To Your Good Health: Pharmacy, doctor must monitor switch from brand-name to generic thyroid meds


DEAR DR. ROACH: My 81-year-old father takes 100 mcg of Synthroid. Due to the high cost of insurance, and the need to change his Medicare policy, we are trying to lower his prescription costs. One way is to get the generic. His doctor told us today that the Food and Drug Administration allows a 40 percent variability in the generic, so he must stick with the same manufacturer. We are hesitant to switch, based on many of the reviews I have read about people not having the same results with the generic. What are your thoughts on this? — K.H.

ANSWER: Of the many questions I get on generic versus brand-name drugs, it’s Synthroid that generates the most concern. I often hear concerns that the FDA allows a high variation, but in fact, until 2007, the variation allowed was plus or minus 10 percent. This means that the pill must contain between 90 and 110 percent of the amount stated for the active ingredient. This standard is the same whether the drug is brand name or generic. However, because thyroid hormone levels need to be more precisely regulated than other drugs (too much or too little, and the person can have symptoms), in 2007 the FDA changed the regulation for thyroid preparations in particular to between 95 and 105 percent of stated potency throughout a product’s shelf life. Because of this, a generic prescription is a reasonable option, in my opinion.

For people who want to be extra careful after changing to a generic, the level should be checked several times frequently following the switch, and I recommend working with your pharmacist to make sure you get the same generic manufacturer with each prescription. Most pharmacists are willing to do this.

Some people insist that only the brand name makes them feel right. I am never sure whether this is due to a difference in the amount of hormone, its ability to be absorbed or by the expectation that a generic is not going to be as good.

Most physicians, including myself, choose generics for themselves and their families.

DEAR DR. ROACH: Could a version of the kind of stent used to hold open coronary arteries be used to hold open urethras in men with prostate problems? — F.M.

ANSWER: The theory is certainly sound. In men with enlarged prostates, the urethra (the tube through which urine flows from the bladder) is compressed as it goes right through the center of the prostate. A stent, which could hold the urethra open, would allow better flow of urine, reducing symptoms and improving quality of life. Several such stents are already commercially available and are used in certain circumstances, mostly in people who don’t do well with medication and who are at too high a risk for surgery. The reason you haven’t heard much about these stents is their complication rate. It’s high: About one man in six who gets one needs to have it removed. The main reason for this is that the stent moves from where it is needed to where it isn’t.

I hope (and suspect) that these problems can be minimized. Additional ways of dealing with this common condition, which causes not only annoyance but medical complications (especially infection, but occasionally kidney damage), would be welcome.