General Information for Pharmacists
CDC has issued recommendations for clinicians on the use of antiviral medications for the treatment and prevention of influenza for the 2009-2010 season. The Food and Drug Administration (FDA) has authorized emergency use of oseltamivir (Tamiflu_) and zanamivir (Relenza under certain circumstances not included in the FDA-approved uses or outside of the FDA-approved uses in response to the declaration of a public health emergency involving 2009 H1N1 influenza A virus made by the Secretary of Health and Human Services on April 26, 2009. Additionally, FDA has recently issued an Emergency Use Authorization for the use of an unapproved (investigational) intravenous drug (peramivir) for the treatment of 2009 H1N1 influenza virus in certain hospitalized adult and pediatric patients.
The current public health emergency has affected the nation’s pharmacists as a greater number of people than usual seek to fill prescriptions for influenza antiviral drugs or antibiotics to treat secondary infections, in addition to seeking advice on over-the-counter cough and cold medications. This may have an impact on supplies and availability of antiviral medications and other materials that may be needed to fill such prescriptions.
Antiviral Availability
At this time, CDC discussions with the antiviral supply chain (manufacturers, distributors and retailers) indicate that supplies of the Tamiflu® adult capsule formulation (75 mg) and pediatric capsule formulations (30 mg and 45 mg) and Relenza® Inhalation Powder are meeting current demand for these products. However, the FDA and Roche (maker of Tamiflu®) have determined that supplies of Tamiflu® Oral Suspension are limited.Pharmacies should be aware of the importance of providing patients with these influenza medications as quickly as possible when they are prescribed. Having product at the pharmacy store level, including doses of Tamiflu® and Relenza®, and supplies to compound Tamiflu® Oral Suspension, will be critical to ensure that patients needing treatment receive it as quickly as possible.
- Limited Availability of Commercial Tamiflu® Oral Suspension
Supplies of commercially-manufactured Tamiflu® Oral Suspension are limited. In response to this, Tamiflu® Oral Suspension has been released from the CDC Strategic National Stockpile to enhance availability at state and local levels. Some of these lots of suspension product have an expired date on the label. Under the emergency use authorization for Tamiflu® FDA has authorized the use of certain lots of expired Tamiflu®. Based on scientific review, FDA found that some Tamiflu® may be used past the expiration date printed on the package. If you want to look up the lot number for your Tamiflu to see if it has been authorized for use past its expiration date, please see the listing of antivirals at or nearing expiry.
When local supplies of commercially-manufactured oral suspension are limited, physicians should consider infants and children less than one year of age or less than 33 lbs to be the highest priority for receiving the commercial suspension.- FDA: Information for Healthcare Professionals – Authorization of Use of Expired Tamiflu for Oral Suspension
- Supply of Ingredients Needed to Compound Tamiflu® Oral Suspension
Tamiflu® capsules (75 mg) may be compounded using either of two vehicles: Cherry Syrup (Humco) or Ora-Sweet SF (sugar-free) (Paddock Laboratories). As of October 28, 2009, these products may be in short supply in some locations if there is increased demand for compounding an oral suspension from Tamiflu® 75 mg capsules.
Humco reports that they have increased production of Cherry Syrup and that they are releasing new production weekly to wholesalers. If pharmacists are having difficulty obtaining Humco Cherry Syrup, they may contact Humco directly to locate supplies at 1-800-662-3435. Paddock Laboratories reports that they have increased production of Ora-Sweet SF and they are releasing new production daily to customers.- FDA: Tamiflu Oral Suspension Shortage Information
Antiviral Prescription and Dispensing Considerations
Oseltamivir (Tamiflu®)
- Complete information for the Emergency Use Authorization for Tamiflu® is available from CDC.
- CDC: Emergency Use Authorization for Tamiflu®
- Alternatives to Tamiflu® Oral Suspension for Pediatric Patients
While commercially-manufactured Tamiflu® Oral Suspension (12 mg/mL) is the preferred product for pediatric and adult patients who have difficulty swallowing capsules or where lower doses are needed, this product may not be locally available.
For patients who are less than one year old, there is one alternative:- a suspension compounded by a retail pharmacy (see links below)
- a suspension compounded by a retail pharmacy (see links below)
- 30mg, 45mg, or 75 mg capsules, which may be mixed into a sweetened liquid by a caregiver if the child cannot swallow capsules (see links below).
- Tamiflu® Oral Suspension Compounded by a Retail Pharmacy
Compounding an oral suspension from Tamiflu® 75mg capsules as described in the FDA-approved manufacturer package insert is an alternative when commercially-manufactured oral suspension formulation is not readily available. Tamiflu® 75 mg capsules may be compounded using either of two vehicles: Cherry Syrup (Humco) or Ora-Sweet SF (sugar-free) (Paddock Laboratories). Other supplies needed include mortar and pestle and a standard pharmacy bottle, such as an amber glass or amber polyethyleneterephthalate (PET) bottle.
