Medscape is available in 5 Language Editions – Choose your Edition here.


Nocardiosis Medication

  • Author: George Kurdgelashvili, MD; Chief Editor: Michael Stuart Bronze, MD  more...
Updated: Feb 16, 2016

Medication Summary

General treatment guidelines for nocardiosis are hindered by (1) lack of controlled clinical trials of therapy; (2) difficult, and, in the past, poorly standardized in vitro susceptibility testing leading to widely disparate reports of in vitro antimicrobial susceptibility[23, 24] ; (3) lack of firm data on correlation of in vitro susceptibility with in vivo therapeutic efficacy; and (4) the changing taxonomy of Nocardia species. Therapy should likely be guided by in vitro susceptibility testing at a specialized laboratory experienced at testing Nocardia strains.

Sulfonamides have long been the first-line antimicrobial therapy for nocardiosis. Among the sulfonamides, sulfadiazine is generally preferred because of its CNS and CSF penetration. Although not convincingly demonstrated superior, trimethoprim-sulfamethoxazole (TMP-SMZ) is considered the therapy of choice by most authorities. Divided doses of 5-10 mg/kg/d of the trimethoprim component should be administered to produce sulfonamide levels of 100-150 mcg/mL; such levels should possibly be confirmed in individuals with severe disease.

Additional or alternative parenteral therapies include carbapenems (imipenem or meropenem, but not ertapenem), third-generation cephalosporins (cefotaxime or ceftriaxone), and amikacin, alone or in combination. Imipenem plus amikacin may be the preferred regimen in sulfonamide-allergic individuals. Linezolid in vitro activity and in vivo efficacy has been reported.[25] Tigecycline also has reported activity in vitro.[1]

For most serious Nocardia infections, combination therapy has been recommended.[1] Combination therapy should be continued until clinical improvement occurs and confirmation of in vitro drug susceptibility has been acquired.

Alternative oral therapies include minocycline and amoxicillin/clavulanate, in addition to linezolid. These may be used initially in mild-to-moderately severe disease or as sequential therapy after an induction course of parenteral therapy. Modern fluoroquinolones often have demonstrable in vitro activity against Nocardia species but have failed therapeutically.

Duration of treatment is generally prolonged to minimize risk of disease relapse. Immunocompetent patients with non-CNS nocardiosis may be successfully treated with 6-12 months of antimicrobial therapy. Immunosuppressed patients and those with CNS disease should receive 12 months of therapy or longer if escalation of immunosuppression takes place (such as graft or organ rejections). In For patients on chronic steroid or cytotoxic therapy, prolonged maintenance of anti-nocardial therapy may be indicated. Appropriate clinical monitoring should be conducted during protracted antimicrobial therapy.[1]



Class Summary

Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.

Sulfadiazine (Microsulfon)


Exerts its bacteriostatic action by competitive antagonism of paraaminobenzoic acid (PABA). Microorganisms that require exogenous folic acid and do not synthesize folic acid are not susceptible to the action of sulfonamides. In difficult cases, may be important to document peak serum levels (2 h after PO dose are 100-150 mg/L).

Trimethoprim-sulfamethoxazole (Bactrim, Septra)


Inhibits bacterial growth by inhibiting synthesis of dihydrofolic acid.

Meropenem (Merrem IV)


Bactericidal broad-spectrum carbapenem antibiotic that inhibits cell-wall synthesis. Effective against most gram-positive and gram-negative bacteria. Has slightly increased activity against gram-negative organisms and slightly decreased activity against staphylococci and streptococci compared to imipenem.

Cefotaxime (Claforan)


Third-generation cephalosporin with gram-negative spectrum. Lower efficacy against gram-positive organisms. Arrests bacterial cell wall synthesis, which in turn inhibits bacterial growth.

Ceftriaxone (Rocephin)


Third-generation cephalosporin with broad-spectrum, gram-negative activity; lower efficacy against gram-positive organisms; higher efficacy against resistant organisms. Arrests bacterial growth by binding to one or more penicillin-binding proteins.

Amikacin (Amikin)


For gram-negative bacterial coverage of infections resistant to gentamicin and tobramycin. Effective against Pseudomonas aeruginosa.

Irreversibly binds to 30S subunit of bacterial ribosomes and blocks recognition step in protein synthesis, which causes growth inhibition. Use patient's IBW for dosage calculation.

