Then I went to CVS for Claritin-D - the machine wouldn't allow me to be the large pack of twenty-four hour pills - I don't think it's been less than two weeks since buying the Mucinex-D - then again, they were having a lot of issues with their machines. It certainly allowed me to be the 12-hour version but I didn't notice she gave me the smallest pack - ten tablets - if I have to take two a day, that's only five days. Ridic.