IV to PO Conversions
Adult conversion reference for common inpatient medications. For oral switch decisions, confirm patient meets clinical criteria for PO conversion before changing route.
General IV to PO Switch Criteria
Most patients are appropriate for IV-to-PO conversion when they meet ALL of the following:
- • Hemodynamically stable
- • Afebrile for 24–48 hours (varies by indication)
- • Tolerating oral diet or has a functional GI tract
- • No malabsorption, severe vomiting, or significant ileus
- • Adequate enteral access (NG/OG tube acceptable if approved formulation)
- • Source control achieved (for infections)
- • Bioavailability of oral form is adequate for the indication
Specific indications (CNS infection, endocarditis, bacteremia, severe infections) may require longer IV courses regardless of clinical improvement. Verify against institutional protocols.
44 medications shown
| Drug | IV dose | PO dose | Ratio | Oral F | Notes |
|---|---|---|---|---|---|
Levofloxacin (Levaquin) | 250–750 mg q24h | 250–750 mg q24h | 1:1 | ~99% | One of the cleanest IV-to-PO conversions; PO and IV interchangeable. Avoid concurrent divalent cations (Mg, Ca, Fe, Al) — separate 2 h before or 6 h after. |
Ciprofloxacin (Cipro) | 200–400 mg q8–12h | 250–750 mg q12h | IV 400 mg ≈ PO 500 mg (≈ PO 750 mg for severe infections) | ~70% | IV:PO not 1:1 — use higher PO dose. Same divalent cation interaction. Avoid in pseudomonal bacteremia or other severe infections where IV is preferred. |
Moxifloxacin (Avelox) | 400 mg q24h | 400 mg q24h | 1:1 | ~90% | 1:1 conversion. QT prolongation risk. Not for UTI (poor urinary concentrations). |
Metronidazole (Flagyl) | 500 mg q8h | 500 mg q8h | 1:1 | ~100% | Excellent oral bioavailability. PO often preferred unless NPO. Avoid alcohol. |
Linezolid (Zyvox) | 600 mg q12h | 600 mg q12h | 1:1 | ~100% | 1:1 conversion. Major cost-saving opportunity — PO significantly less expensive than IV. Watch serotonergic interactions and thrombocytopenia with prolonged courses. |
Doxycycline | 100 mg q12h | 100 mg q12h | 1:1 | ~90–100% | 1:1 conversion. Avoid divalent cations. Take with food to reduce GI upset (does not significantly reduce absorption). |
Clindamycin (Cleocin) | 600–900 mg q8h | 300–450 mg q6–8h | Not 1:1; PO doses smaller and more frequent | ~90% | PO dosing is by capsule (150 or 300 mg). Higher C. difficile risk. |
Trimethoprim-sulfamethoxazole (Bactrim) | Dosed by TMP, 5 mg/kg q6–12h for serious infections | 1 DS tab (160/800) q12h typical; weight-based for PCP | TMP component 1:1 | ~90–100% | Convert by TMP component. PO usually adequate unless NPO or severe infection. |
Amoxicillin / Amoxicillin-clavulanate | Ampicillin (or ampicillin-sulbactam) used IV instead | Amoxicillin 500–1000 mg q8h; amox-clav 875/125 q12h | Ampicillin IV 1–2 g q6h ≈ amoxicillin PO 500–1000 mg q8h | Amoxicillin ~75–90% | Cross-conversion (ampicillin → amoxicillin). Amox-clav PO commonly used as step-down for ampicillin-sulbactam IV. |
Cefazolin → Cephalexin (Keflex) | Cefazolin 1–2 g q8h | Cephalexin 500 mg q6h or 1 g q8h | Not 1:1 — cephalexin given more frequently | Cephalexin ~90% | Common step-down for cellulitis and SSTI from IV cefazolin. |
