Pharmacy
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| SECTION 1 Introduction Behavioral Objectives SECTION 3 Side Effects and Limitations of Treatments SECTION 4 TABLES
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 Controlling Influenza Across the Health System:
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Define the role of the pharmacist in managing influenza patients |
As pharmacists look for new opportunities to improve patient care, the prevention and treatment of influenza offer exciting opportunities. State pharmacy practice acts are increasingly allowing pharmacists to administer influenza vaccines. With the advent of new medications for influenza treatment, pharmacists have an opportunity to increase awareness of new options for treatment and prevention of influenza and to work with patients and prescribers to ensure appropriate therapy is offered and used
In temperate regions of the Northern Hemisphere yearly influenza epidemics peak during December through March.4 Influenza infection tends to occur in seasonal outbreaks, with sporadic cases noted throughout the year.2 In temperate regions of the Southern Hemisphere, the influenza season peaks during May through August. Because influenza epidemics can occur throughout the year in different parts of the world, it should be included in the differential diagnosis of all febrile respiratory illness during the summer, particularly among travelers to the tropics or the Southern Hemisphere or among persons traveling with large international groups.4
The annual estimated direct economic costs of influenza range from $1 billion to $3 billion with costs during epidemics exceeding $12
billion.3,5 Influenza can result in significant health care costs through the use of outpatient visits, hospitalizations, and emergency room
visits.5 Influenza-related hospitalization rates are highest among persons 65 years and older, with 200 to 1,000 hospitalizations occurring per 100,000 persons per
year.2 Influenza raises employers costs through increased rates of employee absenteeism, decreased productivity, and increased costs of health care. The Centers for Disease Control and Prevention (CDC) reported that annual lost earnings due to influenza illness and mortality range from $10 billion to $15
billion.5
The Influenza Virus
Influenza viruses are enveloped RNA viruses that invade the epithelial cells lining the respiratory tract. Infection is transmitted from person to person by inhalation of aerosolized droplets that contain viral particles. In addition, animals such as swine and fowl, may become infected with influenza virus and serve as reservoirs for human infection.2
Replication of influenza viruses within cells of the respiratory tract result in direct injury to the nasal and tracheobronchial epithelium. This injury leads to clinical signs and symptoms such as cough, reduced tracheobronchial clearance, and altered pulmonary function. Influenza infection also elicits an immunologic response, as indicated by the production of various tissue cytokines, that contributes to the development of local and systemic symptoms.
Most clinical influenza infections in the U.S. are caused by influenza A virus, while about 35% of cases are due to influenza B.6 Influenza A viruses are classified into subtypes on the basis of the two antigens located on the surface of the virus particles: hemagglutinin (H antigen) and neuraminidase (N antigen). There are different subtypes for both H and N antigen. Influenza B viruses are not divided into subtypes.1,2
Influenza viruses frequently develop changes in their antigens as a result of genetic mutation. Minor changes, referred to as antigenic drift, result in changes in one or a few amino acids in the H or N antigens. A more dramatic change, called an antigenic shift, is a genetic change that results in the development of a new virus with a new surface
glycoprotein.2 This is significant because it results in a lack of antibody protection and could lead to pandemics. The constant development of antigenic variants causes seasonal epidemics and is the reason one or more new virus strains are incorporated into each years influenza
vaccine.1 Influenza B viruses are antigenically more stable than influenza A and thus, are less likely to undergo antigenic changes that lead to
resistance.2
Influenza Surveillance
