Promethazine as a decongestant?
From Mr J. N. Kiiru, MRPharmS
I am intrigued by the labelling information for Night Nurse Liquid, which contains the following: “Promethazine, with decongestant action to dry up runny noses and sniffles, so easing breathing.”
What caught my attention is the claim that promethazine has a decongestant action. Decongestants in over-the-counter remedies are well known (pseudoephedrine, phenylephrine, xylometazoline, etc). They mainly relieve nasal congestion by vasoconstriction of the blood vessels in the nasal mucosa. They also have mild central stimulant action, which renders them marketable as non-sedating.
Promethazine has none of those effects. Promethazine is an H1 receptor-blocking agent (antihistamine). In addition to its antihistaminic action, it provides clinically useful sedative and antiemetic effects.
In community pharmacy, that distinction is important. For example, pharmacy assistants are taught that patients who suffer from hypertension should avoid decongestants because they can increase blood pressure. I telephoned GSK’s medicines information department for clarification but it offered no explanation.
It said it would reply to me via email but I am still waiting. Surprisingly, the decongestant claim is not made for Night Nurse Capsules despite identical ingredient composition.
Can GSK be deliberately redefining decongestion specifically for Night Nurse Liquid in order to qualify its label claim for promethazine?
I have contacted the head of patient information quality at the Medicines and Healthcare products Regulatory Agency, who wrote back to me in these terms: “I have noted your comments and am in agreement with the points you have raised. The statement regarding promethazine being a decongestant has been on the labelling for many years but I agree that this is not appropriate. It is in fact a sedating antihistamine which has secondary antimuscarinic effects which may result in a drying of mucous membranes but this is not the main action of this active moiety. I am not persuaded by anything I have read either in the SPC or in other reference sources that this active could be described as a decongestant. It is my view that mention of a decongestant on this product is misleading since as you point out hypertensive patients will know not to self-medicate with products which claim a decongestant action. We will be writing to the marketing authorisation holder to request changes to the packaging to address this.”
Jeremiah N. Kiiru
MERLE BEAL, consumer and medical affairs director, GlaxoSmithKline Consumer Healthcare, responds: The current Night Nurse Liquid carton does, indeed, state “Promethazine, with decongestant action to dry up runny noses and sniffles, so easing breathing”. This wording has been included on the carton for over 20 years and was approved by the MHRA. In consultation with the MHRA at the end of 2011, GlaxoSmithKline undertook to revise the wording to be more consistent with the information given in the product leaflet, which states that promethazine hydrochloride is an antihistamine that dries up a runny nose and aids restful sleep.
New artwork for the carton that includes this clarification has been commissioned and submitted to the MHRA for review. Once approved, the new carton for Night Nurse Liquid will be introduced. Further queries on this matter can be directed to the medical information direct line (tel +44 (0)20 8047 250).
Citation: The Pharmaceutical JournalURI: 11099529
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