Ceftriaxone → Cefpodoxime / Cefdinir / Cefuroxime axetil | Ceftriaxone 1–2 g q24h | Cefpodoxime 200–400 mg q12h · Cefdinir 300 mg q12h or 600 mg q24h · Cefuroxime axetil 250–500 mg q12h | Not 1:1; oral cephalosporins have lower bioavailability and narrower spectrum | Cefpodoxime ~50% · Cefdinir ~25% · Cefuroxime axetil ~50% | Significant spectrum loss with oral cephalosporins. May not be appropriate for all ceftriaxone indications — verify susceptibilities before switch. |
Vancomycin (PO) | NOT interchangeable. IV vancomycin treats systemic infections. | CDI: 125 mg q6h × 10 days (standard) or 500 mg q6h for severe/complicated | N/A — different indications | Negligible systemic absorption | PO vancomycin is not absorbed systemically. Do NOT convert IV vancomycin to PO vancomycin for systemic infection. |
- IV dose
- 250–750 mg q24h
- PO dose
- 250–750 mg q24h
- Ratio
- 1:1
- Oral F
- ~99%
One of the cleanest IV-to-PO conversions; PO and IV interchangeable. Avoid concurrent divalent cations (Mg, Ca, Fe, Al) — separate 2 h before or 6 h after.
- IV dose
- 200–400 mg q8–12h
- PO dose
- 250–750 mg q12h
- Ratio
- IV 400 mg ≈ PO 500 mg (≈ PO 750 mg for severe infections)
- Oral F
- ~70%
IV:PO not 1:1 — use higher PO dose. Same divalent cation interaction. Avoid in pseudomonal bacteremia or other severe infections where IV is preferred.
- IV dose
- 400 mg q24h
- PO dose
- 400 mg q24h
- Ratio
- 1:1
- Oral F
- ~90%
1:1 conversion. QT prolongation risk. Not for UTI (poor urinary concentrations).
- IV dose
- 500 mg q8h
- PO dose
- 500 mg q8h
- Ratio
- 1:1
- Oral F
- ~100%
Excellent oral bioavailability. PO often preferred unless NPO. Avoid alcohol.
- IV dose
- 600 mg q12h
- PO dose
- 600 mg q12h
- Ratio
- 1:1
- Oral F
- ~100%
1:1 conversion. Major cost-saving opportunity — PO significantly less expensive than IV. Watch serotonergic interactions and thrombocytopenia with prolonged courses.
- IV dose
- 100 mg q12h
- PO dose
- 100 mg q12h
- Ratio
- 1:1
- Oral F
- ~90–100%
1:1 conversion. Avoid divalent cations. Take with food to reduce GI upset (does not significantly reduce absorption).
- IV dose
- 600–900 mg q8h
- PO dose
- 300–450 mg q6–8h
- Ratio
- Not 1:1; PO doses smaller and more frequent
- Oral F
- ~90%
PO dosing is by capsule (150 or 300 mg). Higher C. difficile risk.
- IV dose
- Dosed by TMP, 5 mg/kg q6–12h for serious infections
- PO dose
- 1 DS tab (160/800) q12h typical; weight-based for PCP
- Ratio
- TMP component 1:1
- Oral F
- ~90–100%
Convert by TMP component. PO usually adequate unless NPO or severe infection.
- IV dose
- Ampicillin (or ampicillin-sulbactam) used IV instead
- PO dose
- Amoxicillin 500–1000 mg q8h; amox-clav 875/125 q12h
- Ratio
- Ampicillin IV 1–2 g q6h ≈ amoxicillin PO 500–1000 mg q8h
- Oral F
- Amoxicillin ~75–90%
Cross-conversion (ampicillin → amoxicillin). Amox-clav PO commonly used as step-down for ampicillin-sulbactam IV.
- IV dose
- Cefazolin 1–2 g q8h
- PO dose
- Cephalexin 500 mg q6h or 1 g q8h
- Ratio
- Not 1:1 — cephalexin given more frequently
- Oral F
- Cephalexin ~90%
Common step-down for cellulitis and SSTI from IV cefazolin.
