Recently I was prescribed an antibiotics (levofloxacin) treatment of 500mg daily for 7 days. Being in Indonesia the doctors generally don't give any information and I took my first dose at exactly the same time as a high dosage vitamin/mineral supplement. Later I read that this actually may have pretty much voided the first dose entirely, see WebMD concerning "taking other products that may bind to it" or Wikipedia:
When levofloxacin is taken with anti-acids containing magnesium hydroxide or aluminum hydroxide, the two combine to form insoluble salts that are difficult to absorb from the intestines. Peak serum concentrations of levofloxacin may be reduced by 90% or more, which can prevent the levofloxacin from working. Similar results have been reported when levofloxacin is taken with iron supplements and multi-vitamins containing zinc
Is this enough reason to buy an extra dose on my own and continue for 1 more day or is there enough safety margin built into these treatments that account for some incorrect usage?