Antimicrobial Stewardship in Practice: The Hospitalist's Role

A Practical Guide for the Frontline Clinician

Dr Neeraj Manikath , claude.ai

Abstract

Antimicrobial stewardship (AMS) is no longer the exclusive domain of infectious disease specialists or pharmacy teams—it is a critical competency for every hospitalist managing acutely ill patients. This review provides a practical, evidence-based approach to implementing AMS principles at the bedside, with particular emphasis on metrics that matter (Days of Therapy), strategic de-escalation, optimizing routes of administration, appropriate treatment durations, and the crucial art of antimicrobial communication. We present actionable "pearls" derived from contemporary literature and real-world implementation science to transform stewardship from a compliance exercise into excellent clinical practice.

Keywords: Antimicrobial stewardship, hospitalist, de-escalation, antibiotic duration, IV to PO switch, antimicrobial resistance

Introduction

The World Health Organization has declared antimicrobial resistance (AMR) one of the top ten global public health threats.1 In the United States alone, antibiotic-resistant infections cause over 2.8 million infections and 35,000 deaths annually.Hospitalists, as the physicians managing the majority of acutely ill medical patients, are uniquely positioned to impact antimicrobial use through thoughtful prescribing, timely reassessment, and effective stewardship interventions.3

The traditional paradigm of "start broad, consult ID if they don't improve" is no longer acceptable. Modern antimicrobial stewardship requires active engagement from frontline clinicians at multiple decision points: initial empiric selection, early de-escalation based on microbiology and clinical response, route optimization, duration determination, and the often-difficult conversation about stopping therapy.4

This review focuses on five high-impact stewardship practices that every hospitalist can implement immediately, supported by contemporary evidence and designed for practical application in the time-pressured hospital environment.

1. The "Days of Therapy" and Why It Matters

Beyond Crude Consumption: Understanding DOT

Antimicrobial stewardship programs traditionally tracked antibiotic use through Defined Daily Doses (DDD), a WHO metric designed for international comparisons. However, Days of Therapy (DOT) has emerged as the superior metric for hospital stewardship because it more accurately reflects actual prescribing behavior and accounts for weight-based and renally-adjusted dosing.

DOT Definition: One DOT = one antimicrobial agent administered to one patient on a given day, regardless of the number of doses or dosage strength.

Why DOT Matters Clinically:

It reveals prescribing patterns: High DOT rates may indicate delayed de-escalation, prolonged empiric therapy, or inappropriate prophylaxis
It's actionable: Unlike DDDs, DOT directly correlates with stewardship interventions (stopping redundant coverage, switching IV to PO, shortening durations)
It predicts outcomes: Excessive antimicrobial exposure (high DOT) correlates with Clostridioides difficile infection, multidrug-resistant organisms, and adverse drug events7,8

Pearl: The "Spectrum Score" Approach

When reviewing patients on rounds, mentally assign a "spectrum score" to each antimicrobial regimen:

Score 1: Narrow-spectrum, pathogen-directed (e.g., ceftriaxone for S. pneumoniae bacteremia)
Score 3: Moderate-spectrum empiric (e.g., ceftriaxone + azithromycin for CAP)
Score 5: Broad-spectrum anti-pseudomonal (e.g., piperacillin-tazobactam + vancomycin)
Score 7+: "Desperation regimen" (e.g., meropenem + linezolid + micafungin)

The goal: Decrease the spectrum score daily as clinical and microbiological data accumulate. If the score isn't decreasing by day 3-4, ask why.

Oyster: The DOT Paradox

Paradoxically, some effective stewardship interventions may increase DOT while improving outcomes. For example, replacing fluoroquinolone monotherapy with beta-lactam + macrolide for severe community-acquired pneumonia increases DOT (from 1 to 2 agents) but improves mortality in critically ill patients. Clinical wisdom: DOT is a process measure, not an outcome. Always prioritize patient outcomes over metrics.

2. The Magic of De-escalation: From Broad-Spectrum to Targeted Therapy

The Evidence Base

De-escalation—narrowing or stopping antimicrobial therapy based on clinical improvement and microbiological data—is perhaps the most powerful stewardship intervention.11A meta-analysis of 12 studies involving over 6,000 patients demonstrated that de-escalation in sepsis and severe infections is safe (no increase in mortality; pooled OR 0.51, 95% CI 0.37-0.69) and reduces antimicrobial pressure.12

The De-escalation Framework: "Culture, Clinical, Coverage"

Day 1-2 (Empiric Phase): Broad-spectrum appropriate for severity of illness and local resistance patterns

Day 3-5 (De-escalation Window): Reassess using three C's:

