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• Gaviscon Infant® is effective symptomatically in infant reflux-associated symptoms
  Mike A Thomson
  Published on: 14 November 2005
• Gaviscon on gastro-oesophageal reflux in infants: A poorly effective treatment?
  Francesco Cresi
  Published on: 22 August 2005
• Absence of wash-out period between Gaviscon and placebo may be responsible for anomalous findings
  Vishal Paisal
  Published on: 20 July 2005

• Published on: 14 November 2005

  Gaviscon Infant® is effective symptomatically in infant reflux-associated symptoms

  • Mike A Thomson, Paediatric Gastroenterologist

  Dear Editor

  In response to the comments of Paisal (1), regarding our study on the influence of Gaviscon Infant® on gastro-oesophageal reflux in infants studied by the new physiologically appropriate modality of combined intraluminal oesophageal pH/impedance (2), we would like to make the following points.

  Commenting on the study design he points to two studies which found benefit of Gaviscon. What he...

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  Dear Editor

  In response to the comments of Paisal (1), regarding our study on the influence of Gaviscon Infant® on gastro-oesophageal reflux in infants studied by the new physiologically appropriate modality of combined intraluminal oesophageal pH/impedance (2), we would like to make the following points.

  Commenting on the study design he points to two studies which found benefit of Gaviscon. What he fails to point out, and perhaps realise, is that one of these studies was carried out using what could be regarded now, since the advent of clinical application of impedance, as the sub- standard physiological denominator i.e. pH alone (3), and the other study is in adults and uses completely different forms of Gaviscon from the one we employed, and the actions of these preparations and their gastric emptying properties are likely to be very different (4) – hence any inference drawn from this study to make conclusions regarding gastro-oesophageal Gaviscon Infant® exposure should be subject to significant critical scrutiny, and then dismissed as irrelevant to our study, which was carried out in a different age group and employing a different preparation. Given that studies using the correct modern measurement tool i.e. combined intraluminal impedance and pH exist for other preparations such as thickening agents showing that methodology of comparison of different randomised feeding events in a 24 hour period is robust in identifying post-prandial reflux differences, we feel it is very likely that in our study the conclusions drawn would not be influenced by hypothetical slow gastric emptying of Gaviscon. (5) Hence the criticism that because no wash out period was present in our study it was this that prevented any observable objective reflux differences between Gaviscon and placebo, is not upheld.

  However, it is worth emphasising that whilst in the abstract we point to a difference in the height of reflux migration as the only statistically significant difference, it is small - hence conclusions regarding the mode of action of the definite observed improvement in clinical symptoms by parents in this cohort of infants due to this preparation cannot be drawn on the basis of this study.

  The inference that this preparation does not work in infant reflux should not be drawn from this study, merely that the mode of action is not shown with this accurate and appropriate physiological tool. In the discussion section we make reference to this and suggest reasons for this. For instance it may be that Gaviscon Infant® has an action by coating the distal oesophagus thereby preventing mucosal injury from refluxed substances such as acid, pepsin, or bile acids. The actual reflux continues, as evidenced by this study (presuming adequate power for statistical significance), but the injury resultant from it may be diminished. This is an important question raised by this study, and the main conclusion that it now seems that the mode of action for the observed clinical efficacy of Gaviscon Infant® , which is an observed and measurable phenomenon, is not by preventing reflux per se, must be emphasised. The obvious sequela of this, as detailed in the discussion section, should therefore be that further studies are necessary to determine how this widely-used and effective product has an effect clinically in infants and children.

  Further studies are needed and could also be conducted over longer periods of time, such as 24 hours placebo v 24 hours treatment with wash out periods between, which would help to answer some of the points raised regarding the design of our study by Paisal 1 and the group of Cresi et al (6), but it my be that this design would be harder to justify ethically. Clearly, as we know that this product is effective clinically in infant reflux as first line therapy, we require a greater understanding of its mode of action, necessitating further enquiry with well conducted interventional studies examining in different ways the clinically observable beneficial effect of Gaviscon Infant® on the reflux- oesophagitis axis in infants.

  References

  1. Paisal V. Absence of wash-out period between Gaviscon and placebo may be responsible for anomalous findings. Arch Dis Child. 2005;90:5;460.

  2. Del Buono R, Wenzl TG, Ball G, Keady S, Thomson M. Effect of Gaviscon Infant on gastro-oesophageal reflux in infants assessed by combined intraluminal impedance/pH. Arch Dis Child. 2005; 90: 460-463. 3. Buts JP, Barudi C, Otte JB. Double-blind controlled study on the efficacy of sodium alginate (Gaviscon) in reducing gastroesophageal reflux assessed by 24 h continuous pH monitoring in infants and children. Eur J Pediatr. 1987;146:156-158.

  4. Washington N, Greaves JL, Iftikhar SY. A comparison of gastro- oesophageal reflux in volunteers assessed by ambulatory pH and gamma monitoring after treatment with either Liquid Gaviscon or Algicon Suspension. Aliment Pharmacol Ther. 1992;6:579-588.

  5. Wenzl TG, Trachterna M, Silny J, Heimann G, Skopnik H. Effect of thickened feeding on gastro-esophageal reflux in infants - a placebo- controlled study using intraluminal impedance (Abstract). J Pediatr Gastroenterol Nutr. 2000;30:S206.

  6. Cresi F, Savino F, Marinaccio C, Silvestro L. Gaviscon on gastro- oesophageal reflux in infants: A poorly effective treatment? Arch Dis Child. 2005;90:5;460.

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  Conflict of Interest:
  None declared.

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• Published on: 22 August 2005

  Gaviscon on gastro-oesophageal reflux in infants: A poorly effective treatment?

  • Francesco Cresi, Paediatric Specialist
  • Other Contributors:
    • Francesco Savino, Cristina Marinaccio, Leandra Silvestro

  Dear Editor,

  We read with interest the recent article by Del Buono et al. evaluating the effect of sodium and magnesium alginate (Gaviscon) on gastro-oesophageal reflux (GER) in infants [1]. It provides an objective assessment of the effects of a drug widely used in the treatment of paediatric GER by means of a double-blind drug vs placebo trial, in which the effects of each treatment were evaluated by means of...

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  Dear Editor,

  We read with interest the recent article by Del Buono et al. evaluating the effect of sodium and magnesium alginate (Gaviscon) on gastro-oesophageal reflux (GER) in infants [1]. It provides an objective assessment of the effects of a drug widely used in the treatment of paediatric GER by means of a double-blind drug vs placebo trial, in which the effects of each treatment were evaluated by means of the simultaneous application of multichannel intraluminal impedance and pH-metry (MII/pH). The authors show that Gaviscon reduces this height, probably because it increases the viscosity of the gastric content and hence acts in the same way as thickened feeding [2]. They also found that fewer acid reflux episodes occurred after Gaviscon, though the difference was not significant. By contrast with the evidence produced in other studies [3], therefore, these results seem to suggest that Gaviscon Infant has little effect on GER when assessed in objective terms. It is, however, possible that the significance of some of the differences they observed has been weakened by the influence of sleep and wakefulness on GER episodes [4].

  During 53 MII/pH 24h monitorings in infants with GER symptoms at our Centre, we noted a significant difference between the number of episodes during wakefulness (535 hr) and sleep (450 hr): 3.2 ± 4.1 episodes per hr versus 1.8±3.3; p<0.001; CI 0.93±1.87). Del Buono et al. gave six milk meals plus drug or placebo according to a 3+3 schedule. If we suppose that a infant sleeps 12 hours a day, then the probability that "sleep" and "wakefulness" periods were equally distributed between Gaviscon and placebo in each of their 20 patients can be no more than 50%. This probability drops even further if account is taken of the fact that infants with GER sleep less than normal. The difference in GER frequency between sleep and wakefulness, coupled with the asymmetrical distribution of these phases, constitutes a "confounding factor" responsible for great variability of all the frequency data (no. episodes per hour, no. of acid episodes, no. of postprandial episodes per hour, etc.), whereas it may have little influence on GER "quality" (duration; pH and height).

