Tamiflu 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 (Tamiflu) is an antiviral medicine used to treat or prevent the flu (influenza). It works by stopping the flu virus from spreading in your body, which can help you feel better faster or prevent you from getting sick if you've been exposed.
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 start to feel well.
If you have difficulty swallowing the medication, consult your doctor. In some cases, your doctor may instruct 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 be sure to discuss this with your doctor or pharmacist.
Storing and Disposing of Your Medication
Store the medication at room temperature in a dry place, avoiding storage in a bathroom. 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 location, out of the reach of children and pets.
Missing 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 start to feel well.
If you have difficulty swallowing the medication, consult your doctor. In some cases, your doctor may instruct 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 be sure to discuss this with your doctor or pharmacist.
Storing and Disposing of Your Medication
Store the medication at room temperature in a dry place, avoiding storage in a bathroom. 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 location, out of the reach of children and pets.
Missing 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.
- Stay home and rest to recover and prevent spreading the flu to others.
- Drink plenty of fluids to stay hydrated.
- Practice good hand hygiene (frequent hand washing).
- Avoid close contact with others while sick.
Available Forms & Alternatives
Available Strengths:
Generic Alternatives:
Dosing & Administration
Adult Dosing
Standard Dose:
Treatment: 75 mg twice daily for 5 days; Prophylaxis: 75 mg once daily for at least 10 days (post-exposure) or up to 6 weeks (community outbreak)
Dose Range:
75 - 75 mg
Condition-Specific Dosing:
treatment:
Initiate within 48 hours of symptom onset
prophylaxis:
Initiate within 48 hours of exposure
Pediatric Dosing
Neonatal:
Treatment: Not routinely recommended for infants <2 weeks of age, but may be considered in severe cases (off-label, consult guidelines); Prophylaxis: Not established for infants <1 year of age.
Infant:
Treatment (2 weeks to <1 year): Weight-based dosing (e.g., 3 mg/kg twice daily for 5 days); Prophylaxis (1 year to <13 years): Weight-based dosing (e.g., 3 mg/kg once daily for 10 days).
Child:
Treatment (1 to 12 years): Weight-based dosing (e.g., â¤15 kg: 30 mg BID; >15-23 kg: 45 mg BID; >23-40 kg: 60 mg BID; >40 kg: 75 mg BID) for 5 days. Prophylaxis (1 to 12 years): Weight-based dosing (e.g., â¤15 kg: 30 mg QD; >15-23 kg: 45 mg QD; >23-40 kg: 60 mg QD; >40 kg: 75 mg QD) for 10 days.
Adolescent:
Treatment (>12 years): 75 mg twice daily for 5 days; Prophylaxis (>12 years): 75 mg once daily for at least 10 days.
Dose Adjustments
Renal Impairment:
Mild:
No adjustment needed (CrCl >60 mL/min)
Moderate:
Treatment: 30 mg twice daily; Prophylaxis: 30 mg once daily (CrCl 30-60 mL/min)
Severe:
Treatment: 30 mg once daily; Prophylaxis: 30 mg every other day (CrCl 10-30 mL/min)
Dialysis:
Hemodialysis: Treatment: 30 mg after each hemodialysis cycle; Prophylaxis: 30 mg after alternate hemodialysis cycles. Peritoneal Dialysis: Treatment: 30 mg single dose; Prophylaxis: 30 mg once weekly.
Hepatic Impairment:
Mild:
No adjustment needed
Moderate:
No adjustment needed
Severe:
No adjustment needed
Pharmacology
Mechanism of Action
Oseltamivir phosphate is a prodrug that is hydrolyzed to oseltamivir carboxylate (OC), an active metabolite. OC is a potent and selective inhibitor of influenza A and B virus neuraminidase, an enzyme that is essential for viral replication and release from infected cells. By inhibiting neuraminidase, OC prevents the release of new virions from infected cells and their spread to uninfected cells, thereby reducing viral shedding and disease duration.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 80% (of oseltamivir carboxylate from prodrug)
Tmax:
2-3 hours (for oseltamivir carboxylate)
FoodEffect:
Food does not significantly affect absorption, but may improve gastrointestinal tolerability.
