I usually have to take telfast once a year when the weather changes and I begin to have a runny nose, watery eyeoung childrens, cough and eventually loose my voice. i'm 60 ,healthy, do exercise and am a music therapist for young children. I took the flue shot a month ago but am exposed to small children and therefore at risk. my daughter has asthma, and I'm aware that I react allergically to dust (sneeze a lot) and also when I hike in nature my nose begins to run... Usually tetlfast works well but this time I feel that one tablet a day isn't enough--all the symptoms come back at about midnight. I also take vit c.