question: it is common that antibiotic eg amoxycillin taken while on warfarin dosage increases INR level, but my INR level in this situation has decreased to 1.4 (range 2-3); I have completed my week long dosage of the antibiotic and felt OK with no adverse symptons all along. My GP directed me to continue the same warfarin dosage and have INR check in a week for further directions