Endocarditis - injection drug users

Valeria Fabre, M.D., John G. Bartlett, M.D.



  • Fever, malaise, chest/back pain, cough, dyspnea, arthralgia/myalgia, neurologic sx, wt loss, night sweats.
    • Back pain could represent vertebral osteomyelitis, discitis and/or epidural abscess
  • Endocarditis rates especially due to MRSA appear to be rising, commiserate with the U.S. opioid epidemic[2].
  • Suspect endocarditis in any IDU with fever without an otherwise identifiable source.
  • Pathogens: S. aureus- 60%, Streptococcal species- 20%, P. aeruginosa- 10%, Candida - 5%, S. epidermidis- 2%.
  • Right-sided endocarditis, most common, tricuspid valve involved in 60% of cases.


  • Duke Clinical Criteria: 2 Major OR 1 Major + 3 Minor OR 5 Minor.
    • Major (microbiology):
    • Major (valve):
      • Echocardiography w/ vegetation definitive/oscillating mass
      • New valve regurgitation
    • Minor:
      • Predisposing cardiac condition or IDU
      • Fever ≥ 38°C (100.4°F)
      • Vascular phenomenon (arterial emboli, mycotic aneurysm, intracerebral bleed, conjunctival hemorrhages, Janeway lesions)
      • Immune phenomenon (glomerulonephritis, Osler nodes, Roth spots, positive rheumatoid factor
      • Positive blood cultures not meeting above criteria
      • Echocardiographic valve abnormality but not diagnostic for vegetation



  • Patients with active substance abuse are often reluctant to stay in hospitals or nursing facilities to receive IV-based treatment.
  • Short-course therapy (2 wks) with IV abx may be possible for some patients with uncomplicated TV endocarditis (see below).
  • Oral therapy: rarely advocated but sometimes used depending on clinical circumstances when IV therapy not possible or patient leaves against medical advice, limited clinical data available.

Antibiotics: empiric

Pathogen-specific recommendations

See PROSTHETIC VALVE endocarditis for PVIE regimens.


  • Indications: severe heart failure, uncontrolled infection, persistent bacteremia despite abx, fungal endocarditis, unstable prosthetic valve, periannular extension.
    • Tricuspid valve: may consider valvectomy or vegetectomy + valvuloplasty.
    • Aortic or mitral valve: usually requires replacement.
  • Issues: some cardiac surgeons are reluctant to operate for IE, requiring assurance there will be drug rehabilitation or refusing if second or third valve replacement.
    • Available literature does not suggest a mortality difference in patients with endocarditis between IDU and non-IDU populations[3].


  • Usual presentation: fever, chest x-ray with septic emboli, blood culture yields S. aureus, echocardiogram - tricuspid valve vegetations.
  • Surgery: prognosis for prosthetic valve without drug rehabilitation is poor.
    • For tricuspid valve endocarditis - valvectomy is an option.
  • Concurrent HIV infection increases mortality rate when CD4 counts < 200.
  • Trans-esophageal echocardiogram (TEE) recommended for patients with an initial negative trans-thoracic echocardiogram (TTE) if sufficient clinical suspicion remains that would inform treatment decision, those with inadequate TTE view or intracardiac complication on TTE.

Pathogen Specific Therapy


1st Line Agent

2nd Line Agent

Basis for recommendation

Baddour LM, et al Infective Endocarditis in Adults: Diagnosis, Antimicrobial Therapy, and Management of Complications: A Scientific Statement for Healthcare Professionals From the American Heart Association.132:1435, 2015United StatesCirculation01477630009-7322pp. 1435-8626373316

Comment: Current IE management guidelines by the American Heart Association


Jackson KA, et al Invasive Methicillin-Resistant Staphylococcus aureus Infections Among Persons Who Inject Drugs - Six Sites, 2005-2016.67:625, 2018United StatesMMWR Morb Mortal Wkly Rep78024290149-2195pp. 625-62829879096

Comment: Persons who inject drugs have 16.3x more invasive MRSA infections than others. The rate of MRSA infections increased dramatically from 4.1% in 2011 to 9.2% in 2016. Infection types were frequently those associated with nonsterile injection drug use causing invasive MRSA infections, including endocarditis, osteomyelitis, and skin and soft tissue infections.

