Prophylactic antibiotic - timing and dosage - Dr. Sanjeev Singh AIMS, Kochi

Prophylactic antibiotic
 – timing and dosage
     Dr. Sanjeev Singh
        AIMS, Kochi

Meaning - Webster
Medical Definition of prophylaxis
plural pro·phy·lax·es \-ˈlak-ˌsēz\play
: measures designed to preserve health and prevent the spread of disease :
protective or preventive treatment

Definition
• Antibiotic prophylaxis refers to the prevention
  of infection complications using antimicrobial
  therapy
• Surgical antibiotic prophylaxis is defined as
  the use of antibiotics to prevent infections at
  the surgical site.

Indications
  •   Immune compromised
  •   Cardiac valves, prosthetics in body
  •   Visit to another country
  •   Surgery

SIGN 104 • Antibiotic prophylaxis in surgery. A national clinical guideline. July 2008

• A single antibiotic dose, given immediately
  before the start of surgery, may be just as
  effective in preventing infection, while
  reducing the risk of drug side effects

                        http://www.surgeryencyclopedia.com/Pa-St/
                        Prophylaxis-Antibiotic.html#ixzz407iM1Dr3

Classification
Classification
                    of operative wounds and risk ofRisk
               Criteria
                                                    infection
                                                        (%)
Clean                  Elective, not emergency, nontraumatic, primarily closed; < 2
                       no acute inflammation; no break in technique; respiratory,
                       gastrointestinal, biliary and genitourinary tracts not
                       entered
Clean-contaminated     Urgent or emergency case that is otherwise clean;              4 hours old

                 Cruze PJ, Ford. The epidemiology of wound infection. A 10-year prospective study of 62,939 wounds.
                 Surg Clin North Am. 1980 Feb;60(1):27-40.

Common surgical pathogens
• clean procedures - skin flora, including S. aureus
  and coagulase-negative staphylococci
• clean-contaminated procedures (abdominal
  procedures and heart, kidney, and liver
  transplantations) - gram-negative rods
  and enterococci in addition to skin
  flora

            ASHP Report . Am J Health-Syst Pharm—Vol 70 Feb 1, 2013,204-5

• The use of antimicrobial agents for dirty
  procedures or established
  infections is classified as treatment of
  presumed infection, not prophylaxis

• Choice of antibiotics should be made
  according to data on pharmacology,
  microbiology, clinical experience and economy

• Antibiotics should be chosen with kinetics that
  will ensure adequate serum and tissue levels
  throughout the risk period.

Ideal antibiotic
• good tolerability
• Low toxicity
• High concentration at all sites
        – systemic vs local

• Long acting
• Cephalosporin

MIC
Minimum Inhibitory Concentration (MIC) is the
lowest concentration of an antimicrobial that
will inhibit the visible growth of a
microorganism after overnight incubation.

Vancomycin
• Routine use of vancomycin prophylaxis is not
  recommended for any procedure

• Included in the regimen of choice when a cluster
  of MRSA cases (e.g., mediastinitis after
  cardiac procedures) or methicillin resistant
  coagulase-negative staphylococci SSIs have been
  detected at an institution.

  Scottish Intercollegiate Guidelines Network. Antibiotic prophylaxis in surgery.
  www.sign.ac.uk/pdf/sign104.pdf (accessed 2009 Jul 30).

Advantage of long acting antibiotic
• A single dose covers the whole perioperative risk
  period - even if the operation is delayed or long-lasting
• Repeat administrations for prophylaxis are not
  necessary, so that additional doses are less likely to be
  forgotten
• Less risk of development of resistance and less side
  effects
• Increased compliance and reduced errors of
  administration
• Possibly better-effectiveness (less material and labor
  cost, less septic perioperative complications)

Factors that affect physicians’
                        compliance
    •   Cultural factors
    •   Educational background
    •   Training
    •   Nurse and pharmacist influences,
    •   Medication supply
    •   Logistics

Ali A. Al-Dabbagh, and Mazin A. Hajy. How Good is Compliance with Surgical Antibiotic
Prophylaxis Guidelines in Erbil/ Iraq?. 2nd International Conference on Medical, Biological and
Pharmaceutical Sciences (ICMBPS'2013) June 17-18, 2013 London (UK)

Cleveland Clinic Guidelines for Antimicrobial Usage 2012-2013

American Society of Health-System Pharmacists. 2013

Timing
      • The antibiotic should be administered ideally 30
        minutes before incision in order to achieve
        relevant tissue concentration.
      • In operations lasting longer than three hours a
        second dosage is recommended.
      • There is no evidence to support a prolongation of
        antibiotic administration to 24 or 48 hours in
        most instances.
      • Single dose is cheaper and does not increase the
        risk of the developement of bacterial resistance
Classen D C, Evans R S, Pestotnik S L, Horn S D, Menlove R L, Burke J P. The timing of prophylactic administration of
antibiotics and the risk of surgical-wound infection. N Engl J Med. 1992;326:281–286.

• For surgical procedures, intravenous
  prophylactic antibiotics should be given within
  60 minutes before the skin is incised and as
  close to time of incision as practically possible.
• vancomycin should be given by intravenous
  infusion starting 90 minutes prior to skin
  incision.

  Scottish Inter collegiate guidance network (SIGN). Antibiotic prophylaxis in
                     Surgery . Edinburg .2008, updated 2014

• Fluoroquinolones and Vancomycin, require
  administration over one to two hours
• therefore, the administration of these agents
  should begin within 120 minutes before
  surgical incision.

                        ASHP Therapeutic guidelines

• NICE and the Infectious Diseases Society of
  America (IDSA) recommends that
  -for Caesarean section, antibiotic prophylaxis
  to reduce maternal infectious complications
  can be given pre-incision or after cord
  clamping
• National Collaborating Centre for Women’s and Children’s Health. Caesarean
  section. London: NICE; 2011. [cited 01/05/2013].

  Bratzler DW, Dellinger EP, olsen KM, Perl TM, Auwaerter PG, Bolon MK, et al. Clinical
  practice guidelines for antimicrobial prophylaxis in surgery. Am J Health Syst Pharm
  2013;70(3):195-283.

Dosage
• A single standard therapeutic dose of
  antibiotic is sufficient for prophylaxis under
  most circumstances

Duration
• A single dose of antibiotic with a long enough
  half-life to achieve activity throughout the
  operation is recommended.
• up to 24 hours of antibiotic prophylaxis should
  be considered for arthroplasty.

Additional dosage
• An additional intraoperative dosage of
  antibiotic is recommended for cardiac surgery
  longer than four hours when using an
  antibiotic with pharmacokinetics equivalent to
  cefazolin.

Zanetti G, Giardina R, Platt R. Intraoperative redosing of cefazolin and risk
for surgical site infection in cardiac surgery. Emerging Infectious Diseases
2001;7(5):828-31

• In the event of major intraoperative blood loss
  in adults (>1,500 ml) or (children 25ml/kg)
  additional dosage of prophylactic antibiotic
  should be considered after fluid replacement.

How many days
• If prophylactic antibiotic given more than 24
  hours it is no longer a prophylaxis but
  therapeutic schedule