Drug
Interactions




Ian Lloyd
Pharmacist
Peoples Pharmacy

.....Just the phrase “drug interaction” brings up images of ambulances and emergency room visits. While this might be the case for some drug interactions, luckily this is a rare occurrence. Odds are if you are taking more than five medications, at least two of them will interact. In most cases, your Doctor or Pharmacist knows about the interaction. Sometimes two medications have been prescribed because they interact. Hopefully, I have you interested in this month’s article. Lets discuss drug interactions; the dangerous, the known and the boring.
.....A drug interaction is just what it sounds like; one drug affecting how another drug acts within the body. This can happen in a few ways. One way is that one drug can increase or decrease the quantity of another drug within the body. Perhaps I should explain a little better. Your body is very efficient at removing medications. So when you first start taking a new medication, your body sets to work to remove it and this is fine. If a another drug is introduced, this system might be disrupted, temporarily or permanently. This may cause the amount of the first drug in your body to either rise or fall. If this persists, the increased drug levels might cause more side effects, or if they drop you might lose the effectiveness of the

first drug.
.....These are the most worrisome types of drug interactions, but luckily they rarely occur. Your Pharmacist and Doctor often use computer databases to ensure these interactions don't occur.
.....Another way drugs can interact is when one drug enhances or antag
onizes the effectiveness of another medication. Sometimes this might be intentional. The classic example of this is using multiple medications to help treat high blood pressure. In many cases, the exact cause of high blood pressure is not known, it could be caused by a few factors. If one medication does not reduce your blood pressure. to the desired range, another medication might be given. These medications are technically interacting by enhancing the reduction in blood pressure. In some circumstances this might be useful. If you raise the dose of the first medication this might cause more side effects, but if you add a lower dose of another medication it

might lower the blood pressure as desired with fewer side effects.
If you are concerned about drug interactions, talk to your Doctor or Peoples Pharmacist. They may have access to computer databases which will determine if any of your drugs might interact. They may also be able to determine if any herbal, vitamins or other supplements might interact with your medications. You could also check the Internet for drug interaction information. With all information found on the Internet, double check with your Peoples Pharmacist for accuracy.
.....Did you know that vitamins, herbals, over the counter medications and even foods can interact with drugs? Well it is true. There are quite a few vitamins that can interfere with the actions of certain drugs. The most problematic are mineral supplements. Minerals (calcium, magnesium, etc) can prevent certain antibiotics from being absorbed from the stomach. This same interaction also applies to drugs that help treat osteoporosis. In these cases, the drugs work by binding to calcium, either within bacteria or in your bones. If these drugs encounter calcium in the stomach, they will bind to it there and will not be able to reach the part of your body where they are needed. The same might also be true of thyroid hormone medica