For Clinicians


Bioabsorbable Polymers

Medtronic Infection Control technology – based on inventions by Joachim Kohn, PhD, surrounding unique biodegradable polymer technology (i.e., tyrosine-derived polyarylates) – has received a world-wide license from Rutgers, The State University of New Jersey, which covers a broad range of absorbable materials and drug delivery technology. Additionally, Medtronic Infection Control has licensed from Baylor College of Medicine and The University of Texas MD Anderson Cancer Center combination drug patents and associated technologies to address the problem of postsurgical infection and fibrosis. Medtronic Infection Control is deploying its capabilities across a broad range of combination medical products and currently holds more than 70 foreign and domestic patents that permit the design, synthesis, and use of thousands of unique absorbable polymers.

The technology used in the TYRX™ product line:

  • Is easily manipulated for a wide variety of end-use applications from microspheres and gels to coatings and partially load-bearing plastics
  • Contains multiple hydrogen bonding sites that promote long-term drug elution and little or no "burst" effect
  • Degrades in a relatively linear fashion and as a result, has minimal acidity, and is much less likely to promote inflammation and scarring

TYRX™ has a unique family of tyrosine-based bioabsorbable polymers that can be tailored or "tuned" to:

  • Elute single or multiple drugs
  • Elute drugs at a controllable rate and time
  • Absorb at a predetermined rate, and
  • Possess a wide variety of mechanical properties

TYRX™ tyrosine-based bioabsorbable polymers are designed to degrade to natural metabolites or substances with known safety history:

  • Absorb benignly in vivo
  • Elicit minimal inflammatory response, and have been employed in FDA-cleared implantable medical devices

Antibiotic Combination

There is a strong clinical rationale behind the combination of minocycline and rifampin selected for the TYRX™ Antibacterial Envelopes and future TYRX™ antibacterial products. Minocycline and rifampin have been shown to provide a broad spectrum of activity against a wide range of antibiotic-sensitive and antibiotic-resistant bacteria, including methicillin- and vancomycin-resistant strains.

In addition, the results from five Randomized Clinical Trials (RCTs) have demonstrated that minocycline and rifampin coatings help reduce medical device implant infections.

chart 1-4

chart 5-9


In vitro testing5,6 with central venous catheters has demonstrated that the combination of minocycline and rifampin is safe, effective, and:

  • Superior to a combination of chlorhexidine and silver sulfadiazine
  • Superior to vancomycin, clindamycin, novobiocin, and minocycline alone, and
  • Equivalent to ceftazidime or amphotericin B against gram-negative bacilli and Candida albicans

Additionally, in in vitro studies, the TYRX™ Antibacterial Envelope has demonstrated antimicrobial activity against methicillin resistant S aureus (MRSA), S aureus, S epidermidis, A baumanii, E aerogenes, and P mirabilis, which represent a majority of the infections reported in Cardiac Implantable Electronic Device (CIED) related infections.


  1. Gilbert DN et al. The Sanford Guide to Antimicrobial Therapy.39th ed. 2012: Antimicrobial Therapy Inc., Hyde Park, VT.
  2. Zinner SH et al, J Infect Dis.1981;144(4):365-371.
  3. Darouiche RO et al. Int J Antimicrob Agents. 1995;6(1):31-36.
  4. Segreti J et al. Diagn Microbiol Infect Dis. 1989;12(3):253-255.
  5. Hanna H et al. J Clin Oncol. 2004;22(15):3163-3171.
  6. Leon C et al. Intensive Care Med. 2004;30(10):1891-1899.
  7. Zabramski JM et al. J Neurosurg.2003;98(4):725-730.
  8. Chatzinikolaou I et al. Am J Med.2003;115(5):352-357.
  9. Raad I et al. Ann Intern Med. 1997;128(4):267-274.



Update on CIED infections and their management: a scientific statement from the American Heart Association, endorsed by the Heart Rhythm Society.8


  • Cefazolin and vancomycin can have important clinical limitations when used as a single agent to prevent CIED infection.6-11
  • Coagulase(-) Staphylococcus species and S aureus are responsible for ~70% of CIED infections and are increasingly resistant to methicillin.1-7

*Data from blood cultures


  1. Baddour LM et al. Circulation.2010;121(3):458-477.
  2. Lekkerkerker JC et al. Heart.2009;95(9):715-720
  3. de Oliveira JC et al. Circ Arrhyth Electrophysiol.2009;2(1):29-34.
  4. Da Costa A et al. Circulation. 1998;97(18): 1791-1795.
  5. Chua J et al.Ann Intern Med. 2000;133(8):604-608.
  6. Wisplinghoff H et al CID. 2004;39(3):309-317
  7. NNIS System Report. Am J Infect Control 2004;32(8):470-485.
  8. Klug D et al. Circulation. 2007;116(12):1349-1355.
  9. Gilbert DN et al.The Sanford Guide to Antimicrobial Therapy 39th ed. 2012: Antimicrobial Therapy Inc.; Hyde Park, VT.
  10. Tarakji et al. Heart Rhythm. 2010;7(8):1043-1047.
  11. Kachroo et al. Ann Pharmacother. 2006;40(3):381.


Bacterial infection is one of the most common causes of CIED complications… and is on the rise.

  • Incidence of infection increased by 210% over a 15-year period.1
  • The increased rate of infection likely due to:
    • Older patients receiving devices
    • More patient comorbidities
    • Longer procedures
    • Mix of CIED devices is changing
    • Number of pulse generator replacements and upgrades are increasing
    • Revision procedures
    • More resistant S aureus and coagulase (-) Staphylococcus species (e.g., S epidermidis)



  1. Greenspon A et al. J Am Coll Cardiol.2011;58(10):1001-1006.


The TYRX™ Absorbable Antibacterial Envelope and the original TYRX™ Antibacterial Envelope have identical antibiotic efficacy for the pathogens listed above.

The amount of drug dose contained in the TYRX™ Antibacterial Envelope is <10% of the recommended daily oral dose of minocycline and rifampin.1

Cefazolin and vancomycin are infrequently used in combination.

  • Substantial overlap (both have activity against gram (+) organisms).1
  • Neither has strong profile against gram (-) organisms.



  1. Gilbert DN et al. The Sanford Guide to Antimicrobial Therapy 39th ed. 2012: Antimicrobial Therapy Inc.; Hyde Park, VT.
  2. Zinner SH et al. J Infect Dis. 1981;144(4):365-371.
  3. Darouiche RO et al. Int J Antimicrob Agents. 1995;6(1):31-36.
  4. Segreti J et al. Diagn Microbiol Infect Dis. 1989;12(3):253-255.