- IV dose
- Ceftriaxone 1–2 g q24h
- PO dose
- Cefpodoxime 200–400 mg q12h · Cefdinir 300 mg q12h or 600 mg q24h · Cefuroxime axetil 250–500 mg q12h
- Ratio
- Not 1:1; oral cephalosporins have lower bioavailability and narrower spectrum
- Oral F
- Cefpodoxime ~50% · Cefdinir ~25% · Cefuroxime axetil ~50%
Significant spectrum loss with oral cephalosporins. May not be appropriate for all ceftriaxone indications — verify susceptibilities before switch.
- IV dose
- NOT interchangeable. IV vancomycin treats systemic infections.
- PO dose
- CDI: 125 mg q6h × 10 days (standard) or 500 mg q6h for severe/complicated
- Ratio
- N/A — different indications
- Oral F
- Negligible systemic absorption
PO vancomycin is not absorbed systemically. Do NOT convert IV vancomycin to PO vancomycin for systemic infection.
| Drug | IV dose | PO dose | Ratio | Oral F | Notes |
|---|---|---|---|---|---|
Fluconazole (Diflucan) | 100–800 mg q24h | 100–800 mg q24h | 1:1 | ~90% | 1:1 conversion. PO preferred when tolerated. |
Voriconazole (Vfend) | 6 mg/kg q12h × 2, then 4 mg/kg q12h | 200–300 mg q12h (or weight-based 4 mg/kg) | Weight-based; PO and IV similar at maintenance | ~96% in healthy volunteers (variable in patients) | Therapeutic drug monitoring recommended. Take PO 1 h before or after meals. Multiple CYP2C19/3A4 interactions. |
Posaconazole (Noxafil) | 300 mg q12h × 2, then 300 mg q24h | DR tab: 300 mg q12h × 2, then 300 mg q24h (1:1 with IV). Suspension NOT interchangeable. | 1:1 between IV and DR tab; suspension different | Variable; suspension highly food-dependent | Suspension absorption unreliable. Prefer DR tab for IV-to-PO conversion. |
- IV dose
- 100–800 mg q24h
- PO dose
- 100–800 mg q24h
- Ratio
- 1:1
- Oral F
- ~90%
1:1 conversion. PO preferred when tolerated.
- IV dose
- 6 mg/kg q12h × 2, then 4 mg/kg q12h
- PO dose
- 200–300 mg q12h (or weight-based 4 mg/kg)
- Ratio
- Weight-based; PO and IV similar at maintenance
- Oral F
- ~96% in healthy volunteers (variable in patients)
Therapeutic drug monitoring recommended. Take PO 1 h before or after meals. Multiple CYP2C19/3A4 interactions.
- IV dose
- 300 mg q12h × 2, then 300 mg q24h
- PO dose
- DR tab: 300 mg q12h × 2, then 300 mg q24h (1:1 with IV). Suspension NOT interchangeable.
- Ratio
- 1:1 between IV and DR tab; suspension different
- Oral F
- Variable; suspension highly food-dependent
Suspension absorption unreliable. Prefer DR tab for IV-to-PO conversion.
| Drug | IV dose | PO dose | Ratio | Oral F | Notes |
|---|---|---|---|---|---|
Pantoprazole (Protonix) | 40 mg q24h or q12h | 40 mg q24h | 1:1 | ~77% | PO equally effective for most indications. Switch as soon as tolerating PO. IV reserved for active GI bleed and NPO patients. |
Esomeprazole (Nexium) | 20–40 mg q24h | 20–40 mg q24h | 1:1 | ~50–90% (dose-dependent) | PO preferred when tolerated. |
Famotidine (Pepcid) | 20 mg q12h | 20 mg q12h or 40 mg q24h | 1:1 | ~40–50% | Despite lower bioavailability, dosing is the same. Renally adjusted. |
- IV dose
- 40 mg q24h or q12h
- PO dose
- 40 mg q24h
- Ratio
- 1:1
- Oral F
- ~77%
PO equally effective for most indications. Switch as soon as tolerating PO. IV reserved for active GI bleed and NPO patients.
