Oseltamivir 30mg Capsules
It is used to treat or prevent the flu. It may be given to you for other reasons. Talk with the doctor.
Drug Class
Antiviral
Pharmacologic Class
Neuraminidase inhibitor
Pregnancy Category
C
FDA Approved
Oct 1999
DEA Schedule
Not Controlled
Overview
What is this medicine?
Oseltamivir is an antiviral medicine used to treat or prevent the flu (influenza). It works by stopping the flu virus from spreading in your body. It's most effective when started within the first 1-2 days of flu symptoms.
How to Use This Medicine
Taking Your Medication
To take this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food, but if it causes stomach upset, take it with food. Continue taking the medication as directed by your doctor or healthcare provider, even if you feel well.
If you have difficulty swallowing the medication, consult your doctor. In some cases, your doctor may advise you to mix the capsule contents with a sweet liquid, such as chocolate syrup, caramel topping, corn syrup, or light brown sugar dissolved in water. Alternatively, a liquid suspension can be prepared from the capsules, but you should discuss this with your doctor or pharmacist.
Storing and Disposing of Your Medication
Store the medication at room temperature in a dry place, avoiding bathrooms. If a liquid suspension is prepared from the capsules, store it in the refrigerator, but do not freeze. Discard any unused portion after 35 days if stored in the refrigerator, or after 5 days if stored at room temperature. Keep all medications in a safe place, out of the reach of children and pets.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it is less than 2 hours until your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses.
To take this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food, but if it causes stomach upset, take it with food. Continue taking the medication as directed by your doctor or healthcare provider, even if you feel well.
If you have difficulty swallowing the medication, consult your doctor. In some cases, your doctor may advise you to mix the capsule contents with a sweet liquid, such as chocolate syrup, caramel topping, corn syrup, or light brown sugar dissolved in water. Alternatively, a liquid suspension can be prepared from the capsules, but you should discuss this with your doctor or pharmacist.
Storing and Disposing of Your Medication
Store the medication at room temperature in a dry place, avoiding bathrooms. If a liquid suspension is prepared from the capsules, store it in the refrigerator, but do not freeze. Discard any unused portion after 35 days if stored in the refrigerator, or after 5 days if stored at room temperature. Keep all medications in a safe place, out of the reach of children and pets.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it is less than 2 hours until your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses.
Lifestyle & Tips
- Take the medication exactly as prescribed, even if you start to feel better.
- Complete the full course of treatment.
- Oseltamivir is not a substitute for the annual flu vaccine. Get vaccinated every year to prevent the flu.
- Practice good hygiene: wash hands frequently, cover coughs and sneezes, avoid touching eyes/nose/mouth.
- Stay home when sick to prevent spreading the flu to others.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
Treatment: 75 mg orally twice daily for 5 days. Prophylaxis: 75 mg orally once daily for 10 days (post-exposure) or up to 6 weeks (community outbreak). (Note: 30mg capsules are typically used for dose adjustments or pediatric patients, not standard adult dosing unless combined to reach 75mg or for specific renal impairment doses.)
Dose Range:
30 - 75 mg
Condition-Specific Dosing:
Treatment of Influenza (Adults):
75 mg (e.g., one 75mg capsule or two 30mg capsules + one 15mg capsule if available, or three 30mg capsules for 90mg if 75mg is not achievable) orally twice daily for 5 days.
Prophylaxis of Influenza (Adults):
75 mg orally once daily for 10 days (post-exposure) or up to 6 weeks (community outbreak).
Severe Renal Impairment (CrCl 10-30 mL/min):
Treatment: 30 mg orally once daily for 5 days. Prophylaxis: 30 mg orally every other day.
Pediatric Dosing
Neonatal:
Treatment (term infants <1 year): 3 mg/kg orally twice daily for 5 days. Prophylaxis: Not routinely recommended for infants <1 year.
Infant:
Treatment (1 to <12 months): 3 mg/kg orally twice daily for 5 days. Prophylaxis: Not routinely recommended for infants <1 year.
Child:
Treatment (1 to 12 years, weight-based): 15 kg or less: 30 mg orally twice daily for 5 days. >15 kg to 23 kg: 45 mg orally twice daily for 5 days. >23 kg to 40 kg: 60 mg orally twice daily for 5 days. >40 kg: 75 mg orally twice daily for 5 days. Prophylaxis (1 to 12 years, weight-based): Same doses as treatment, but once daily for 10 days (post-exposure) or up to 6 weeks (community outbreak).
Adolescent:
Treatment (>12 years): 75 mg orally twice daily for 5 days. Prophylaxis (>12 years): 75 mg orally once daily for 10 days (post-exposure) or up to 6 weeks (community outbreak).
Dose Adjustments
Renal Impairment:
Mild:
No dose adjustment required (CrCl >60 mL/min).
Moderate:
No dose adjustment required (CrCl 30-60 mL/min).
Severe:
Treatment (CrCl 10-30 mL/min): 30 mg orally once daily for 5 days. Prophylaxis (CrCl 10-30 mL/min): 30 mg orally every other day.
