Dosing & Uses
Dosage Forms & Strengths
capsule
- 30mg
- 45mg
- 75mg
powder for oral suspension
- 6mg/mL
Influenza A and B Prophylaxis
75 mg PO qDay for at least 10 days
Dosing considerations
- Initiate within 48 hours of exposure
- For community outbreak, may administer for up to 6 weeks
Influenza A and B Treatment
75 mg PO q12hr for 5 days
Dosing considerations
- Initiate within 48 hours of influenza symptom onset
H1N1 Influenza A (Swine Flu) Prophylaxis (Off-label)
75 mg PO qDay
Dosing considerations
- Postexposure prophylaxis: Initiate within 7 days of exposure and continue for at least 10 days
- Preexposure prophylaxis (community outbreak): Initiate during potential exposure period and continue for 10 days after last known exposure
- Consider longer duration (>5 days) in severely ill patients who remain severely ill after 5 days of therapy
H1N1 Influenza A (Swine Flu) Treatment (Off-label)
75 mg PO q12hr for 5 days
Dosing considerations
- Initiate within 48 hours of influenza symptom onset
Dosage Modifications
Renal impairment
Treatment
- CrCl >60 to 90 mL/min: No dosage adjustment necessary
- CrCl >30 to 60 mL/min: 30 mg PO BID
- CrCl >10 to 30 mL/min: 30 mg PO qDay
- End-stage renal disease (ESRD), not undergoing dialysis: Not recommended (not studied)
- ESRD CrCl ≤10 mL/min; on hemodialysis: 30 mg PO immediately and then 30 mg after every hemodialysis cycle; treatment duration not to exceed 5 days
- ESRD CrCl ≤10 mL/min; on CAPD: Single dose of 30 mg administered immediately
Prophylaxis
- CrCl >60 mL/min: No dose adjustment necessary
- CrCl >30 to 60 mL/min: 30 mg PO qDay
- CrCl >10 to 30 mL/min: 30 mg PO every other day
- End-stage renal disease (ESRD), not undergoing dialysis: Not recommended (not studied)
- ESRD CrCl ≤10 mL/min; on hemodialysis: 30 mg PO immediately and then 30 mg after alternate hemodialysis cycle
- ESRD CrCl ≤10 mL/min; on CAPD: 30 mg immediately and then 30 mg once weekly
Hepatic impairment
- Mild-to-moderate: No doage adjustment necessary
- Severe: Not studied
Dosage Forms & Strengths
capsule
- 30mg
- 45mg
- 75mg
powder for oral suspension
- 6mg/mL
Influenza A and B Prophylaxis
<1 year
- Safety and efficacy not established for prophylaxis
1-12 years
- <15 kg: 30 mg PO qDay x10 days
- 15-23 kg: 45 mg PO qDay x10 days
- 23-40 kg: 60 mg PO qDay x10 days
- >40 kg: 75 mg PO qDay x10 days
≥13 years
- 75 mg PO qDay for at least 10 days
Dosing considerations
- Initiate within 48 hours of exposure
- For community outbreak, may administer for up to 6 weeks
Influenza A and B Treatment
<2 weeks
- Safety and efficacy not established for treatment
2 weeks to <1 year
- 3 mg/kg PO q12hr for 5 days
1-12 years
- <15 kg: 30 mg PO q12hr for 5 days
- 15-23 kg: 45 mg PO q12hr for 5 days
- 23-40 kg: 60 mg PO q12hr for 5 days
- >40 kg: 75 mg PO q12hr for 5 days
≥13 years
- 75 mg PO q12hr for 5 days
Dosing considerations
- Start within 24-48 hours of symptom onset
H1N1 Influenza A (Swine Flu) Prophylaxis (Off-label)
<1 year
- <3 months: Data limited; not recommended unless situation judged critical
- 3-5 months: 20 mg PO qDay x10 days
- 6-11 months: 25 mg PO qDay x10 days
≥1 year
- <15 kg: 30 mg PO qDay x10 days
- 15-23 kg: 45 mg PO qDay x10 days
- 23-40 kg: 60 mg PO qDay x10 days
- >40 kg: Administer as in adults
H1N1 Influenza A (Swine Flu) Treatment (Off-label)
Acute illness and age <1 year
- <3 months: 12 mg PO q12hr x5 days
- 3-5 months: 20 mg PO q12hr x5 days
- 6-11 months: 25 mg PO q12hr x5 days
Acute illness and age ≥1 year
- <15 kg: 30 mg PO q12hr x5 days
- 15-23 kg: 45 mg PO q12hr x5 days
- 23-40 kg: 60 mg PO q12hr x5 days
- >40 kg: Administer as in adults
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Adverse Effects
1-10%
Abdominal pain
Conjunctivitis
Ear disorder
Epistaxis
Insomnia
Nausea
Vomiting
Vertigo
<1%
Aggravation of diabetes
Anemia
Arrhythmia
Confusion
Delirium
Hemorrhagic colitis
Hepatitis
Humerus fracture
Peritonsillar abscess
Pneumonia
Pseudomembranous colitis
Pyrexia
Rash
Seizure
Transaminases increased
Toxic epidermal necrolysis
Unstable angina
Swelling of face or tongue
Postmarketing Reports
Hypothermia
Diaper rash (2 weeks to <1 year of age)
Dermatitis
Urticaria
Eczema
Stevens-Johnson Syndrome
Erythema multiforme
Gastrointestinal bleeding
Abnormal liver function tests
Warnings
Contraindications
Hypersensitivity
Cautions
Use caution in patients with chronic cardiac disease, severre hepatic impairment, renal imapairment, respiratory disease
Delirium and abnormal behavior leading to injury, and in some cases resulting in fatal outcomes, reported in patients with influenza who were receiving therapy; relationship to therapy not established
