I'm sorry to hear your child's cough has worsened at night despite the medication. Relent Plus Syrup contains cetirizine (an antihistamine) and ambroxol (a mucolytic), which usually help with cough and allergy symptoms by thinning mucus and reducing allergic reactions. However, sometimes cough can worsen due to irritation or other underlying causes.

Here are some steps you can take:

• Keep your child well-hydrated with warm fluids like herbal teas or warm water to help soothe the throat and loosen mucus.
• Use a humidifier or place a bowl of water near a heat source in the child's room to keep the air moist, which can reduce nighttime coughing.
• Elevate the child's head slightly during sleep by using an extra pillow to help prevent mucus from pooling in the throat.
• Avoid exposure to irritants such as smoke, strong perfumes, or dust that can worsen cough.
• If the cough is severe, persistent beyond 7-10 days, or accompanied by difficulty breathing, high fever, or wheezing, seek prompt evaluation.

Since the cough worsened after starting medication, it is important to consult your child's pediatrician to reassess the treatment and rule out other causes like infections or asthma. Do not stop or change medications without medical advice.

If your child experiences any side effects like excessive drowsiness, rash, or difficulty breathing, seek immediate medical attention.

Please consult a pediatrician for a thorough evaluation and appropriate management.To narrow down potential causes, we will need some more information.Please enter your age.