TIME TO FIGHT! TREATING AND PREVENTING INFLUENZA Tracey Padilla, RPh. DMAT CA11 October 2009

WHAT IS THE DIFFERENCE BETWEEN AVIAN FLU AND SWINE FLU?

Who gets treatment? Per CDC interim recommendations for : 1- Any patient HOSPITALIZED with suspected or confirmed influenza. 2- Recommended for patients who are at HIGHER risk for influenza-related complications (e.g. children 65 years old, immunosuppressed/compromised patients, persons with chronic health conditions such as pulmonary, cardiovascular, renal, hepatic, hematologic, neurologic, neuromuscular, or metabolic disorders, obesity.)

continued 3- Any suspected influenza patient with warning signs/symptoms (eg. Dyspnea, tachypnea, unexplained oxygen desaturation) consistent with acute lower respiratory tract illness. 4-Treatment, when indicated, should start without delay (within 48 hours of illness onset). Early initiation is more likely to provide benefit. Hospitalized patients seem to benefit regardless of early treatment.

DO NOT WAIT FOR LAB CONFIRMATION TO TREAT. TESTS ONLY 10-70% ACCURATE? TESTS TAKE VALUABLE TIME

Antiviral Agents for Treatment Same medications recommended for seasonal and H1N1 influenza strains : Oseltamivir (Tamiflu) Zanamivir (Relenza) Not recommended for strains: Amantadine (Symmetrel) Rimantidine (Flumadine)

These recommendations could change… Stay tuned to:

Influenza antiviral medications can reduce the severity and duration of influenza illness and reduce the risk of influenza-related complications including severe illness and death.

Who should NOT get treatment? Treatment or prophylaxis is generally not required for patients with suspected influenza who present with UNCOMPLICATED febrile illness or are NOT at higher risk for complications.

CDC recommendations are changing frequently. For most recent recommendations and information:

Oseltamavir (Tamiflu) Dosing ADULTS AND ADOLESCENTS (13 years and older): Treatment =75mg PO/NG BID x 5 days (start within 2 days of onset of symptoms) Unlabelled uses: Critically ill-patients or those with BMI > 30 consider dosing 150mg BID and/or extending treatment duration to 10 days (MMWR 2009)

Renal Dosing Adjustment CrCl = 10-30ml/min : 75mg PO/NG QDAY x 5 days High dose (critically ill H1N1 or Obese) and CrCl = 10-30ml/min : 150mg QDAY x 5-10 days CAPD (unlabeled dose) 30mg PO/NG once weekly Hemodialysis (unlabeled dose) 30mg PO/NG after every OTHER session

Pediatric Dosing (1-12 years old) >40kg: 75mg PO/NG BID x 5 days 24-40kg: 60mg PO/NG BID x 5 days 16-23kg: 45mg PO/NG BID x 5 days =<15kg: 30mg PO/NG BID x 5 days

Pediatric Dosing (less than 12 months ) 6-11 months: 25mg PO/NG BID x 5 days 3-5 months: 20mg PO/NG BID x 5 days < 3 months: 12mg PO/NG BID x 5 days

Tamiflu for Oral Suspension Manufactured Oral Suspension in short supply -potential dosing errors from markings on dose syringe provide vs MD directions. Emergency Compounding of suspension at 12-15mg/ml make from oral capsules using cherry syrup (Humco) or Ora-Sweet-SF (Paddock). Expiration 10 days or package insert

Oh Crap, my suspension is expired! MAYBE NOT! EMERGENCY USE AUTHORIZATION 4/27/2009 FDA SLEP (Shelf Live Extension Program) Allows for use of SOME lots of expired Tamiflu suspension beyond manufacturer’s exp. date

Oseltamivir Prophylaxis Dosing POST EXPOSURE PROPHYLAXIS is generally not recommended due to risk of developing resistance. If warranted, initiate within 2 days of contact with infectious individual during their infectious period. Should be started within “infectious period” of 1 day before through 24 hours after fever ends for patient.

