Fellow's quick read · Infectious Diseases
Outpatient parenteral antimicrobial therapy (OPAT)
IDSA 2018 (Norris et al.) · reviewed 2026-07-14
Personal study digest for a new ID fellow, built from the full text of the 2018 IDSA OPAT clinical practice guideline (17 GRADE recommendations; grades shown verbatim). The "What's changed since 2018" section is reviewer synthesis of newer evidence, each claim cited. Not a substitute for the full guideline.
In one line
OPAT = giving IV antimicrobials outside the hospital, ≥2 doses on different days with no intervening admission. The 2018 guideline covers logistics, not durations. Three non-negotiables: ID review before it starts, a working access + monitoring system, and a defined stop date — and first ask whether IV is even needed.◆Who is a candidate — and where
- Almost every patient is eligible for some form of OPAT; the real question is the setting. Three delivery models: home (patient/caregiver ± home-infusion nursing; self-administered OPAT [S-OPAT] runs without a home nurse), infusion center (HCW-administered, Medicare Part B–covered, limited to once-daily agents), and skilled nursing facility (on-site nurses, but higher C. difficile / resistant-organism exposure and most costly to the system).
- Patients (or caregivers) may self-administer OPAT (strong, Rec 1) — and may do so without a visiting nurse if a system exists to monitor for access complications and drug adverse events (weak, Rec 2).
- Elderly patients may be treated at home (strong, Rec 4), assuming cognition, mobility, dexterity, and team communication are addressed.
- Persons who inject drugs: no recommendation (Rec 3) — decide case by case. Infants <1 month: no recommendation (Rec 5).
◆Setup the fellow drives
- Infectious-diseases expert review of the plan BEFORE initiation — for EVERY patient (strong, Rec 17). The guideline's stewardship gate.
- First dose of a new parenteral drug may be given at home under supervision of personnel qualified and equipped to treat anaphylaxis, if no prior allergy to the same class (weak, Rec 6).
- Because almost any agent can now be infused at home, drug choice is driven more by the model than by pharmacokinetics — infusion-center OPAT is effectively limited to once-daily agents.
◆Vascular access — matching device to course
| Scenario | Preferred device | Why / grade |
|---|---|---|
| Short adult course (<14 days) | Midline catheter rather than a central venous catheter | Avoids central-line risks for a brief course (weak, Rec 7) |
| OPAT with vancomycin | Central catheter NOT mandatory — a non-central catheter is acceptable | Mandatory central access is unnecessary (weak, Rec 8) |
| Advanced CKD | Tunneled central catheter rather than a PICC | Preserve upper-extremity veins for future dialysis access — prior PICC is linked to a non-functioning AV fistula (OR 2.8). Avoid PICCs at CKD stage 3b (eGFR <45) or on RRT (strong, Rec 9) |
| Most children | PICC rather than a long-term central catheter | (strong, Rec 13) |
| Other vesicants (nafcillin, acyclovir) | No device recommendation | Insufficient evidence (Rec 8) |
◆Monitoring
- Serial laboratory monitoring should be done (strong, high-quality — Rec 14). But the guideline deliberately declines to mandate which tests or how often (evidence insufficient). Its best-practice drug tables do, however, list weekly CBC-diff, BMP (K/Cr/BUN), and liver profile (ALT/AST/ALK phos/Tbili) for most agents — so "weekly labs" is best-practice convention, not a graded requirement.
- Vancomycin levels measured regularly throughout the course (strong, Rec 15); optimal frequency undefined, usual practice once weekly with stable renal function.
- No generalized rule on office-visit frequency (Rec 16) — set by the treating physician per patient, infection, tolerance, and social factors.
◆Key decisions a fellow owns
- Does this even need IV? Ask before committing to OPAT — many bone/joint and endocarditis courses can finish orally (see What's changed).
- Could a long-acting lipoglycopeptide skip the line? Dalbavancin/oritavancin can deliver "OPAT without a catheter" for selected infections.
- Device selection — especially tunneled catheter over PICC in advanced CKD to protect dialysis veins.
