Severe disease
For initial empirical therapy of severe nocardiosis (see Nocardiosis disease categories for treatment), use three drugs until results of susceptibility tests are available. If either trimethoprim+sulfamethoxazole or linezolid is contraindicated or not tolerated, seek expert advice for empirical therapy. If the patient is hypersensitive to trimethoprim+sulfamethoxazole, drug desensitisation is recommended—seek expert advice.
For initial empirical therapy of nocardiosis in patients with severe disease, use:
trimethoprim+sulfamethoxazole 320+1600 mg (child 1 month or older: 8+40 mg/kg up to 320+1600 mg) intravenously or orally, 12-hourly. For dosage adjustment in adults with kidney impairment, see trimethoprim+sulfamethoxazole dosage adjustment nocardiosis, severe trimethoprim + sulfamethoxazole trimethoprim+sulfamethoxazole trimethoprim+sulfamethoxazole
PLUS
linezolid 600 mg intravenously or orally, 12-hourly (child younger than 12 years: 10 mg/kg up to 600 mg intravenously or orally, 8-hourly). For dosage adjustment in adults with kidney impairment, see linezolid dosage adjustment nocardiosis, severe linezolid linezolid linezolid
PLUS EITHER
1 amikacin (adult and child) 20 mg/kg intravenously, daily or amikacin (adult and child) 10 mg/kg intravenously, 12-hourly. Monitor plasma concentration from the first dose—see Principles of aminoglycoside use for dosage adjustment and principles of use nocardiosisamikacin amikacin amikacin
OR
1 imipenem 500 mg (child: 15 mg/kg up to 500 mg) intravenously, 6-hourly1. For dosage adjustment in adults with kidney impairment, see imipenem+cilastatin dosage adjustment nocardiosisimipenem imipenem+cilastatin imipenem+cilastatin
OR
2 meropenem 2 g (child: 40 mg/kg up to 2 g) intravenously, 8-hourly; administer the dose over 3 hours. For dosage adjustment in adults with kidney impairment, see meropenem dosage adjustment. nocardiosismeropenem meropenem meropenem
Meropenem has a lower risk of seizures than imipenem, but there are less published data to support its use for nocardiosis. Isolates may be resistant to meropenem but susceptible to imipenem.
Modify therapy based on the results of species identification and susceptibility testing, if possible. When susceptibility is known, continue therapy with two antimicrobials to which the organism is susceptible for 3 weeks, or up to 6 weeks for CNS disease and in immunocompromised patients.
Follow initial therapy with oral eradication therapy for up to 12 months’ total duration (initial + eradication therapy). Patients who remain immunocompromised may require maintenance therapy indefinitely—seek expert advice. For eradication therapy, if susceptible, use:
trimethoprim+sulfamethoxazole 160+800 mg (child 1 month or older: 4+20 mg/kg up to 160+800 mg) orally, 12-hourly for up to 12 months’ total duration (initial + eradication therapy). For dosage adjustment in adults with kidney impairment, see trimethoprim+sulfamethoxazole dosage adjustment. trimethoprim + sulfamethoxazole trimethoprim+sulfamethoxazole trimethoprim+sulfamethoxazole
If there is resistance to trimethoprim+sulfamethoxazole, or if the patient is hypersensitive to trimethoprim+sulfamethoxazole and desensitisation cannot be performed, alternative options for oral eradication therapy include amoxicillin+clavulanate, minocycline, linezolid or moxifloxacin, depending on susceptibility.