A spoonful of sugar really does help the medicine go down, according to the results of a new review.

Dr. Denise Harrison, of the Royal Children's Hospital in Melbourne, and colleagues found that giving less than half a teaspoon of a sugary solution to infants up to 12 months of age reduces crying and pain due to vaccination. 

'We already have glucose solutions in the clinic that we can use, but we really need the request to come from the parents.'— Karen Booth, registered nurse

The large-scale statistical review, which Harrison led while at Toronto's Hospital for Sick Children, appears online ahead of print in this week's Archives of Disease in Childhood, combined immunization data from 1,618 infants.

Harrison says giving sugar solutions by mouth to newborns before painful procedures is known to be effective at reducing pain, but until now there was no evidence to support the practice in older babies.

"We located a potential 700 published trials for inclusion in our study, but found only 14 randomly administered a sugary solution or water or no treatment to infants older than a month", says Harrison.

The sweeter the better

Where possible, the team analyzed the incidence of crying, the length of time the children cried and their pain scores, which can include assessments of facial expression, arm and leg movements, breathing and heart rate, in addition to crying.

The amount of sugar made a difference, but because a wide variety of volumes and concentrations were used in the different trials, the researchers can't say what the ideal dose is.

"We were, however, able to combine and analyze three trials where the infants all received a 30 per cent glucose solution and found that, compared with those given water, they were 20 per cent less likely to cry," says Harrison. "This is much sweeter than flat lemonade."

"Interestingly, breast milk is not very sweet by comparison, and expressed milk seems to be no more effective than water. But when babies are breast fed, the combination of milk and the sucking is a very effective technique."

Short-term pain relief

Registered nurse Karen Booth, who is on the board of directors of the Australian Practice Nurses Association, says she uses a number of distraction techniques prior to and during vaccination, including giving "snake lollies" or candy to the older children.

Booth is excited by the new findings and hopes that that they will have a positive effect on parents who are reluctant to have their children vaccinated because of concerns regarding pain.

"Some mothers get quite distressed," she says. "Others are reluctant to give babies sweet things because of the misconception that it will give them a sweet tooth."

Harrison says the study supports the use of a small amount of a sweet solution for children undergoing a range of painful procedures.

"I have no problem with that," says Booth. "We already have glucose solutions in the clinic that we can use, but we really need the request to come from the parents."

The pain-relieving effects of sweet solutions given to older infants were also found to be more moderate than those in newborns.

"The effects seem to wear off more quickly in the older infants so, ideally, you'd give a small amount of a sweet solution — greater than 20 per cent — two minutes before the first injection and then additional drops before every needle," says Harrison.

But, Harrison cautions that this technique should not be used at home as the effect is short-lasting and you could end up giving the baby a lot of sugar, which is bad for their teeth.