[A multicenter randomized controlled study of the efficacy and safety of oseltamivir in the treatment of influenza in a high risk population].
ABSTRACT To evaluate the efficacy and safety of oseltamivir in the treatment of influenza in a high risk population.
A randomized, open, control trial was conducted from Nov. 2002 to Feb. 2003. Patients with chronic respiratory disease, such as chronic bronchitis, obstructive emphysema, bronchial asthma, bronchiectasis or chronic cardiac disease, and with symptoms of influenza were enrolled. They should satisfy the following criteria: Fever > or = 37.8 degrees C plus at least two of the following influenza symptoms: coryza/nasal congestion, sore throat, cough, myalgia/muscle aches and pain, fatigue, headache and chills/sweats. Within 48 h after the onset of the symptoms, the patients were randomly assigned to oseltamivir group (oseltamivir 75 mg, twice daily for 5 days) or control group (symptom relief medicine only).
Fifty-six of the 108 recruited patients were identified as influenza-infected through laboratory test. They were defined as intent-to-treat infected population (ITTI) (27 oseltamivir, 29 control). The duration of influenza symptom was 64 h shorter (36.7%) and AUC score of the influenza symptom was decreased by 618 (43.1%) in the oseltamivir group as compared with those in the control group. The fever duration was 46.8 h (45.0%) less in the oseltamivir group than that in the control group. It took 6 d for the oseltamivir group and 11 days for the control group to recover to the basic health status. Secondary complications such as bronchitis, sinusitis and pneumonia occurred 11% (3/27) in the oseltamivir group and 45% (13/29) in the control group. The treatment expense for influenza and its complication was 587.4 RMB in the oseltamivir group and 786.5 RMB in the control group, which showed no significant difference (P = 0.246).
It is suggested that oseltamivir is effective and well tolerated in patients with chronic respiratory or cardiac diseases. It can reduce the fever duration and severity of influenza symptom, and decrease the incidence of secondary complications and antibiotic use, while does not increase the total medical cost.
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ABSTRACT: To evaluate the efficacy and safety of oseltamivir treatment in a population at high risk for influenza. This was a randomized, open-label, controlled trial involving Chinese patients with chronic respiratory diseases (chronic bronchitis, obstructive emphysema, bronchial asthma or bronchiectasis) or chronic cardiac disease. Patients showing symptoms of influenza were randomly assigned to receive oral oseltamivir 75 mg twice daily for 5 days (oseltamivir group), or symptomatic treatment (control group) within 48 h after symptom onset. The main outcome measures were duration and severity of illness in influenza-infected patients. Other outcome measures included incidence of complications, antibiotic use, hospitalization and total medical cost. Of the 118 recruited patients, 56 were identified as influenza-infected through laboratory tests (oseltamivir, N = 27; control, N = 29). Relative to symptomatic treatment, oseltamivir significantly reduced the duration of influenza symptoms by 36.8% (p = 0.0479), and the severity by 43.1% (p = 0.0002). In addition, oseltamivir significantly reduced the duration of fever by 45.2% (p = 0.0051), and the time to return to baseline health status by 5 days (p = 0.0011). The incidence of complications (11% vs. 45%, p = 0.0053) and antibiotic use (37% vs. 69%, p = 0.0167) were also significantly lower in the oseltamivir group compared with the control group. The cost of treating influenza and its complications was comparable between the two groups (p = 0.2462). Oseltamivir is effective and well tolerated in high-risk patients with chronic respiratory or cardiac diseases. It can reduce the duration and severity of influenza symptoms and decrease the incidence of secondary complications and antibiotic use, without increasing the total medical cost.Current Medical Research and Opinion 02/2006; 22(1):75-82. DOI:10.1185/030079906X80297 · 2.37 Impact Factor
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ABSTRACT: Pharmacokinetic studies of oseltamivir in very elderly patients (> or = 80 y) have not previously been performed. To compare the pharmacokinetics of oseltamivir and the active carboxylate metabolite in healthy young and very elderly Japanese subjects. Young (20-35 y, fasting, n = 7) and very elderly subjects (> or = 80 y, fed, n = 5) were enrolled in single-center studies and received a single oral dose of oseltamivir 75 mg. Plasma and urine samples were collected (24 h) for pharmacokinetic analysis, and safety was assessed. The time to maximum plasma concentration (tmax) for oseltamivir was delayed in the very elderly compared with the young subjects (2.30 vs 0.71 h, respectively). Furthermore, oseltamivir maximum plasma concentration (Cmax) and AUC(inf) were 52% and 80% higher, respectively, in the very elderly compared with the young subjects. Oral clearance was 45% lower in elderly patients, possibly due to the effects of administration of oseltamivir with a meal. For the active metabolite, oseltamivir carboxylate, Cmax and AUC(inf) values were, respectively, 22% and 91% higher in the very elderly subjects than in the young subjects, while oral clearance was 50% lower in the elderly population. The increased exposure of the active metabolite is likely to correlate with an age-related decline in renal function. For both oseltamivir and the active metabolite, there was large interpatient variability in the Cmax values. The data reported here indicate that oseltamivir would be effective in both of these populations, as trough concentrations for the active metabolite at 12 and 24 hours exceeded the 50% inhibitory concentration against the neuraminidase of influenza A and B isolates by more than 50-fold. Oseltamivir was well tolerated in both groups. Exposures (AUC(inf)) to both the parent drug and active metabolite were increased by more than 80% in the small number of very elderly subjects presented here. However, oseltamivir was well tolerated by these subjects.Annals of Pharmacotherapy 10/2006; 40(10):1724-30. DOI:10.1345/aph.1H174 · 2.92 Impact Factor
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ABSTRACT: Influenza imposes an annual burden on individuals, society, and healthcare systems. This burden is increased by the development of complications that are often more severe than the primary infection. Here, we examine the main complications associated with influenza and review the effectiveness of antiviral therapy in reducing the incidence of such events. The content of this review is taken from the study of the authors' extensive collection of reference materials, examination of the bibliographical content of relevant papers, and the results of Medline searches. The most commonly encountered complications in adults are sinusitis, pharyngitis, bronchitis, and, particularly in the elderly, bacterial pneumonia. Such complications may exacerbate pulmonary complaints. Children are particularly prone to post-influenza croup and otitis media. Complications involving the central nervous system, heart, or skeletal muscle also occur in influenza patients. Influenza-associated complications impose sizeable healthcare costs in terms of outpatient contacts, hospitalizations, and antibiotic use. Vaccination is the primary prevention strategy for influenza and its complications, but has limitations. Neuraminidase inhibitors have demonstrated efficacy in reducing the incidence of influenza-associated complications in populations with different ages and risks. Influenza complications place a large burden on healthcare providers and society. Neuraminidase inhibitors can reduce the incidence of such complications, particularly in high-risk groups.Infection 07/2009; 37(3):186-96. DOI:10.1007/s15010-009-8241-1 · 2.86 Impact Factor