  We thus believe that assessment of efficacy of the treatment of GER by means of MII/pH requires longer observation periods (e.g. 24h-placebo vs 24h-drug), or at all events consideration of the influence of sleep and wakefulness on GER episodes.

  References

  1.Del Buono R, Wenzl TG, Ball G, Keady S, Thomson M. Effect of Gaviscon Infant on gastro-oesophageal reflux in infants assessed by combined intraluminal impedance/pH. Arch Dis Child. 2005; 90: 460-463.

  2.Wenzl TG, Schneider S, Scheele F, Silny J, Heimann G, Skopnik H. Effects of thickened feeding on gastroesophageal reflux in infants: a placebo-controlled crossover study using intraluminal impedance. Pediatrics 2003; 111: 355-9.

  3.Buts JP, Barudi C, Otte JB. Double-blind controlled study on the efficacy of sodium alginate (Gaviscon) in reducing gastroesophageal reflux assessed by 24 h continuous pH monitoring in infants and children. Eur J Pediatr. 1987; 146: 156-8.

  4.Schilter B. Gastro-oesophageal reflux in children: comparison of different durations, positions and sleep-awake periods of pH monitoring in the same patient. Eur J Pediatr. 1993; 152: 880-3.

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  Conflict of Interest:
  None declared.

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• Published on: 20 July 2005

  Absence of wash-out period between Gaviscon and placebo may be responsible for anomalous findings

  • Vishal Paisal, Clinical Observer

  Dear Editor,

  Oesophageal pH monitoring has been used to monitor gastro-oesophageal reflux (GOR). However, Buono et al. point out that this method will not record instances of 'neutral-reflux' after a feed (1). They say that multiple intraluminal impedance measurement is a more appropriate way to assess GOR. Using the technique they have found that Gaviscon does not reduce reflux. The number and height of reflux with Gav...

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  Dear Editor,

  Oesophageal pH monitoring has been used to monitor gastro-oesophageal reflux (GOR). However, Buono et al. point out that this method will not record instances of 'neutral-reflux' after a feed (1). They say that multiple intraluminal impedance measurement is a more appropriate way to assess GOR. Using the technique they have found that Gaviscon does not reduce reflux. The number and height of reflux with Gaviscon infant was not different from periods with placebo.

  Alongside impedance measurement, Buono et al. also performed conventional pH monitoring. They found that Gaviscon did not reduce acid reflux in their study. This contradicts the findings of previous studies which found Gaviscon reduces acid reflux.[2, 3] Differences in the study design are responsible for this difference. Buts et al. used random allocation to Gaviscon or placebo treatment.[2] Washington on the other hand used a cross-over design but the cross-over was performed one week apart.[3] In contrast to this, in the present study, 6 random administrations of Gaviscon infant and placebo were employed in a 24 hour period (3+3). There was no wash-out period between drug and placebo. In effect all patients in this study were given Gaviscon three times in 24 hours. It is not surprising that there was no difference between patients. We cannot therefore accept the findings of this study without serious reservations.

  References

  1. Del Buono R, Wenzl TG, Ball G, Keady S, Thomson M. Effect of Gaviscon Infant on gastro-oesophageal reflux in infants assessed by combined intraluminal impedance/pH. Arch Dis Child. 2005; 90: 460-463.

  2. Buts JP, Barudi C, Otte JB. Double-blind controlled study on the efficacy of sodium alginate (Gaviscon) in reducing gastroesophageal reflux assessed by 24 h continuous pH monitoring in infants and children. Eur J Pediatr. 1987; 146: 156-158.

  3. Washington N, Greaves JL, Iftikhar SY. A comparison of gastro-oesophageal reflux in volunteers assessed by ambulatory pH and gamma monitoring after treatment with either Liquid Gaviscon or Algicon Suspension. Aliment Pharmacol Ther. 1992; 6: 579-588

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  Conflict of Interest:
  None declared.

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