What is Tamiflu? How does it work? Who needs it?

Navigation Links
What is Tamiflu?
Without a vaccine, antivirals fill a key role
Tamiflu uses and dosages
Other facts about Tamiflu
What Tamiflu is not
Should you buy a personal supply of Tamiflu?
Where do you get Tamiflu?
Further reading - Tamiflu

 

What is Tamiflu?

Tamiflu is an antiviral drug - a drug that fights viruses. In particular, Tamiflu fights influenza ("flu") viruses. When you get the flu, Tamiflu can make the sickness last a shorter time and be less severe. It doesn't cure the flu; there is no cure for the flu. Rather, it can reduce the length and severity of the flu.

In a nutshell, Tamiflu hinders a reproducing virus that's trying to spread from one cell to infect other cells. In a little more detail....

How does Tamiflu work? Viruses cannot reproduce on their own. To reproduce, a virus latches onto a living cell inside some organism, inserts its genetic material into that "host" cell, and takes over the cell's reproductive "machinery." The virus makes copies of itself - maybe hundreds. (Sooner or later, this kills the infected cell - causing disease.) All of those new viruses break out of the host cell and start the process over, attacking other cells. But what if the new viruses can't get out? This is where Tamiflu comes in. Tamiflu traps the new viruses inside the host cell. Eventually, the viruses die. If you want to really get scientific: Two proteins on the surface of the virus enable it to enter and exit the host cell. The first protein, hemagluttinin, lets the virus attach to the cell and inject genetic material inside. The second protein, neuraminidase, then opens the cell membrane to let the new viruses out. Tamiflu inhibits the work of neuraminidase; that's why you hear Tamiflu called a "neuraminidase inhibitor." Another tidbit: Hemagluttinin is the "H" and Neuraminidase is the "N" used in naming virus subtypes - like H5N1, the avian flu virus that everyone's worried about right now.

 

Without a vaccine, antivirals fill a key role

Vaccination is considered the first line of defense against influenza. But, at present, there is not a vaccine specific to influenza A H5N1. The World Health Organization (WHO) states that "Vaccines effective against a pandemic virus are not yet available. ...Because the vaccine needs to closely match the pandemic virus, large-scale commercial production will not start until the new virus has emerged and a pandemic has been declared." (The flu vaccines produced each year for regular seasonal flu will not protect against a new pandemic flu.)

In the interim, the antivirals Tamiflu and Relenza are considered the best available pharmaceutical tools against any pandemic flu virus. It is hoped that antivirals will slow the flu's spread and buy time for vaccine development and production.

Tamiflu uses and dosages

USED FOR TREATMENT: Tamiflu and another neuraminidase inhibitor, zanamivir (commercially known as Relenza), are proven to be effective in treating the regular seasonal influenza in adults and in children one year and older. The World Health Organization expects the H5N1 strain of human flu virus would be susceptible to Tamiflu and Relenza, as well. However, clinical data on a newly emerged virus like H5N1 is limited. (By the way, Tamiflu comes in pill or liquid form. Relenza is an inhaled aerosol.)

TREATMENT DOSAGE: Tamiflu is available by prescription and must be started within two days of first symptoms of flu. Normally, you take Tamiflu twice a day for five days, for a total of 10 pills. (Medically speaking, a normal "course" of Tamiflu consists of 10 "doses.") Treatment for two people would require 20 pills, etc.

It's worth noting that the normal dosage of Tamiflu for treating regular seasonal flu may not be adequate for pandemic flu. Dr. Michael Osterholm, Director of the Center for Infectious Disease Research and Policy (CIDRAP) noted in a March 22, 2006 interview that H5N1 grows much faster than seasonal flu. As a result, "if you don't have the drug onboard in those first 24 hours, it may only have limited impact," he said. In addition, "This is a very different virus. We may have to double the dosage for twice the length of time." His conclusion: "The problem we have is not whether Tamiflu is available and will work, but can you get it soon enough and in high enough amounts? How do you get the drug to somebody in the first 12 hours of their illness?" [NOTE: This need for almost immediate access is a key reason to stock your own supply of Tamiflu, rather than depend upon centralized government stockpiles.] [UPDATE 3-29-06: I address this in more detail here.]

