Letters to the Editor
Cefaclor and serum sickness-like reactions
- Michael Starr
- Aust Prescr 1999;22:28-31
- 1 April 1999
- DOI: 10.18773/austprescr.1999.032
The Editorial Executive Committee welcomes letters, which should be less than 250 words. Before a decision to publish is made, letters which refer to a published article may be sent to the author for a response. Any letter may be sent to an expert for comment. When letters are published, they are usually accompanied in the same issue by their responses or comments. The Committee screens out discourteous, inaccurate or libellous statements. The letters are sub-edited before publication. Authors are required to declare any conflicts of interest. The Committee's decision on publication is final.
Editor, – The association between serum sickness or serum sickness-like reactions and cefaclor has been well documented.1-9 The Pharmaceutical Benefits Advisory Committee has recently amended the listing for cefaclor in the Schedule of Pharmaceutical Benefits. The listing now includes the caution that 'serum sickness-like reactions have been reported with this drug, especially in children'. In response, the Medical Director of Eli Lilly, the manufacturer of Ceclor, has circulated a letter to all doctors (22 October1998). This letter misconstrues the facts and is misleading.
The letter states that the amendment regarding serum sickness-like reactions is unnecessary as `the incidence has remained rare (0.024%) and unchanged since launch'. In fact, published studies have estimated a rate 20 times or more higher than that quoted in the drug's product information.1,2 Indeed, in the article from the Lilly Research Laboratories that quotes the 0.024%figure, the author himself states: `This incidence differs from findings reported in the literature'!8 Most of the subjects in that study were adults and the rate was higher in children.8
The letter makes the disingenuous statement that serum sickness has been associated with many antibiotics. Several studies have found that the rate is higher for cefaclor than other antibiotics.1-5 During4 years of retrospective and prospective monitoring of serum sickness at this hospital, 48 children have been identified with antibiotic-associated serum sickness.1,7 Of these, 42 (88%) were related to cefaclor. In the prospective study, cefaclor was responsible for 95% of serum sickness linked to antibiotics.7 In another study of 3487 children who had been prescribed amoxycillin, cefaclor, or both, the relative risk of serum sickness after cefaclor was 19 times that of amoxycillin.2
The letter suggests that serum sickness-like reactions differ from classic serum sickness. This distinction is not clinically relevant. The clinical features are not trivial; allergic skin disease, arthritis and fever may be present in both. Furthermore, 25% or more result in presentation to an emergency department or admission.9 The letter also states that `no such caution has been added anywhere (else in the world)'.However, the Canadian Adverse Drug Reaction Monitoring Program issued a similar caution in 1996.9
I concur with the letter's advice that the choice of antimicrobial therapy should be based on the likely pathogens and the spectrum of activity of the antibiotic. For these reasons, many conditions for which cefaclor is currently prescribed (otitis media and tonsillitis) would be better managed with either no antibiotic or a narrow-spectrum penicillin (phenoxymethylpenicillin or amoxycillin).
Finally, the letter recommends to doctors that they be waryof those who 'may try to misrepresent or exaggerate the facts'. It would be hove Eli Lilly to heed its own advice.
Consultant Paediatrician and Infectious Diseases Fellow
Department of Microbiology and Infectious Diseases
Royal Children's Hospital
Consultant Paediatrician and Infectious Diseases Fellow, Department of Microbiology and Infectious Diseases, Royal Children's Hospital, Melbourne, Vic.