Distribution:
Vd:
Approximately 23 L (for oseltamivir carboxylate)
ProteinBinding:
Low (approximately 3% for oseltamivir carboxylate)
CnssPenetration:
Limited, but detectable levels in CSF (approximately 10-15% of plasma concentrations)
Elimination:
HalfLife:
6-10 hours (for oseltamivir carboxylate)
Clearance:
Primarily renal clearance (glomerular filtration and tubular secretion)
ExcretionRoute:
Renal (urine)
Unchanged:
>90% (as oseltamivir carboxylate in urine)
Pharmacodynamics
OnsetOfAction:
Rapid (within hours of first dose)
PeakEffect:
Reduction in viral load and symptom improvement typically within 24-48 hours
DurationOfAction:
Effect lasts for the dosing interval (12-24 hours)
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Immediately
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 medical attention right away:
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
Neurological problems, particularly if you have the flu, which can lead to death, especially in children. Seek help immediately if you experience:
+ Confusion
+ Changes in behavior
+ Speech problems
+ Shakiness
+ Seizures
+ Hallucinations
A severe skin reaction, known as Stevens-Johnson syndrome or toxic epidermal necrolysis, which can cause long-term health problems and even death. Get medical help right away if you notice:
+ 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 contact your doctor or seek medical help if you're bothered by any of the following:
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 about side effects, contact 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 medical attention right away:
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
Neurological problems, particularly if you have the flu, which can lead to death, especially in children. Seek help immediately if you experience:
+ Confusion
+ Changes in behavior
+ Speech problems
+ Shakiness
+ Seizures
+ Hallucinations
A severe skin reaction, known as Stevens-Johnson syndrome or toxic epidermal necrolysis, which can cause long-term health problems and even death. Get medical help right away if you notice:
+ 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 contact your doctor or seek medical help if you're bothered by any of the following:
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 about side effects, contact 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 headache)
- Signs of bacterial infection (e.g., high fever, productive cough with colored mucus, earache)
- Unusual behavior, confusion, hallucinations, or self-injury (especially in children and adolescents)
- Severe allergic reaction (e.g., rash, hives, swelling of face/lips/tongue, difficulty breathing)
- Severe nausea or vomiting that prevents keeping the medication down
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, 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 how your body processes the medication.
This list is not exhaustive, and it is crucial to discuss all your health concerns and medications with your doctor. Please provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
* Your complete medical history, including any health problems you have
Before starting, stopping, or changing the dose of any medication, including this one, consult with your doctor to ensure your safety. It is vital to verify that it is safe to take this medication in combination with your other medications and health conditions.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, 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 how your body processes the medication.
This list is not exhaustive, and it is crucial to discuss all your health concerns and medications with your doctor. Please provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
* Your complete medical history, including any health problems you have
Before starting, stopping, or changing the dose of any medication, including this one, consult with your doctor to ensure your safety. It is vital to verify that it is safe to take this medication in combination with your other medications and health conditions.
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 has recommended that you receive a flu shot, it is crucial that you follow their advice and get vaccinated. This medication is specifically designed to treat the flu, not the common cold.
Additionally, taking this medication will not prevent you from spreading the flu to others.
If you are considering getting a flu vaccine, consult with your doctor before doing so, especially if you have recently taken this medication. Similarly, if you have recently received a flu vaccine, discuss this with your doctor before starting this medication.
If you are pregnant, planning to become pregnant, or are breastfeeding, it is vital to discuss the potential benefits and risks of this medication with your doctor, as this will help you make an informed decision about your treatment and the well-being of your baby.
This medication is not a substitute for a flu shot. If your doctor has recommended that you receive a flu shot, it is crucial that you follow their advice and get vaccinated. This medication is specifically designed to treat the flu, not the common cold.
Additionally, taking this medication will not prevent you from spreading the flu to others.
If you are considering getting a flu vaccine, consult with your doctor before doing so, especially if you have recently taken this medication. Similarly, if you have recently received a flu vaccine, discuss this with your doctor before starting this medication.
If you are pregnant, planning to become pregnant, or are breastfeeding, it is vital to discuss the potential benefits and risks of this medication with your doctor, as this will help you make an informed decision about your treatment and the well-being of your baby.
Overdose Information
Overdose Symptoms:
- Nausea
- Vomiting
- Diarrhea
- Abdominal pain
- Headache
- Dizziness
- In rare cases, more severe neurological symptoms have been reported.
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
Major Interactions
- Live attenuated influenza vaccine (LAIV) (e.g., FluMist Quadrivalent): Oseltamivir may inhibit the replication of LAIV. Avoid use of oseltamivir for 2 weeks before and 48 hours after LAIV administration.