The Influenza Branch of the CDC collects data on influenza rates in the U.S. each year from October through mid-May. The goals of the surveillance program include: (1) determining when influenza viruses are circulating, identifying circulating strains, and detecting changes in the viruses; (2) monitoring influenza-related illness in the U.S.; and, (3) measuring the impact of influenza on deaths in the U.S. This program is carried out in conjunction with the World Health Organization Collaborating Laboratory System, 122 cities across the U.S., state and territorial epidemiologists reports,
and the U.S. Influenza Sentinel Physicians Surveillance Network.7
Diagnosis of Influenza
Appropriate and rapid diagnosis of influenza is critical for appropriate patient care (Table 1). Diagnosis is typically made based on clinical presentation. It is important to differentiate between influenza and bacterial infections, which may require antibiotic therapy. Symptoms of influenza include the sudden onset of malaise and fever, followed by upper and lower respiratory tract manifestations, myalgia, and headache. Fever and other systemic symptoms typically last for 3 days. Respiratory symptoms, such as cough, may persist for 1 to 2 or more weeks.1,2
| Table
1. Importance of Accurate Influenza Diagnosis |
| allows initiation of appropriate antiviral therapy and supportive care promotes appropriate use of antibiotics facilitates appropriate initiation of antiviral prophylaxis in at-risk individuals provides an early picture of local influenza patterns limits development of secondary complications |
Since treatment is most beneficial if begun early in the disease course, the CDC has proposed a clinical diagnosis that includes fever of at least 100° F orally and at least one of the following symptoms: cough, sore throat or rhinorrhea (Table 2).2 A recent study indicated that fever early in the course of infection may be a good marker to distinguish between influenza and noninfluenza respiratory illness in adults.8
| Table
2. Screening for Influenza: Signs, Symptoms, and Risk Factors2 |
| fever > 100° F early in illness course
cough, sore throat, and/or runny nose muscle aches and pains sudden onset of symptoms recent contact with influenza case
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In an ambulatory care setting, pharmacists can screen for influenza by questioning patients presenting with signs and symptoms of influenza. Since patients may mistake influenza for a cold, screening efforts could initially focus on those patients requesting or purchasing nonprescription cough or cold products. Patients suspected of having bacterial infections or viral complications of influenza, such as viral pneumonia, should be encourage to seek appropriate medical care rather than begin self-treatment.9
In the community setting, culturing for influenza is not generally done, but viral culturing can be performed. Positive cultures are typically detected at 4 to 20 days postexposure.2 Culture results help differentiate influenza from other viruses and aid in determining the circulating viruses for inclusion in yearly vaccine content.1,10,11 New, rapid culture techniques that can detect influenza viruses in 30 minutes or less are available for clinic use.1,11
Detecting influenza symptoms in long-term care residents and the elderly may be difficult. In a study of long-term care facility patients, only 42% of patients cultured for influenza virus had an oral temperature of 100° F.12 Among the elderly, cough may be the most common symptom, being present in 93% to 97% of individuals.2
Influenza Prevention
Preventing influenza infection avoids symptoms, complications, and the risk of epidemics or pandemics. Preventive measures include the influenza vaccine and chemoprophylaxis with antiviral agents. Immunization is the recommended means of prevention while chemoprophylaxis is useful for certain populations and situations. Despite the prevalence and seriousness of influenza, prophylaxis tends to be under utilized.
Influenza Vaccine
Vaccination is the most cost-effective method of preventing influenza in adults and
children.13 The current vaccine contains three attenuated (killed) virus strains, usually two type A and one type
B.1 The composition of the vaccine is determined by the Food and Drug Administrations Vaccines and Related Biologic Products Advisory Committee and is based on antigenic analyses of recently isolated influenza viruses, epidemiologic data, and postvaccination serological studies in
humans.4
The CDC Advisory Committee on Immunization Practices (ACIP)1 provides recommendations for influenza vaccine use. The current recommendations focus on individuals who are at high risk of developing influenza and its complications (Table 3). The ACIP also recommends immunizations for health care workers and others who may transmit the influenza virus to high-risk populations (Table 4).