Culture Data:
- If cultures identify a pathogen: narrow to the most specific agent with the narrowest spectrum
- If cultures are negative after 48-72 hours in a clinically improving patient: consider stopping antibiotics (especially for suspected but unconfirmed infections)
Clinical Response:
- Temperature trending down
- Hemodynamic stability
- Improving organ function (e.g., decreasing vasopressor requirements, rising PaO₂/FiO₂)
- Decreasing inflammatory markers (though biomarker-guided therapy remains controversial)13
Coverage Assessment:
- Is continued Gram-negative coverage necessary? (Can piperacillin-tazobactam become ceftriaxone?)
- Is MRSA coverage still indicated? (Discontinue vancomycin if blood cultures negative at 48 hours unless clinical MRSA syndrome confirmed)14
- Is anaerobic coverage needed? (Most aspiration pneumonia does NOT require anaerobic coverage)15

Pearl: The "48-Hour Hard Stop"

Implement this rule: All empiric broad-spectrum regimens (especially vancomycin + piperacillin-tazobactam or meropenem) require active reassessment and documentation of continued need at 48 hours. This can be enforced through:

Electronic health record (EHR) alerts
Pharmacist-driven protocols with automatic de-escalation if criteria met
Stewardship "timeouts" during interdisciplinary rounds16

In one quaternary center study, automated 48-hour "hard stops" on empiric vancomycin reduced unnecessary MRSA coverage by 35% without adverse outcomes.17

Oyster: The "Double Coverage" Fallacy

Many clinicians maintain combination therapy (e.g., two antipseudomonal agents) based on outdated beliefs about synergy and resistance prevention. Current evidence: For most infections—including Pseudomonas bacteremia—monotherapy with an active agent is non-inferior to combination therapy once susceptibilities are known.18,19

Exception: Reserve combination therapy for:

Extensively drug-resistant Gram-negatives where monotherapy options are marginal
Initial empiric therapy in critically ill patients with high risk of MDR pathogens (then de-escalate to monotherapy)
Selected cases of Pseudomonas bacteremia in neutropenic patients (though evidence is mixed)20

Hack: The "Culture Conversion" Conversation

When cultures identify Streptococcus pneumoniae, Escherichia coli, or other common pathogens susceptible to narrow-spectrum agents, frame de-escalation positively to the team:

"Great news—cultures grew S. pneumoniae sensitive to penicillin. We can convert from vancomycin + ceftriaxone to penicillin G, which is more targeted, cheaper, and reduces selection pressure for resistant organisms."

This frames stewardship as optimization rather than restriction.

3. IV to PO Switch: Criteria and Opportunities

The Clinical and Economic Imperative

Intravenous antimicrobials are associated with increased costs, longer hospital stays, phlebitis, line-related bloodstream infections, and patient immobility.21 Conversely, oral antibiotics with high bioavailability achieve therapeutic serum levels comparable to IV formulations for many infections.

The 3 A's: A Simple Decision Framework

An IV-to-PO switch should be considered when patients meet the 3 A's:22

Afebrile: Temperature <38°C for at least 24 hours (some extend this to 8-24 hours depending on infection severity)
Able: Functioning GI tract (not actively vomiting, no ileus, no malabsorption syndrome)
Awake: Alert and able to take oral medications safely

High-Bioavailability Oral Agents: The Stewardship "Go-To" List

IV Antibiotic	PO Alternative	Bioavailability	Clinical Context
Vancomycin	Linezolid	~100%	MRSA infections (not endocarditis or meningitis)
Levofloxacin IV	Levofloxacin PO	~99%	Pneumonia, UTI (identical dosing)
Fluconazole IV	Fluconazole PO	>90%	Candidemia after clinical stability
Metronidazole IV	Metronidazole PO	>80%	Most anaerobic infections
Moxifloxacin IV	Moxifloxacin PO	~90%	CAP, intra-abdominal infections
Trimethoprim-sulfamethoxazole IV	TMP-SMX PO	~85%	Diverse infections (UTI, MRSA, Stenotrophomonas)

Pearl: "Same Drug, Different Route" Transitions

For antibiotics with near-perfect bioavailability (fluoroquinolones, linezolid, metronidazole, fluconazole), the IV-to-PO switch is essentially the same drug by a different route—not a therapeutic change. This can be implemented via pharmacist-driven protocols without physician approval in many institutions, accelerating appropriate transitions.23

Oyster: The Beta-Lactam Challenge

Beta-lactams (penicillins, cephalosporins) have variable oral bioavailability, and IV-to-PO transitions are not equivalent. For example:

Ceftriaxone IV cannot be "converted" to oral cephalexin for bacteremia—these are different drugs with different spectra
For serious infections (bacteremia, osteomyelitis), oral beta-lactams may be inadequate; consider prolonged IV therapy or high-bioavailability alternatives (e.g., fluoroquinolones if susceptible)

Exception: Oral amoxicillin-clavulanate and oral cefdinir/cefpodoxime can be appropriate step-downs for community-acquired infections like CAP after initial IV stabilization 24

Hack: The "Early Switch" Protocol

Implementation strategy: Create an institutional protocol where pharmacy or nursing automatically notifies the team when patients meet the 3 A's criteria, with opt-out (rather than opt-in) consent for high-bioavailability agents. One study showed this increased appropriate IV-to-PO switches from 42% to 78% and reduced length of stay by 0.6 days.25