Moderate Interactions
- Probenecid: Co-administration with probenecid results in an approximate 2.5-fold increase in exposure to oseltamivir carboxylate due to competition for renal tubular secretion. Clinical significance is generally minor, but dose adjustment may be considered in patients with severe renal impairment.
Minor Interactions
- Other renally eliminated drugs: Theoretical potential for competition for renal tubular secretion, but generally not clinically significant due to high therapeutic index of oseltamivir.
Monitoring
Baseline Monitoring
Influenza diagnosis (clinical or laboratory confirmed)
Rationale: To confirm appropriate indication for antiviral therapy.
Timing: Prior to initiation of therapy
Routine Monitoring
Symptom improvement
Frequency: Daily during treatment
Target: Resolution or reduction of fever, cough, body aches, etc.
Action Threshold: Lack of improvement or worsening symptoms may indicate treatment failure, resistance, or bacterial superinfection.
Adverse effects (e.g., nausea, vomiting, headache, neuropsychiatric events)
Frequency: Daily during treatment
Target: Absence or mild, tolerable side effects
Action Threshold: Severe or persistent adverse effects may warrant discontinuation or re-evaluation.
Symptom Monitoring
- Worsening respiratory symptoms (e.g., shortness of breath, chest pain)
- Signs of bacterial superinfection (e.g., persistent fever, productive cough, purulent sputum)
- Unusual behavior, confusion, hallucinations, delirium, or self-injury (especially in pediatric and adolescent patients)
- Severe rash or allergic reactions
Special Patient Groups
Pregnancy
Oseltamivir is classified as Pregnancy Category C. While animal studies have not shown teratogenicity, human data are limited. However, observational studies and registries have not identified an increased risk of major birth defects or adverse pregnancy outcomes. The benefits of treating influenza in pregnant women, who are at higher risk for severe complications, generally outweigh the potential risks. Use should be considered if the potential benefit justifies the potential risk to the fetus.
Trimester-Specific Risks:
First Trimester:
Limited human data, but no clear evidence of increased risk of major birth defects.
Second Trimester:
Limited human data, no clear evidence of increased risk.
Third Trimester:
Limited human data, no clear evidence of increased risk. Treatment of influenza in late pregnancy is important due to increased risk of severe maternal outcomes.
Lactation
Oseltamivir and its active metabolite are excreted into human milk. However, the amount transferred to breast milk is low, and infant exposure is minimal. The American Academy of Pediatrics considers oseltamivir compatible with breastfeeding. Monitor breastfed infants for potential adverse effects (e.g., gastrointestinal upset).
Infant Risk:
Low risk
Pediatric Use
Approved for treatment of influenza in patients 2 weeks of age and older, and for prophylaxis in patients 1 year of age and older. Dosage is weight-based. Neuropsychiatric events (e.g., delirium, hallucinations, abnormal behavior) have been reported, primarily in pediatric and adolescent patients, particularly in Japan. Patients should be closely monitored for these symptoms.
Geriatric Use
No specific dosage adjustment is required based on age alone. However, elderly patients are more likely to have age-related decline in renal function, which necessitates dosage adjustment based on creatinine clearance. Monitor for adverse effects, as elderly patients may be more susceptible.
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 annual influenza vaccination.
- Oseltamivir is effective against both influenza A and B viruses.
- It is not effective against the common cold or other viral infections.
- An oral suspension formulation is available for patients who cannot swallow capsules.
- Patients should be advised to complete the full 5-day course of treatment, even if symptoms improve earlier.
Alternative Therapies
- Baloxavir marboxil (Xofluza) - another antiviral for influenza, different mechanism (cap-dependent endonuclease inhibitor)
- Zanamivir (Relenza) - another neuraminidase inhibitor, administered via inhalation
- Peramivir (Rapivab) - another neuraminidase inhibitor, administered intravenously
Cost & Coverage
Average Cost:
Varies widely (e.g., $100-$200+) per 10 capsules (75mg)
Generic Available:
Yes
Insurance Coverage:
Generics typically Tier 1 or 2; Brand name may be Tier 2 or 3. Coverage varies by insurance plan.
General Drug Facts
If your symptoms or health issues persist or worsen, it is 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 it's a good idea to check with your pharmacist for more information. If you have any questions or concerns about this medication, don't hesitate to discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.