Yes, Allegra is an antihistamine and Singulair is a leukotriene receptor antagonist so they are two different types of drug.
There are apparently no reactions between them. There is an interaction checker in the dark blue at the top of this page, for future help for you.
Search for questions
Still looking for answers? Try searching for what you seek or ask your own question.
Updated 21 Mar 2011 • 1 answer
Updated 19 Jan 2015 • 2 answers
Updated 18 Jan 2015 • 1 answer
Updated 8 Dec 2015 • 1 answer
Updated 6 Jul 2017 • 1 answer