Minocycline (Minocin)


Treats infections caused by susceptible gram-negative and gram-positive organisms, in addition to infections caused by susceptible Chlamydia, Rickettsia, and Mycoplasma.

Amoxicillin and clavulanate (Augmentin)


Drug combination treats bacteria resistant to beta-lactam antibiotics. In children >3 mo, base dosing protocol on amoxicillin content. Because of different amoxicillin/clavulanic acid ratios in 250-mg tab (250/125) vs 250-mg chewable tab (250/62.5), do not use 250-mg tab until child weighs >40 kg.

Linezolid (Zyvox)


Prevents formation of functional 70S initiation complex, which is essential for bacterial translation process. Bacteriostatic against enterococci and staphylococci and bactericidal against most strains of streptococci. Used as alternative in patients allergic to vancomycin and for treatment of vancomycin-resistant enterococci.

Contributor Information and Disclosures

George Kurdgelashvili, MD Clinical Associate Professor of Medicine, Department of Medicine, University of Oklahoma College of Medicine; Assistant Chief of Medical Service, Director of Diagnostic Center Clinic, Chair of Infection Prevention and Control Committee, Attending Physician, Infectious Diseases Section, Oklahoma City Veterans Affairs Medical Center

George Kurdgelashvili, MD is a member of the following medical societies: Infectious Diseases Society of America, HIV Medicine Association, Veterans Affairs Society of Practitioners in Infectious Diseases

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

John W King, MD Professor of Medicine, Chief, Section of Infectious Diseases, Director, Viral Therapeutics Clinics for Hepatitis, Louisiana State University Health Sciences Center; Consultant in Infectious Diseases, Overton Brooks Veterans Affairs Medical Center

John W King, MD is a member of the following medical societies: American Association for the Advancement of Science, American College of Physicians, American Federation for Medical Research, Association of Subspecialty Professors, American Society for Microbiology, Infectious Diseases Society of America, Sigma Xi

Disclosure: Nothing to disclose.

Chief Editor

Michael Stuart Bronze, MD David Ross Boyd Professor and Chairman, Department of Medicine, Stewart G Wolf Endowed Chair in Internal Medicine, Department of Medicine, University of Oklahoma Health Science Center; Master of the American College of Physicians; Fellow, Infectious Diseases Society of America

Michael Stuart Bronze, MD is a member of the following medical societies: Alpha Omega Alpha, American Medical Association, Oklahoma State Medical Association, Southern Society for Clinical Investigation, Association of Professors of Medicine, American College of Physicians, Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Additional Contributors

Thomas J Marrie, MD Dean of Faculty of Medicine, Dalhousie University Faculty of Medicine, Canada

Thomas J Marrie, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians, American Society for Microbiology, Association of Medical Microbiology and Infectious Disease Canada, Royal College of Physicians and Surgeons of Canada

Disclosure: Nothing to disclose.

  1. Wilson JW. Nocardiosis: updates and clinical overview. Mayo Clin Proc. 2012 Apr. 87(4):403-7. [Medline].

  2. Euzeby Jean P. List of prokaryotic names with standing in nomenclature. Available at Accessed: 11/20/2014.

  3. Beaman BL, Beaman L. Nocardia species: host-parasite relationships. Clin Microbiol Rev. 1994 Apr. 7(2):213-64. [Medline].

  4. Centers for Disease Control and Prevention. Available at Accessed: June 7, 2013.

  5. Smego RA Jr, Moeller MB, Gallis HA. Trimethoprim-sulfamethoxazole therapy for Nocardia infections. Arch Intern Med. 1983 Apr. 143(4):711-8. [Medline].

  6. Lavalard E, Guillard T, Baumard S, Grillon A, Brasme L, Rodríguez-Nava V, et al. Brain abscess due to Nocardia cyriacigeorgica simulating an ischemic stroke. Ann Biol Clin (Paris). 2013 Jun 1. 71(3):345-348. [Medline].

  7. Boiron P, Locci R, Goodfellow M, et al. Nocardia, nocardiosis and mycetoma. Med Mycol. 1998. 36 Suppl 1:26-37. [Medline].

  8. Castro JG, Espinoza L. Nocardia species infections in a large county hospital in Miami: 6 years experience. J Infect. 2007 Apr. 54(4):358-61. [Medline].

