Elevated PT, APPT and PT/ INR possibly associated with doxycycline and cefoperazone co-administration: A case report.

What is known and objective Little is known regarding changes in blood coagulation parameters associated with tetracycline antibiotics. We report a possible case of elevated PT, APPT and PT/ INR associated with doxycycline and cefoperazone co-administration. Case summary An 83-year-old Chinese male inpatient with severe pneumonia, chronic renal insufficiency and malnutrition experienced elevated PT, APPT and PT/ INR which occurred within a few days of doxycycline added to his cefoperazone treatment and returned to normal after removal of it. What is new and conclusion Very close monitoring of coagulation parameters might be advisable in those subjects when administering doxycycline and cefoperazone concomitantly. [ABSTRACT FROM AUTHOR]