oseltamivir (Rx)

Brand and Other Names:Tamiflu
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Dosing & Uses

AdultPediatric

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
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Interactions

Interaction Checker

and oseltamivir

No Results

     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

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            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

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            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
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            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.

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            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)

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            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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            Images

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            Formulary

            FormularyPatient Discounts

            Adding plans allows you to compare formulary status to other drugs in the same class.

            To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

            Adding plans allows you to:

            • View the formulary and any restrictions for each plan.
            • Manage and view all your plans together – even plans in different states.
            • Compare formulary status to other drugs in the same class.
            • Access your plan list on any device – mobile or desktop.

            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
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            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.