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Marsh and colleagues  raise the spectre of a possible association
the use of sildenafil and the development of retinopathy of prematurity
in a 26-week gestation baby with pulmonary hypertension. We are
that this report offers no real evidence for its claims and that a
lifesaving agent is being unfairly maligned.
The report describes the use of...
The report describes the use of intravenous sildenafil of
16 days in a 525 g preterm with a very difficult intensive care course.
management included a litany of recognised causes of ROP, including
extreme prematurity, >6 weeks mechanical ventilation with 80-100%
oxygen, and bacterial and fungal infections.
Despite this, Marsh et al chose to incriminate sildenafil as the
The suggestion is even more perplexing as the baby had already received
inhaled nitric oxide at high levels (40ppm for 2-3 weeks) prior to the
sildenafil; both are vasodilators and have the same mechanism of action.
The authors make the
further statement that they observed a recent increase in
treatable ROP in their unit, coinciding with the use of sildenafil.
As far as we are aware there is no evidence in the literature that
any significant effect on either retinal or choroidal blood vessels.
Pache et al
reported  that in adults, siledenafil induced a 5.8% dilatation of
vessels but this was not confirmed by Grunwald et al  on either retinal
choroidal circulations . To date there is no data on the effect of
the developing ocular circulations.
We entirely agree that vigilant monitoring and responsible
effects is mandatory for any new drug application. To our knowledge the
only available intravenous sildenafil is
released on a named patient basis in a prospective study in neonates.
How did the authors obtain and administer the drug in neonates?
Sildenafil and inhaled nitric oxide are experimental therapies within
preterm population and as clinicians we have a responsibility to ensure
they are used as part of prospective randomised controlled trials with
appropriate short and long term follow up. Although being well
such unconvincing reports may impede the use of agents which might have
an important future role in the management of primary pulmonary
hypertension of the newborn.
Conflict of interest
The authors have acted in an independent consultant capacity (CMP, AJP,
and are in receipt of financial support in the form of a research grant
AJP) from the manufacturers of sildenafil, Pfizer Ltd.
Pierce CM, Consultant Paediatric Intenisivist(1)Petros AJ, Consultant Paediatric Intenisivist(1)
Fielder AR, Professor of Ophthalmology(2)
1.Neonatal Intensive Care Unit
Great Ormond Street Hospital
London WC1N 3JH
2. Department of Visual Neuroscience
Imperial College London
Room 9L02, Charing Cross Campus
St Dunstan's Road
London, W6 8RP
Phone 44 (0)20 8383 3693
Fax 44 (0)20 8383 3651
(1) Marsh CS. Marden B, Newsom R. Severe retinopathy of prematurity
(ROP) in a premature baby treated with sildenafil acaetate (Viagra) for
pulmonary hypertension. Br J Ophthalmol 2004; 84: 306-307
(2) Pache M, Meyer P, Prünte C, Orgül S, Nuttli I, Flammer J.
induces retinal vasodilatation in healthy subjects. Br J Ophthalmol
(3) Grunwald JE, Siu KK, Jacob SS, Dupont J. Effect of sildenafil
the ocular circulation. Am J Ophthalmol 2001; 131: 751-755
(4) Grunwald JE, Metelisina T, Grunwald L. Effect of sildenafil
retinal blood vessel diameter. Am J Ophthalmol 2002; 133: 809-812
pede the use of agents which might have an important future role in the
management of primary pulmonary hypertension of the newborn.