Tamiflu
Two antiviral medications, Tamiflu and Relenza, have been chosen as the drugs of choice to treat the H5N1 avian influenza virus in humans. Many governments including the U.S. government are currently stockpiling the drug Tamiflu in case of a bird flu pandemic.
In 1999, the FDA approved Tamiflu for the treatment of influenza A and B viruses. The Swiss pharmaceutical company Roche manufactures the drug Tamiflu. Tamiflu is also referred to by the generic name oseltamivir.
Tamiflu belongs to a class of antiviral medications referred to as neuraminidase inhibitors. All influenza viruses contain neuraminidase proteins on the surface of the viral cell.
How does Tamiflu work?
An enzyme referred to as neuraminidase can break the bonds that hold new influenza virus particles to the outside of an infected cell. If the bonds become broken, the free influenza virus may infect other cells and spread the infection. Neuraminidase inhibitors block the enzyme neuraminidase. This will prevent new influenza virus particles from being released, thus limiting the spread of infection.
Tamiflu is available only by a doctor’s prescription. Tamiflu comes in two forms: capsules and oral suspension. If you have difficulty swallowing pills, the oral suspension form may be a better alternative for you.
Tamiflu can be safely used in adults and children older than 1 year. Children under the age of 1 should not take Tamiflu, unless otherwise directed by a physician.
Tamiflu has not been tested in pregnant women. If you are pregnant or may become pregnant, tell your doctor before taking this medication. Tamiflu may possibly be passed into breast milk, but this is not known for sure. If you are breastfeeding or wish to breast feed, please tell your doctor.
Your doctor should be informed of the medications you are currently taking, which include vitamins, over the counter, and prescription medications. If you are taking the medication Probenecid or Benemid please tell your doctor. This medication can interact with the drug Tamiflu.
Certain medical conditions may affect the use of Tamiflu. If you have any of the following medical conditions, please inform your doctor. These medical conditions include:
- Heart disease
- Kidney disease
- Liver disease
- Lung disease
- Viral illnesses not caused by influenza A or B
- Serious medical problems in need of admission to a hospital
How do you take Tamiflu for the treatment of the H5N1 bird flu?
For the best results, Tamiflu should be taken within 2 days of symptom onset. Tamiflu capsules may be taken on an empty stomach or with food. If you wish to lessen the chance of an upset stomach, take Tamiflu with food. Tamiflu should be taken for 5 days. Always finish the course of treatment with the medication, even if you begin to feel better before then.
How do you take Tamiflu for the prevention of the H5N1 bird flu after exposure?
Individuals who have been exposed to the H5N1 bird flu should begin taking Tamiflu within 2 days of exposure to the virus. Tamiflu may be taken with food or on an empty stomach. Tamiflu should be taken for at least 10 days.
If you prefer to take Tamiflu in oral suspension, make sure to use the specially marked measuring device. This device should come with the medication, which will help you to accurately measure the dose. If the device is not present or is damaged, contact your pharmacist.
What is the proper dose of Tamiflu?
What your doctor prescribes for you may be a different dose from these averages. Your prescription is based on your current circumstance. You should always follow your doctor’s orders on the label of your prescription. These are average doses of Tamiflu for the treatment of the flu.
- Teenagers and Adults: The dosage is 75 milligrams twice a day, for 5 days.
- Children 1 year of age or older: Children doses are based on the child’s body weight. Usually the dosage is between 30 and 75 milligrams taken twice a day for 5 days.
- Children up to the age of 1 year old: This dose must be determined by your doctor.
These are average doses for the prevention of the flu.
- Teenagers and Adults: The dosage is 75 milligrams taken twice a day for 10 days.
- Children 1 year of age or older: Children doses are based on the child’s body weight but usually are between 30 and 75 milligrams. The medication is taken twice a day for 10 days.
- Children up to the age of 1 year old: This dose must be determined by your doctor.
You should try not to miss a dose of Tamiflu. If you do miss a dose, take the dose ASAP unless the dose is within two hours of the next dose. If you have missed several doses, notify your doctor. This may affect your recovery.
Tamiflu should be kept out of the reach of children. You should store Tamiflu at room temperature away from heat or moisture. Tamiflu in oral suspension may be stored at room temperature or in the refrigerator. Do not freeze Tamiflu in oral suspension.
What are the side effects of Tamiflu?
Every medicine on the market has potential to cause undesired side effects. Tamiflu does have a lower incidence of side effects but common side effects include:
- Diarrhea
- Nausea or upset stomach
- Vomiting
- Bronchitis
- Difficulty sleeping
- Dizziness
What is anaphylaxis?
Occasionally a medication can cause an anaphylaxis reaction. Anaphylaxis is a sudden, severe, and potentially life threatening allergic reaction that can be caused by food, medication, insect stings, or latex. Common symptoms of an anaphylactic reaction include:
- Tingling sensation
- Itching
- Metallic taste in mouth
- Hives
- Difficulty breathing
- Sensation of warmth
- Swelling of the mouth and throat
- Vomiting
- Cramping
- Diarrhea
- Drop in Blood Pressure
- Loss of consciousness
Symptoms may begin as quickly as minutes after exposure to the allergen or progress over hours. If you develop any symptoms of anaphylaxis while taking Tamiflu, discontinue the medication and seek immediate medical attention.
Do not keep outdated medication. You should always follow your doctor’s orders for taking your prescription medications. If your symptoms do no improve after taking Tamiflu for the full course of treatment, notify your doctor.
References:
1. Flu Drugs
2. Mayo Clinic; Oseltamivir
