CDC: Antivirals not ruled out for low-risk flu patients

Robert Roos  News Editor

Nov 23, 2010 (CIDRAP News) – The Centers for Disease Control and Prevention's (CDC's) guidance on antiviral treatment for influenza focuses mainly on treating patients who are seriously ill or at risk for flu complications, but the CDC is not telling clinicians to refrain from using the drugs in uncomplicated cases, a CDC expert emphasized today.

"We're not saying, 'Don't treat previously healthy patients who are not at high risk," Tim Uyeki, MD, MPH, said in a conference call designed to inform clinicians about the CDC's latest antiviral recommendations. Uyeki, who is deputy chief for science in the Epidemiology and Prevention Branch of the CDC's Influenza Division, said clinicians should use their judgment in deciding about antiviral treatment for such patients.

The CDC released its antiviral guidance for the 2010-11 flu season last week. The recommendations, which generally match last year's, call for using prompt antiviral treatment in patients with confirmed or suspected flu who are hospitalized or severely ill and in those who face an increased risk of complications because of their age or medical conditions.

The recommended antivirals are the neuraminidase inhibitors, oseltamivir (Tamiflu) and zanamivir (Relenza), because more than 99% of currently circulating flu viruses are sensitive to them, according to the CDC.

Although oseltamivir is not approved for infants under 1 year old, the CDC recommends its use in this group when indicated, because infants are at risk for complications.

Uyeki said the CDC's advice is that antiviral treatment can be considered for previously healthy, non-high-risk patients, depending on clinical judgment, if treatment can be started within 48 hours of illness onset. The guidance says that such patients are not likely to benefit from antiviral treatment begun later than that.

In a question-and-answer period, a physician listening to the call commented that there is no test that can predict early in the course of suspected flu whether the patient will get worse or do well. Consequently, he asked Uyeki, "Why not recommend prescribing neuraminidase inhibitors for all such patients and recommend they report back if side effects occur, as opposed to limiting the recommendation and telling patients to report if they deteriorate?"

Uyeki replied that for previously healthy patients with early, uncomplicated flu, "We're not saying do not treat; we're saying clinical judgment can be utilized. It's up to the clinician to make a treatment decision."

He added that there may have been some confusion during the 2009 H1N1 pandemic. "We were prioritizing those at high risk for complications. But now we're continuing those recommendations but also clarifying that we never have said, 'Do not treat previously healthy, non-high-risk persons.'"

"Our recommendations are just recommendations; they are not the law," Uyeki added. He also commented that most previously healthy people will recover from flu without antiviral treatment, but some will experience complications, including secondary bacterial infections.

In other questions, Uyeki was asked whether an outpatient should be treated with an antiviral if he or she presents with flu-like symptoms despite having been vaccinated against flu.

He replied that flu vaccines have "reasonably good" effectiveness but are less effective in some patients, especially the elderly. Even when the vaccine is well matched to the circulating viruses, "certainly a vaccinated person can be infected with influenza virus and develop illness," he said. "So influenza vaccination status should not be used to exclude a diagnosis of influenza virus infection."

Today's conference call was part of the CDC's Clinician Outreach and Communication Activity (COCA) program.

See also:

Nov 23 COCA call slides