'Cough syrups not for kids under 5; low body weight makes dosing risky'

The Coldrif cough syrup tragedy has once again exposed gaps in India’s drug safety system. Dr Lancelot Pinto, consultant respirologist at P D Hinduja National Hospital, explains why such contamination is fatal, and when cough syrups are truly needed

Coldrif cough syrup, linked to the deaths of at least 14 children in Madhya Pradesh, Rajasthan, and Kerala, was found to contain 48.6% diethylene glycol, nearly 500 times the safe limit. Can you explain how ingesting such a toxic chemical affects children?

Diethylene glycol should not be present, in any amount, in a medication. Diethylene glycol (DEG) and ethylene glycol (EG) are industrial solvents used in antifreeze, paints, brake fluids, and not meant for human consumption. Since they are inexpensive solvents, unscrupulous manufacturers use them as a substitute for more expensive, safe and approved excipients such as glycerol. Such a substitution is harmful to humans, especially to children, in whom the low body weight, and limited capacity to metabolize and excrete the chemical make the exposure more potent per ml of ingestion. A ‘permissible limit’ is allowed only because trace contamination is often inevitable and such trace contamination that is usually below the level of detection (typically 0.1% or less) is considered harmless. Ingesting DEG at high doses can cause kidneys to fail within a day, neurologic manifestations such as seizures, failure of the liver and pancreas, and the acidic environment in the blood can cause multiple organs, such as the heart and lungs, to fail. Even if the child survives, they are likely to have lifelong complications, especially if the dose is high.

There have been protests against the arrest of the doctor who prescribed the syrup. Where does the primary responsibility lie — with the doctor, manufacturer or regulatory authorities?

To the best of my knowledge, Coldrif was not a banned syrup. If it was legally manufactured and marketed, it must have been subjected to regulatory approvals. The combination of medications used in the syrup is not toxic when prescribed as indicated, and the deaths were the result of adulteration, not the drugs themselves. Doctors cannot be blamed for this.



Do general physicians today have a tendency to over-prescribe cough syrups?

In 2024, the revenue in the Cold & Cough Remedies market in India amounted to $1.49bn (the per person revenue in India was $1.03 in 2024). There is definitely an overuse of cough syrups, both as a result of overprescription and over-the-counter use. A significant proportion of coughs are self-limiting, and an equal proportion need treatment of the cause (reflux, asthma, post-nasal drips are frequent culprits) rather than syrups.

Many cough syrups are available over the counter in India. How dangerous is it when these are bought without considering the correct age group?

The best cough suppressants are often opioids or opioid derivatives. These have addiction potential and are often abused. Antihistamines present in cough syrups can cause drowsiness, difficulty in concentration, in addition to affecting cognition, and can cause serious injuries and falls, especially at both ends of the age spectrum. It is very easy to make mistakes in taking the correct dose, and the difference between the right dose and a dangerous dose can be a few ml in children.

What does research say about the effectiveness of cough syrups?

Bronchodilators such as terbutaline in cough syrups can help with coughs associated with bronchospasm (inhalers are superior and safer but tend to be more expensive). Opioids work well in certain types of coughs but should be absolutely avoided in children and the elderly. Cough syrups can have a soothing effect because of their viscosity, coating the nerve endings in the throat which can cause irritant coughs. However, honey, chocolate and even sucking on non-medicated lozenges have been shown to have a similar effect.

What is your approach to integrating it into the overall treatment plan?

A cough is a protective defence mechanism that helps clear mucus, often secreted in response to an irritant or an infection. When it is acute and associated with an infection, it is often self-limiting and does not warrant any specific treatment. Coughs that last longer than 4-6 weeks need to be investigated and the underlying cause treated. Asthma, reflux and post-nasal drip tend to be the commonest causes in children and adults. In certain refractory coughs (such as those associated with diseases such as lung fibrosis), opioid cough syrups have a definitive role, but this is for a small minority of all coughs. Cough syrups should be avoided in children, especially those under 5, as the low body weight makes dosing precarious, and the risk-to-benefit ratio is, therefore, high.

The market has many herbal syrups. Could they also pose health risks?

The words ‘herbal’ or ‘natural’ should not be assumed to be synonymous with ‘safe’. I would be very careful about using any medication that has not gone through rigorous scientific testing.