What is a Drug Interaction?

A drug interaction occurs when a drug interferes in a negative way with another drug or medical condition. These interactions can occur between two drugs, by combining medications with particular foods or drinks, or by a drug interfering with another medical condition. It does not only happen with prescription drugs, it can happen with over the counter medications, vitamins and supplements, and illegal substances.

Every medication is designed to create a certain effect in the body. Drug interactions typically occur when the intentions of one drug interferes with the intentions of the other. For example, antacids coat the stomach, making it harder for other drugs to get into a person's system. Drugs can also interact with a medical condition. Blood thinners help to prevent clotting, heart attacks, and strokes, and are often prescribed to individuals with certain heart conditions. If someone has weak blood vessel walls, or if they bruise easily, then blood thinners can cause a bleeding disorder.

Medications can also interact with illegal drugs or with alcohol. Most prescription medications are not supposed to be taken with alcohol, as alcohol can alter the way the medication acts. Vitamins, herbal remedies, or supplements can also negatively interact with other medications. Many people do not realize that different herbs, even ones found in teas, can interfere with their medications.


The most common symptoms of a drug interaction are headaches, nausea, dizziness and fatigue. It can also cause heartburn or a change in blood pressure. In some cases, drug interactions can lead to constipation or diarrhea, muscle weakness, tremors, anxiety, or clumsiness. In extreme cases, drug interactions can lead to severe medical problems or even death.

Many complications due to a drug interaction are preventable. When you visit your doctor, bring a list of any medications you are currently taking, even if you only take them occasionally. Check with your doctor or pharmacist before beginning any new treatment, even for over the counter medications. Have one pharmacy that your entire family uses, so that the pharmacist has an accurate record of any medications you may be on. Many pharmacies automatically check your files to look for any potential interactions.

Be sure to read the labels on any medication very carefully before you begin treatment, and take only the recommended dosage. There are many websites and books that can help you check for any potential drug interactions. If you are experiencing the symptoms of a drug interaction, call your doctor or head to the nearest hospital, especially if the symptoms are severe. Remember that a drug interaction can be deadly; immediate treatment may mean the difference between life or death.



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Post 2

@goldensky - Lipitor should not be taken with any form of grapefruit. Grapefruit blocks the enzymes in the small intestine that breaks down medications causing the drug level to increase in your blood stream. There’s a drug interactions checker at that explains this in more detail.

The thing about grapefruit is that it stays in your system for awhile, anywhere from 24 hours to 3 days. So I would stop eating the fruit altogether while taking lipitor. Otherwise it may increase your risk of causing serious muscle and organ damage.

You really should talk to your doctor about it. Maybe he/she could prescribe something that grapefruit has no effect on.

Post 1

My doctor just prescribed me with lipitor to help reduce my cholesterol. I’ve been hearing a lot of talk lately about grapefruit interactions on certain drugs. Is lipitor one of them?

If so, is it still okay to eat the fruit itself? Can I eat it at a different time of the day than when I’m taking my medicine? Grapefruit juice has so many nutritional values that I didn’t think to tell my doctor that I drink it or that it would even be a problem.

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