Q: My husband has a prescription that says “take on an empty stomach,” but he refuses to do this, saying it’s inconvenient and it doesn’t matter. We are arguing about this. What will happen if he doesn’t follow directions?
– H.G., Sacramento, Calif.
A: His medicine may not work as well. The caution, “take on an empty stomach” is there to alert patients that food will interfere with the amount of drug that ultimately gets into the bloodstream or possibly slow down the effectiveness. This is the case with many medications, including thyroid hormones, tetracycline, fluoroquinolone antibiotics and some antihistamines.
Say you have a serious prostate infection and you’re on an antibiotic with a label warning you to “take on an empty stomach.” It’s 1:30 p.m. and you decide to eat lunch and take your medication with the meal. In this case, you might lose between 5 and 30 percent of the drug (maybe more if you have eaten calcium-rich foods, which interfere with fluoroquinolone antibiotics such as Cipro and Levaquin). As a result, less medicine gets to your prostate to fight the bacteria that has invaded and, if you do this all the time, you could suffer longer and need more medicine.
With some drugs – for example, osteoporosis drugs (bisphosphonate drugs) like Fosamax, Actonel and Boniva – even the tiniest amount of food gets in the way. They have to be taken with water only; you can’t even nosh on a cracker. I know it’s distressing. These drugs upset the stomach and a little food would help, but again, your absorption goes down dramatically. Therefore, they should be taken without food.
Here’s a good rule of thumb for a prescription recommended to be taken on an empty stomach: You can take it either one hour before or two hours after a meal.
Q: I’ve just begun taking the antidepressant Prozac (fluoxetine). It’s been about a week and a half. It doesn’t seem to be helping at this point. Should I stop it?
– W.O., Gainesville, Fla.
…
A: As a general rule, I don’t think people should suddenly stop medications. There can be negative consequences to doing so without your doctor’s approval – especially with antidepressants. For most people, Prozac may take three to four weeks to give you the full effect. Take the medicine in the morning and be aware that typical side effects include nausea, taste changes, painful urination, insomnia, agitation and even sexual problems. If you experience uncomfortable side effects, ask your doctor to lower your dose or switch your medication.
Suzy Cohen is a registered pharmacist. Contact her at dearpharmacist.com.