USED FOR PREVENTION: In addition to treating the flu, clinical trials have shown Tamiflu is effective in preventing the flu when taken once daily for at least ten days. This would be done after close contact with someone who has the flu. So, for example, if someone in your household is diagnosed with the flu, other members of the family might take Tamiflu in an effort to avoid getting sick.

Other facts about Tamiflu

• Different kinds of viruses cause different kinds of disease. Tamiflu works on influenza viruses.
• This drug is technically known as oseltamivir phosphate. "Tamiflu" is the brand name given to it for marketing purposes.
• Tamiflu is a challenge to manufacture, involving a complex, 10-step process that takes approximately 6-8 months.
• Product History: Tamiflu was first approved by the U.S. Food and Drug Administration (FDA) for treating flu in adults in October 1999. It was approved for preventing flu in people 13 years and older in November 2000. A liquid ("oral suspension") version for children one year and older (or adults who can't swallow a capsule) was approved in December 2000. The FDA approval to use Tamiflu for flu prevention was extended down to age one in December 2005.

What Tamiflu is not

Tamiflu is not a vaccine.

Tamiflu is not an antibiotic. (Antibiotics treat infection caused by bacteria instead of infection caused by viruses. The flu is caused by an influenza virus.)

Should you buy a personal supply of Tamiflu?

The short answer: If you think H5N1 is a risk and Tamiflu is an effective flu treatment, and you want to be sure you have access to Tamiflu when and if you, your family, your neighbors, or your employees need it, yes, buy some.

If you're undecided, consider the following:

• As noted above, there is no vaccine against H5N1. In that vacuum, Tamiflu is considered one of the best available pharmaceutical tools against any pandemic flu. (Again, the vaccines for regular seasonal flu will not protect against a new pandemic flu.)
• Tamiflu supplies are limited. Before concerns arose about H5N1, the amount of Tamiflu produced was based on the amount needed to treat normal seasonal flu. If a pandemic flu appears, a much, much greater quantity will be needed. Tamiflu's manufacturer, Roche, is increasing production internally and through external partners. But it will take time to achieve adequate quantities and fill government stockpiles worldwide. In the interim, some businesses and individuals are buying their own supplies.
• Until adequate supplies are available, antivirals likely will be rationed on some prioritized basis. The WHO said in November 2005:
  

  Since supplies are severely constrained, countries now stockpiling antiviral drugs need to decide in advance on priority groups for administration. Frontline health care workers would be an obvious first choice, but such decisions are the responsibility of governments.

• Roche says Tamiflu must be administered promptly - within two days after flu symptoms begin. Even assuming adequate supplies, will federal and local governments and health care systems be able to distribute Tamiflu to individuals within a day or two (at most)? Bear in mind, government and health care systems may be stressed at the time.
  

  U.S. Secretary of Health and Human Services, Michael Leavitt, told a gathering in Indiana on March 23, 2006 that he's concerned about such distribution issues:
  

  "We can stockpile a lot of antivirals, but if we can't get pills in the palms of people's hands in 24 to 48 hours, it won't do any good," Michael Leavitt told an audience.

  (This reflects Dr. Michael Osterholm's concerns noted earlier under the "Tamiflu uses and dosages" subheading.)
• Reminder: Antiviral drugs are not the only tools during a pandemic flu. Rather, they are key tools mainly for one phase of your experience. If a flu pandemic were to occur, think of (a) the time before you are exposed or sick, (b) the time while you are exposed or sick, and (c) the aftermath - you're exposed but don't get sick, or you get sick and recover or die.
  

  Antivirals are pharmaceutical tools, used mainly in the middle phase above - a medical treatment if you're exposed or sick. Admittedly, Tamiflu also can prevent the flu. But due to cost and supply shortages, governments likely would use Tamiflu that way only for people in critical jobs - selected health care workers, law enforcement officers, utility workers, and truckers, for example.
  

