is their a substitute for deconamine sr?

Deconamine SR is a combination of chlorpheniramine (which is an antihistamine) and pseudoephedrine (which is a decongestant).

Many products containing pseudoephedrine have either been discontinued or reformulated because of the pseudoephedrine component (pseudoephedrine is used in the illicit manufacture of methamphetamine).

The closest thing to pseudoephedrine is phenylephrine - so you just need to ask your pharmacist for a product containing chlorpheniramine and phenylephrine. There are many different brands available including Sudafed PE Sinus & Allergy and Actifed Cold and Allergy.