| Table
3. High-Risk Persons Who Should Be Immunized Against Influenza1 |
| persons aged 65 years or older
residents of nursing homes and other chronic-care facilities that house persons of any age who have chronic medical conditions adults and children who have chronic disorders of the pulmonary or cardiovascular systems, including asthma adults and children who have required regular medical follow-up or hospitalization during the preceding year because of chronic metabolic disease (including diabetes mellitus) renal dysfunction, hemoglobinopathies, or immunosuppression (including immunosuppression caused by medications) children and teenagers (aged 6 months to 18 years) who are receiving long-term aspirin therapy and might be at risk for developing Reye syndrome after influenza women who will be in the second or third trimester of pregnancy during the influenza season |
Immunization should also be considered for other patient groups. There is some evidence that supports the use of the vaccine in persons with altered immune systems, such as transplant patients and those infected with human immunodeficiency virus (HIV). Individuals traveling to countries experiencing influenza outbreaks are advised to be immunized or, if the vaccine is unavailable during summer travel times, to consider carrying antiviral medications for either prophylaxis or treatment. Consideration is being given to expanding vaccine recommendations to include children less than 5 years old and adults aged 50 to 64 years old.1 The American Academy of Family Physicians now recommends that persons aged 50 years or older should be vaccinated against influenza each fall.14
| Table
4. Persons Who Should Be Vaccinated to Reduce Influenza Transmission1 |
| physicians, nurses, and other personnel in both hospital and outpatient-care settings employees of nursing homes and chronic-care facilities who have contact with patients or residents employees of assisted living and other residences for persons in high-risk groups persons who provide home care to persons in high-risk groups household members (including children) of persons in high-risk groups |
Vaccine effectiveness
The efficacy of the inactivated influenza vaccine is influenced by several factors (Table 5). It prevents illness in about 70% to 90% of healthy persons younger than 65 years.1 Studies of the inactivated influenza virus vaccine have reported about a 25% reduction in illness, a 43% reduction in days of illness, a 44% reduction in health care visits, a 30% reduction in weekly case rates, a 54% reduction in influenzal illnesses, and a 53% reduction in work days lost due to febrile respiratory tract illness.15
| Table
5. Factors Affecting the Effectiveness of the Inactivated Influenza Vaccine1,24 |
| antigenic match between the vaccine and circulating virus strains
age of the vaccine recipient immunocompetence of the vaccine recipient the interval between vaccination exposure and the virulence and degree of transmissibility of the epidemic strains |
The vaccine may be less effective in the elderly, particularly those in nursing homes, due to an inadequate immune response compared to younger individuals.2,10 However, even with lower antibody titers, the vaccine can prevent secondary complications and reduce hospitalization and death. Among elderly persons living in the community, influenza vaccine is 30% to 70% effective in preventing hospitalization for pneumonia and influenza. Among elderly in nursing homes, the vaccine can be 50% to 60% effective in preventing hospitalization or pneumonia and 80% effective in preventing death.1
The effectiveness of the vaccine for individuals with HIV infections varies. The ability of the vaccine to induce the production of adequate antibody titers, and thus provide immunity, appears to be dependent on the immune status of the individual.1
Immunizations have been shown to be effective in preventing disease among employed populations. One study of health care workers in geriatric long-term care facilities found that staff vaccination was associated with reductions in total patient mortality from 17% to 10%.16 A study of textile workers found that vaccinated workers had fewer days of influenza-like illness than unvaccinated workers.17 The investigators estimated that $2.58 was saved for every $1 invested in the vaccination program.
Vaccine Safety
The most common vaccine side effect is soreness at the injection site, which occurs in about 10% to 64% of patients and can last up to 2 days.1 Vaccination can be followed by fever, malaise, myalgia, and other systemic symptoms that most frequently occur in persons with no previous exposure to the influenza virus. These reactions begin 6 to 12 hours after vaccination and can persist for 1 to 2 days.1,2 Vaccination does not cause influenza since the inactivated vaccine includes a killed virus. While several cases of Guillain-Barre Syndrome (GBS) were associated with the 1976 swine flu vaccine, recent data suggest that the actual incidence may be only slightly more than one additional case per million persons vaccinated.1
Allergic reactions after vaccination are rare, but use of the vaccine without physician consultation is not recommended for persons with an anaphylactic hypersensitivity to eggs or to other components of the vaccine.1 It is recommended that the vaccine not be given to persons with acute febrile illness until their symptoms have abated. Minor illness with or without fever, however, is not a contraindication.