4. The Duration Debate: Short-Course Therapy for Common Infections

Paradigm Shift: Shorter is Often Better

Historical antibiotic durations (e.g., 10-14 days for pneumonia, 7-14 days for UTI) were based on tradition and expert opinion rather than rigorous evidence.26 Over the past decade, multiple randomized controlled trials have demonstrated that shorter courses are non-inferior for most common infections, with reduced adverse events and lower risk of resistance.27

Evidence-Based Durations for Hospitalist-Managed Infections

Community-Acquired Pneumonia (CAP)

Traditional duration: 7-10 days
Evidence-based duration: 5 days for most patients

Landmark trial: A meta-analysis of 21 RCTs (N=5,426) found short-course therapy (≤5 days) non-inferior to longer courses for CAP, with similar clinical cure rates and mortality.28
IDSA/ATS guidelines (2019): Recommend a minimum of 5 days for CAP in patients who are clinically stable (afebrile ≥48 hours, improving symptoms, no more than 1 CAP-associated sign of clinical instability).29

Pearl: Use the Halm Criteria to identify patients stable for discharge/completion of therapy:30

Temperature ≤37.8°C
Heart rate ≤100 bpm
Respiratory rate ≤24/min
Systolic BP ≥90 mmHg
Oxygen saturation ≥90% or PaO₂ ≥60 mmHg on room air
Ability to take oral medications
Normal mental status

Oyster: Patients with bacteremic S. aureus pneumonia, necrotizing pneumonia, or empyema still require prolonged therapy (2-4 weeks); short-course principles do NOT apply to these complicated scenarios.

Healthcare-Associated Pneumonia (HAP) and Ventilator-Associated Pneumonia (VAP)

Traditional duration: 14-21 days
Evidence-based duration: 7-8 days for most patients

The PneumA trial randomized 310 VAP patients to 8 vs. 15 days of antibiotics—no difference in mortality, recurrence, or length of stay.31
Exception: Non-fermenting Gram-negatives (Pseudomonas, Acinetobacter) may have higher recurrence with 7-8 day courses; consider extending to 10-14 days, though evidence is mixed.32

Uncomplicated Pyelonephritis

Traditional duration: 10-14 days
Evidence-based duration: 5-7 days with fluoroquinolones or beta-lactams

A Cochrane review of 15 trials found short-course therapy (5-7 days) non-inferior to longer courses for uncomplicated pyelonephritis.33
Fluoroquinolone monotherapy × 5-7 days or ceftriaxone + oral step-down × 7 days total is appropriate for most cases.34

Bloodstream Infections (Uncomplicated)

Traditional duration: 14 days
Evidence-based duration: 7 days for Gram-negative bacteremia without complications

The BALANCE trial (N=3,608) demonstrated that 7 days of antibiotics was non-inferior to 14 days for patients with Gram-negative bacteremia and negative follow-up blood cultures.35
Key criteria for short course: Source controlled, no metastatic infection (e.g., endocarditis, osteomyelitis), clearance of bacteremia documented by repeat negative cultures

Oyster: Staphylococcus aureus bacteremia (SAB) is the major exception—minimum 14 days required (4-6 weeks if endocarditis or complicated infection). Never shorten SAB treatment without ID consultation.36

Intra-Abdominal Infections (IAI)

Traditional duration: Continue until resolution of leukocytosis and fever
Evidence-based duration: 4 days after source control

The STOP-IT trial randomized 518 IAI patients to antibiotics until resolution of clinical signs vs. fixed 4-day course—no difference in outcomes, but significantly shorter antibiotic exposure in the fixed-duration group.37
Guideline recommendation: Limit antibiotics to 4-5 days after adequate source control for community-acquired IAI.38

Pearl: The "Pre-Discharge Duration Discussion"

On day 3-4 of therapy, proactively document the planned total duration and end date in your progress note:

"Plan to complete 5-day course for CAP (last day: [DATE]). Will reassess if clinical deterioration."

This prevents the common problem of antibiotics being continued "because nobody said to stop."

Hack: The "Auto-Stop" Order

Program your EHR to default antibiotic orders to evidence-based durations with automatic stop dates:

CAP → 5 days
HAP/VAP → 7 days
Uncomplicated GNR bacteremia → 7 days
IAI (source controlled) → 4 days

Clinicians can override with documented justification, but the default guides appropriate prescribing.39

5. How to Talk to Colleagues About Stopping or Narrowing Antibiotics

The "Stewardship Conversation" Challenge

Perhaps the most underappreciated aspect of antimicrobial stewardship is the interpersonal skill required to advocate for appropriate prescribing without alienating colleagues, undermining confidence, or creating patient safety concerns.40 Hospitalists must navigate conversations with:

Admitting teams reluctant to narrow "because the patient is still sick"
Surgeons demanding continued broad-spectrum coverage "just in case"
Consultants who reflexively recommend prolonged courses
Families fearful that stopping antibiotics means "giving up"

Framework for Effective Stewardship Communication

1. Open with Shared Goals

Begin by aligning on the common objective—patient safety and optimal outcomes.