SAME DOSE as treatment Frequency ONCE DAILY Duration days (protection lasts for length of dosing period.) Continue for 10 days after last contact. Not recommended for children < 3 months (no data)

Updated CDC Recommendations 10/16/09 An emphasis on early recognition of illness and treatment as an alternative to chemoprophylaxis after a suspected exposure.

Persons at ongoing occupational risk for exposure (e.g., healthcare personnel, public health workers, or first responders who are working in communities with influenza outbreaks) should carefully follow guidelines for appropriate personal protective equipment. Efforts to reduce the risk of exposure or infection for healthcare personnel should include appropriate administrative controls (i.e. Stay home if you are sick!)

...and finally These findings underscore the importance of careful and limited use of antiviral medications for chemoprophylaxis and the need for persons taking antiviral medications to continue to follow recommendations for hand and respiratory hygiene to prevent the spread of antiviral resistant viruses.

Updated CDC Recommendation Consideration for antiviral chemoprophylaxis should generally be reserved for persons at higher risk for influenza-related complications who have had contact with someone likely to have been infected with influenza. However, early treatment is an emphasized alternative to chemoprophylaxis after a suspected exposure...

Continued… Household or close contacts (with risk factors for influenza complications) of confirmed or suspected cases can be counseled about the early signs and symptoms of influenza, and advised to immediately contact their healthcare provider for evaluation and possible early treatment if clinical signs or symptoms develop…

…and finally Early recognition of illness and treatment when indicated is preferred to chemoprophylaxis for vaccinated persons after a suspected exposure. Updated 10/16/2009

Who should consider prophylaxis? Persons at higher risk of influenza complications (heart disease, asthmatic, diabetes…) Healthcare workers Public health workers First responders

Oseltamivir (Tamiflu) Side Effects Most occurred at a frequency which was less than or equal to control: MOST COMMON: GI upset (nausea, vomiting, abdominal pain) =< 10-15% Headache (dose related) Rare but serious: Anaphylaxis, severe dermatological reactions including Stevens-Johnson Syndrome and neuropsychiatric events (self-injury, confusion, delirium especially in adolescents)

Oseltamivir (Tamiflu) Drug Interactions and Warnings No known interactions where it is recommended to avoid concomitant use. Pregnancy Risk Category “C”

Zanamivir (Relenza )Dosing Must be used with DISKHALER delivery device provided: Adults and children over 7 years old: Two 5mg inhalations BID x 5 days

Timing of zanamivir (Relenza) Administer at the same time each day Patients scheduled to use an inhaled bronchodilator should use their bronchodilator PRIOR to zanamivir. Should get 2 doses on 1 st day (doses on 1 st day should be at least 2 hours apart; subsequent days space approximately 12 hours apart)

Pediatric Dosing of Zanamivir (Relenza) Age>= 7 years: Refer to Adult dosing

Zanamivir (Relenza) Prophylaxis Dosing POST EXPOSURE PROPHYLAXIS is generally not recommended due to risk of developing resistance. Children >= 5 years and Adults: DOSING same as treatment Frequency ONCE DAILY Duration x 10 days Start within 1 & ½ days of exposure

Zanamivir Side Effects Most Common: Headache (2-24%): (dose related?) GI side effects (8-19%): Throat/Tonsil Pain Respiratory (7-20%): nasal signs/symptoms and cough, bronchospasm

Zanamivir (Relenza) Drug Interactions and Warnings No known interactions where it is recommended to avoid concomitant use. May decrease the levels/effects of Influenza Virus Vaccine Not recommended for patients with LACTOSE allergy or chronic respiratory disease Pregnancy Risk Category “C”

FDA MedWatch Warning 10/09/09 DO NOT USE RELENZA POWDER IN NEBULIZERS OR VENTILATORS! -RESULTED IN DEATH OF A PATIENT. Compassionate Use Trials for Relenza for IV use and Inhalation (Late Stage Trials) by GSK