Hall R, et al Drug-Use and Post-Operative Mortality Following Valve Surgery for Infective Endocarditis: A Systematic Review and Meta-Analysis.Dec 22United StatesClin Infect Dis92032131058-483830590480

Comment: This study examined 13 studies including 1593 patients of which 341 were IDU-IE in the meta-analysis. IDU-IE patients more frequently had tricuspid valve infection, Staphylococcus infection, and heart failure before surgery. Meta-analysis revealed no statistically significant difference in 30-day post-surgical mortality or in-hospital mortality between the two groups.

Huang G, Barnes EW, Peacock JE Repeat Infective Endocarditis in Persons Who Inject Drugs: "Take Another Little Piece of my Heart".5:, 2018United StatesOpen Forum Infect Dis1016370452328-8957pp. ofy30430555849

Comment: One year mortality for patients who injected drugs and had a second bout of endocarditis was 36.3%. Staphylococcus aureus was the most common offending pathogen but occurred less commonly than in patient’s first bout of IE.

Thiagaraj AK, et al A novel approach in the management of right-sided endocarditis: percutaneous vegectomy using the AngioVac cannula.13:211, 2017EnglandFuture Cardiol1012393451479-6678pp. 211-21728326804

Comment: A minimally invasive approach may hold some promise with further study in assisting control of infection in patients with TV disease.

Shrestha NK, et al Injection Drug Use and Outcomes After Surgical Intervention for Infective Endocarditis.Jun 19Ann Thorac Surg15030100R0003-497526095108

Comment: Study from Cleveland Clinic found a 10x risk of death or reoperation in the 3-6 month period after cardiac surgery in those who use injection drugs. Available followup after 6 mos shows a much smaller risk.

Al-Omari A, et al Oral antibiotic therapy for the treatment of infective endocarditis: a systematic review.14:, 2014EnglandBMC Infect Dis1009685511471-2334p. 14024624933

Comment: Authors review 7 trials examining oral therapy for bacterial endocarditis. The largest study used ciprofloxacin and rifampin for right-sided disease with equivalent results to traditional IV therapy (Heldman 1996) but still was not sufficiently powered. Other smaller studies offer varying quality and outcomes.

Comment: Review of S. aureus endocarditis in 133 patients including 53 IDU's. Mortality of right sided endocarditis in IDUs was 3.7% vs. 82% in cases associated with IV lines.
Rating: Important

Fernández Guerrero ML, et al Endocarditis caused by Staphylococcus aureus: A reappraisal of the epidemiologic, clinical, and pathologic manifestations with analysis of factors determining outcome.88:1, 2009United StatesMedicine (Baltimore)2985248R0025-7974pp. 1-2219352296

Comment: Review of 247 cases of endocarditis in San Francisco, 74% were IDUs, most heroin users. OR for IDUs vs. others: S. aureus 5.5, E. faecalis 0.2. tricuspid valve 4.4, mitral valve 0.4.
Rating: Important

Jain V, et al Infective endocarditis in an urban medical center: association of individual drugs with valvular involvement.57:132, 2008EnglandJ Infect79084240163-4453pp. 132-818597851Lodise TP, et al Impact of empirical-therapy selection on outcomes of intravenous drug users with infective endocarditis caused by methicillin-susceptible Staphylococcus aureus.51:3731, 2007United StatesAntimicrob Agents Chemother03150610066-4804pp. 3731-317664322

Comment: Retrospective study of IE due to MSSA who received empiric vancomycin versus beta-lactam or beta-lactam + vanc. Vancomycin patients switched to beta-lactam therapy once susceptibility results became available had outcomes inferior to those for patients treated with a beta-lactam from the initiation of therapy. Based on the observed results, empirical therapy with both a beta-lactam and an anti-methicillin-resistant S. aureus agent should be considered for serious S. aureus infections
Rating: Important

Comment: IDU's accounted for 167/1797 (9.2%) in global collaborative study.
Rating: Important

Wang A, et al Contemporary clinical profile and outcome of prosthetic valve endocarditis.297:1354, 2007United StatesJAMA75011600098-7484pp. 1354-6117392239

Comment: Incidence of endocarditis with HIV and IDU risk decreased from 20.5/1000 person years in the pre-HAART era to 6.6/1000 person years in the HAART era. Most common pathogen - S. aureus - 69% including MRSA in 28%. At one year 52% were dead and 16% had a recurrence.