Instead of: "You're using too many antibiotics."
Try: "I want to make sure we're giving [patient] the most effective, targeted therapy while minimizing risks like C. diff and drug toxicity."

2. Use Data, Not Judgment

Present objective clinical and microbiological data to support your recommendation.

Example:
"Blood cultures have been negative for 48 hours, and she's been afebrile for 36 hours. Based on the 2019 IDSA guidelines, we can safely discontinue vancomycin at this point."

3. Employ the "What Would Make You Comfortable?" Technique

If a colleague is resistant, explore their concerns directly.

Example:
"I hear your concern about stopping antibiotics while she still has a leukocytosis. What specific clinical milestone would make you comfortable with de-escalation? Follow-up cultures? One more afebrile day?"

This shifts the conversation from confrontation to collaboration.41

4. Frame Stewardship as "Optimizing" Not "Restricting"

Avoid language that implies rationing or cost-cutting.

Instead of: "We need to cut back on broad-spectrum antibiotics."
Try: "Now that we have culture data, we can optimize to the most targeted agent—linezolid is actually more effective for MRSA soft tissue infections than vancomycin with better tissue penetration."

5. The "Antibiotic Timeout"

Implement a structured interdisciplinary discussion (akin to a surgical timeout) at 48-72 hours of therapy:42

Review indication: Is there a documented infection or is this empiric for possible infection?
Review cultures: Do results allow narrowing?
Review response: Is the patient improving? Deteriorating?
Review duration: What is the planned end date?

This provides a non-threatening forum for stewardship conversations.

6. Leverage Pharmacy and ID Consultation

If direct hospitalist-to-hospitalist or hospitalist-to-consultant conversations are unproductive, involve antimicrobial stewardship pharmacists or ID physicians as neutral third parties. They can provide recommendations without the interpersonal dynamics of frontline team-to-team conflict.43

Pearl: The "Culture Negative, Clinically Well" Algorithm

For patients with negative cultures after 48-72 hours who are clinically improving:

Present the data:
"All cultures are negative, inflammatory markers trending down, patient afebrile and improving. In this scenario, continuing empiric broad-spectrum antibiotics increases risk of C. diff and resistance without added benefit."

Offer a safety net:
"We can stop now and monitor closely. If there's any clinical deterioration, we can always restart."

This acknowledges uncertainty while advocating for evidence-based practice.44

Oyster: The "Never Say Never" Principle

Avoid absolutes like "This patient definitely doesn't need antibiotics." Medicine is probabilistic, and stewardship recommendations should reflect this:

Instead of: "This is not an infection; stop the antibiotics."
Try: "Based on available data, infection is less likely. We could consider stopping antibiotics while monitoring closely for clinical changes."

This maintains credibility if the clinical situation evolves.45

Hack: The "Stewardship Template" Note

Create a standardized note template for stewardship recommendations:

ANTIMICROBIAL STEWARDSHIP RECOMMENDATION

Current regimen: [List antibiotics, day of therapy]

Indication: [e.g., CAP, HAP, bacteremia]

Cultures: [Results, including negatives]

Clinical status: [Vital signs, inflammatory markers, trends]

Recommendation:
☐ De-escalate to [narrow-spectrum agent]
☐ Convert IV → PO
☐ Shorten duration to [X days total]
☐ Discontinue [specific agent]

Evidence base: [Cite guideline or trial]

Risk/benefit: [Address specific patient factors]

Happy to discuss further—contact ASP at [extension]

This formalizes stewardship as a clinical service (like any consultation) and provides documentation for quality metrics.46

Conclusion: The Hospitalist as Steward

Antimicrobial stewardship is not an optional quality improvement project—it is a core clinical competency for hospitalists in the 21st century. Every antibiotic prescription is an opportunity to practice stewardship: selecting the narrowest-spectrum agent appropriate for the infection, planning de-escalation from the moment of empiric initiation, optimizing the route of administration, defining a rational duration, and advocating effectively for appropriate use.

The interventions outlined in this review—tracking DOT, implementing 48-hour hard stops, applying the 3 A's for IV-to-PO switches, adopting evidence-based short-course durations, and mastering stewardship communication—are immediately actionable and supported by robust evidence.

The bottom line: Excellent antimicrobial stewardship is simply excellent clinical medicine. When we prescribe antibiotics thoughtfully, reassess frequently, and stop promptly when appropriate, we simultaneously optimize individual patient outcomes and preserve the effectiveness of these life-saving drugs for future generations.

As hospitalists, we cannot afford to delegate this responsibility. The stewardship is the practice.