Immunization Rates
Between 1989 and 1997, immunization rates among the elderly increased from 33% to 65.5%.1 However, this rate is still not optimal. Reasons for not being immunized were collected in the 1996 Medicare Current Beneficiary Survey (Table 6). The survey revealed that many respondents did not know that the vaccination was needed, and many nonvaccinated respondents had concerns about vaccine effectiveness and side effects.18
Even among health care workers, there are numerous reports of low vaccination rates.19,20 An aggressive vaccination campaign in one hospital lead to only 32% of health care workers being vaccinated. Degrees of immunization differed among health professions, with higher immunization rates being associated with higher income, advanced age, and longer employment.19
Table 6 (standard
orientation)
Future Vaccines
New vaccines that elicit a greater immune response and efficacy, even in the face of antigenic drift, are in development. Vaccine production without the use of chicken eggs is also being
investigated.2 Intranasal administration of live attenuated influenza vaccines has been shown to be effective in preventing influenza in children and
adults.1,21 In a randomized controlled trial of 456 employees, the live, attenuated intranasal vaccine significantly decreased the number of severe febrile illnesses and febrile upper respiratory tract
illnesses.21
Chemoprophylaxis
Due to low rates of immunization and varying rates of vaccine effectiveness, chemoprophylaxis is an important component of influenza prevention. Antiviral medications currently available in the U.S. include amantadine, rimantadine, zanamivir, and oseltamivir. Various characteristics of these medications are listed in Table 7.
Table 7 Antiviral Medications 1,2,11,13,37,38
Amantadine and rimantadine are chemically related drugs that interfere with the replication cycle of influenza A viruses.2 These medications are ineffective against influenza B virus because the B variant lacks the M2 proteinthe primary target for both agents.22,23
The new neuraminidase inhibitors are active against both influenza A and influenza B viruses. Neuraminidase, a viral enzyme located on the influenza virus surface, promotes the cellular release and respiratory tract spread of viruses by destroying the receptors for viral hemagglutinin (the protein that binds the virus to the host cell). Neuraminidase cleaves the terminal sialic acid residues of receptors present on host cells and newly synthesized viral glycoprotein. It may also reduce the ability of respiratory mucus to inactivate the virus. The neuraminidase inhibitors bind to the conserved active enzyme site of neuraminidase and appear to inhibit the release of viruses from infected cells and subsequent spread to adjacent cells.6,13,22,24
The ACIP considerations for chemoprophylaxis are presented in Table 8. The duration of prophylaxis depends upon the target population and indication. In the community setting, chemoprophylaxis is most cost-effective if taken only during the period of peak influenza activity. For institutional outbreaks, chemoprophylaxis should be given for at least 2 weeks or for 1 week after exposure to the virus. If given for immediate protection to those recently immunized, therapy should continue for 2 weeks after vaccination.1,2 Prophylaxis during the entire influenza season may be considered for high-risk patients who are unable to receive or respond to the vaccine.
