Cough and cold products such as Robitussin should not be used to treat children younger than 6 years without the advice of a doctor, according to WebMD. Children younger than 12 should not take some products, such as long-acting tablets and capsules.
No evidence shows that this medication is safe or effective for children of that age, reports WebMD. In addition, Robitussin doesn't cure or hasten recovery from the common cold, and it may lead to serious side effects in a child.
Mental or mood changes, such as confusion and hallucinations, shaking, and weakness are unlikely but serious side effects of Robitussin, advises WebMD. A fast, slow or irregular heartbeat is a rare but very serious side effect.
Robitussin is a combination medication containing guaifenesin, dextromethorphan and pseudoephedrine. It's used to treat cough, chest congestion and stuffy nose symptoms resulting from the common cold, flu, allergies, hay fever and other breathing illnesses, such as sinusitis and bronchitis, states WebMD.
Guaifenesin, an expectorant, makes it easier to cough up mucus in the lungs by thinning and loosening it, WebMD explains. Dextromethorpan, a cough suppressant, eases coughing by affecting the part of the brain responsible for the urge to cough. Pseudoephedrine, a decongestant, provides some relief from stuffy nose symptoms, according to Drugs.com.