Using Antimicrobials Responsibly

Antimicrobials are one of the only medications that can have individual and societal implications.

Societal Implications

Persons who are given antimicrobials are likely at risk of being colonized with resistant bacteria and can shed these bacteria into the environment.

These resistant bacteria are then "picked up" unknowingly by others through a cough, sneeze or even by touching a contaminated surface such as a bedrail.

Thus resistance can spread from a patient to their families and into the environment.

Individual Implications

Antimicrobials can have adverse effects on the patient.

Viral illness and rashes are common but can be falsely attributed as a side effect of antimicrobials or an allergy.

About 30% of patients who receive antimicrobials can have transient diarrhea and many more can have nausea.

C. difficile is increasingly common in children as a result of antimicrobial use, and all antimicrobials carry this risk.

It is our responsibility as physicians and prescribers to use antimicrobials only when needed and for the shortest possible duration to minimize this impact on the patient and society.

Responsible Prescribing Reminders

Is the syndrome viral? For example, influenza can cause severe symptoms and can be treated with an antiviral agent rather than an antimicrobial. Consider a bacterial complication if the patient has been sick for over a week or worsens after a few days.

Can the antimicrobial treatment be delayed until culture results are available? For example, can a pharyngitis treatment wait until cultures are available?

Have I used local antibiogram data to identify the susceptibility profile of the probable pathogens in order to select empiric therapy?

ALWAYS take cultures since this guides therapy and it is probable that the bacteria are susceptible to common antimicrobials if the patient has not recently received antimicrobials.

Most commonly used antimicrobials (including ampicillin and cephalosporins) cover many pathogens and unless the patient is gravely ill, one does not need 2 antimicrobials.

Do not take cultures of areas that do not look infected.

When can I shorten the duration or stop antimicrobial therapy? Many infections are treated with 10 to 14 days of therapy however; the longer one has antimicrobials, the higher risk of carrying resistant bacteria and C. difficile. Use of shorter courses particularly in treatment of sinus, skin and respiratory infections should be encouraged.

Allergies are rare so if the history is not one of anaphylaxis, respiratory compromise or acute onset of hives, have a healthy skepticism for a true allergy.

Most blood cultures grow a pathogenic bacteria within 24 hours. Strongly consider discontinuing antimicrobials if the blood culture is negative at 24-36 hours.

Many infections are treated with 10 to 14 days of therapy however; the longer one has antimicrobials, the higher risk of carrying resistant bacteria and C. difficile. Use of shorter courses particularly in treatment of sinus, skin and respiratory infections should be encouraged. The duration should be based on clinical response and apart from endocarditis, meningitis and some bloodstream infections, the optimal duration is not known.

In individual patients, routine or prolonged use of broad spectrum antimicrobials leads to carriage of bacteria that have developed resistance to many antimicrobials. It is therefore recommended that for oxazolidinones (line­zolid), quinolones (cipro­floxacin, levo­floxacin, moxi­floxacin) and carbapenems (mero­penem) an Infectious Diseases consultation should be requested if the drug will be continued beyond 12-24 hours.

In addition, the use of vancomycin as empiric therapy should not be continued for more than 48 hours.