Montelukast
"I had been taking Zyrtec D for a few years now for indoor allergies. My allergist told me if it works don't change it. Fast forward, I went for a physical and my dr convinced me to try singulair. I figured why not, paying only a few dollars compared to the price of Zyrtec. I didn't look up any reviews and just started taking it. I noticed I was packing on the pounds like every day so I stopped everything that I had recently changed in my routine. Now that I looked up all the reviews many people have had the same issue even though it is not listed as a side effect. I stopped the medicine a month ago and only took it for 30 days. Still havin trouble losing the weight even with exercising and eating right. Very frustrating! Do not take."