Gebo KA, et al Incidence of, risk factors for, clinical presentation, and 1-year outcomes of infective endocarditis in an urban HIV cohort.43:426, 2006United StatesJ Acquir Immune Defic Syndr1008920051525-4135pp. 426-3217099314

Comment: Prospective trial of S. aureusendocarditis showed daptomycin (6mg/kg/day) was "not interior" to vancomycin therapy.
Rating: Important

Fowler VG, et al Daptomycin versus standard therapy for bacteremia and endocarditis caused by Staphylococcus aureus.355:653, 2006United StatesN Engl J Med02555620028-4793pp. 653-6516914701

Comment: Author note the epidemic spread of MRSA in injection drug users across Europe and N. America. Nasal carriage is a risk for infection and IDU's have high risks of colonization.

Bassetti S, Battegay M Staphylococcus aureus infections in injection drug users: risk factors and prevention strategies.32:163, 2004GermanyInfection03653070300-8126pp. 163-915188077

Comment: Prospective study of 2,529 injection drug users x 10 yrs showed incidence of endocarditis was 7/1000 pt yrs which is about 100-fold higher than for non-ID users. Major pathogen - S. aureus in 76%, Strep 13% & Staph unspecified 7%.

Wilson LE, et al Prospective study of infective endocarditis among injection drug users.185:1761, 2002United StatesJ Infect Dis04136750022-1899pp. 1761-612085322

Comment: Author presents 3 cases including two with HIV.

Petrosillo N, et al Endocarditis caused by Aspergillus species in injection drug users.33:e97, 2001United StatesClin Infect Dis92032131058-4838pp. e97-911565094

Comment: The authors report a prospective study of cloxacillin vs vancomycin x 14d for S. aureusendocarditis in IDUs. All patients also received aminoglycosides. Cloxacillin proved superior to vancomycin with cure rates of 100% & 60%, respectively.
Rating: Important

Fortún J, et al Short-course therapy for right-side endocarditis due to Staphylococcus aureus in drug abusers: cloxacillin versus glycopeptides in combination with gentamicin.33:120, 2001United StatesClin Infect Dis92032131058-4838pp. 120-511389505

Comment: The authors conclude that there is no unifying hypothesis to explain this clearly established association.

Frontera JA, Gradon JD Right-side endocarditis in injection drug users: review of proposed mechanisms of pathogenesis.30:374, 2000UNITED STATESClin Infect Dis92032131058-4838pp. 374-910671344Heldman AW, et al Oral antibiotic treatment of right-sided staphylococcal endocarditis in injection drug users: prospective randomized comparison with parenteral therapy.101:68, 1996UNITED STATESAm J Med02672000002-9343pp. 68-768686718

Comment: This is one of the few published prospective controlled trials of treatment of endocarditis. The attempt was to find an adequate oral agent for IDU with S. aureusendocarditis. The authors showed cipro + rifampin x 4wks was as good as nafcillin + gent x 4wks; the side effects clearly favored the oral regimen. The practical use of this oral regimen has been confounded by the increasing resistance of S. aureus to fluoroquinolones and the issue of reliability/compliance of this population to an oral regimen.

Comment: The authors review 144 cases of IE in injection drug users including 45 with HIV S. aureus accounted for 65% of cases. Mortality was higher with CD4 count <200 (but this is from the pre-HAART era).