- IV dose
- 20–40 mg q24h
- PO dose
- 20–40 mg q24h
- Ratio
- 1:1
- Oral F
- ~50–90% (dose-dependent)
PO preferred when tolerated.
- IV dose
- 20 mg q12h
- PO dose
- 20 mg q12h or 40 mg q24h
- Ratio
- 1:1
- Oral F
- ~40–50%
Despite lower bioavailability, dosing is the same. Renally adjusted.
| Drug | IV dose | PO dose | Ratio | Oral F | Notes |
|---|---|---|---|---|---|
Metoprolol tartrate | 2.5–5 mg slow IV push, may repeat q5min × 3 doses | 25–100 mg q6–12h (tartrate) or daily (succinate) | IV:PO ≈ 1:2.5 (5 mg IV ≈ 12.5–25 mg PO) | ~40–50% | Common conversion mistake — PO dose is significantly higher than IV. Tartrate and succinate are NOT interchangeable in dosing schedule. |
Furosemide (Lasix) | Variable | Typically 2× the IV dose | IV:PO = 1:2 | ~50% (highly variable, 10–100%) | Highly variable absorption, especially in HF with gut edema. Some patients require IV-only dosing. When converting, double the dose. |
Diltiazem | Continuous infusion for rate control | ER 120–360 mg q24h, or IR 30–90 mg q6–8h | Complex — not a simple conversion; consult institutional protocol | ~40% | Transition from IV infusion to PO requires overlap. Start PO and continue IV for 1–2 h until PO takes effect. |
Amiodarone | Load 150 mg over 10 min, then 1 mg/min × 6 h, then 0.5 mg/min | Load 400–800 mg/day divided × 1–3 weeks, then 200–400 mg/day | Not 1:1 — IV and PO loading dramatically different | ~50% | Long half-life (40–60 days). Transition strategy varies. PO load is grams over weeks while IV load is mg over hours. |
Hydralazine | 10–20 mg q4–6h prn | 10–50 mg q6h | Not 1:1; PO doses generally higher | ~30–50% (acetylator-dependent) | First-pass metabolism reduces PO bioavailability. Increase PO dose accordingly. |
- IV dose
- 2.5–5 mg slow IV push, may repeat q5min × 3 doses
- PO dose
- 25–100 mg q6–12h (tartrate) or daily (succinate)
- Ratio
- IV:PO ≈ 1:2.5 (5 mg IV ≈ 12.5–25 mg PO)
- Oral F
- ~40–50%
Common conversion mistake — PO dose is significantly higher than IV. Tartrate and succinate are NOT interchangeable in dosing schedule.
- IV dose
- Variable
- PO dose
- Typically 2× the IV dose
- Ratio
- IV:PO = 1:2
- Oral F
- ~50% (highly variable, 10–100%)
Highly variable absorption, especially in HF with gut edema. Some patients require IV-only dosing. When converting, double the dose.
- IV dose
- Continuous infusion for rate control
- PO dose
- ER 120–360 mg q24h, or IR 30–90 mg q6–8h
- Ratio
- Complex — not a simple conversion; consult institutional protocol
- Oral F
- ~40%
Transition from IV infusion to PO requires overlap. Start PO and continue IV for 1–2 h until PO takes effect.
- IV dose
- Load 150 mg over 10 min, then 1 mg/min × 6 h, then 0.5 mg/min
- PO dose
- Load 400–800 mg/day divided × 1–3 weeks, then 200–400 mg/day
- Ratio
- Not 1:1 — IV and PO loading dramatically different
- Oral F
- ~50%
Long half-life (40–60 days). Transition strategy varies. PO load is grams over weeks while IV load is mg over hours.
