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First, it's important to carefully consider the source of information and then to discuss the information you find with your health care professional. These questions and answers can help you determine whether the health information you find on the Internet or receive by e-mail from a Web site is likely to be reliable. The medicines that sold online can be fake (counterfeit or 'copycat' medicines); can be too strong or too weak, or have dangerous ingredients, or have expired (are out-of-date), or haven't been approved or checked for safety and effectiveness, can be made using non-safe standards, or not safe to use with other medicine or products you use. Be sure your privacy is protected: look for privacy and security policies that are easy-to-find and easy-to-understand. Don't give any personal information such as social security number, credit card, or medical or health history, unless you are sure the website will keep your information safe and private.
The benefits of medicines are the helpful effects you get when you use them, such as lowering blood pressure, curing infection or relieving pain. The risks of medicines are the chances that something unwanted or unexpected could happen to you when you use them. Risks could be less serious things, such as an upset stomach, or more serious things, such as liver damage. Before using any medicine--as with many things that you do every day--you should think through the benefits and the risks in order to make the best choice for you. There are several types of risks from medicine use: a) The possibility of a harmful interaction between the medicine and a food, beverage, dietary supplement (including vitamins and herbals), or another medicine. Combinations of any of these products could increase the chance that there may be interactions. b) The chance that the medicine may not work as expected. c) The possibility that the medicine may cause additional problems. For example, every time you get into a car, there are risks---the possibility that unwanted or unexpected things could happen. You could have an accident, causing costly damage to your car, or injury to yourself or a loved one. But there are also benefits to riding in a car: you can travel farther and faster than walking, bring home more groceries from the store, and travel in cold or wet weather in greater comfort. To obtain the benefits of riding in a car, you think through the risks. You consider the condition of your car and the road, for instance, before deciding to make that trip to the store. The benefit and risk decision is sometimes difficult to make. The best choice depends on your particular situation. You must decide what risks you can and will accept in order to get the benefits you want. Before starting any new medicine or dietary supplement (including vitamins or herbal supplements), ask your doctor again if there are possible interactions with what you are currently using. You have to know what to do if you experience side effects and when to notify your doctor, and know when you should notice an improvement and when to report back.
There are more opportunities today than ever before to learn about your health and to take better care of yourself. It is also more important than ever to know about the medicines you take. Early in a drug's development, companies conduct research to detect or predict potential interactions between drugs. Experts evaluate the drug-interaction studies as part of assessing a drug's safety. When a drug is taken orally, it usually travels from the stomach to the liver, where it can be metabolized-the process of breaking down and removing chemicals from the body. Enzymes are complex proteins that act as catalysts in starting or speeding up chemical reactions. They cause a specific chemical change in other substances without being changed themselves. A drug may affect these enzymes by inhibiting them, which causes reduced activity of the enzyme and a buildup of the drug in the body. Or drugs may "induce" the enzymes, which causes increased activity of the enzyme and a reduction of the drug in the body. It used to be that the only way to test for drug interactions was in people. Now drug companies can take five test tubes with the five major pathways for metabolism and put their drugs in to see whether it's metabolized by CYP450. This allows to generate a list of possible interactions based on their findings. This phase of research in test tubes, known as in vitro studies, allows researchers to perform drug-interaction studies in labs by testing a drug with other drugs that have the same route. This has made the research faster and more accurate. If two drugs go through the same enzyme, the presence of one drug can prevent the metabolism of the other. So this allows you to look at the worst-case scenarios and ask: 'What if we put this drug with that one, knowing that they have the same route?'" Three phases of clinical trials in humans must happen before a drug can be marketed. Phase 1 studies focus on a drug's side effects and how the drug is metabolized and eliminated from the body. Phase 2 studies focus on a drug's effectiveness. And Phase 3 studies gather more information on safety and effectiveness, which includes using the drug in combination with other drugs. Over the last several years, there has been a substantial increase in the number of drug-interaction studies the FDA sees in new drug applications. If drug interactions are significant enough, they can prevent a drug from being approved by the FDA. If the agency determines that known drug interactions can be managed and that a drug's benefits outweigh the risks for the intended population, a drug will be approved. Drug-interaction information then goes into the drug's labeling in the sections on "clinical pharmacology," "precautions," "warnings," "contraindications," and "dosage and administration." In addition to having a good grasp of drugs and their effects, doctors take medication histories, and they consult with other members of their team to guide them in making decisions about drug interactions. They also use concise drug summaries and resources on pharmacological principles. Health professionals also use computer systems with drug-interaction screening software, electronic prescribing, and other technology. Mark Langdorf, M.D., chair of the department of emergency medicine at the University of California, Irvine, says, "In a busy emergency room, you have to quickly find out what a patient is taking and how those drugs could interact with other treatments." But it is good way -- consumers remind doctors of everything they take when they are prescribed a new medication. So a patient might say: "Now remember, I'm also taking birth control pills. Is there a risk of interaction with this new medicine?" Some antibiotics, such as rifampin, can lower the effectiveness of birth control pills. Sildenafil, the active ingredient in the erectile dysfunction drug Viagra, should not be taken with nitrates for heart treatment because of the potential for dangerously low blood pressure.
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