Q. I have been on Prozac for approximately five years. I began with 20 mg but recently, with my doctor’s okay, I increased the dose to 40 mg. 20 didn’t seem to be working any more. I have been on the higher dose for about 3 months, but it is not helping either.
I do not have a psychiatrist. Is my body not tolerating this drug any more? Should I be switched to another drug? I am not sure my family doctor knows what to do.
A. Joseph Glenmullen, MD, author of Prozac Backlash, has discussed the phenomenon of serotonin-based antidepressants losing effectiveness. He describes this situation as “Prozac poop-out.”
Dr. Glenmullen is a Harvard psychiatrist and reports that up to a third of patients may eventually need higher doses to get the same effectiveness. Sometimes, even bigger doses may not relieve depression for some patients. Your physician may need to consider a different type of medication or strategy if your depression persists.
Q. I just read your caution about avoiding cranberry juice while taking Coumadin. Does this extend to other cranberry products, like cranberry sauce or dried cranberries?
My mom has been on Coumadin for years, and she really gets black and blue when she bumps into something. She is coming for the holidays and I want to be sure not to give her anything that will exacerbate her condition.
A. A warning from British drug regulators suggests that cranberry juice may increase the risk of bleeding in people taking Coumadin (warfarin). We are awaiting more research on this interaction, but in the meantime we think it would be prudent for people on this anticoagulant to avoid cranberries in any form. The fact that your mother bruises so easily is a warning sign that she may be especially vulnerable.
We are sending you our Guides to Food, Drug and Coumadin Interactions for more details on how this medication can be affected by foods and other compounds. Anyone who would like copies, please send $2 in check or money order with a long (no. 10) stamped (60 cents), self-addressed envelope: Graedons’ People’s Pharmacy, No. FD-195, P. O. Box 52027, Durham, NC 27717-2027.
Some foods and drugs reduce the effectiveness of Coumadin, while others increase it. Recent reports suggest that even a multivitamin containing vitamin K could interfere with the benefits of this medication.
Q. Is there any difference between over-the-counter Claritin and the Claritin my doctor used to prescribe?
When my doctor switched me from prescription Zantac to Zantac-75 he told me I would have to take two pills instead of one. Is the same situation true for Claritin?
A. In the past, the FDA frequently approved lower doses when a prescription drug went OTC. More recently, however, doses haven’t been altered. Claritin and Prilosec OTC are identical in dose to their earlier prescription counterparts.
Q. What is potassium salt? I was told to use it for my mild hypertension. Is it available in supermarkets?
A. Many salt substitutes (Lite Salt, NoSalt, Morton Salt Substitute) contain potassium chloride and are available in supermarkets. These are a good alternative for table salt, since they may help lower blood pressure. Please check with your doctor to make sure potassium is safe with any blood pressure medicine you are taking.