Key Pearls and Oysters: Summary

Pearls

The Spectrum Score: Assign a daily "spectrum score" to antimicrobial regimens and aim to decrease it as clinical data accumulate
The 48-Hour Hard Stop: All empiric broad-spectrum regimens require active reassessment at 48 hours
The 3 A's: Afebrile, Able, Awake—simple criteria for IV-to-PO conversion
The Halm Criteria: Use these validated stability criteria to determine CAP treatment completion
Pre-Discharge Duration Discussion: Document the planned end date of antibiotics on day 3-4 to prevent inadvertent continuation
The "Culture Negative, Clinically Well" Algorithm: Stopping antibiotics in improving patients with negative cultures is safe and evidence-based

Oysters

The DOT Paradox: Some stewardship interventions increase DOT while improving outcomes—always prioritize patient outcomes over metrics
The "Double Coverage" Fallacy: Combination therapy for Gram-negatives is rarely necessary once susceptibilities are known
The Beta-Lactam Challenge: IV-to-PO beta-lactam switches are not equivalent; oral alternatives often have different spectra and bioavailability
The SAB Exception: Never shorten S. aureus bacteremia treatment without ID consultation—minimum 14 days required
The "Never Say Never" Principle: Avoid absolutes in stewardship recommendations; medicine is probabilistic

Hacks

The "Culture Conversion" Conversation: Frame de-escalation as optimization rather than restriction
The "Early Switch" Protocol: Implement opt-out IV-to-PO protocols for high-bioavailability agents
The "Auto-Stop" Order: Default EHR antibiotic orders to evidence-based durations
The "Antibiotic Timeout": Structured 48-72 hour team discussions using a standardized framework
The "Stewardship Template" Note: Formalize recommendations with evidence-based documentation

References

World Health Organization. Antimicrobial resistance: global report on surveillance. Geneva: WHO; 2014.
Centers for Disease Control and Prevention. Antibiotic Resistance Threats in the United States, 2019. Atlanta, GA: U.S. Department of Health and Human Services, CDC; 2019.
Srinivasan A, et al. Antimicrobial stewardship: a hospitalist's role in the era of antibiotic resistance. J Hosp Med. 2018;13(11):792-795.
Barlam TF, Cosgrove SE, Abbo LM, et al. Implementing an antibiotic stewardship program: guidelines by the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America. Clin Infect Dis. 2016;62(10):e51-e77.
World Health Organization Collaborating Centre for Drug Statistics Methodology. Definition and general considerations. Available at: https://www.whocc.no/ddd/definition_and_general_considera/. Accessed January 2025.
Ibrahim OM, Polk RE. Antimicrobial use metrics and benchmarking to improve stewardship outcomes: methodology, opportunities, and challenges. Infect Dis Clin North Am. 2014;28(2):195-214.
Baggs J, Fridkin SK, Pollack LA, Srinivasan A, Jernigan JA. Estimating national trends in inpatient antibiotic use among US hospitals from 2006 to 2012. JAMA Intern Med. 2016;176(11):1639-1648.
Slimings C, Riley TV. Antibiotics and hospital-acquired Clostridium difficile infection: update of systematic review and meta-analysis. J Antimicrob Chemother. 2014;69(4):881-891.
Stenehjem E, Hersh AL, Buckel WR, et al. Impact of implementing antibiotic stewardship programs in 15 small hospitals: a cluster-randomized intervention. Clin Infect Dis. 2018;67(4):525-532.
Waterer GW, Somes GW, Wunderink RG. Monotherapy may be suboptimal for severe bacteremic pneumococcal pneumonia. Arch Intern Med. 2001;161(15):1837-1842.
Tabah A, Cotta MO, Garnacho-Montero J, et al. A systematic review of the definitions, determinants, and clinical outcomes of antimicrobial de-escalation in the intensive care unit. Clin Infect Dis. 2016;62(8):1009-1017.
Silva BNG, Andriolo RB, Atallah ÁN, Salomão R. De-escalation of antimicrobial treatment for adults with sepsis, severe sepsis or septic shock. Cochrane Database Syst Rev. 2013;(3):CD007934.
Schuetz P, Wirz Y, Sager R, et al. Effect of procalcitonin-guided antibiotic treatment on mortality in acute respiratory infections: a patient level meta-analysis. Lancet Infect Dis. 2018;18(1):95-107.
Liu C, Bayer A, Cosgrove SE, et al. Clinical practice guidelines by the Infectious Diseases Society of America for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children. Clin Infect Dis. 2011;52(3):e18-e55.
Marik PE. Aspiration pneumonitis and aspiration pneumonia. N Engl J Med. 2001;344(9):665-671.
Filice GA, Drekonja DM, Thurn JR, et al. Use of a computer decision support system and antimicrobial therapy appropriateness. Infect Control Hosp Epidemiol. 2013;34(6):558-565.
Rybak MJ, Le J, Lodise TP, et al. Therapeutic monitoring of vancomycin for serious methicillin-resistant Staphylococcus aureus infections: a revised consensus guideline and review by the American Society of Health-System Pharmacists. Am J Health Syst Pharm. 2020;77(11):835-864.
Paul M, Silbiger I, Grozinsky S, Soares-Weiser K, Leibovici L. Beta lactam antibiotic monotherapy versus beta lactam-aminoglycoside antibiotic combination therapy for sepsis. Cochrane Database Syst Rev. 2006;(1):CD003344.
Vardakas KZ, Tansarli GS, Bliziotis IA, Falagas ME. β-Lactam plus aminoglycoside or fluoroquinolone combination versus β-lactam monotherapy for Pseudomonas aeruginosa infections: a meta-analysis. Int J Antimicrob Agents. 2013;41(4):301-310.
Tamma PD, Cosgrove SE, Maragakis LL. Combination therapy for treatment of infections with gram-negative bacteria. Clin Microbiol Rev. 2012;25(3):450-470.
Cyriac JM, James E. Switch over from intravenous to oral therapy: A concise overview. J Pharmacol Pharmacother. 2014;5(2):83-87.
Mertz D, Koller M, Haller P, et al. Outcomes of early switching from intravenous to oral antibiotics on medical wards. J Antimicrob Chemother. 2009;64(1):188-199.
Shrayteh ZM, Rahal MK, Malaeb DN. Practice of switch from intravenous to oral antibiotics. Springerplus. 2014;3:717.
Sandberg T, Skoog G, Hermansson AB, et al. Ciprofloxacin for 7 days versus 14 days in women with acute pyelonephritis: a randomised, open-label and double-blind, placebo-controlled, non-inferiority trial. Lancet. 2012;380(9840):484-490.
Kuti EL, Kuti JL, Nightingale CH, Nicolau DP. Pharmacoeconomic impact and clinical outcomes of a pharmacist-managed i.v. to p.o. antimicrobial conversion program. Expert Rev Pharmacoecon Outcomes Res. 2006;6(6):627-632.
Spellberg B. The new antibiotic mantra—"Shorter is better." JAMA Intern Med. 2016;176(9):1254-1255.
Vaughn VM, Flanders SA, Sneller A, et al. Excess antibiotic treatment duration and adverse events in patients hospitalized with pneumonia: a multihospital cohort study. Ann Intern Med. 2019;171(3):153-163.
Dimopoulos G, Matthaiou DK, Karageorgopoulos DE, Grammatikos AP, Athanassa Z, Falagas ME. Short- versus long-course antibacterial therapy for community-acquired pneumonia: a meta-analysis. Drugs. 2008;68(13):1841-1854.
Metlay JP, Waterer GW, Long AC, et al. Diagnosis and treatment of adults with community-acquired pneumonia. An official clinical practice gui

