Antimicrobial Regimen Selection and Stewardship

Flashcards covering key vocabulary terms related to antimicrobial regimen selection, host and drug factors, antimicrobial therapy, and stewardship from the lecture notes.

Antibiotic prophylaxis

The prevention of infection complications using antimicrobial therapy.

Empiric antimicrobial regimen

An antimicrobial regimen begun before the offending organism is identified and sometimes before the documentation of the presence of infection.

Definitive regimen (antimicrobial)

An antimicrobial regimen instituted when the causative organism is known.

Fever

A controlled elevation of body temperature above the normal range (average oral 36.7°C to 37°C or 98°F–98.6°F), with temperatures greater than 37°C (98.6°F) considered a hallmark of infectious diseases.

Drug-induced fever

Persistent fever in the absence of infection or other underlying condition, coinciding temporally with the administration of the offending agent and disappearing promptly on its withdrawal.

Local Signs of Infection

Classic signs of pain and inflammation manifesting as swelling, erythema, tenderness, and purulent drainage.

Antibiogram

A periodic summary of antimicrobial susceptibilities of local bacterial isolates, used to assess local susceptibility rates, aid in selecting empiric antibiotic therapy, and monitor resistance trends over time within an institution.

Community-acquired infection

An infection acquired outside a healthcare setting, such as at home.

Nosocomial infection (Hospital-acquired infection)

An infection acquired in a hospital or nursing home environment.

Antimicrobial Allergies

Hypersensitivity reactions to antimicrobial agents, most commonly cited for penicillin and penicillin-related compounds, requiring careful consideration for administration.

Age (Host Factor in Antimicrobial Selection)

Influence on antimicrobial therapy due to physiological differences, such as undeveloped hepatic and liver functions in neonates, and decreased renal function in persons older than 65 years.

Pregnancy (Host Factor in Antimicrobial Selection)

A condition where pharmacokinetic disposition of certain drugs can be altered, potentially resulting in lower maternal serum antimicrobial concentrations and a need for increased dosages.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency

An inherited metabolic abnormality where patients can develop significant hemolysis when exposed to certain drugs like sulfonamides, nitrofurantoin, and antimalarials.

Abacavir hypersensitivity reaction

A severe reaction to the antiretroviral drug abacavir, consisting of fever, rash, abdominal pain, and respiratory distress, associated with the presence of a human leukocyte antigen allele HLA-B*5701.

Organ Dysfunction (Host Factor)

Impaired liver or renal function requiring adjustment of antibiotic doses, as significant accumulation can occur for certain drugs (e.g., clindamycin, erythromycin for liver; cephalexin, amoxicillin for renal).

Concomitant Drugs (Host Factor)

Any concurrent therapy that the patient is receiving, which can influence drug selection, dose, and monitoring due to potential for drug interactions or increased risk of adverse effects.

Concomitant Disease States (Host Factor)

Underlying medical conditions (e.g., granulocytopenia, immunosuppressive diseases like malignancies or AIDS) that predispose patients to particular infectious diseases or alter the type of infecting organism.

Pharmacokinetic and Pharmacodynamic Considerations

The integration of drug absorption, distribution, metabolism, excretion (pharmacokinetics) and drug effects on the body (pharmacodynamics) for choosing antimicrobial therapy to ensure efficacy and prevent resistance.

Tissue Penetration (Antimicrobial)

The ability of an antimicrobial agent to reach the site of infection, determining the proper route of administration, such as parenteral therapy for deep-seated infections or oral therapy for ambulatory patients.

CNS toxicities (Antimicrobial)

Adverse effects on the central nervous system associated with certain antimicrobial agents, including penicillins, cephalosporins, quinolones, and imipenem.

Hematologic toxicities (Antimicrobial)

Adverse effects on blood components, such as neutropenia (nafcillin), platelet dysfunction (piperacillin), hypoprothrombinemia (cefotetan), bone marrow suppression (chloramphenicol), and megaloblastic anemia (trimethoprim).

Nephrotoxicity (Antimicrobial)

Reversible kidney damage that can occur with the use of certain antimicrobial agents, such as aminoglycosides and vancomycin.

Ototoxicity (Antimicrobial)

Irreversible damage to the ear, a specific adverse effect associated with aminoglycosides.

Combination Antimicrobial Therapy

The use of multiple antimicrobials to broaden the spectrum of coverage for empirical therapy, achieve synergistic activity, or prevent the emergence of resistance.

Synergism (Antimicrobial Therapy)

A phenomenon where the combined effect of two or more antimicrobial drugs is greater than the sum of their individual effects, commonly seen with aminoglycosides and β-lactams.

Antagonistic effects (Antimicrobial Therapy)

A negative interaction where one antimicrobial drug reduces the effectiveness of another, such as when cefoxitin or imipenem induce β-lactamases, leading to inactivation of penicillins.

Criteria for switching to oral therapy

Indicators for transitioning from intravenous to oral antimicrobial therapy, including overall clinical improvement, lack of fever for 8 to 24 hours, decreased WBC count, and a functioning GI tract.

Acquired Resistance

When bacteria change their genetic makeup, rendering an antimicrobial agent that was originally active against them no longer effective, often through mechanisms like drug inactivation by β-lactamases.

Intrinsic Resistance

When an antimicrobial agent never had activity against a particular bacterial species (e.g., gram-negative bacteria are naturally resistant to vancomycin).

Antimicrobial Stewardship Programs

Initiatives aimed at optimizing antimicrobial selection, dosing, route, and duration of therapy to maximize clinical cure or prevention of infection while limiting unintended consequences like resistance, adverse drug events, and cost.

Restricted Antimicrobials (AMS Program)

Specific antibiotics (e.g., 4th generation cephalosporins, carbapenems, vancomycin) that require pre-authorization by an Infectious Disease Specialist or AMS Clinician within the Antimicrobial Stewardship Program.

Monitored Antimicrobials (AMS Program)

Specific antibiotics (e.g., 3rd generation cephalosporins, fluoroquinolones, aminoglycosides) that are subject to audit and feedback by the AMS Team within the Antimicrobial Stewardship Program.

De-escalation (Antimicrobial Therapy)

The process of switching from broad-spectrum empiric antimicrobial therapy to a narrower-spectrum antimicrobial once the causative organism and its susceptibility are known.

Antimicrobial Resistance Surveillance Program (ARSP)

A system that monitors and disseminates information on antimicrobial resistance patterns, utilizing tools like WHONET and providing local antibiograms to practitioners.

ARSP reportable pathogens

A designated list of microorganisms monitored for antimicrobial resistance, including species such as Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa.