i never knew this until xmas this year when dd was taken to hospital (by blue light ambulance ) she was 15 at the time and menigitis was the first thought both doc and para-medics had (btw - this came on so quickly its not true!)
in fact, she had severe sinus infection, which, when told, made me feel totally stupid for 'wasting' nhs resources and angry for the fact that i thought my dd was in fact, dying.
had i known previously i would have tried the combined dosage!
btw - i have used both this summer when it happened again, the difference is amazing.