deline of the American Thoracic Society and Infectious Diseases Society of America. Am J Respir Crit Care Med. 2019;200(7):e45-e67.

Halm EA, Fine MJ, Marrie TJ, et al. Time to clinical stability in patients hospitalized with community-acquired pneumonia: implications for practice guidelines. JAMA. 1998;279(18):1452-1457.
Chastre J, Wolff M, Fagon JY, et al. Comparison of 8 vs 15 days of antibiotic therapy for ventilator-associated pneumonia in adults: a randomized trial. JAMA. 2003;290(19):2588-2598.
Kalil AC, Metersky ML, Klompas M, et al. Management of adults with hospital-acquired and ventilator-associated pneumonia: 2016 clinical practice guidelines by the Infectious Diseases Society of America and the American Thoracic Society. Clin Infect Dis. 2016;63(5):e61-e111.
Pohl A. Modes of administration of antibiotics for symptomatic severe urinary tract infections. Cochrane Database Syst Rev. 2007;(4):CD003237.
Gupta K, Hooton TM, Naber KG, et al. International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: a 2010 update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases. Clin Infect Dis. 2011;52(5):e103-e120.
Yahav D, Franceschini E, Koppel F, et al. Seven versus 14 days of antibiotic therapy for uncomplicated Gram-negative bacteremia: a noninferiority randomized controlled trial. Clin Infect Dis. 2019;69(7):1091-1098.
Holland TL, Arnold C, Fowler VG Jr. Clinical management of Staphylococcus aureus bacteremia: a review. JAMA. 2014;312(13):1330-1341.
Sawyer RG, Claridge JA, Nathens AB, et al. Trial of short-course antimicrobial therapy for intraabdominal infection. N Engl J Med. 2015;372(21):1996-2005.
Solomkin JS, Mazuski JE, Bradley JS, et al. Diagnosis and management of complicated intra-abdominal infection in adults and children: guidelines by the Surgical Infection Society and the Infectious Diseases Society of America. Clin Infect Dis. 2010;50(1):133-164.
Heil EL, Kuti JL, Bearden DT, Dupont RP. The essential role of pharmacists in antimicrobial stewardship. Infect Control Hosp Epidemiol. 2016;37(7):753-754.
Linkin DR, Paris S, Fishman NO, Metlay JP. Inaccurate communications in telephone calls to an antimicrobial stewardship program. Infect Control Hosp Epidemiol. 2006;27(7):688-694.
Sikkens JJ, van Agtmael MA, Peters EJG, et al. Behavioral approach to appropriate antimicrobial prescribing in hospitals: the Dutch Unique Method for Antimicrobial Stewardship (DUMAS) participatory intervention study. JAMA Intern Med. 2017;177(8):1130-1138.
Pulcini C, Williams F, Molinari N, Davey P, Nathwani D. Junior doctors' knowledge and perceptions of antibiotic resistance and prescribing: a survey in France and Scotland. Clin Microbiol Infect. 2011;17(1):80-87.
Dodds Ashley ES, Kaye KS, DePestel DD, Hermsen ED. Antimicrobial stewardship: philosophy versus practice. Clin Infect Dis. 2014;59(Suppl 3):S112-S121.
Nussenblatt V, Avdic E, Berenholtz S, et al. Ventilator-associated pneumonia: overdiagnosis and treatment are common in medical and surgical intensive care units. Infect Control Hosp Epidemiol. 2014;35(3):278-284.
Livorsi DJ, Nair R, Lund BC, Alexander B, Beck BF, Scheetz MH, Perencevich EN. Antibiotic stewardship implementation: challenges and lessons learned from a multihospital collaborative study. Infect Control Hosp Epidemiol. 2017;38(9):1116-1119.
Pollack LA, Srinivasan A. Core elements of hospital antibiotic stewardship programs from the Centers for Disease Control and Prevention. Clin Infect Dis. 2014;59(Suppl 3):S97-S100.
Tamma PD, Avdic E, Li DX, Dzintars K, Cosgrove SE. Association of adverse events with antibiotic use in hospitalized patients. JAMA Intern Med. 2017;177(9):1308-1315.
Doernberg SB, Abbo LM, Burdette SD, et al. Essential resources and strategies for antibiotic stewardship programs in the acute care setting. Clin Infect Dis. 2018;67(8):1168-1174.
Vaughn VM, Gandhi TN, Conlon A, et al. Antibiotic overuse after discharge from US hospitals, 2016-2019. JAMA. 2021;326(18):1873-1875.
Lee TC, Frenette C, Jayaraman D, Green L, Pilote L. Antibiotic self-stewardship: trainee-led structured antibiotic time-outs to improve antimicrobial use. Ann Intern Med. 2014;161(10 Suppl):S53-S58.

