I enjoy working with my patients to identify and address the causes of their health problems. For me, it’s one of the most rewarding parts of being a family doctor. Sometimes, I discover that a patient’s problem has a relatively simple solution.
That was the case for my patient Shirley (not her real name). She’s a new patient who has a condition called hypothyroidism. This means that her thyroid gland does not make enough thyroid hormones. For a number of years, Shirley has been taking a medicine called a synthetic thyroid hormone every day to replace her body’s thyroid hormones.
Shirley came in for a blood test to measure her thyroid-stimulating hormone (TSH) level. This test helps me determine if she is taking the correct dosage of her thyroid medicine. It showed that she had a high TSH level, which told me that her medicine was not working as well as it should. I was surprised because it seemed like Shirley was taking an appropriate dosage of the synthetic thyroid hormone.
Looking at Shirley’s medical record, I could see that she had prescriptions for multiple medicines. She was also taking a multivitamin and an over-the-counter (OTC) calcium supplement called calcium carbonate every day. I asked Shirley some specific questions about her daily routine. She told me she was taking her synthetic thyroid hormone at the same time as some of her other medicines, including the multivitamin and calcium supplement.
Shirley didn’t realize that calcium carbonate can decrease the body’s absorption of synthetic thyroid hormones. Multivitamins that contain iron can also interfere with absorption. I told her that she should take her multivitamin and calcium carbonate at least 4 hours before or 4 hours after taking her thyroid medicine. In addition, I cautioned Shirley that she shouldn’t start taking any new supplements or vitamins without talking to me first.
As we talked, I discovered that Shirley was also taking her medicines without considering the time of day or whether they needed to be taken with or without food. I explained that her medicines wouldn’t work as well if she took them incorrectly. (Learn more about how to get the most from your medicine.)
I asked her to bring all of her medicine bottles to her next visit. During that visit, we discussed how she should take her medicines. Directly on the label of each medicine, I wrote when to take it and whether or not it should be taken with food. I’ve found that my patients remember and understand my instructions better when I write them down, especially if I use red ink.
Since that visit, Shirley has been feeling better and responding well to her medicines. Her TSH level is back in the normal range. She also feels more confident that she is taking her prescription medicines, multivitamin, and calcium supplement correctly. I’m glad that I could give Shirley the information she needs to take better care of herself.
Quick Tip
Some vitamins and supplements can affect the way your body processes prescription and OTC medicines. When this happens, your medicine may not work the way it should. This is called a drug-supplement interaction. It can cause serious problems. Don’t start taking a vitamin or supplement without talking to your family doctor first.
