MIKE STOBBE AP Medical Writer ATLANTA (AP) — The maker of Tamiflu on Wednesday said there's a shortage of the children's version of the drug — the first-line treatment for swine flu and seasonal flu. Switzerland-based Roche Holdings is sending a notice to doctors and pharmacists about a shortage of the liquid version of Tamiflu for children and how to handle prescriptions in the meantime. The company has been facing increasing demand for Tamiflu since swine flu first appeared in April, and has decided to focus production on adult-strength pills, which it can make faster than children's formulations, company spokeswoman Kristina Becker said Wednesday. The adult-dosage pills are still in good supply, and pharmacies can grind them and turn them into smaller doses for children, she said. Tamiflu is one of two drugs that work against swine flu. Another flu treatment, Relenza, is in good supply as well, government health officials said this week in a message to pharmacists. Swine flu has been on the upswing, with 21 states reporting widespread cases, according to the latest report from the Centers for Disease Control and Prevention. And seasonal flu is a looming threat as the weather turns colder. Tamiflu is the most-prescribed treatment for people with seasonal flu. When given shortly after symptoms appear, it can shorten the severity and duration of illness. Jim Cohn, a spokesman for Walgreen's, which operates pharmacies in all 50 states, said the chain has seen shortages in the South. "I would not say this is a crisis," he said. The adult dosage is a 75-milligram pill twice a day. Children's dosages are based on how much they weigh. They are usually given either smaller pills or the medicine in a sweetened liquid. Earlier this month, Roche notified doctors and pharmacists of its production decision. The Roche message planned for Wednesday reminded them that shortages of pediatric doses may appear. It also cautioned them to be careful while using pills to fill prescriptions for liquids. Treating children with Tamiflu is tricky even when the drug is in normal supply, said Dr. Ruth Parker of Emory University, who co-authored a short report on the topic released Wednesday by the New England Journal of Medicine. She noted instances in which instructions on the pharmacy label for kid's liquid Tamiflu were different from the manufacturer's label,"It's already confusing. This (shortage) doesn't help," Parker said. She urged parents to open up a Tamiflu prescription when they pick it up and go over the information with a pharmacist to make sure they understand how much to give. Health officials say that in the event of shortages, Tamiflu should be prioritized for people who are hospitalized and for those at risk for severe flu complications, including young children, pregnant women, the elderly and people with chronic health conditions. Tamiflu is made at several facilities, including some in the United States. The company has been increasing production, and by next year it is expected to have jumped 10-fold since 2005. By that time, the company will be making 33 million courses of treatment per month, Becker said. A course of treatment is two doses daily for five days, she added.