H1N1 update: WHO restates H1N1 drugs recommendations

WHO restates H1N1 drugs recommendations

GENEVA, Aug 12 — Adults and children who are severely ill with H1N1 flu or at high risk of complications should be treated with antivirals like Tamiflu, the World Health Organisation (WHO) said today.

But otherwise healthy people with mild flu-like symptoms need not be given the drugs to combat swine flu, it said.

The United Nations agency reiterated advice first issued on May 21 on the use of antivirals for patients infected with the H1N1 virus, which applies to patients above one year old.

“WHO continues to recommend use of antivirals as treatment for people who are severely ill or are at risk of other health complications,” it said in a statement sent to journalists.

Prompt antiviral treatment with oseltamivir, the generic name for Tamiflu made by Swiss drug maker Roche Holding, is recommended for “at risk” groups including pregnant women.

“Antivirals need not be administered for otherwise healthy individuals with mild flu like symptoms,” it said.

British researchers said this week that children should not routinely be treated with flu drugs like Tamiflu since there is no clear evidence they prevent complications and the medicines may do more harm than good.

They called for a rethink of current widespread use of antivirals among under-12s in the light of an analysis of clinical data from past outbreaks of seasonal flu showing scant benefits and potentially harmful side effects.

In its statement, the WHO said its expert panel had recently reviewed its guidance on the use of antivirals as treatment for patients with H1N1 pandemic flu.

The experts had considered clinical evidence, including that used in the British Medical Journal for review, which the WHO noted had concerned seasonal and not pandemic H1N1 flu.

“The recommendation doesn’t change,” WHO spokeswoman Alphaluck Bhatiasevi told Reuters.

Roche said there were significant clinical data showing Tamiflu to be effective and well tolerated in children, and the data had been taken into account by both US and European drug regulators in approving the medicine for youngsters. — Reuters

Oseltamivir prescribed within 1 day of clinical diagnosis of influenza reduced risks...

Oseltamivir Prevents Complications of Influenza in High-Risk Children

Oseltamivir prescribed within 1 day of clinical diagnosis of influenza reduced risks for complications and hospitalization in children with chronic conditions.

In a manufacturer-sponsored study, investigators examined the effects of oseltamivir on influenza-related complications in children with chronic diseases. Using an administrative claims database, the investigators compared outcomes in 1634 children who received an oseltamivir prescription within 1 day of influenza diagnosis and 3721 children who did not receive antiviral therapy after influenza diagnosis. All children (age range, 1–17 years) were considered to be at high risk for complications because of a chronic disease (including HIV/AIDS, asthma, cancer) and received diagnoses of influenza between the 2000 and 2006 flu seasons.

During the 14 days after influenza diagnosis, children who received oseltamivir were less likely than those who did not receive oseltamivir to be hospitalized (0.6% vs. 1.3%) and to have pneumonia (1.0% vs. 1.9%), a respiratory illness other than pneumonia (19.8% vs. 23.8%), and otitis media (2.8% vs. 4.9%).

In analyses adjusting for potential confounders, all these differences were statistically significant except for the difference in pneumonia outcomes. Results were similar 30 days after diagnosis.

Comment: This study is an excellent example of comparative effectiveness research. Using observational data, these investigators found that oseltamivir prevents complications of influenza in high-risk children.

These children were not infected with the novel H1N1 ("swine flu") virus.

However, readers should note that the FDA has granted emergency approval for the use of oseltamivir for treatment or prevention of 2009 influenza A (H1N1) in adults and children — including those younger than 1 year. For specific information, visit the CDC website.

— Howard Bauchner, MD

Published in Journal Watch Pediatrics and Adolescent Medicine August 5, 2009

Citation(s):

Piedra PA et al. Effects of oseltamivir on influenza-related complications in children with chronic medical conditions. Pediatrics 2009 Jul; 124:170.

Medline Abstract: Effects of oseltamivir on influenza-related complications in children with chronic medical conditions.

Piedra PA, Schulman KL, Blumentals WA.

OBJECTIVE: This study investigated the influence of oseltamivir on influenza-related complications and hospitalizations for children and adolescents, 1 to 17 years of age, with chronic medical conditions or neurologic or neuromuscular disease.

METHODS: In a retrospective study, outcomes for patients who were given oseltamivir within 1 day after influenza diagnosis were compared with those for patients who received no antiviral therapy.
Anonymous data from MarketScan databases (Thomson Reuters, Cambridge, MA) were used to identify patients from 6 influenza seasons between 2000 and 2006. The study outcomes were frequencies of pneumonia, respiratory illnesses other than pneumonia, otitis media, and hospitalization.

RESULTS:
Oseltamivir was prescribed for 1634 patients according to the study criteria, and 3721 patients received no antiviral therapy for their influenza.

After adjustment for demographic and medical history variables, oseltamivir was associated with significant reductions in the risks of respiratory illnesses other than pneumonia, otitis media and its complications, and all-cause hospitalization in the 14 days after influenza diagnosis.

Analyses for 30 days after influenza diagnosis also showed significant risk reductions for respiratory illnesses other than pneumonia, otitis media and its complications, and all-cause hospitalization with oseltamivir.

CONCLUSION:
When it was prescribed at influenza diagnosis, oseltamivir was associated with reduced risks of influenza-related complications and hospitalizations for children and adolescents at high risk of influenza complications.