Unblinding

Participants in the CAP-IT trial should be given 2 doses of amoxicillin syrup from the bottle with the yellow label (bottle A) for days 1-3 (6 doses in total); the syrup could be 125mg/5ml or 250 mg/5ml.

Participants are then given 2 doses per day of syrup from the blue bottle(s) (bottles B/C) - this is either amoxicillin 125mg/5ml or amoxicillin 250 mg/5ml or placebo. Dose volume is written on the bottles and patient card.

CAP-IT is a double-blind trial. This means that neither the carer nor the child’s doctor will know which treatment the child has received.

Almost all clinical scenarios can be managed by assuming a trial participant is taking 250mg/5ml amoxicillin and withholding the trial medication. We only expect unblinding in the CAP-IT trial to be necessary in situations of significant overdose of trial medication. Ingested volumes indicated below from any CAP-IT drug bottle would be considered significant:

 

Weight range (kg) Prescribed dose of CAP-IT medication Ingested volume (unblinding should be considered)
< 6.4 4.5 ml twice a day 25 ml
6.5 - 8.4 6 ml twice a day 25 ml
8.5 - 10.4 7.5 ml twice a day 50 ml
10.5 - 13.4 9.5 ml twice a day 50 ml
13.5 - 16.9 12 ml twice a day 75 ml
17 - 20.9 15 ml twice a day 75 ml
21 - 24 or heavier 16.5 ml twice a day 100 ml

If unblinding is felt to be clinically essential, all NHS doctors are able to find out a participant's treatment allocation through the unblinding process. Where unblinding is being considered, wherever possible, the case should first be discussed with the MRC CTU. A flow diagram of the unblinding process can be found here.

To contact MRC CTU
Phone: +44 (0)20 7670 4763 (during normal working hours)
Email: mrcctu.capit@ucl.ac.uk

Medication labels on the bottles

All NHS doctors can directly access treatment information in an emergency using the link below, and entering their GMC number and NHS or HNSCI email address in addition to the participant's CAP-IT trial ID and Medication ID. These details can be found on the medication labels on the bottles/packets. The participant's trial ID and Medication ID can also be found on their CAP-IT trial card. Unblinding details will be sent to the NHS email address provided.

UNBLINDING SHOULD ONLY BE PERFORMED BY AN NHS DOCTOR AND SHOULD ONLY BE CONSIDERED WHERE KNOWLEDGE OF TREATMENT ALLOCATION IS ESSENTIAL TO GUIDE CLINICAL MANAGEMENT

In the event that you are unable to contact the MRC CTU and you consider unblinding to be essential for the participant's immediate management, please proceed to unblind the participant. MRC CTU should be contacted as soon as possible after unblinding.

Unblind a participant