My 12-year-old son took Sinarest tablets twice by mistake in one day. Should I be worried about side effects?

This is a very common concern, and while a mistake like this is worrying, for a 12-year-old, taking two Sinarest tablets in one day is generally not expected to cause a severe emergency, but does increase the risk of side effects. Seek medical advice immediately if he shows any severe symptoms like extreme confusion, difficulty breathing, unresponsiveness, severe stomach pain, or a very fast or irregular heartbeat.
Sinarest is a combination of Paracetamol (Acetaminophen), a decongestant (Phenylephrine), and an antihistamine (Chlorpheniramine). The primary concern with a double dose is the potential for increased side effects from these ingredients.
What to Watch Out For (Symptoms of Increased Side Effects): Since your son is fine now, monitor him closely for the next 12 to 24 hours for the following common signs of a slightly higher dose:
Increased Drowsiness/Sleepiness or Dizziness (due to the antihistamine).
Dry Mouth, Dry Nose, or Dry Throat.
Mild Headache or Upset Stomach/Nausea.
Restlessness, Jitteriness, or Fast Heartbeat (less common, due to the decongestant).
What You Should Do:
Do not give any more doses of Sinarest or any other medicine containing Paracetamol or other cold ingredients for the rest of the day.
Ensure hydration: Give him plenty of fluids (water, juice) to help his body process the medication.
Seek medical advice immediately if he develops any severe symptoms such as extreme confusion, difficulty breathing, unresponsiveness, severe stomach pain, or a very rapid or irregular heartbeat.
In most cases involving a single accidental double dose, especially in older children, mild side effects are the most likely outcome. If you remain very anxious or have any specific concerns about the dosage or ingredients, it is always safest to consult a doctor or pharmacist for personalised advice based on his weight and the exact timing of the doses.