Hello dear user! I have gone through your query and understood your concerns! Thank you for sharing them on healthcaremagic. The medication you have used is an anti histaminic drug, used to remove the symptoms of common cold such as running nose or tearing eyes. It doesn t treat cold. If your son has (as you mentioned above) severe cold, he must be seen by a doctor, for a full examination. Has he fevers? Is his throat sore? An auscultation of his lungs must be done. If something has changed, he must take the proper medications, including antibiotics. Other supportive drugs, vitamins and minerals may be used, to increase his immunity strength and lower side effect of medications. Please go to your healthcare center if his condition is not like the past common colds he has passed, and if he has fevers. I hope this answer was helpful to you! Please kindly rate it as helpful and write a short review about your experience with me! I would appreciate that a lot. Thank you and best regards! DR ERIOL.