Took Singulair for approx. two weeks due to ears "popping" and fe...

Took Singulair for approx. two weeks due to ears "popping" and feeling full of fluid, even though ENT could detect nothing. First week seemed like miracle drug, ears cleared up and allergies greatly abated. Second week, developed constant pain in hip joints and lower back, and tingling in feet, and terrible acid reflux. Since it was the only new med I'd been taking, I took myself off to see if that was the cause. Within 24 hours, all hip joint pain, tingling in feet and reflux was gone. My son is 3 and has been on Singulair for a year for allergies/asthma and it has helped him tremendously, esp. since he uses a nebulizer in winter months. This past winter the nebulizer use was way down. He is a sweet layed back kid but has started becoming hyper and agressive and a lot of disobedience, which could be just his age. In any case, I've taken him off as well to see if Singulair has caused any adverse effects on his health or behavior.