| Table
8. Considerations for Influenza A Chemoprophylaxis1 |
| unvaccinated individuals exposed to influenza those whose vaccination occurred within 2 weeks before exposure prevention during institutional influenza outbreaks vaccine-contraindicated high-risk patients persons who are at high risk of influenza complications and who are vaccinated after influenza activity has begun persons who provide care to those at high risk of influenza individuals who may have an inadequate antibody response to the vaccine (e.g., transplant recipients, persons infected with HIV) |
Drinka and Associates25 suggest that if prophylaxis is initiated for a suspected outbreak, the need for continued chemoprophylaxis should be confirmed by culture. If changes in viral strains are seen during prophylaxis, switching to another agent should be considered. It should be recognized that influenza A outbreaks can be preceded or followed by other viral agents (e.g., parainfluenza virus) and be confused with influenza in clinical
presentation.11
Effectiveness of Chemoprophylaxis
Amantadine and rimantadine have both been approved by the Food and Drug Administration (FDA) for prophylaxis in adults and children. Prophylactic administration of amantadine and rimantadine to healthy adults is about 70% to 90% effective in preventing signs and symptoms of clinical disease. Both medications appear to be equally
efficacious.1,2,11,13
While clinical research supports the use of neuraminidase inhibitors for the prevention of influenza, neither has received FDA approval for this indication in adults or children. In experimentally induced influenza, intranasal zanamivir was found to be 82% effective against infection and 95% effective in preventing febrile illness due to influenza A.26 Monto et al8 found that zanamivir once daily for 4 weeks in 553 young healthy adults was 67% efficacious in preventing influenza signs and symptoms when compared to placebo (P<0.001). The efficacy rate increased to 84% when only influenza-positive individuals who were febrile were considered (P=0.001). All influenza infections occurring during the season, with and without symptoms, were prevented in 31% of cases (P=0.03).8
Research also supports the effectiveness of oseltamivir for influenza prevention. In a study of healthy adults aged 18 to 40 years inoculated with influenza virus, 67% of the 12 placebo patients and 38% of the 21 oseltamivir recipients had serologic evidence of infection (P=0.16).27 While 33% of the placebo recipients experienced infection-related respiratory illness (P<0.01) and 50% had virus recovered from respiratory sections, none of the oseltamivir recipients had symptoms or viral recovery (P<0.001). Oseltamivir resulted in significant reductions in illness burden and inflammatory response in the respiratory tract. Oseltamivir was also studied for long-term prophylaxis against influenza illness at different sites throughout the U.S. during the winter of 1997-1998.28 In a randomly assigned group of 1559 adults, the laboratory-confirmed protective efficacy of oseltamivir was 74% at all sites (P<0.001) and 82% at high-incidence sites (P<0.001). Once-daily oseltamivir completely protected against culture-proven influenza. The overall influenza infection rate, irrespective of symptoms, was also lower for oseltamivir than placebo (5.3% versus 10.6% respectively, P<0.001).
Treatment of Influenza
Influenza can be effectively treated with antiviral medications. The goals of treatment are given in Table 9. When administered early in the course of illness, these agents shorten the duration and reduce the severity of illness. Amantadine and rimantadine have been used in children 9 years old or older. Zanamivir is approved for use in adolescents 12 years old or older, while oseltamivir is approved for treatment in adults only.1,2,6,29,30 The most common considerations when using these agents are listed in Table 10.
| Table
9. Therapeutic Goals in Respiratory Viral Infections |
| symptom relief improvement in functional status --- - psychomotor performance prevention of complications --- - sinusitis --- - otitis media --- - reactive airways reduction in transmission to contacts |
A number of studies have documented the therapeutic effectiveness of amantadine and rimantadine in limiting the duration of influenza A symptoms.31-34 These medications have been studied in adults, the elderly, and children, and have been shown to decrease the duration of influenza symptoms by 1 to 2 days. The effect of these medications on influenza complications is not clear. A study by Doyle and associates of 105 adults who had been inoculated with influenza A virus and treated with either rimantadine 100 mg twice daily or placebo found pronounced decreases in sinus pain and chest congestion but no changes in the incidence of otologic complications.35 No controlled studies related to the effect of amantadine on the complications of influenza A have been published.1
Table 10. Considerations for Influenza Drug Therapy Selection
Several studies have documented the benefits of the neuraminidase inhibitors. A double-blind placebo-controlled study of 1256 persons randomized to receive zanamivir by inhalation and nasal spray two or four times daily or placebo revealed that zanamivir reduced symptom duration by 1 day (P=0.012 2x/day; P=0.014 4x/day).36 A reduction of 1 to 1.5 days of symptoms occurred if treatment was initiated within 30 hours of symptom onset (P=0.015 2x/day; P=0.001 4x/day). Compared to patients receiving placebo, febrile patients and high-risk patients receiving zanamivir experienced a 1.5-day reduction in symptoms (P=0.049); afebrile patients had a 0.75-day reduction in time to alleviation of symptoms (P=0.049). Among 158 high-risk patients who were influenza-positive, a 1.5-day reduction in symptom duration was seen when zanamivir was administered twice daily (P=0.14). Zanamivir also reduced the number of nights of disturbed sleep and shortened the time to return to normal activities. In another study, Hayden and associates26 found that zanamivir reduced the median duration of viral shedding by 3 days and the frequency of febrile illness by 85%.