Additional Practical Resources for Implementation

Recommended Stewardship Tools and Calculators

Antibiogram interpretation tools: Local susceptibility data should guide empiric therapy selection
Pharmacokinetic calculators: For vancomycin, aminoglycosides, and renally-eliminated agents
IDSA/SHEA Guidelines Repository: https://www.idsociety.org/practice-guideline/
CDC Core Elements Toolkit: Free implementation resources at https://www.cdc.gov/antibiotic-use/core-elements/hospital.html

Institutional Stewardship Metrics to Track

Process measures:
- DOT per 1,000 patient-days (overall and by antibiotic class)
- Proportion of empiric broad-spectrum regimens reassessed by 48-72 hours
- IV-to-PO conversion rate among eligible patients
- Compliance with guideline-recommended durations
Outcome measures:
- C. difficile infection rates
- Multidrug-resistant organism (MDRO) acquisition rates
- All-cause mortality (should not increase with effective stewardship)
- Length of stay
- Antibiotic-related adverse events

Building a Business Case for Stewardship

For hospitalists advocating for institutional stewardship resources:

Cost savings: Appropriate antibiotic use reduces drug costs, prevents C. difficile infections ($15,000-$30,000 per case), and decreases length of stay47
Regulatory requirements: The Joint Commission and CMS mandate antimicrobial stewardship programs as a condition of participation48
Medicolegal protection: Following evidence-based guidelines provides documentation of standard-of-care practice
Quality metrics: Many payers now tie reimbursement to stewardship metrics and infection prevention

Future Directions: Emerging Stewardship Opportunities

1. Post-Discharge Stewardship

Recent data demonstrate that 30-50% of antibiotic prescriptions at hospital discharge are longer than necessary.49 Hospitalists should:

Document the planned TOTAL duration (not just "discharge on X for 10 days")
Communicate clearly with outpatient providers about the rationale and end date
Consider "auto-stop" prescriptions that terminate on a specific date

Example discharge summary language:
"Completed 5 days of IV ceftriaxone for E. coli bacteremia (source: UTI). Transitioned to PO ciprofloxacin on discharge to complete 7-day TOTAL course. STOP DATE: [specific date]. Do not refill beyond this date unless clinical deterioration."

2. Rapid Diagnostics Integration

Molecular diagnostics (e.g., PCR panels for respiratory pathogens, blood culture rapid ID/AST) can accelerate de-escalation:

Positive respiratory viral PCR → discontinue antibacterial therapy in appropriate clinical contexts
Blood culture rapid MRSA PCR negative at 24 hours → discontinue vancomycin
Rapid AST → narrow to targeted agent 24-48 hours earlier than traditional methods

Hospitalists should partner with microbiology labs to understand turnaround times and create protocols for acting on rapid diagnostic results.

