Does Grapefruit Juice Enhance Tramadol?

Grapefruit can change the way your body metabolizes many drugs. Because of this effect, you may have more side effects than usual if you take medications with grapefruit. While this effect does not occur with every drug, it could occur with tramadol, although drug inserts for the drug do not list this as a possible reaction. Ask your doctor about the potential effects of drinking grapefruit juice or eating any other grapefruit products while taking tramadol.

Causes
The compounds that cause problems with drug metabolism appears to be furanocoumarins, found mostly in the grapefruit flesh but also in the sac, peel and seeds. These compounds inhibit the intestinal cytochrome P450 3A4 system, which plays an essential role in the first-pass metabolism of drugs as they pass through the liver and intestine. In first-pass metabolism, the potency of a drug is reduced in the liver. Grapefruit products inactivate the system, so that more of the active part of the drug passes through to the intestines for absorption. Tramadol undergoes first-pass metabolism; taking tramadol with CYP3A4 inhibitors may reduce metabolic clearance of the drug, according to Drugs.com.

Effects
Consuming grapefruit products inhibits cytochrome P450 3A4 starting 30 minutes after ingestion and lasts for 24 to 72 hours, pharmacist Amy Stump reports in the August 2006 issue of the “American Family Physician.” Grapefruit can increase cytochrome P450 3A4 concentration by up to 47 percent. Because more drug passes into the bloodstream, side effects intensify.

Dangers
Tramadol, a drug similar to opiates, reduces pain. Side effects include sedation, dizziness, confusion, nausea, vomiting, seizure, hallucinations, vertigo and tachycardia. If these effects intensify, they could lead to symptoms of overdose, including seizures, breathing difficulties, slow heart rate, flaccid muscles, extreme sedation or circulatory collapse.

Considerations
Drugs most affected by grapefruit are those that not only undergo first-pass metabolism but those that also have low bioavailability and those that have a narrow therapeutic range. If a drug has a narrow therapeutic range, even a small increase in the amount absorbed can cause problems. Tramadol has high bioavailability, between 70 and 90 percent, according to Margarete Fischer, M.D., of the German Bosch Institute of Clinical Pharmacology. She does add that inhibitors of drug metabolism could affect tramadol’s metabolism. The safest bet is to ask your doctor whether you should avoid grapefruit products.

Side Effects of Grapefruit Seed Extract

Grapefruit is high in vitamin C, soluble fiber, and antioxidants which makes it a good addition to any diet. A 2006 study in the "Journal of Agricultural and Food Chemistry" found that grapefruit can help lower blood triglyceride levels, especially in patients suffering from coronary artery disease. As a dietary supplement, it is available as grapefruit seed extract in pill, liquid or powder form. You should always consult your doctor before you take any supplement.

Effect on Enzymes
Grapefruit can inhibit the activity of certain liver and small intestine enzymes, reports a 1996 study in the journal, "Drug Metabolism and Disposition." Enzymes are catalysts that cause reactions to occur. In this case, the effect is on the digestive system. By inhibiting this enzymatic activity, concentrations of medications which rely on this mechanism for digestion can reach higher concentrations in the blood. According to Drugs.com, adverse reactions may result if you are taking calcium channel blockers or estrogen. The reduction of enzymatic activity can lead to elevated concentrations of these drugs in your blood.

Muscle Weakness
Because grapefruit seed extract affects liver function, the risk for interactions with prescription drugs that also interact with the liver can be increased by taking this herbal supplement. Statin drugs are prescribed to lower blood cholesterol levels, but also have the potential to cause liver damage. The decrease in enzyme function can increase the concentration of these drugs. A rare side effect of statin drugs is a muscle weakening disease called Rhabdomyolysis. Because grapefruit seed extract alters statin metabolism, the possibility exists that you may be more at risk of developing this condition, according to a 2003 study in the "Journal of the American Medical Association."

Decreased Absorption of Medications
Grapefruit seed extract can also impair your body's ability to absorb medications, thereby decreasing their effectiveness. Fexofenadine is a non-sedating antihistamine prescribed for seasonal allergies. Grapefruit seed extract can inhibit your body's absorption of this drug by your system. It can also affect the absorption of other drugs including itraconazole, an antifungal, antibiotic and quinidine. Quinidine is an anti-malaria drug. However, it also is used for treating irregular heartbeat patterns. Grapefruit seed extract can potentially have very serious side effects on your cardiovascular system. Do not take grapefruit seed extract if you are on prescription medications without discussing possible drug interactions with your doctor.

How to Eat Grapefruit With High Blood Pressure

Grapefruit and grapefruit juice is nutritious and contains many important nutrients, including vitamin C, soluble fiber and potassium. In some cases, not getting enough potassium can cause your blood pressure to rise, so eating grapefruit may help you lower your blood pressure. People taking prescription medications should be careful about consuming grapefruit, however, as grapefruit can interfere with the clearance of some drugs, including those used for high blood pressure, increasing the side effects of these medications.

Step 1
Talk to your doctor before you start any new medications if you consume grapefruit. Some of the substances in grapefruit can interfere with the liver's ability to break down medications, causing higher than normal blood levels of these drugs. This includes calcium channel blockers, which are often prescribed for the treatment of hypertension.

Step 2
Consume grapefruit or grapefruit juice every day. According to Colorado State University, 1 cup of grapefruit juice contains 360mg of potassium and a half of a pink grapefruit contains 135mg of potassium. The University of Maryland Medical Center recommends that you get 2,000 mg of potassium each day, which will help you prevent high blood pressure, and consuming grapefruit can be a part of this plan.

Step 3
Limit your sodium intake. Increasing your potassium intake may not be as effective at lowering your blood pressure if you also consume high amounts of sodium. Keep your sodium intake between 1,500 and 2,300mg per day.