Dialysis:
Hemodialysis: Treatment: 30 mg orally after every other hemodialysis session. Prophylaxis: 30 mg orally after every other hemodialysis session. Peritoneal Dialysis: Treatment: 30 mg orally once, then 30 mg orally once weekly. Prophylaxis: 30 mg orally once weekly.
Hepatic Impairment:
Mild:
No dose adjustment required.
Moderate:
No dose adjustment required.
Severe:
No dose adjustment required.
Pharmacology
Mechanism of Action
Oseltamivir is a prodrug that is hydrolyzed to oseltamivir carboxylate, an active metabolite. Oseltamivir carboxylate is a potent and selective inhibitor of influenza A and B virus neuraminidase enzymes. Neuraminidase is a viral enzyme essential for viral replication, specifically for the release of new virions from infected cells and for the further spread of infectious virus in the host. By inhibiting neuraminidase, oseltamivir prevents the cleavage of sialic acid residues from the surface of infected cells, thereby preventing the release of progeny virus particles.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 80% (of oseltamivir carboxylate from oseltamivir phosphate)
Tmax:
Oseltamivir: 1-2 hours; Oseltamivir carboxylate: 3-4 hours
FoodEffect:
Food does not significantly affect the peak plasma concentration or AUC of oseltamivir carboxylate. Can be taken with or without food, but taking with food may improve tolerability.
Distribution:
Vd:
Oseltamivir carboxylate: Approximately 23 L
ProteinBinding:
Oseltamivir: <3%; Oseltamivir carboxylate: Approximately 3%
CnssPenetration:
Limited, but detectable levels of oseltamivir carboxylate are found in the cerebrospinal fluid (CSF) (approximately 10-15% of plasma concentrations).
Elimination:
HalfLife:
Oseltamivir: 1-3 hours; Oseltamivir carboxylate: 6-10 hours
Clearance:
Oseltamivir carboxylate is primarily eliminated by renal excretion (glomerular filtration and tubular secretion).
ExcretionRoute:
Renal (primarily as oseltamivir carboxylate)
Unchanged:
More than 90% of the absorbed dose is excreted as oseltamivir carboxylate in urine.
Pharmacodynamics
OnsetOfAction:
Rapid (within hours of first dose, as active metabolite reaches therapeutic concentrations)
PeakEffect:
Peak plasma concentrations of active metabolite reached within 3-4 hours.
DurationOfAction:
Sustained antiviral activity for 12-24 hours, supporting twice-daily or once-daily dosing.
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Nervous system problems, particularly in people with the flu, which can lead to death, especially in children. Be aware of:
+ Confusion
+ Changes in behavior
+ Speech problems
+ Shakiness
+ Seizures
+ Hallucinations
A severe skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis), which can cause serious health problems and potentially death. Seek help immediately if you experience:
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Red or irritated eyes
+ Sores in your mouth, throat, nose, or eyes
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. Contact your doctor or seek medical help if you experience:
Diarrhea
Upset stomach
Vomiting
* Headache
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns, don't hesitate to reach out to your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Nervous system problems, particularly in people with the flu, which can lead to death, especially in children. Be aware of:
+ Confusion
+ Changes in behavior
+ Speech problems
+ Shakiness
+ Seizures
+ Hallucinations
A severe skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis), which can cause serious health problems and potentially death. Seek help immediately if you experience:
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Red or irritated eyes
+ Sores in your mouth, throat, nose, or eyes
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. Contact your doctor or seek medical help if you experience:
Diarrhea
Upset stomach
Vomiting
* Headache
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns, don't hesitate to reach out to your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Worsening flu symptoms or development of new symptoms (e.g., difficulty breathing, chest pain, severe vomiting, confusion) â seek immediate medical attention.
- Unusual behavior, confusion, hallucinations, or self-injury, especially in children and adolescents (rare but reported neuropsychiatric events).
- Severe skin reactions (e.g., rash, blistering, peeling skin, mouth sores) â seek immediate medical attention.
- Allergic reactions (e.g., hives, swelling of face/lips/tongue/throat, difficulty breathing).
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, any of its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have kidney disease, as this may affect your ability to take this medication.
This list is not exhaustive, and it is crucial to discuss all your medications, including prescription and over-the-counter drugs, natural products, and vitamins, with your doctor and pharmacist. They will help you determine if it is safe to take this medication in combination with your other medications and health conditions.
Remember, do not start, stop, or change the dose of any medication without first consulting your doctor to ensure your safety.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, any of its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have kidney disease, as this may affect your ability to take this medication.
This list is not exhaustive, and it is crucial to discuss all your medications, including prescription and over-the-counter drugs, natural products, and vitamins, with your doctor and pharmacist. They will help you determine if it is safe to take this medication in combination with your other medications and health conditions.
Remember, do not start, stop, or change the dose of any medication without first consulting your doctor to ensure your safety.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
This medication is not a substitute for a flu shot. If your doctor recommends that you receive a flu shot, it is crucial that you follow their advice. The flu shot is a separate preventive measure that provides protection against the flu.