The MIST (Management of Influenza in the Southern Hemisphere Trialists) study evaluated inhaled zanamivir in 455 patients 12 years of age or older who had influenza-like illness of 36-hours duration or less.37 Zanamivir produced symptom relief an average of 1.5 days earlier than placebo in the intent-to-treat group (P=0.011). Individuals who were febrile at study entry experienced symptom relief 2 days earlier if treated with zanamivir (P<0.001). The medication was particularly effective for high-risk individuals: symptom relief occurred 2.5 days earlier (P=0.048), fewer complications occurred, and use of complication-associated antibiotics was decreased.
A study of oseltamivir versus placebo in 1348 healthy nonimmunized adults with acute febrile respiratory illness found that oseltamivir reduced the time to symptom alleviation by 25% to 30% (P<0.017, P<0.006 respectively).38 Symptom severity was reduced by more than 35% as compared to placebo. Illness duration declined by 40% in those individuals in whom therapy was begun within 24 hours of symptom onset (P<0.02).38 Similarly, oseltamivir significantly reduced time to viral shedding cessation in a study of 69 subjects with laboratory-documented infection who had been started on oseltamivir 28 hours after inoculation. The median time to resolution of illness was reduced about 2 days and the incidence of upper respiratory tract illness, middle ear pressure abnormalities, and fever was lower in the oseltamivir-treated group compared to placebo.27
The effect of oseltamivir on the prevention of influenza complications was noted in three studies. A combined 887 infected patients received oseltamivir within 36 hours of symptom onset. Oseltamivir, as compared to placebo, reduced antibiotic use for secondary illnesses, such as bronchitis and pneumonia, by 43% to
63%.38 Ongoing studies are studying the efficacy of oseltamivir in healthy elderly patients (>65 years old). These studies note a reduction in median time to improvement similar to that of younger
adults.29
Side Effects and Limitations Associated with Antiviral Medications
Nausea and vomiting are the most common side effects of amantadine and rimantadine. More serious adverse events involve the central nervous system and include confusion, anxiety, aggression, hallucinations, ataxia, dizziness, and
seizures.1,2,11 These effects are more common with amantadine than with rimantadine. Mild impairment of psychomotor function may also occur with
amantadine.11 Side effects tend to diminish or disappear within the first week of treatment even if the medication is
continued.1,11 Most severe reactions have occurred in patients with renal insufficiency, seizure disorders, certain psychiatric disorders, and elderly persons who were taking high doses of
amantadine.1
The frequency and type of side effects associated with zanamivir have generally been similar to
placebo.24,34,35 However, use of zanamivir in patients with underlying asthma or chronic obstructive pulmonary disease has resulted in deterioration of respiratory function. The FDA recommends that these patients be properly monitored and observed and that supportive care, including short-acting bronchodilators, be
available.9,30 A major issue with zanamivir is the need for administration via a patient-activated inhalation delivery system. Appropriate
use of this product requires patient education and patient willingness to use such a device. There is concern that persons, particularly
the elderly and young children, may have difficulty inhaling the
medication.6,24
Oseltamivir is associated with a higher incidence of nausea and vomiting compared to placebo. This appears to be limited to the first or second day of therapy and has not resulted in excess withdrawals from therapy in clinical trials.28 Ingesting the medication with food may help to prevent these side effects. There has been no overall difference in safety noted with oseltamivir therapy in healthy patients greater than 65 years old and younger adults.29
Viral Resistance
A major shortcoming of amantadine and rimantadine is the development of resistant strains of influenza A. Amantadine-resistant viruses are cross-resistant to rimantadine and vice versa.1 Drug-resistant viruses can appear in up to one third of patients treated with amantadine or rimantadine. Antiviral-resistant influenza strains can replace sensitive strains within 2 to 3 days of starting therapy.1
The development of resistant influenza strains is thought to be very uncommon with the neuraminidase inhibitors because of the highly conserved active site of the neuraminidase
