Promethazine DM syrup is a cough and cold product that eases breathing problems associated with common respiratory conditions. It is a prescription medicine and should be used as directed by your health care provider. Dextromethorphan hydrobromide and promethazine hydrochloride are the two main ingredients that play a key role in alleviating symptoms of upper respiratory infections. A teaspoon of the syrup delivers around 15 mg of dextromethorphan and 6.25 mg of promethazine. Alcoholic content of the syrup is around 7%. Alcohol in cough syrups acts as a solvent, ensures that all the ingredients are dissolved properly, and helps maintain consistency of the liquid. There are quite a few inactive ingredients that help to improve chemical stability and add color and flavor to the syrup. They are mentioned below:

• Ascorbic acid
• Citric acid
• Menthol
• Methylparaben
• Orange-pineapple flavor
• Propylene glycol
• Propylparaben
• Saccharin sodium
• Sodium citrate
• Sodium benzoate
• Sucrose

When it comes to relieving deep, barking cough associated with common respiratory ailments, promethazine DM syrup may be recommended. Dextromethorphan added in the syrup displays antitussive (anticough) properties, thereby, helping to relieve cough. Antitussive agents are cough suppressants that quieten your urge to cough. Dextromethorphan works on a specific part of the brain that suppresses the cough reflex. Promethazine displays antihistamine properties, meaning they block histamine response to allergy triggers. It is a powerful antihistamine that helps treat histamine-related symptoms. As we all know, when exposed to allergens, the body releases histamines (chemicals secreted by the mast cells) that cause sneezing, watery eyes, itching, and runny nose. Taking this syrup as directed can certainly help control allergy symptoms. This combination of promethazine and dextromethorphan is also effective to calm down symptoms associated with common cold, seasonal flu, and hay fever. Promethazine DM, though effective to relieve respiratory problems, can cause a few bothersome side effects. So, taking this antihistamine and cough suppressant combination can cause the following side effects that are relatively common:

• Dizziness
• Drowsiness
• Sweating
• Nausea
• Dry mouth
• Constipation

These side effects are likely to reduce or go away completely after lowering the dosage. Also, you may no longer experience these side effects, once the body adjusts to the medication. The following side effects are rare, yet serious and must be immediately brought to the attention of a qualified doctor:

• Slow heart rate (bradycardia)
• Seizures
• Trouble urinating
• Hallucination
• Feeling faint
• Hypertension
• Liver dysfunction that causes yellowing of skin or eyes

The dosage is primarily dependent on the age of the patient.

• For adults: a teaspoon of the syrup every 4 to 6 hours; not to exceed 30 mL in a day.
• For children (6 to under 12 years): half to one teaspoon every 4 to 6 hours is given; not to exceed 20 mL in a day.

This is given depending upon the severity of the symptoms. Children in the age group of 2-6 years are usually given quarter to half a teaspoon of syrup every 4 to 6 hours. Children who haven't crossed 2 years of age are not a candidate for treatment with promethazine DM syrup. They are deemed unfit as the syrup can cause hypoventilation (respiratory depression). Also, children over 2 years should be administered the minimum possible dose to keep side effects at bay. Also, this syrup is not recommended to relieve common cold symptoms in children who have not reached 6 years of age. Health care providers, in most cases, do not prescribe this syrup to relieve chronic lung disorders such as emphysema, asthma, and bronchitis. Disclaimer: The information provided in this article is solely for educating the reader. It is not intended to be a substitute for the advice of a medical professional.