Ratio Cotridin Teva Syrup 100 ml combination medication is used to treat symptoms caused by the common cold, flu, allergies, or other breathing illnesses (such as sinusitis, bronchitis). Ratio Cotridin Teva Syrup 100 ml relieves watery eyes, itchy eyes/nose/throat, runny nose, and sneezing. Codeine is an opioid cough suppressant (antitussive) that affects a certain part of the brain, reducing the urge to cough.