From Mr N. J. G. Stow, FRPharmS
SIR,—I was very interested to read of Pat Clark's concerns over the labelling of Thornton and Ross's glycerin, lemon and honey (PJ, October 30, p708) as I experienced an embarrassing confrontation with the husband of a patient earlier this year. He requested a simple cough mixture for his wife who suffered with hypertension; with complete confidence, I recommended a bottle of this mixture. Shortly after the purchase he returned and took me to task for selling a bottle clearly labelled, "Use with caution if you have diabetes, heart or kidney disease". Having sold this preparation with complete safety for 50 years I was at a loss to understand why this warning now appeared on the label. I wrote to Thornton and Ross. After reading its reply I was still not clear as to the exact nature of the problem likely to be encountered by a patient with these conditions. I wrote to the Society's information department and, in her reply, Miss Khan wrote: "I have checked the technical information service's in-house department database (RPSePIC), International Abstracts and PubMedline (Medline via the internet). Although anecdotal references do appear concerning adverse effects of glycerin therapy on the heart and kidneys, I have been unable to locate details of definitive dosages at which the effects are most likely to occur in human subjects." Thornton and Ross has now changed the warning to read: "Ask your doctor or pharmacist before use if suffering from heart and kidney disease." What advice do I give regarding this apparent unquantified danger? I am inclined to the view expressed by Pat Clarke that this is surely labelling gone mad.
Noel Stow Bury St Edmunds, Suffolk
Mr NEVILLE G. EDWARDS (sales and marketing director, Thornton & Ross) replies: I refer to the recent letters by Pat Clarke and Noel Stow, regarding the contraindications on the labelling of one of our products - Care Glycerin, Lemon & Honey.
One of the reasons behind the recent labelling changes has been to make pharmacists and consumers better informed on the precise nature and implications of the various ingredients included in these common and popular medicinal remedies. The Thornton & Ross label for Care Glycerin Lemon & Honey has included cautionary wording for those "suffering from heart or kidney disease" since mid 1995. The changes made in 1999 give precautionary information which is now required by statute. The specific warnings in question relate to glycerol, a significant component of this product, and these are based on the information contained in various editions of Martindale (the Extra Pharmacopoeia).