Day 27: Musical Chairs With Antiviral Meds

We must all be on guard against pharmaceutical panaceas: As John Barry points out in The Great Influenza, desperate doctors in 1918 shot patients up with typhoid vaccine, quinine, even hydrogen peroxide. If half the subjects survived, any abomination was hailed as a breakthrough.

Today every Web hustler is selling antivirals—mainly Tamiflu and Relenza, though sometimes Adamantanes. A lot of people are buying them. Sometimes the stuff is real. Most is for the birds: counterfeit.

What are these things?

A BIRD’S VIEW OF MAN’S PUNY SCIENCEFirst, let’s trash the Adamantanes. Not only are they not members of a trippy New Wave group‘s fan club, amantadine and rimantadine probably won’t even be useful. The Chinese fed them to poultry for so long that H5N1 thinks they’re chicken feed. (I can’t hold back: Here’s Ant Music for you.)

Then there’s Peramivir. This newbie intravenous antiviral took the field during the swine flu pandemic. A mixed record, countered by Washington’s avid interest in the success of anything that would add to the antiviral arsenal, has kept it in the game. Experts haven’t yet cheered conclusively.

That leaves Tamiflu (oseltamivir) and Relenza (zanamivir). Neither kills flu virus, but each can slow it down while your immune system powers up. They can make infected patients feel better, faster—if they medicate at the first sign of sickness.

Tamiflu in particular faces questions about the process by which it was approved. Its use has been associated with some disturbing side effects (detailed below).

Tamiflu is cheaper, comes in pills, and works throughout our bodies. Relenza must be applied directly to the lungs— inhaled as a dry powder through a breath-activated plastic device called a Diskhaler. It can’t be given to small children, as Tamiflu can. Relenza is dodgy for asthmatics and others with diminished lung capacity. It can cause lung problems. If you’re already too sick to breathe well, you’ll never get it down.

Unfortunately for those who need it, avian flu made Tamiflu trendy and then swine flu got everyone to take it. Chinese farmers may have fed it to their poultry. The WHO has been slathering Indonesia with it for years, much the way various states and cities have lately thrown pills and powders at contacts of isolated H5N1 cases.

Tamiflu fever can conceivably be dangerous—particularly for kids—according to the U.S. Food & Drug Administration. Use of the antiviral has prompted scary side effects in young people in Japan, where 25 patients under 21 had died as of 2007. In Britain, 18% of schoolchildren reported "mild neuropsychiatric side effects." The FDA has inelegantly warned about “postmarketing reports (mostly from Japan) of delirium and abnormal behavior leading to injury, and in some cases resulting in fatal outcomes, in patients with influenza who were receiving Tamiflu.”

Resistance to Tamiflu crept in during the 2008-9 flu season, when our old pal seasonal H1N1 suddenly mutated to acquire immunity to it. (Here’s Dr. Racaniello’s technical analysis.) A longstanding theory that influenza would have to give up some bite in order to defeat Tamiflu turned out to be wrong: Resistant seasonal flu proved no less nasty.

Still, when swine flu came, Tamiflu seems generally to have helped. Against H5N1, it shows some signs of faltering. A lot of the Tamiflu stockpiled by governments and corporations has passed its expiration dates.

Relenza: Less Charming, More Effective

Relenza’s cost and complexity may have helped maintain its effectiveness against H5N1. Chickens can’t use Diskhalers. The WHO didn’t hand them out to peasants. Unless you’re pregnant, nursing, or over 65, we still have Relenza. (I know I do.)

Could this antiviral lose its punch? Optimists stress that its molecular structure differs from Tamiflu’s. Because Relenza resembles the very sugars that influenza must target in order to spread, experts hope H5N1 won’t be able to reproduce well if it stops binding with Relenza.

It’s crucial to take it within 48 hours of showing flu symptoms. (The first 24 are optimal.) Refrigeration is unnecessary, but don’t store it over 85 degrees (30 Centigrade).

Know your flu symptoms—the rapid onset of fever, chills, aching muscles, cough, weakness, and fatigue! Memorize that list. Know, too, the common cold, which lacks the flu’s fever, muscle pain, and fatigue.

Beware psychosomatic illness: A hypochondriac with hay fever is a terrible thing to behold. Twice a year, in spring and fall, New York is stuffed with them. I don’t want to see my neighbors inhaling white powder unless they really need it. (Let’s rephrase that: unless it’s really good for them.)

Relenza’s side effects seem less dangerous than those of Tamiflu, which (again) is associated with suicidal impulses and attempts. Reported cases of confusion, delirium, and impulsive behavior among Relenza users—none fatal—may stem more from patients’ reaction to flu than to the drug, which doesn’t easily enter our central nervous systems. Let’s hope none of us ever needs to use it.