly rich in Vitamin C. So much so that just half of a grapefruit provides 46.86 mg, (78.1% of the recommended daily intake). The Vitamin C in grapefruit helps to maintain a healthy immune system, reduce symptoms of the common cold, and can also reduce the severity of inflammatory conditions such as asthma, rheumatoid arthritis and osteoarthritis.

If that wasn’t enough, grapefruit contains chemical compounds called limonoids, which decrease the risk of death from cancers such as breast, stomach and pancreatic, and the fruit lowers the chance of death from heart attack or stroke. This is partly because grapefruit is highly effective at lowering blood levels of LDL (‘bad’) cholesterol, with red grapefruit lowering triglycerides as well. It lowers the bad cholesterol because it contains a soluble fibre known as ‘pectin’ which has been shown in studies to slow down the progression of atherosclerosis; a hardening of the arteries that can occur for many reasons including high cholesterol.

Cholesterol is where a major concern arises in regards to grapefruit. For those suffering with high cholesterol, the majority are prescribed statin medication such as Rosuvastatin (Crestor), Atorvastatin (Lipitor), Lovastatin (Mevacor) and Simvastatin (Zocor). You may not be aware but statins and grapefruit do not mix! Although Crestor is widely thought to be safe, grapefruit can make the active ingredients in Lipitor, Mevacor and Zocor more potent, a combination that could prove fatal.

This happens as grapefruit contains high levels of the flavanoid naringin, which interferes with enzymes in the body such as cytochrome P-450 and P-glycoprotein. Both of these enzymes work at breaking down drugs like statins and many others, into more usable chemicals, which are subsequently moved around the body. However, the compounds in grapefruit cause a drug interaction by inhibiting this metabolism process of the medications in the digestive system, resulting in a build-up of the drug’s ingredient in the bloodstream and causing a toxic poisoning.

The dangerous level of statins in the body may cause liver damage or a rare disease associated with statins, called ‘rhabdomyolysis’. This condition is the breakdown of muscle fibre that then triggers the release of muscle fibre contents called myoglobin into the bloodstream which is followed by kidney failure (where waste and urine cannot be removed) and severe muscle damage.

It is not just grapefruit you need to consider though when taking pharmaceutical drugs. Pomelos and Seville oranges, a type of bitter orange sometimes used in marmalades and compotes, may also cause interactions with medicines.  Be warned that interactions can occur even if you eat or drink a small amount of these fruits and researchers are working to find other types of food that could dangerously react with particular medications.

If you are prescribed any medicines, not just statins, then you should immediately check with your own doctor to make sure that it is safe to consume grapefruit products or indeed any citrus fruits whilst also taking your medication. Your doctor could advise you to completely exclude any grapefruit product in your diet, lower your dose of medication if you are adamant about still having grapefruit in your diet, or possibly advise a different medication for you.
We have mainly discussed the certain statins that can have an adverse effect with grapefruit; however there are many other types of drugs that interact with the fruit. These include:

. Anti-anxiety – Buspirone (Buspar).
. Anti-arrhythmia – Amiodarone (Cordarone), Aronedarone (Multaq).
. Anti-depressant – Sertraline (Zoloft).
. Antihistamine – Fexofenadine (Allegra).
. Cough medicine – Dextromethorphan (Coricidin, Delsym, Dimetapp, NyQuil, Robitussin Vicks and other generic cough medicines).
. Erectile dysfunction – Sildenafil citrate (Viagra).
. High blood pressure – Felodipine (Plendil), Isradipine (DynaCirc), Nicardipine (Cardene), Nifedipine (Procardia), Nimodipine (Nimotop), Nisoldipine (Sular).