Aim As the administration of palivizumab, shown to provide effective passive prophylaxis to respiratory syncytial virus (RSV) and reduce RSV-related hospitalisation in high-risk infants,¹ will continue and remains a high-cost drug, it is important to ensure continual review of the outpatient immunisation clinic. The aim of this study was to investigate if clinical outcome was affected by the current dosing schedule and suggest possible measures to improve the efficiency and cost-effectiveness of the clinic.

Method The following data were collected for all patients receiving palivizumab between October 2014 and March 2015; indication for treatment, weight at start and end of treatment, details of dose and date given and reasons for discontinuation or transfer of treatment. The following were then calculated from the data; rates of RSV- related hospitalisation, median dose administered (mg/kg) basedon predicted weight (using the standardised neonatal and infant close monitoring growth charts) to ascertain under or over dosing and current and additional costs of any suggested service developments. A two-tailed paired student t-test was used to assess statistical significance. The study methodology was approved by the local research ethics committee and the Caldicott guardian.

Results 0.98% and 3.92% of all patients receiving palivizumab contracted RSV with an underlying cardiac condition or prematurity respectively. Median weight gain over the 5 month period was 37.18% (n=54, p<0.001). Median dose (mg/kg) based on predicted weight was 15.6, 15, 14.29, 13.79, 13.33 from clinic 1 to 5 respectively. Median percentage difference from target dose of 15 mg/kg was 4.01, 0,–4.76, −8.05,–11.1 from clinic 1 to 5 respectively. The estimated incremental cost for weighing and dosing each patient at every clinic was £7,077.66 (6.3%).

Conclusion Patients receiving palivizumab for RSV prophylaxis require to be weighed more frequently and subsequently prescribed a more appropriate dose at the outpatient immunisation clinic if optimal doses are to be achieved. However, the sub-optimal dosing did not affect RSV-related hospitalisation rate when compared with rates in current literature² and further work is required to model mean trough concentrations achieved from the median doses administered.³ The increased cost of prescribing a dose based on increased weight can be justified due to expected improvementin patient outcome and potential reduction in RSV-related hospitalisation. As pharmacists are being actively encouraged to become independent prescribers within the next few years,⁴ it would be an ideal opportunity to utilise this resource in an effort to potentially improve prescribing efficiency within the clinic and provide additional benefits such as improved parent/carer education.

References

1. The Impact-RSV Study Group. Palivizumab, a humanised respiratory syncytial virus monoclonal antibody, reduces hospitalisation from respiratory syncytial virus infection in high-risk infants. Paediatrics1998;102:531–537.

2. Deshpande SA, Northern V. Community child health, public health, and epidemiology: The clinical and health economic burden of respiratory syncytial virus disease among children under 2 years of age in a defined geographical area. Arch Dis Child2003;88:1065–1069.

3. Zaaijer HL. Vandenbroucke-grauls CMJE, Franssen EJF. Optimum Dosage Regimen of Palivizumab?Therapeutic Drug Monitoring2002;24:444–445.

4. The Scottish Government. Prescription for excellence: A vision and action plan for the right pharmaceutical care through integrated partnerships and innovation 2013. http://tinyurl.com/z9etgch [Accessed: 03/08/2017].