- IV dose
- 10–20 mg q4–6h prn
- PO dose
- 10–50 mg q6h
- Ratio
- Not 1:1; PO doses generally higher
- Oral F
- ~30–50% (acetylator-dependent)
First-pass metabolism reduces PO bioavailability. Increase PO dose accordingly.
| Drug | IV dose | PO dose | Ratio | Oral F | Notes |
|---|---|---|---|---|---|
Warfarin | IV rarely used; PO is standard | Variable, INR-guided | N/A | ~100% | IV warfarin not commonly used. Conversion not typically needed. |
Heparin → Enoxaparin or Warfarin | Continuous infusion | N/A — different agents | Not a conversion; requires overlap | — | Different agents requiring overlap. See institutional anticoagulation protocols. |
- IV dose
- IV rarely used; PO is standard
- PO dose
- Variable, INR-guided
- Ratio
- N/A
- Oral F
- ~100%
IV warfarin not commonly used. Conversion not typically needed.
- IV dose
- Continuous infusion
- PO dose
- N/A — different agents
- Ratio
- Not a conversion; requires overlap
- Oral F
- —
Different agents requiring overlap. See institutional anticoagulation protocols.
| Drug | IV dose | PO dose | Ratio | Oral F | Notes |
|---|---|---|---|---|---|
Methylprednisolone → Prednisone (Solu-Medrol) | Variable (e.g., 40–125 mg q6h) | Prednisone — 4 mg methylprednisolone ≈ 5 mg prednisone | Methylprednisolone:prednisone = 4:5 | Prednisone ~80% | Equivalent doses differ by potency. Same conversion applies to IV-to-PO methylprednisolone (1:1). |
Hydrocortisone → Hydrocortisone PO / Prednisone PO | Hydrocortisone IV 50–100 mg q8h | Hydrocortisone 20 mg = prednisone 5 mg = methylpred 4 mg | Based on equivalent potency | Variable | For adrenal insufficiency, transition based on equivalent doses. |
Dexamethasone | Variable by indication | Same dose as IV | 1:1 | ~80% | 1:1 conversion. Very long half-life. |
- IV dose
- Variable (e.g., 40–125 mg q6h)
- PO dose
- Prednisone — 4 mg methylprednisolone ≈ 5 mg prednisone
- Ratio
- Methylprednisolone:prednisone = 4:5
- Oral F
- Prednisone ~80%
Equivalent doses differ by potency. Same conversion applies to IV-to-PO methylprednisolone (1:1).
- IV dose
- Hydrocortisone IV 50–100 mg q8h
- PO dose
- Hydrocortisone 20 mg = prednisone 5 mg = methylpred 4 mg
- Ratio
- Based on equivalent potency
- Oral F
- Variable
For adrenal insufficiency, transition based on equivalent doses.
- IV dose
- Variable by indication
- PO dose
- Same dose as IV
- Ratio
- 1:1
- Oral F
- ~80%
1:1 conversion. Very long half-life.
| Drug | IV dose | PO dose | Ratio | Oral F | Notes |
|---|---|---|---|---|---|
Acetaminophen (Tylenol / Ofirmev) | 1000 mg q6h (max 4000 mg/day) | 1000 mg q6h (max 4000 mg/day) | 1:1 | ~80% | IV very expensive. Strong cost-saving opportunity to switch when tolerating PO. |
Morphine | Variable | IV:PO = 1:3 (10 mg IV ≈ 30 mg PO) | 1:3 | ~25% | Use opioid conversion calculator for precise conversions including breakthrough dosing. |
Hydromorphone (Dilaudid) | Variable | IV:PO = 1:5 (2 mg IV ≈ 10 mg PO) | 1:5 | ~25% | Use opioid conversion calculator. |
Oxycodone | Not available in US | PO only | N/A | ~60–87% | N/A for IV-to-PO conversion. |
Fentanyl | IV / transdermal | Not converted to oral fentanyl in typical practice | N/A | — | For chronic pain, convert IV/transdermal fentanyl to oral morphine equivalents via opioid calculator. |
- IV dose
- 1000 mg q6h (max 4000 mg/day)
- PO dose
- 1000 mg q6h (max 4000 mg/day)
- Ratio
- 1:1
- Oral F
- ~80%
IV very expensive. Strong cost-saving opportunity to switch when tolerating PO.
