question: 40 yr old patient was taking warfarin 4 gms for DVT prophylaxis. She was given  ceftriaxone 8 hrs i.v. for a dental infection. Later the lady experienced episode of  vaginal bleeding and darkening of urine. What is the cause?
opa: Gut ﬂora was inhibited by ceftriaxone
opb: Ceftriaxone is an enzyme inducer
opc: Both have additional thrombocytopenic eﬀect
opd: Ceftriaxone inhibits metabolism of warfarin