Thank you for asking question on health care magic
As you have rightly pointed out both medicines are related to cough.
Tuspel plus is a bronchodilator
and an expectorant whereas relent
plus contains antihistamie and mucolytic
if your problem is only cold and cough you may continue relent plus.
both syrups need not be given
but a rational alternative is sinarest
syrup if associated with fever.
if no fever sinarest AF syrup given 3 times daily.
Hope this answer will serve your purpose
Please feel free to ask any more queries if required
Associate professor of pediatrics