3. Antibiotic "Time-Outs"

Modeled after surgical time-outs, structured antibiotic time-outs at 48-72 hours involve the entire care team and have been shown to improve stewardship compliance by 30-40%.50 Key components:

Pause for 2-3 minutes during rounds
Review indication, cultures, clinical response, and planned duration
Document team consensus on continued need

4. Stewardship in the Age of Artificial Intelligence

Emerging AI-driven clinical decision support tools can:

Flag patients on prolonged courses who meet criteria for discontinuation
Predict antimicrobial resistance patterns to guide empiric therapy
Identify discordant therapy (continued vancomycin despite negative MRSA screens)

Hospitalists should engage with hospital informatics teams to pilot and validate these technologies.

Final Thoughts: The Stewardship Mindset

Effective antimicrobial stewardship requires a fundamental shift in prescribing culture—from defensive medicine ("cover everything, just in case") to evidence-based precision ("treat what's likely, narrow what's known, stop when appropriate").

This is not about rationing antibiotics or compromising patient care. Rather, it is the recognition that every antibiotic carries risk—individual risk (drug toxicity, C. difficile, selection of resistance) and societal risk (ecological pressure on our shared microbial environment).

As hospitalists managing the sickest patients during their most vulnerable moments, we must be stewards in the truest sense: caretakers of a precious resource that we hold in trust for future generations.

The stewardship mindset asks at every decision point:

Is this antibiotic necessary?
Is this the narrowest effective spectrum?
Is this the optimal route and dose?
When will I reassess?
When will I stop?

These questions, asked consistently and answered with evidence, define excellence in hospital medicine.

Acknowledgments

The authors acknowledge the global antimicrobial stewardship community whose dedication to preserving antibiotic effectiveness has generated the evidence base for this review. We thank the hospitalists, pharmacists, nurses, and microbiologists on the front lines who practice stewardship daily, often without recognition.

Disclosure Statement

The authors report no conflicts of interest relevant to this article.

Author Contributions

Manuscript concept, literature review, drafting, and critical revision were performed by the author. The author takes full responsibility for the content.

CME Questions (For Journal Submission)

Question 1: According to current IDSA/ATS guidelines, what is the recommended minimum duration of antibiotic therapy for uncomplicated community-acquired pneumonia in a clinically stable patient?

A) 3 days
B) 5 days
C) 7 days
D) 10 days

Answer: B (5 days for patients who are afebrile ≥48 hours with improving symptoms and no more than one CAP-associated sign of instability)

Question 2: Which of the following oral antibiotics has bioavailability >90% and can be considered equivalent to IV administration for most indications?

A) Cephalexin
B) Amoxicillin
C) Linezolid
D) Dicloxacillin

Answer: C (Linezolid has ~100% bioavailability; beta-lactams have variable and generally lower bioavailability)

Question 3: In the BALANCE trial, what was the demonstrated safe duration for uncomplicated Gram-negative bacteremia with documented source control?

A) 3 days
B) 7 days
C) 10 days
D) 14 days

Answer: B (7 days was non-inferior to 14 days for uncomplicated GNR bacteremia)

Question 4: What is the minimum recommended duration for Staphylococcus aureus bacteremia without endocarditis or complicated infection?

A) 7 days
B) 10 days
C) 14 days
D) 21 days

Answer: C (14 days is the minimum; 4-6 weeks required for endocarditis or complicated infections)

Word Count: ~8,500 words

Target Journal: Clinical Infectious Diseases, Journal of Hospital Medicine, Open Forum Infectious Diseases

Teaching Points for Postgraduate Learners

Case-Based Application Exercise

Case: A 68-year-old woman with COPD is admitted with fever, productive cough, and infiltrate on chest X-ray. Blood cultures drawn. Started on ceftriaxone 1g IV daily + azithromycin 500mg IV daily for severe CAP.

Day 1: Febrile to 38.9°C, tachypneic, on 4L NC, WBC 16,000
Day 3: Afebrile × 24h, oxygen requirement down to 2L, WBC 11,000, blood cultures negative × 48h, S. pneumoniae urinary antigen positive

Stewardship Questions:

Can you stop azithromycin? Yes—typical pathogen identified, clinically improving
Can you convert ceftriaxone IV to PO? Yes—meets the 3 A's (afebrile, able to take PO, awake)
What PO option? Amoxicillin 1g TID or cefpodoxime 200mg BID
What total duration? 5 days total (Day 3 + 2 more days = 5 days)
Can you stop vancomycin if it was started empirically? Yes—MRSA coverage not indicated for CAP with identified typical pathogen

This single case demonstrates multiple stewardship principles in action.

This comprehensive review provides postgraduate critical care trainees with both the evidence base and practical tools to implement antimicrobial stewardship as a core component of clinical excellence. The integration of pearls, oysters, and hacks—combined with specific communication strategies—equips hospitalists to navigate the complex interpersonal and clinical challenges of modern antimicrobial prescribing.

Thursday, October 2, 2025