Calls to tackle inappropriate paediatric formulations
A study that reveals the wide variation in unlicensed liquid captopril formulations used in UK hospitals and paediatric cardiac centres has led to calls for more research to develop age-appropriate formulations.
Researchers at Glenfield Hospital, Leicester, conducted a national survey
after observing that a variety of captopril formulations were being used
by pharmacies serving paediatric patients whose care was being co-ordinated
by the hospital.
The researchers say that the discrepancies they found (see Panel below)
suggest that children might not be getting the most effective dose for
their
condition, and that they may be being put at risk (published
online in
Archives of Disease in Childhood on 15 March 2007).
Study findings
The researchers questioned clinical and paediatric pharmacists
at 13 paediatric cardiac centres and 13 hospitals referring patients
to these centres.
They found that four of the 26 organisations dispensed captopril
tablets for crushing and dissolving in water for paediatric patients.
The remaining 22 used nine different liquid formulations, which
came from a variety of sources.
Three hospitals recommended formulations for use after discharge
that were different from those that had been used while the child
was an inpatient. And 10 specialist centres and their referring
hospitals used completely different liquid formulations.
The researchers also discovered that, with one exception, there
were no hard data to confirm the stated shelf life of the formulations
prepared by specials manufacturers and those made up on site. |
Commenting
on the study, Sara Arenas-López, specialist paediatric
pharmacist, Evelina Children’s Hospital, Guy’s & St Thomas’ NHS
Foundation Trust, London, said: “The problem reported by the authors
is a long-standing worldwide unresolved issue in paediatric cardiology.”
She explained that most captopril preparations used to treat children
are not properly studied in terms of quality assurance analysis and bioavailability,
consistency of clinical effects and adverse reactions. “This creates
a problem in clinical practice since each child behaves completely differently
at the time of titrating the dose to optimal effect. There is no clear
correlation between the dose needed and the dose actually given,” she
said.
Guy’s and St Thomas’ imports a licensed liquid formulation
from Australia. “Among all the available options it is the option
offering least risk. … However, importation of this product also
presents a challenge as the continuity of supply is unreliable,” she
said.
Ms Arenas-López added that further research was needed, along
with a commitment from manufacturers. “Could the Australian manufacturer
not apply for the marketing authorisation in the UK,” she asked.
Catherine Tuleu, lecturer and deputy director of the Centre for Paediatric
Pharmacy Research, The School of Pharmacy, University of London, echoed
Ms Arenas-López’s concerns: “The only way to address
the problem is to research and develop age-appropriate formulations for
children.”
Dr Tuleu said that the situation should improve for new chemical entities
because of recent incentives — an extra six months’ patent
protection — introduced in EU regulations that came into force
earlier this year.
“The problem remains for off-patent medicines such as captopril,
although the EC has announced … a funding scheme that will ease
the situation. It will support studies on better paediatric use of off-patent
medicines
currently used off-label, including the development of appropriate formulations,
the assessment of pharmacokinetics, efficacy and safety,” she added. |
The
Pharmaceutical Journal
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