Pulvirenti JJ, et al Infective endocarditis in injection drug users: importance of human immunodeficiency virus serostatus and degree of immunosuppression.22:40, 1996UNITED STATESClin Infect Dis92032131058-4838pp. 40-58824964

Comment: Duke criteria as basis for diagnosis of endocarditis.
Rating: Important

Durack DT, Lukes AS, Bright DK New criteria for diagnosis of infective endocarditis: utilization of specific echocardiographic findings. Duke Endocarditis Service.96:200, 1994UNITED STATESAm J Med02672000002-9343pp. 200-98154507

Comment: Injection drug users with S. aureus tricuspid valve endocarditis were treated with cloxacillin 2gm q 4h IV + amikacin 7.5mg/kg q 12h x 2 wks. Among 72, 67 were cured, 4 needed longer course & 1 died in the hospital. This is the largest study of the 2 wk regimen.

Torres-Tortosa M, et al Prospective evaluation of a two-week course of intravenous antibiotics in intravenous drug addicts with infective endocarditis. Grupo de Estudio de Enfermedades Infecciosas de la Provincia de Cádiz.13:559, 1994GERMANYEur J Clin Microbiol Infect Dis88042970934-9723pp. 559-647805683

Comment: The authors from Detroit with what appears to be the greatest experience with tricuspid valve surgery in IDUs with endocarditis review 61 cases. 1)Tricuspid valve replacement 100% mortality due to inability to control infection, reinfection due to IDU, or inability to comply with anticoagulation; 2) Tricuspid valvectomy (55 pts): acute mortality 11%; 9/10 who died 6mo-13 yrs later died from complications of injection drug use.

Arbulu A, Holmes RJ, Asfaw I Surgical treatment of intractable right-sided infective endocarditis in drug addicts: 25 years experience.2:129, 1993ENGLANDJ Heart Valve Dis93120960966-8519pp. 129-37; discussion 138-98261149

Comment: The distribution of valves in 67 addicts with endocarditis was tricuspid in only 27 (40%) - low than usually reported. Pathogens were S. aureus - 58% & strep species 25%.

Graves MK, Soto L Left-sided endocarditis in parenteral drug abusers: recent experience at a large community hospital.85:378, 1992UNITED STATESSouth Med J04045220038-4348pp. 378-801566138

Comment: The authors present an alternative to tricuspid valve removal for refractory endocarditis in addicts. Vegetectomy with valvuloplasty is now frequently preferred.

Straumann E, Stulz P, Jenzer HR Tricuspid valve endocarditis in the drug addict: a reconstructive approach ("vegetectomy").38:291, 1990GERMANYThorac Cardiovasc Surg79033870171-6425pp. 291-42264037

Comment: A famous prospective study that compared Nafcillin x 4wks + gent x 2 wks vs. nafcillin alone in non-addicts with S. aureusendocarditis. Combination treatment showed more rapid sterilization of blood cultures, but no difference in outcome by clinical parameters. The authors concluded gentamicin did not add significantly; nevertheless, most authorities (and the AHA Council on endocarditis) advocate 3-5days of an aminoglycoside.
Rating: Important

Korzeniowski O, Sande MA Combination antimicrobial therapy for Staphylococcus aureus endocarditis in patients addicted to parenteral drugs and in nonaddicts: A prospective study.97:496, 1982UNITED STATESAnn Intern Med03723510003-4819pp. 496-5036751182

Comment: The authors provide a follow-up of patients who underwent tricuspid valvectomy. Most tolerated the lack of a tricuspid valve in the early post-op period, but many eventually required valve replacement at a second procedure due to refractory right heart failure.

Arbulu A, Asfaw I Tricuspid valvulectomy without prosthetic replacement. Ten years of clinical experience.82:684, 1981UNITED STATESJ Thorac Cardiovasc Surg03763430022-5223pp. 684-917300401

Comment: The authors draw from their experience with P. aeruginosaendocarditis in addicts in Detroit. Their recommendations are provided here - high dose tobramycin (8mg/kg/d) to achieve peak levels of 15-20ug/ml combined with an anti-pseudomonal penicillin or ceftazidime.

Reyes MP, Lerner AM Current problems in the treatment of infective endocarditis due to Pseudomonas aeruginosa.5:314, 1983UNITED STATESRev Infect Dis79058780162-0886pp. 314-216405476
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Last updated: February 5, 2019