Most effective when used within 24-48 hr of onset of symptoms
Safety and efficacy for prophylaxis of influenza not established for <1year of age
Oral suspension should be mixed prior to dispensing
Safety and efficacy in immunocompromised patients not established
Therapy is not a substitute for influenza virus vaccine
Serious skin/hypersensitivity reactions such as Stevens-Johnson Syndrome, toxic epidermal necrolysis and erythema multiforme; discontinue therapy and initiate appropriate treatment if allergic-like reactions occur or are suspected
Prescribers should be alert to potential for secondary bacterial infections and treat them as appropriate
Neuropsychiatric events
- Delirium and abnormal behavior leading to injury, including fatalities, reported postmarketing in patients with influenza receiving oseltamivir
- Because these events were reported voluntarily during clinical practice, frequency cannot be estimated, but occurrence is uncommon
- Reported primarily among pediatric patients and often had an abrupt onset and rapid resolution
- Unable to establish causality between these events and oseltamivir
- These events may occur in the setting of encephalitis or encephalopathy, but can occur without obvious severe disease; closely monitor oseltamivir-treated patients with influenza for signs of abnormal behavior
Oral suspension and hereditary fructose intolerance
- Fructose can be harmful to patients with hereditary fructose intolerance
- One dose of 75 mg oral suspension delivers 2 g of sorbitol; this is above the daily maximum limit of sorbitol for patients with hereditary fructose intolerance, and may cause dyspepsia and diarrhea
Pregnancy & Lactation
Pregnancy
There are no adequate and well–controlled studies in pregnant women to inform a drug–associated risk of adverse developmental outcomes; available published epidemiological data suggest that the drug, taken in any trimester, is not associated with an increased risk of birth defects; however, these studies individually are limited by small sample sizes, use of different comparison groups, and some lacked information on dose, which preclude a definitive assessment of the risk
Pregnant women are at higher risk of severe complications from influenza, which may lead to adverse pregnancy and/or fetal outcomes including maternal death, still births, birth defects, preterm delivery, low birth weight and small for gestational age
Animal data
- In animal reproduction studies, no adverse developmental effects were observed at clinically relevant exposures
Lactation
Based on limited published data, have shown the drug to be present in human milk at low levels considered unlikely to lead to toxicity in the breastfed infant; postmarketing experience has not reported any information to suggest serious adverse effects to drug exposure via breast milk in infants; it is not known if drug affects human milk production; developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for therapy and any potential adverse effects on breastfed child from drug or from underlying maternal condition
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Inhibits viral neuraminidases; stops release of virus from cells and prevents virus from crossing mucous lining of respiratory tract
Absorption
Bioavailability: 75%
Peak plasma time: 2.5-6 hr
Distribution
Protein bound: 3% (oseltamivir carboxylase); 42% (oseltamivir)
Vd: 23-26 L
Elimination
Half-life: 1-3hr (oseltamivir); 6-10 hr (oseltamivir carboxylate)
Excretion: Feces; urine (>90% as oseltamivir carboxylate)
Administration
Oral Administration
Tablets and oral suspension may be take with or without food
Tolerability may be enhanced if taken with food
Emergency Preparation of Oral Suspension from 75 mg Capsules
Extemporaneously prepared oral suspension from capsules may be needed if commercially available oral suspension unavailable
Instructions below are for 100 mL of 6 mg/mL suspension
1. Place 7 mL of distilled water into a polyethyleneterephthalate (PET) or glass bottle
2. Empty content of eight 75-mg capsules (ie, 600 mg) into bottle
3. Gently swirl the suspension to ensure adequate wetting of the powder for at least 2 minutes
4. Slowly add 91 mL of Ora-Sweet, cherry syrup, or simple syrup
5. Close bottle and shake well for about 30 minutesInstruct patient to shake well before use
Stable for 5 days at room temperature or 5 weeks refrigerated at 2-8°C (36-46°F)
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Patient Handout
Formulary
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