Recommendations for crushing Circadin® (melatonin) tablets for safe and reliable delivery via pediatric nasogastric tubes

Melatonin is an important drug in pediatric medicine which often requires delivery through a narrow bore nasogastric tube (e.g. FR6; 1300 µm internal diameter) for patients that cannot swallow tablets. Although Circadin® 2 mg tablets are often crushed for nasogastric delivery, there is an absence of evidence for the effectiveness of different methods for producing powders that can be administered without risk of blocking nasogastric tubes. Our aim was to develop a robust protocol for crushing Circadin tablets and suspending the powder for safe administration via paediatric nasogastric tubes. Circadin tablets were crushed using four different tablet crushers. For comparison, a pestle and mortar and tablespoon were also used to crush tablets as these techniques are also used in clinical practice. The particle size of powders resulting from different crushing maneuvers was evaluated using sieve analysis, laser diffraction and image-based sizing methods. For all the tablet crushers, five operations produced powders with irregular-shaped individual particles less than 500 µm diameter. A protocol termed ‘King's 5-5-5′ was developed for tablet crushers: powder obtained after 5 crushes was suspended in 5 mL water and delivered through NG tubes with pre and post-administration flushing with 5 mL water. This protocol is simple, low cost, uses readily available materials and enables the safe and reliable delivery of melatonin to paediatric patients without the fear of blocking nasogastric tubes.