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.
| Diuretics | IV | PO |
|---|---|---|
| Furosemide | 1 (20 mg) | 2 (40 mg) |
| Bumetanide | 1 (1 mg) | 1 (1 mg) |
| Torsemide | 1 (20 mg) | 1 (20 mg) |
| 40 mg furosemide IV = 20 mg torsemide PO/IV = 1 mg bumetanide PO/IV | ||
| Glucocorticoids (General Rule: IV dose ≈ PO dose after applying steroid equivalence) | ||
|---|---|---|
| Hydrocortisone | 20mg | GC = MC |
| Prednisone | 5mg (oral only) | GC > MC |
| Prednisolone | 5mg | GC > MC |
| Methylprednisolone | 4mg | GC >> MC |
| Dexamethasone | 0.75mg | GC >>> MC |
| Clinical implication: In patients with heart failure, hypertension, ascites, or fluid-sensitive states, dexamethasone or methylprednisolone are preferred over hydrocortisone or prednisone if mineralocorticoid effect is undesirable | ||
| GI Medications | IV | PO |
|---|---|---|
| Esomeprazole | 1 (40mg) | 1 (40mg) |
| Famotidine | 1 (20mg) | 1 (20mg) |
| Pantoprazole | 1 (40mg) | 1 (40mg) |
| Ondansetron | 1 (4mg) | 2 (8mg) |
| Fluoroquinolones | IV | PO |
|---|---|---|
| Levofloxacin | 1 (750mg) | 1 (750mg) |
| Ciprofloxacin | 1 (400mg) | 1.5 (500-750mg) |
| Moxifloxacin | 1 (400mg) | 1 (400mg) |
| Misc Antibiotics | IV | PO |
|---|---|---|
| Azithromycin | 1 (500mg) | 1 (500mg) |
| Linezolid | 1 (600mg) | 1 (600mg) |
| Metronidazole | 1 (500mg) | 1 (500mg) |
| Doxycycline | 1 (100mg) | 1 (100mg) |
| Trimethoprim-Sulfamethoxazole | 1 (80mg TMP) | 1 (80mg TMP) |
| Rifampin | 1 (600mg) | 1 (600mg) |
| Antifungals | 1 (400mg) | 1 (400mg) |
|---|---|---|
| Isavuconazonium sulfate | 1 (372mg) | 1 (372mg) |
| Posaconazole | 1 (300mg) | 1 (300mg) |
| Voriconazole | 1 (200mg) | 1 (200mg) |
| Anti-seizures | IV | PO |
|---|---|---|
| Brivaracetam | 1 (50mg) | 1 (50mg) |
| Lacosamide | 1 (100mg) | 1 (100mg) |
| Levetiracetam | 1 (200mg) | 1 (200mg) |
| Miscellaneous | IV | PO |
|---|---|---|
|
Digoxin* * Variable bioavailability; titrate cautiously |
1 (125mcg) Adult / 1 (4mcg) Pediatric | 1 (125mcg) Adult / 1.25 (5mcg) Pediatric |
|
Metoprolol** ** Clinical titration required for IV |
1 (5 mg) | ~4 (20mg) |
| Levothyroxine | 1 (50-75mcg) | ~1.3 (100mcg) |
| Folic acid | 1 (1mg) | 1 (1mg) |
| Thiamine | 1 (100mg) | 1 (100mg) |
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
If you found this resource helpful and would like to support ongoing updates, consider contributing at BuyMeACoffee. Viewing the webpage is free. A printer-friendly PDF version of this guide is available for $5.
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 1.
2/21/2026
PharmGuides