The purpose of this study is to determine whether the standard dosage of teicoplanin is adequate to produce timely the trough level > 10 mg/L, which is considered to be effective in the treatment of methicillin-resistant Staphyllococcus aureus (MRSA) bacteremia.

In our hospital, the minimum inhibitory concentration of 100 MRSA isolates in 2003 for teicoplanin is 2 mg/L. Due to its time-dependant bacteriocidal effect, the trough level should exceed 10 mg/L, particularly in the elderly, for MRSA bacteremia. However, it is known that standard dosage of teicoplanin often produces inadequate serum trough levels, and MRSA infections may recurred. Therefore, to evaluate the loading dose required to achieve therapeutic concentration timely, we compare the trough levels between those given standard dose (6 mg/Kg) and those given increasing loading dose (12 mg/Kg). We also monitor the occurrence of adverse drug effects and clinical response.

Inclusion Criteria:

• Patients over 16 years of age who have blood culture-proven MRSA bacteremia and did not receive teicoplanin or vancomycin in the previous one month are enrolled.

Exclusion Criteria:

• Those who are allergic to teicoplanin or who have the need to use higher doses, 12 mg/kg/dose, such as endocarditis, osteomyelitis, septic arthritis and burn patients, are excluded.