The liquid medicine, called Tamiflu OS (for oral suspension), is approved for children 2 weeks old and older.
It attacks the flu virus, helping to lessen the flu's ability to spread in the body. It must be taken within 48 hours of the first symptoms. In clinical trials, it did not cure the flu, but shortened its length by 1.5 days in kids.
Supplies are spotty. "While we have shipped all quantities of Tamiflu OS to distributors, some retail pharmacies may still have it," says Tara Iannuccillo, spokeswoman for Genentech, the drug's maker.
"However, quantities are limited nationwide," she says.
No additional supplies of Tamiflu OS will be available for this season, Iannuccillo says.
"Given the amount of time it takes to manufacture Tamiflu OS, we don't plan to make more for the 2012/13 flu season, as it wouldn't be ready in time," she says.
However, the adult version is still available. Parents can ask their pharmacist to make a liquid suspension for children using the adult Tamiflu capsules, Iannuccillo says.
More About Tamiflu Shortage
Concerns about a Tamiflu shortage began earlier in the season. In mid-January, the FDA warned of upcoming occasional shortages of the children's medicine.
Supplies of Tamiflu for children ran low due the severity of this year's flu season, Iannuccillo says. Compared to past seasons, flu season began earlier this year, according to the CDC.
To ensure continued supplies of the adult version, the FDA is allowing Genentech to distribute 2 million units of the 75-milligram capsules that have an older version of the package insert, says Sarah Clark-Lynn, an FDA spokeswoman.
"These additional reserve supplies of Tamiflu 75-milligram capsules are not outdated," she says. "Only some information included in the labeling is older."
The older labeling does not have dosing information for children aged 2 weeks to less than 1 year, for instance.
The FDA just granted the approval of Tamiflu OS for younger children in December.
Both children's and adults' Tamiflu is $101.50 a package, Iannuccillo says. On average, the co-pay for insured people is $35, she says.
Converting Capsules to Liquid Is Safe
To convert the capsules to liquid, a pharmacist mixes the capsule's contents with a sweetened suspension, says Mike DeAngelis, spokesman for CVS Pharmacy.
His pharmacies report a continuing shortage of Tamiflu liquid, he says, but not the adult capsules.
"It is important to note that the liquid compounding is a practice commonly performed at community pharmacies," he says.
"It is not related to sterile compounding practices that are performed at specialty pharmacies and were involved in last year's meningitis outbreak," he says.
In that outbreak, tainted steroid injections made at a New England compounding pharmacy were linked to more than 700 cases of fungal meningitis and other infections, and 47 deaths, according to the CDC.
This Year's Flu Season
Flu cases may now have peaked, according to the CDC. Even so, the CDC expects flu activity to continue for some time.
During the week ending Feb. 9, flu activity remained high but decreased in most areas, according to the CDC.
Since Oct. 1, 2012, nearly 9,000 lab-confirmed flu-related hospitalizations have been reported, the CDC says.
This season's vaccine is lessening the risk of having the flu by about 60%, the CDC estimates.
It's not too late to get vaccinated, the CDC says. It recommends the flu vaccine as long as the viruses are still circulating.