A pharmaceutical company has been censured for making “falsely optimistic” claims about the success rate of one of its products in treating bedwetting in children.
The Prescription Medicines Code of Practice Authority, which administers the pharmaceutical industry's code of conduct, has ordered Ferring Pharmaceuticals to withdraw literature claiming that up to 71% of patients achieve long term dryness using desmopressin.
Community paediatrician Dr Delia Elliott from the Scott Hospital in Plymouth, Devon, wrote to the BMJ in March 2001 expressing her concerns about the claims. She copied the letter to the code of practice authority, where it was treated as a complaint.
Dr Elliott said that she valued “the appropriate use of desmopressin” in treating childhood bedwetting. But she added that Ferring's literature gave a “falsely optimistic picture of the success rate and [made] no mention of age groups in which the product may be indicated or alternative treatments.”
Ferring quoted studies that suggested that long term use resulted in 71% of patients showing a reduction in wet nights rather than achieving total night-time dryness. The studies used doses of 40 mg over 28 weeks. However, the UK summary of product characteristics states that the dose should be increased from 20 mg to 40 mg “only if needed” and that this dose should be used only for three months.
After a five month investigation the authority found Ferring in breach of the code and ordered promotional material to be withdrawn and rewritten to clarify efficacy rates. Ferring appealed, but the original decision was upheld.
In its ruling the authority said that bedwetting spontaneously resolves in 15% of patients over time, and so long term studies were performed against a “shifting baseline,” making it hard to determine whether the patient became dry because of desmopressin or because of spontaneous resolution.
The authority stated: “Overall the appeal board did not consider that the balance of evidence was such to support the claim ‘Up to 71% of patients achieve long term dryness.’ The claim was referenced to a study in which desmopressin was not used according to the UK summary of product characteristics. The board considered that the claim was misleading and could not be substantiated.”
Tony Waters, head of Ferring's medical division, said that the ruling was “a matter of clarification,” saying, “if we are guilty of anything, it is of being too close and confident with our product.”