- IV dose
- Variable
- PO dose
- IV:PO = 1:3 (10 mg IV ≈ 30 mg PO)
- Ratio
- 1:3
- Oral F
- ~25%
Use opioid conversion calculator for precise conversions including breakthrough dosing.
- IV dose
- Variable
- PO dose
- IV:PO = 1:5 (2 mg IV ≈ 10 mg PO)
- Ratio
- 1:5
- Oral F
- ~25%
Use opioid conversion calculator.
- IV dose
- Not available in US
- PO dose
- PO only
- Ratio
- N/A
- Oral F
- ~60–87%
N/A for IV-to-PO conversion.
- IV dose
- IV / transdermal
- PO dose
- Not converted to oral fentanyl in typical practice
- Ratio
- N/A
- Oral F
- —
For chronic pain, convert IV/transdermal fentanyl to oral morphine equivalents via opioid calculator.
| Drug | IV dose | PO dose | Ratio | Oral F | Notes |
|---|---|---|---|---|---|
Ondansetron (Zofran) | 4–8 mg q8h | 4–8 mg q8h | 1:1 | ~60% | 1:1 conversion. ODT formulation useful for nausea. |
Metoclopramide (Reglan) | 5–10 mg q6h | 5–10 mg q6h | 1:1 | ~80% | 1:1. Watch for extrapyramidal symptoms with prolonged use. |
Promethazine (Phenergan) | 12.5–25 mg q4–6h | 12.5–25 mg q4–6h | 1:1 | ~25% (high first-pass) | Despite lower bioavailability, dosing is conventionally the same. IV carries risk of severe tissue injury — many institutions restrict IV use. |
- IV dose
- 4–8 mg q8h
- PO dose
- 4–8 mg q8h
- Ratio
- 1:1
- Oral F
- ~60%
1:1 conversion. ODT formulation useful for nausea.
- IV dose
- 5–10 mg q6h
- PO dose
- 5–10 mg q6h
- Ratio
- 1:1
- Oral F
- ~80%
1:1. Watch for extrapyramidal symptoms with prolonged use.
- IV dose
- 12.5–25 mg q4–6h
- PO dose
- 12.5–25 mg q4–6h
- Ratio
- 1:1
- Oral F
- ~25% (high first-pass)
Despite lower bioavailability, dosing is conventionally the same. IV carries risk of severe tissue injury — many institutions restrict IV use.
| Drug | IV dose | PO dose | Ratio | Oral F | Notes |
|---|---|---|---|---|---|
Levetiracetam (Keppra) | 500–1500 mg q12h | 500–1500 mg q12h | 1:1 | ~100% | 1:1 conversion. PO preferred when tolerated. |
Phenytoin (Dilantin) | Load 15–20 mg/kg, then 4–6 mg/kg/day | Maintenance similar in mg/kg/day; watch formulation | IV phenytoin to PO phenytoin sodium ≈ 1:1; suspension may differ | ~90% (capsules); lower for suspension | Saturable kinetics. Therapeutic drug monitoring essential. Suspension and capsules not bioequivalent. |
Fosphenytoin → Phenytoin PO | Dosed in phenytoin equivalents (PE) | Phenytoin PO | 1 mg PE fosphenytoin = 1 mg phenytoin PO | ~90% (capsules) | Convert based on PE. |
Valproic acid (Depakote) | Equivalent to total daily PO dose, divided | Variable | 1:1 (total daily IV = total daily PO) | ~100% | 1:1 conversion. Therapeutic drug monitoring. |
- IV dose
- 500–1500 mg q12h
- PO dose
- 500–1500 mg q12h
- Ratio
- 1:1
- Oral F
- ~100%
1:1 conversion. PO preferred when tolerated.
