My 2 year old daughter was recently prescribed this medication. ...

My 2 year old daughter was recently prescribed this medication. She has been having nightmares every night & I give it to her in the morning after breakfast. She will wake up screaming her head off & it often takes over an hour to get her calmed down enough to go back to sleep. But when she does go to sleep, she's out cold for several hours. She's also started hitting & being very violent. At first I thought it was because she couldn't tell us what she wanted, but its been getting worse & worse everyday that she takes Singulair. I guess, we will switch back to Zyrtec for her allergies.