  Ideally, you never want to go past the first phase - you never want to get exposed or sick. Call it "prevention" or "avoidance." For that, there also are non-medical preparedness tools and practices which can help - things like handwashing (frequent & thorough), hand sanitizers, nasal sanitizers, gloves, masks, ultraviolet air purifiers, and space (staying away from other people).
  

  The idea of staying away from other people is known as "social distancing." If you had adequate supplies and did not have to go to work or elsewhere, you could just stay at home during a pandemic. At another level, you might just occasionally go out for a limited time, if necessary. The more you must be in public contact - if you must go to work, for example - the more you might use non-medical tools and techniques, hoping to prevent illness. If you contract bird flu or know you've been exposed to someone with it, you can turn to antiviral tools - Tamiflu or Relenza - either from your own supply or what is available from your pharmacy or government. (Of course, additional medical resources can address fever, pain, dehydration, and other flu symptoms.)

Where do you get Tamiflu?

As with antibiotics, antivirals require a prescription in the United States and other countries. If you want to keep a personal supply of Tamiflu, the best route is to consult your physician and explain your concerns and wishes.

Your doctor or clinic may be happy to prescribe Tamiflu which can be held as an emergency supply. (In fact, they may have their own Tamiflu supply at home.) Or they may not agree. Why? They may simply believe that Tamiflu shouldn't be prescribed unless you already have the flu or have been exposed to the flu. Or, in many cases, their reluctance is based on faulty or irrelevant reasoning like: "As soon as people get a bad cold, they'll grab their Tamiflu and waste it" or "The chance of a pandemic is low." (Risk communications consultants Peter Sandman and Jody Lanard have a very good, 37-page discussion of such specious arguments. I have written summary notes about their paper.)

If your regular physician won't write a prescription, what do you do? Check with your other doctors - maybe an Allergist or an Ear, Nose, & Throat specialist. For your child, ask your pediatrician. Or consider another neighborhood doctor or walk-in clinic. Ask your family and friends if their doctors have prescribed Tamiflu as a standby supply.

Don't feel guilty about being persistent. This isn't an illegal street narcotic; it's an antiviral for treating the flu. Some doctors simply don't want to prescribe it if you're not already sick or exposed. (Or they've been confused by faulty reasoning they've heard.)

If local options don't work (or it's a hassle or you feel like you're "creating a stir" with doctors and friends), you could do an online consultation with a doctor. Be sure to select one where you can exchange health information with a licensed doctor and licensed pharmacist and pharmacy over a secure Internet connection and not simply through email.

If you've never used an online pharmacy, the U.S. Food and Drug Administration says there are several benefits to purchasing approved drugs online:

Legitimate pharmacy sites on the Internet provide consumers with a convenient, private, way to obtain needed medications, sometimes at more affordable prices. The elderly and persons in remote areas can avoid the inconvenience of traveling to a store to purchase medications. Many reputable Internet pharmacies allow patients to consult with a licensed pharmacist from the privacy of their home. Moreover, Internet pharmacies can provide customers with written product information and references to other sources of information, just like the traditional storefront pharmacy. Finally, the increasing use of computer technology to transmit prescriptions from doctors to pharmacies is likely to reduce prescription errors.

For further information, the FDA has a guide about buying prescriptions online.

Further reading - Tamiflu

Tamiflu - Official site (Roche)
How Tamiflu works - Includes Flash movie (Roche)
Tamiflu - For Healthcare Professionals (Roche)
Tamiflu product information (Roche)
Avian influenza frequently asked questions (World Health Organization)
Tamiflu Consumer Information (U.S. Food and Drug Administration)

FOOTNOTE: As stated in this site's Terms & Conditions, this site does not provide medical advice or financial advice, just background information. Always seek the advice of a physician or other qualified health care provider with any questions regarding personal health, medical conditions, medications, and medical treatments.