Prescription / Dosage Problem

I need some help with this problem:

METRONIDAZOLE is prescribed 400mg tds. stock issue is 200mg how many tablets will be given to the patient in 48 hour period.    

Reply (by Keith): So, you have 200mg tabs and the script calls for 400mg T.D.S(Latin: ter die sumendum) Which means three times daily. Therefore the order calls for 1200mg every 24 hour period. There are two 24 hour periods, so 2400mg total needed.


2400mg ÷ 200mg tabs = 12 Tabs