molecule.24 In vitro-produced oseltamivir-resistant and zanamivir-resistant strains with neuraminidase active site mutations exhibit a dramatic decline in infectivity indicating that they are biologically
impaired.22,39 Concerns about possible resistance, though, are still appropriate with more information needed about possible resistance emergence in high-risk populations, such as the
immunocompromised.13,24
Potential Roles for Pharmacists
Pharmacists have a unique opportunity to assist in the prevention and treatment of influenza via drug therapy selection, protocol development, and patient counseling. Pharmacists should consider the factors listed in Table 10 when recommending drug therapy. By providing appropriate counseling, pharmacists can limit influenza spread and encourage appropriate use of antiviral medications (Table 11). Pharmacists also need to encourage prescribers to consider the possibility of bacterial infections, particularly in patients with chronic medical conditions, before prescribing antiviral therapy.9
| Table
11. Therapeutic Goals in Respiratory Viral Infections |
| influenza can be associated with significant morbidity and mortality vaccination strongly advised for those at high risk or those in contact with high-risk individuals therapy is most effective when initiated early in course of illness therapy will decrease symptom severity and duration of symptoms OTC products can be taken for symptomatic relief Inhaler use should be followed carefully Instructions by a health care professional required take medications with food to decrease possible nausea most side effects tend to abate after 1 to 2 days of therapy contact prescriber if symptoms or side effects are severe or do not resolve avoid contact with others to limit spread of influenza |
Depending upon the scope of their state pharmacy practice acts, community-based pharmacists can offer patient care programs that include services such as immunizations, screening for influenza cases, and the initiation of protocol-defined antiviral treatment as appropriate. Given that therapy must begin early in the illness course to be most successful, the publics access to pharmacists makes them ideal health care providers for identifying and counseling patients and monitoring influenza treatment (Table 11).
Pharmacists in institutional settings can develop programs to prevent outbreaks of influenza. An aggressive immunization program aimed at health care workers and high-risk patients should serve as
the backbone for preventing influenza cases. Standing orders for immunization,
chemoprophylaxis, and treatment of high-risk and infected patients and health care workers can help contain the spread of influenza within institutions. Pharmacists can also assist with the
surveillance of influenza cases to confirm influenza virus presence and determine the types of viral strains present.
References
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16. Potter J, Stott DJ, Roberts MA, et al. Influenza vaccination of health care workers in long-term-care hospitals reduces the mortality of elderly patients. J Infect Dis. 1997;175:1-6.
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18. Centers for Disease Control. Reasons reported by Medicare beneficiaries for not receiving influenza and pneumococcal vaccinations: United States, 1996. MMWR. 1999;48(39):886-890.
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20. Grabenstein JD. Clinical and economic rationale for impolementing an adult immunization program for the geriatric resident and staff. Clinical Consult. 1999;14:3-13-12.
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28. Hayden FG, Atmar RL, Schilling M, et al. Use of the selective oral neuraminidase inhibitor oseltamivir to prevent influenza. NEJM. 1999;341:1336-1343.
29. Tamiflu package insert. Roche Pharmaceuticals, Nutley, NJ 1999.
30. Relenza package insert. GlaxoWellcome, Research Triangle Park, NC 1999.
31. Betts RF, Treanor JJ, Graman PS, Bentley DW, Donlin R. Antiviral agents to prevent or treat influenza in the elderly. J Respir Dis. 1987;8(Suppl 12A):S38-S41.
32. Hayden FG, Monto AS. Oral rimantadine hydrochloride therapy on influenza A virus H3N2 subtype infection in adults. Antimicrob Agents Chemother. 1986;29:339-341.
33. Younkin SW, Betts RF, Roth F, Douglas RGJ. Reduction in fever and symptoms in young adults with influenza A/Brazil/78 H1N1 infection after treatment with aspirin or amantadine. Antimicrob Agents Chemother. 1983;23:577-582.
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