- IV dose
- Load 15–20 mg/kg, then 4–6 mg/kg/day
- PO dose
- Maintenance similar in mg/kg/day; watch formulation
- Ratio
- IV phenytoin to PO phenytoin sodium ≈ 1:1; suspension may differ
- Oral F
- ~90% (capsules); lower for suspension
Saturable kinetics. Therapeutic drug monitoring essential. Suspension and capsules not bioequivalent.
- IV dose
- Dosed in phenytoin equivalents (PE)
- PO dose
- Phenytoin PO
- Ratio
- 1 mg PE fosphenytoin = 1 mg phenytoin PO
- Oral F
- ~90% (capsules)
Convert based on PE.
- IV dose
- Equivalent to total daily PO dose, divided
- PO dose
- Variable
- Ratio
- 1:1 (total daily IV = total daily PO)
- Oral F
- ~100%
1:1 conversion. Therapeutic drug monitoring.
| Drug | IV dose | PO dose | Ratio | Oral F | Notes |
|---|---|---|---|---|---|
Diphenhydramine (Benadryl) | 25–50 mg q4–6h | 25–50 mg q4–6h | 1:1 | ~40–60% | 1:1. Watch anticholinergic burden, especially in elderly. |
Diazepam (Valium) | 2–10 mg q4–6h | 2–10 mg q4–6h | 1:1 | ~95% | 1:1. Long half-life. |
Lorazepam (Ativan) | 0.5–2 mg q4–6h | 0.5–2 mg q6–8h | 1:1 | ~90% | 1:1. PO has slower onset. |
Haloperidol (Haldol) | IV/IM 2–10 mg | 5–10 mg | PO ≈ 1.5–2× IV/IM dose | ~60–70% | PO dose generally higher than parenteral. QT monitoring. |
- IV dose
- 25–50 mg q4–6h
- PO dose
- 25–50 mg q4–6h
- Ratio
- 1:1
- Oral F
- ~40–60%
1:1. Watch anticholinergic burden, especially in elderly.
- IV dose
- 2–10 mg q4–6h
- PO dose
- 2–10 mg q4–6h
- Ratio
- 1:1
- Oral F
- ~95%
1:1. Long half-life.
- IV dose
- 0.5–2 mg q4–6h
- PO dose
- 0.5–2 mg q6–8h
- Ratio
- 1:1
- Oral F
- ~90%
1:1. PO has slower onset.
- IV dose
- IV/IM 2–10 mg
- PO dose
- 5–10 mg
- Ratio
- PO ≈ 1.5–2× IV/IM dose
- Oral F
- ~60–70%
PO dose generally higher than parenteral. QT monitoring.
This reference is intended for licensed pharmacy professionals as a quick-reference guide for IV-to-PO conversion in adult patients. Conversion ratios and bioavailability values are derived from package labeling, AHFS Drug Information, and Lexicomp; values may differ between sources and institutional protocols. This reference does not address pediatric dosing, renal/hepatic adjustments, or drug-specific indications that may preclude oral conversion. Always verify against primary sources, institutional protocols, and patient-specific clinical factors before initiating an IV-to-PO switch. Confirm the patient meets clinical criteria for oral conversion.
References
- Lexicomp Online. Wolters Kluwer Clinical Drug Information.
- AHFS Drug Information. American Society of Health-System Pharmacists.
- McEvoy GK, editor. AHFS Drug Information.
- Manufacturer package inserts for each medication.
- Cyriac JM, James E. Switch over from intravenous to oral therapy: A concise overview. J Pharmacol Pharmacother. 2014;5(2):83–87.
Last reviewed: January 1970. Verify against current sources before use.