Weighing side effects versus benefits

DEAR DR. ROACH>> Our mother, 88 years of age, has been prescribed Remeron at a dosage of 7.5 mg once a day. The doctors are telling us this will aid her appetite and assist in putting on some much-needed weight. A few siblings believe, however, the side effects of this drug outweigh the objective, saying she has become listless and sleeps much more. This debate has been going on for almost two years and has caused a major rift in our family. Mom’s doctors advise that it is a very low dose and does not contribute to perceived drowsiness. Do side effects at this dosage outweigh the positives?

— R.C.

ANSWER>> Weight loss, when it’s due to illness such as cancer, can be very problematic. It leads to frailty and increased susceptibility to infection, bone fractures and many other adverse medical outcomes. There have been many medications used to stimulate the appetite, including mirtazapine (Remeron), as weight gain is a side effect when it is used as an antidepressant.

When used for cancerrelated weight gain, about 25% of those on Remeron treatment noted increased appetite, and the same number gained a kilogram or more. About 12% withdrew from the study for reasons including excess sedation and confusion. Among those taking Remeron as an antidepressant, 54% note drowsiness.

Although 7.5 mg is a low dose (15 mg is the usual starting dose for adults), older adults may be more sensitive to the adverse effects, and if your mother is very thin, as you suggest, 7.5 mg may not be such a small dose after all. I suspect that her listlessness and excess sleeping may very well be related to the Remeron. A trial off the drug would answer the question. Alternatives are available. The most commonly used in this situation in my experience is megestrol (Megace). Sedation is not common with megestrol, but it does increase risk of blood clots.

Finally, the data I am quoting are for people with weight loss due to cancer. I don’t know what the cause of weight loss is in your mother. Advanced dementia is a common cause; here, appetite stimulants have also been shown to be beneficial in small studies. If the cause of the weight loss is unknown, finding out why might lead to a more effective treatment.

Contact Dr. Roach at ToYourGoodHealth@med. cornell.edu.