pku watch
It is important that parents under- poor appetite. This may be partly Although it is good practice to
stand that even to a baby, feeding explained by the protein substitute. give ‘stage-by-stage’ weaning
EXPERIENCE WITH KUVAN
®
is a social event and the accep- Although all babies with PKU require advice throughout this process, it is
In July 2005, Katherine consented to participate in the Kuvan
®
clinical trial
tance of a new food is aided by phenylalanine-free protein substitute, also important that parents receive
programme. At this stage she was taking 10 exchanges and four PKU
supplements per day.
caregivers or siblings eating the the daily dosage that is required is general information about wean-
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same food at the same time. Any likely to inhibit appetite as it contains ing, so they have an idea of the
Screening study This trial tested for responsiveness. Katherine took Kuvan
®
10 mg/kg for eight days without altering her normal dietary intake. Her Phe levels
negative adult attitude to any of
a significant source of calories. In- overall process. They need reas-
fell by 76% (from 879 µmol/L to 213 µmol/L), which meant that she qualified as a
fants, who receive calories from one surance that weaning their baby
KUVAN
®
CASE STUDY
the low protein foods or low pheny-
‘responder’ and was able to continue into the placebo-controlled trial.
lalanine diet is unacceptable and
source, will compensate by eating with PKU will not be so different to
Extension study This trial experimented with different doses of Kuvan
®
.
should be discouraged.
less calories at mealtime. It is impor- feeding other children. To help with
Adults and children with hyperphenylalaninaemia (HPA) due to BH
4
deficiency, and
adults and children over the age of four years with HPA caused by phenylketonuria
Katherine took 5 mg/kg of Kuvan
®
for two weeks, at which point her blood Phe
In PKU, there are so many things
tant to accept that inhibition of ap- this, the NSPKU have now produced
(PKU), can now be offered the oral treatment sapropterin dihydrochloride (Kuvan
®
). level was 572 µmol/L. After her dose was increased to 20 mg/kg for two weeks
that have to be remembered
petite may be an issue from the onset a brightly coloured weaning book-
Responsiveness to Kuvan
®
must be established before long-term treatment can be
her blood Phe level was 316 µmol/L.
and fitted into the daily feeding
of weaning. Increasing the energy let, especially written for parents of
commenced.
1
A four-week trial with Kuvan
®
is recommended, starting with 10 mg/kg/day.
Long-term study In this long-term study, Katherine took 15 mg/kg of Kuvan
®
per
babies with PKU. It will be launched
This can be increased to 20 mg/kg if a satisfactory response ( *30% decrease in blood
schedule, that good routine, and
density of weaning foods, by adding
phenylalanine; Phe) is not achieved after one week.
1
day and had an average blood Phe level of 661 µmol/L (range: 492–755).
consistency in carer behaviour and
additional low protein milk, butter at the NSPKU conference, March
Trials have shown that patients with mild HPA are most likely to respond to Kuvan
®
, but
responsiveness is essential. One help-
or margarine, low protein pasta or 2010 and will be available via the
responsiveness has been observed across the HPA/PKU population.
2
In responders, the
KATHERINE TODAY
ful suggestion may be to encourage
cereal is important from the early NSPKU.
number of patients achieving a Phe target of <360 µmol/L was significantly increased in
stages. Supplementation should help
Katherine has continued on a dose of 15 mg/kg (this equates to 11 tablets
With careful management in
those taking Kuvan
®
compared to placebo.
3
In a separate trial, children compliant with a
all caregivers to attend parenting
Phe-restricted diet who responded to Kuvan
®
were able to increase their daily Phe dissolved in water) and has increased her daily exchanges from 10 to 20 since
skills courses and this may aid them
babies require a smaller volume of PKU, the weaning process can
supplement by 21 mg/kg/day compared to baseline.
4
completing the trial. She is still quite restrictive with her diet, but has been able to
in understanding the demands and
solid foods but still achieve their en-
closely replicate the one advised This is the first of three case studies that describes a patient who has been treated with
incorporate a range of new foods including meats and cheese.
expectations associated with child-
ergy requirements. Although admin-
for normal healthy infants. However,
Kuvan
®
. Her name has been changed to protect her identity. She was treated by the inherited
Katherine now reports fewer migraines and has experienced unexpected
istering protein substitute pre-meals
caregiver anxiety and uncertainty
metabolic disease team at the Charles Dent Metabolic Unit, National Hospital for Neurology
care and the actions they need to and Neurosurgery, London. improvement in her teeth, eyes and skin condition. She feels more energetic and
take to achieve the best outcome
whilst the infant is hungry helps with its
may delay the feeding develop- finds it easier to combine caring for her husband with work and volunteering.
for their child.
adherence, it is still better to adminis-
mental progression and this is a
ter it at least 30 minutes or so before
time when things may go wrong.
CASE HISTORY CONCLUSION
Protein supplementation
the meal is due to assist appetite.
During the weaning process it is
Katherine is a 51-year-old healthcare assistant. She cares for her sick husband This patient was relatively well controlled, but since starting Kuvan
®
she has
‘He is never hungry. How do I get
‘I have been so worried about
essential that dietitians invest plenty
and volunteers for a learning disability group. She suffers from mild asthma and been able to relax her diet from 10 to 20 exchanges and maintain a lower blood
weaning. The health visitor could not
of time, energy and effort into
occasional migraines but is otherwise fit and well. Phe level. She also reports physical and psychological improvements.
him to gain weight?’
Mother of a nine-month-old boy who has
give me any advice.’
supporting families. Time spent in
Katherine’s PKU was not diagnosed until she was nine years of age, as she was
poor weight gain.
Parent of a six-month-old baby who
helping ease families through this
born before the introduction of post-natal screening. Katherine struggled with
perceived that weaning would be very
process, will pay dividends in the
school, which prompted a series of investigations and the eventual diagnosis of
Many infants with PKU have a complex. years to come.
IN BRIEF
PKU. She left school aged 16 with low-grade passes in English and cookery and
attended college. At age 21 she took a job as a healthcare assistant.
U Ê x £