Ongoing management of MRSA native bone or joint infection

The suggested duration of antibiotic therapy and timing of oral switch for adults and children with methicillin-resistant Staphylococcus aureus (MRSA) native bone or joint infection depends on whether the patient has osteomyelitis or septic arthritis.

In adults and children with MRSA osteomyelitis or septic arthritis, treatment is determined by the results of susceptibility testing. When it is appropriate to switch to oral therapy, use:

1clindamycin 450 mg (child: 10 mg/kg up to 450 mg) orally, 8-hourly clindamycin clindamycin clindamycin

OR

1doxycycline orally, 12-hourly1 doxycycline doxycycline doxycycline

adult: 100 mg

child less than 21 kg: 2.2 mg/kg2

child 21 to less than 26 kg: 50 mg

child 26 to 35 kg: 75 mg

child more than 35 kg: 100 mg

OR

1trimethoprim+sulfamethoxazole 320+1600 mg (child 1 month or older: 8+40 mg/kg up to 320+1600 mg) orally, 12-hourly. For dosage adjustment in adults with kidney impairment, see trimethoprim+sulfamethoxazole dosage adjustment. trimethoprim + sulfamethoxazole trimethoprim+sulfamethoxazole trimethoprim+sulfamethoxazole

If resistance to all of the oral drugs above is confirmed, and susceptibility to rifampicin and either fusidate sodium or ciprofloxacin has been demonstrated, use a combination ofPark, 2013:

rifampicin 300 mg (child: 7.5 mg/kg up to 300 mg) orally, 12-hourly rifampicin rifampicin rifampicin

PLUS EITHER

1ciprofloxacin 750 mg (child: 20 mg/kg up to 750 mg) orally, 12-hourly34. For dosage adjustment in adults with kidney impairment, see ciprofloxacin oral dosage adjustment ciprofloxacin ciprofloxacin ciprofloxacin

OR

1fusidate sodium 500 mg (child: 12 mg/kg up to 500 mg) orally, 8-hourly5. fusidate sodium fusidate sodium (fusidic acid) fusidate sodium (fusidic acid)

Do not use monotherapy with rifampicin, fusidate sodium or ciprofloxacin.

Rifampicin and fusidate sodium interact significantly with many commonly used medicines; ciprofloxacin also has significant drug interactions. For comprehensive information on drug interactions, consult an appropriate drug information resource.

1 An oral liquid formulation of doxycycline is not marketed in Australia but is available via the Special Access Scheme. For formulation options for children or people with swallowing difficulties, see Don’t Rush to Crush, which is available for purchase from the Advanced Pharmacy Australia website or through a subscription to eMIMSplus.Return
2 When used short term (eg less than 21 days), doxycycline has not been associated with tooth discolouration, enamel hypoplasia or bone deposition so can be used in children of all ages.Return
3 An oral liquid formulation of ciprofloxacin is not commercially available; for formulation options for children or people with swallowing difficulties, see Don’t Rush to Crush, which is available for purchase from the Advanced Pharmacy Australia website or through a subscription to eMIMSplus.Return
4 Ciprofloxacin is not licensed for use in children on the basis of animal studies that showed an adverse effect on cartilage development with quinolone use; however, clinical trial data suggest that adverse musculoskeletal events are usually mild and short term, similar to those observed in adults. Ciprofloxacin can be used in children when it is the drug of choice.Return
5 In adults, if fusidate sodium 500 mg orally, 8-hourly is not tolerated, 500 mg 12-hourly can be used.Return