- What to monitor and how often — and monitor vancomycin by AUC, not trough (see What's changed).
- Catheter-associated DVT: do NOT reflexively pull a well-positioned, functioning line if arm pain/swelling improve with anticoagulation (weak, Rec 11 — evidence extrapolated from cancer patients).
- Define the stop date up front and remove the catheter at completion.
◆Duration & stopping
- OPAT length = the infection's required course. This guideline sets no durations — it defers to the disease- and organism-specific guidelines.
- De-escalate to oral when a good option exists; the goal is the shortest safe parenteral course, then stop.
What's changed since 2018
Reviewer synthesis of newer evidence — not the guideline. Each claim cited; flags where the 2018 text lags current practice.
- The biggest shift is upstream — oral step-down shrinks who needs OPAT at all. OVIVA (bone/joint) and POET (left-sided endocarditis) found oral non-inferior to IV, and SABATO extended early oral switch to low-risk S. aureus bacteremia. The 2018 guideline governs how to run IV-at-home, not whether IV is needed. OVIVA, N Engl J Med 2019;380:425-436 (PMID 30699315; doi:10.1056/NEJMoa1710926) · POET, N Engl J Med 2019;380:415-424 (PMID 30152252; doi:10.1056/NEJMoa1808312) · SABATO, Lancet Infect Dis 2024;24:523-534 (PMID 38244557)
- "OPAT without a line" — long-acting lipoglycopeptides. Dalbavancin (2 × 1500 mg IV, days 1 and 8) for complicated S. aureus bacteremia after culture clearance: DOTS was NOT superior by desirability-of-outcome ranking (47.7%) but met non-inferiority on clinical efficacy (73% vs 72%). Excludes CNS infection, retained prosthetic material, left-sided endocarditis, severe immunocompromise. Trades the catheter + monitoring burden for two infusions. DOTS, JAMA 2025;334:866-877 (PMID 40802264; doi:10.1001/jama.2025.12543)
- Vancomycin monitoring moved from trough to AUC. The 2020 ASHP/IDSA/PIDS/SIDP consensus targets AUC/MIC 400-600 (not trough 15-20) to cut nephrotoxicity — so OPAT vancomycin should be AUC-guided. Rybak, Am J Health Syst Pharm 2020;77:835-864 (PMID 32191793; doi:10.1093/ajhp/zxaa036)
- Still current. ID review before OPAT, serial monitoring, midline for short courses, and tunneled catheter over PICC in advanced CKD all hold. No newer IDSA OPAT guideline since 2018 (confirmed 2026) — the 2018 document remains operative. idsociety.org
- Open / evolving. The 2018 "no recommendation" on OPAT for people who inject drugs is being filled by cohort data supporting it in selected patients (long-acting lipoglycopeptides can avoid an indwelling line); still individualized. Telehealth / remote monitoring of OPAT expanded after 2020.
◆Anki cards (added on the earlier 2026-07-14 run — not re-added)
- ID expert review is required before initiating OPAT — for every patient (strong, Rec 17).
- Advanced CKD → tunneled central catheter, not a PICC (vein preservation); midline for short adult courses.
- Self-administration of OPAT is allowed — even without a visiting nurse if a monitoring system is in place.
- Catheter-associated DVT on OPAT → keep a well-positioned, functioning line if symptoms improve with anticoagulation.
- Held as already in deck: dalbavancin/oritavancin single-dose + DOTS; vancomycin AUC 400-600; OVIVA oral bone/joint; POET oral endocarditis.
Sources: IDSA 2018 OPAT CPG (source-of-record, full text) — Norris AH, et al. Clin Infect Dis 2019;68(1):e1-e35 (PMID 30423035; doi:10.1093/cid/ciy745). Currency: OVIVA (PMID 30699315); POET (PMID 30152252); SABATO (PMID 38244557); DOTS (PMID 40802264; doi:10.1001/jama.2025.12543); vancomycin AUC consensus (PMID 32191793; doi:10.1093/ajhp/zxaa036); IDSA OPAT guideline status (idsociety.org).