IV: PO Conversion Charts
This page serves as a concise reference for common IV-to-PO dose conversions with examples included. Below are key pharmacokinetic principles to guide safe transition from parenteral to oral therapy.
Pharmacist reference • Adult doses unless noted • Ratios shown as ×IV-dose (equivalent mg) • Rev. Jul 2026
| Drug | IV | PO |
|---|---|---|
| Furosemide | 1 (20 mg) | 2 (40 mg) |
| Bumetanide | 1 (1 mg) | 1 (1 mg) |
| Torsemide | 1 (20 mg) | 1 (20 mg) |
| Glucocorticoid | Equiv. dose | Potency (GC : MC) |
|---|---|---|
| Dexamethasone | 0.75 mg | GC >>> MC |
| Hydrocortisone | 20 mg | GC = MC |
| Methylprednisolone | 4 mg | GC >> MC |
| Prednisolone | 5 mg | GC > MC |
| Prednisone | 5 mg (oral only) | GC > MC |
| Drug | IV | PO |
|---|---|---|
| Esomeprazole | 1 (40 mg) | 1 (40 mg) |
| Famotidine | 1 (20 mg) | 1 (20 mg) |
| Metoclopramide | 1 (10 mg) | 1 (10 mg) |
| Ondansetron | 1 (4 mg) | 2 (8 mg) |
| Pantoprazole | 1 (40 mg) | 1 (40 mg) |
| Drug | IV | PO |
|---|---|---|
| Ciprofloxacin | 1 (400 mg) | 1.5 (500–750 mg) |
| Levofloxacin | 1 (750 mg) | 1 (750 mg) |
| Moxifloxacin | 1 (400 mg) | 1 (400 mg) |
| Drug | IV | PO |
|---|---|---|
| Azithromycin | 1 (500 mg) | 1 (500 mg) |
| Clindamycin | 1 (600 mg) | 0.5–0.75 (300–450 mg) |
| *Dose depends on indication | ||
| Doxycycline | 1 (100 mg) | 1 (100 mg) |
| Linezolid | 1 (600 mg) | 1 (600 mg) |
| Metronidazole | 1 (500 mg) | 1 (500 mg) |
| Rifampin | 1 (600 mg) | 1 (600 mg) |
| Trimethoprim–Sulfamethoxazole | 1 (80 mg TMP) | 1 (80 mg TMP) |
| Drug | IV | PO |
|---|---|---|
| Fluconazole | 1 (400 mg) | 1 (400 mg) |
| Isavuconazonium sulfate | 1 (372 mg) | 1 (372 mg) |
| Posaconazole | 1 (300 mg) | 1 (300 mg) |
| Voriconazole | 1 (200 mg) | 1 (200 mg) |
| Drug | IV | PO |
|---|---|---|
| Acyclovir → Valacyclovir | Acyclovir (mg/kg dosing) | Valacyclovir 1000 mg TID |
| *Prodrug switch; indication-dependent | ||
| Ganciclovir → Valganciclovir | Ganciclovir 5 mg/kg | Valganciclovir 900 mg |
| *Prodrug switch (1:1 by regimen) | ||
| Drug | IV | PO |
|---|---|---|
| Brivaracetam | 1 (50 mg) | 1 (50 mg) |
| Lacosamide | 1 (100 mg) | 1 (100 mg) |
| Levetiracetam | 1 (200 mg) | 1 (200 mg) |
| Phenytoin / Fosphenytoin | 1 (500 mg PE) | 1 (500 mg PE) |
| Valproic Acid | 1 (125 mg Q6H) | 1 (500 mg total daily dose) |
| *IV dose should be divided Q6H | ||
| Drug | IV | PO |
|---|---|---|
| Acetaminophen | 1 (1000 mg) | 1 (1000 mg) |
| Digoxin | 1 (125 mcg) Adult | 1 (125 mcg) Adult |
| 1 (4 mcg) Pediatric | 1.25 (5 mcg) Pediatric | |
| *Variable bioavailability; titrate cautiously | ||
| Folic acid | 1 (1 mg) | 1 (1 mg) |
| Haloperidol | 1 (5 mg IV/IM) | ~1.5–2 (7.5–10 mg) |
| *PO ~60–70% bioavailable | ||
| Levothyroxine | 1 (50–75 mcg) | ~1.3 (100 mcg) |
| Metoprolol | 1 (1 mg) | ~2.5 (2.5 mg) |
| *Clinical titration required; standard equivalence ~2.5 mg PO : 1 mg IV | ||
| Thiamine | 1 (100 mg) | 1 (100 mg) |
Dosing basis: Lexicomp, Micromedex, Clinical Pharmacology, UpToDate, and manufacturer labeling (DailyMed).
Antimicrobial IV→PO: Sanford Guide, Johns Hopkins ABX Guide, IDSA/SHEA Stewardship Guidelines (Clin Infect Dis. 2016), and your facility's stewardship criteria.
Key conversions:
• Digoxin — tablets ~60–80% bioavailable (Clin Pharmacol Ther. 1976).
• Valganciclovir 900 mg PO ≈ ganciclovir 5 mg/kg IV (Valcyte PI; VICTOR trial).
• Metoclopramide ~80% oral bioavailability (Reglan PI).
▸ Where sources differ, your institution's formulary and order sets take precedence.
IV → PO Conversion Principles
IV dosing bypasses absorption. Oral dosing accounts for bioavailability (F).
PO dose = IV dose / F
Example: if F = 50%, PO dose is 2x the IV dose
However, dose equivalence does not equal clinical equivalence (i.e. beta lactams, drugs with saturable absorption, or drugs with non-linear kinetics).
When to not assume equivalence:
- Vancomycin – PO is not systemic and only works on the GIT (which is why the oral form is effective against c. difficile)
- Aminoglycosides – no systemic use
- Severe malabsorption rates
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References:
Lexicomp Online; IBM Micromedex; Goodman & Gilman’s The Pharmacological Basis of Therapeutics (14th ed.); and individual U.S. prescribing information (DailyMed) for referenced medications. Accessed February 21, 2026.
This resource is intended for educational and reference purposes only. It is not a substitute for clinical judgment. Institutional policies, protocols, and locally approved guidelines take precedence over the information presented here. Clinicians should always consult their own institution’s policies and applicable references before making therapeutic decisions.
Version 2. 7/4/2026. PharmGuides