  9. Filice GA. Nocardiosis in persons with human immunodeficiency virus infection, transplant recipients, and large, geographically defined populations. J Lab Clin Med. 2005 Mar. 145(3):156-62. [Medline].

  10. Hui CH, Au VW, Rowland K, Slavotinek JP, Gordon DL. Pulmonary nocardiosis re-visited: experience of 35 patients at diagnosis. Respir Med. 2003 Jun. 97(6):709-17. [Medline].

  11. Kilincer C, Hamamcioglu MK, Simsek O, et al. Nocardial brain abscess: review of clinical management. J Clin Neurosci. 2006 May. 13(4):481-5. [Medline].

  12. Lederman ER, Crum NF. A case series and focused review of nocardiosis: clinical and microbiologic aspects. Medicine (Baltimore). 2004 Sep. 83(5):300-13. [Medline].

  13. Lerner PI. Nocardiosis. Clin Infect Dis. 1996 Jun. 22(6):891-903; quiz 904-5. [Medline].

  14. Matulionyte R, Rohner P, Uckay I, et al. Secular trends of nocardia infection over 15 years in a tertiary care hospital. J Clin Pathol. 2004 Aug. 57(8):807-12. [Medline].

  15. Pintado V, Gomez-Mampaso E, Cobo J, et al. Nocardial infection in patients infected with the human immunodeficiency virus. Clin Microbiol Infect. 2003 Jul. 9(7):716-20. [Medline].

  16. Saubolle MA, Sussland D. Nocardiosis: review of clinical and laboratory experience. J Clin Microbiol. 2003 Oct. 41(10):4497-501. [Medline].

  17. Pilsczek FH, Augenbraun M. Mycetoma fungal infection: multiple organisms as colonizers or pathogens?. Rev Soc Bras Med Trop. 2007 Jul-Aug. 40(4):463-5. [Medline].

  18. Martinez Tomas R, Menendez Villanueva R, Reyes Calzada S, et al. Pulmonary nocardiosis: risk factors and outcomes. Respirology. 2007 May. 12(3):394-400. [Medline].

  19. Rosman Y, Grossman E, Keller N, Thaler M, Eviatar T, Hoffman C, et al. Nocardiosis: A 15-year experience in a tertiary medical center in Israel. Eur J Intern Med. 2013 May 29. [Medline].

  20. Lerner PI. Nocardiosis. Clin Infect Dis. 1996 Jun. 22(6):891-903; quiz 904-5. [Medline].

  21. Beaman BL, Beaman L. Nocardia species: host-parasite relationships. Clin Microbiol Rev. 1994 Apr. 7(2):213-64. [Medline]. [Full Text].

  22. Peleg AY, Husain S, Qureshi ZA, et al. Risk factors, clinical characteristics, and outcome of Nocardia infection in organ transplant recipients: a matched case-control study. Clin Infect Dis. 2007 May 15. 44(10):1307-14. [Medline].

  23. Uhde KB, Pathak S, McCullum I Jr, et al. Antimicrobial-resistant nocardia isolates, United States, 1995-2004. Clin Infect Dis. 2010 Dec 15. 51(12):1445-8. [Medline].

  24. Brown-Elliott BA, Biehle J, Conville PS, Cohen S, Saubolle M, Sussland D. Sulfonamide resistance in isolates of Nocardia spp. from a US multicenter survey. J Clin Microbiol. 2012 Mar. 50(3):670-2. [Medline].

  25. Minero MV, Marin M, Cercenado E, Rabadan PM, Bouza E, Munoz P. Nocardiosis at the turn of the century. Medicine (Baltimore). 2009 Jul. 88(4):250-61. [Medline].

High-power microscopic appearance of Nocardia. Image courtesy of CDC.
Photomicrograph of tissue biopsy stained with Gomori methenamine silver demonstrating acute inflammatory response and organisms compatible with Nocardia.
Plain chest radiograph in a patient with nocardiosis. Image courtesy of Applied Radiology, Anderson Publishing, LTD.
Chest CT scan in a patient with pleuropulmonary nocardiosis. Image courtesy of Applied Radiology, Anderson Publishing, LTD.
Brain CT scan in a patient with nocardial brain abscess. Image courtesy of Applied Radiology, Anderson Publishing, LTD.
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.