This medication is specifically designed to treat the flu, not the common cold. It will not provide relief from common cold symptoms.
Additionally, taking this medication will not prevent you from spreading the flu to others. It is essential to continue practicing good hygiene and taking precautions to avoid infecting those around you.
If you are considering getting a flu vaccine, it is crucial to discuss the timing with your doctor, especially if you have recently taken this medication or plan to take it after receiving the vaccine.
Before starting this medication, inform your doctor if you are pregnant, planning to become pregnant, or are breastfeeding. Your doctor will help you weigh the benefits and risks of taking this medication during this time, ensuring the best possible outcome for you and your baby.
This medication is not a substitute for a flu shot. If your doctor recommends that you receive a flu shot, it is crucial that you follow their advice. The flu shot is a separate preventive measure that provides protection against the flu.
This medication is specifically designed to treat the flu, not the common cold. It will not provide relief from common cold symptoms.
Additionally, taking this medication will not prevent you from spreading the flu to others. It is essential to continue practicing good hygiene and taking precautions to avoid infecting those around you.
If you are considering getting a flu vaccine, it is crucial to discuss the timing with your doctor, especially if you have recently taken this medication or plan to take it after receiving the vaccine.
Before starting this medication, inform your doctor if you are pregnant, planning to become pregnant, or are breastfeeding. Your doctor will help you weigh the benefits and risks of taking this medication during this time, ensuring the best possible outcome for you and your baby.
Overdose Information
Overdose Symptoms:
- Nausea
- Vomiting
- Diarrhea
- Abdominal pain
- Headache
- In some cases, neurological symptoms (e.g., seizures, altered mental status) have been reported, particularly in pediatric patients.
What to Do:
In case of suspected overdose, contact a poison control center immediately (e.g., 1-800-222-1222 in the US) or seek emergency medical attention. Treatment is supportive.
Drug Interactions
Moderate Interactions
- Probenecid (increases oseltamivir carboxylate exposure by approximately 2.5-fold via competition for renal tubular secretion; clinical significance generally low, but consider in patients with renal impairment)
- Live attenuated influenza vaccine (LAIV) (Oseltamivir may inhibit the replication of LAIV. Avoid administration of LAIV within 48 hours after stopping oseltamivir, or avoid oseltamivir for 2 weeks after LAIV administration.)
Monitoring
Symptom Monitoring
- Resolution of influenza symptoms (fever, cough, sore throat, body aches, fatigue)
- Development of new or worsening symptoms (e.g., bacterial superinfection, respiratory distress)
- Neuropsychiatric events (e.g., delirium, hallucinations, abnormal behavior), especially in pediatric patients
Special Patient Groups
Pregnancy
Oseltamivir is generally considered acceptable for use during pregnancy when the potential benefits outweigh the potential risks. Untreated influenza can lead to serious complications in pregnant women. Data from observational studies and registries have not shown an increased risk of major birth defects or adverse pregnancy outcomes.
Trimester-Specific Risks:
First Trimester:
Limited data, but no clear evidence of increased risk of major birth defects.
Second Trimester:
Generally considered safe, as influenza infection itself poses greater risks.
Third Trimester:
Generally considered safe, as influenza infection itself poses greater risks.
Lactation
Oseltamivir and its active metabolite are excreted in human milk in low concentrations. The amount ingested by a breastfed infant is very small and unlikely to cause adverse effects. Generally considered compatible with breastfeeding.
Infant Risk:
Low risk. Monitor infant for gastrointestinal upset (e.g., diarrhea, vomiting) or rash, though these are rare.
Pediatric Use
Efficacy and safety have been established in pediatric patients aged 2 weeks and older for treatment, and 1 year and older for prophylaxis. Dosing is weight-based. Neuropsychiatric events (e.g., delirium, hallucinations) have been reported, primarily in pediatric patients, though a causal link has not been definitively established.
Geriatric Use
No specific dose adjustment is required based on age alone. However, elderly patients are more likely to have decreased renal function, which may necessitate dose adjustment based on creatinine clearance.
Clinical Information
Clinical Pearls
- Oseltamivir is most effective when initiated within 48 hours of influenza symptom onset for treatment.
- It is not a substitute for the annual influenza vaccine.
- Can be taken with or without food; taking with food may reduce gastrointestinal side effects (nausea, vomiting).
- Available as capsules and as a powder for oral suspension, which is useful for pediatric dosing or patients who cannot swallow capsules.
- Resistance to oseltamivir can occur, but remains relatively uncommon in circulating influenza strains.
Alternative Therapies
- Zanamivir (Relenza) - inhaled neuraminidase inhibitor
- Peramivir (Rapivab) - intravenous neuraminidase inhibitor
- Baloxavir marboxil (Xofluza) - cap-dependent endonuclease inhibitor
Cost & Coverage
Average Cost:
Varies, typically $50-$100 per 10 capsules (75mg equivalent)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or Tier 2 (for generic), Tier 3 (for brand)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more details. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide information about the medication taken, the amount, and the time it happened.