DS2 was 5 in August and has been taking Singulair since he was about two. He takes a little chewable tablet (paediatric montelukast, 4mg). I'm not sure how much it helps, as he is also on Flixotide (fluticasone propionate), which is an inhaled steroid, and Serevent (salmeterol), which is a long-acting beta-agonist. They are all preventers.
He was put on the Serevent when we returned to the UK from Singapore - before that he took bambuterol, also a long-acting beta-agonist, in a paediatric syrup, but it's not available here.
The two non-steroidal preventers were given to him to try to control the asthma without increasing his steroid dose.
He was hospitalised with bronchiolitis at 9 weeks for 5 days and considered a 'happy wheezer' until about 13 months. From then on, he started to have severe wheezing/asthma every time he got a cold - which was about every 4-6 weeks at that age. He was hospitalised twice more and needed a nebuliser every time he was ill - so he had a pretty hefty line in preventers.
But he hasn't had a bad attack for 18 months now. The doctor wants to keep him on the Singulair and the Serevent, but we took him off Flixotide over the summer. Have started it again now in the winter.
That is probably too much info, but thought it might also be useful to give DS's 'history', so you could see why he takes the Singulair.