Amantadine and rimantadine for influenza A in children and the elderly

  • Review
  • Intervention

Authors

  • Márcia G Alves Galvão,

    1. Municipal Secretariat of Health, Rio de Janeiro, RJ, Brazil
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  • Marilene Augusta Rocha Crispino Santos,

    1. Municipal Secretariat of Health, Rio de Janeiro, RJ, Brazil
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  • Antonio JL Alves da Cunha

    Corresponding author
    1. Instituto de Puericultura e Pediatria Martagao Gesteria - IPPMG, Federal University of Rio de Janeiro, Departamento de Pediatria da Faculdade de Medicina, Rio de Janeiro, RJ, Brazil
    • Antonio JL Alves da Cunha, Departamento de Pediatria da Faculdade de Medicina, Instituto de Puericultura e Pediatria Martagao Gesteria - IPPMG, Federal University of Rio de Janeiro, Av Brig Trompowsky s/n, Cidade Universitaria - Ilha do Fundao, Rio de Janeiro, RJ, 21 940 - 590, Brazil. antonioledo@yahoo.com.br.

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Abstract

Background

Although amantadine (AMT) and rimantadine (RMT) are used to relieve or treat influenza A symptoms in healthy adults, little is known about the effectiveness and safety of these antivirals in preventing and treating influenza A in children and the elderly.

Objectives

The aim of this review was to systematically consider evidence on the effectiveness and safety of AMT and RMT in preventing and treating influenza A in children and the elderly.

Search methods

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2007, issue 3); MEDLINE (1966 to July 2007) and EMBASE (1980 to July 2007).

Selection criteria

Randomised or quasi-randomised trials comparing AMT and/or RMT in children and the elderly with placebo, control, other antivirals or comparing different doses or schedules of AMT and/or RMT or no intervention.

Data collection and analysis

Two review authors independently selected trials for inclusion and assessed methodological quality. Disagreements were resolved by consensus. In all comparisons except for one, the trials in children and in the elderly were analysed separately. Data were analysed and reported using Cochrane Review Manager 4.2. software.

Main results

In children, RMT was effective in the abatement of fever on day three of treatment. AMT showed a prophylactic effect against influenza A infection. AMT and RMT were not related to an increase in the occurrence of adverse effects. RMT also was considered to be well tolerated by the elderly, but showed no prophylactic effect. Different doses were comparable in the prophylaxis of influenza in the elderly, as well as in reporting adverse effects. Zanamivir prevented influenza A more effectively than RMT in the elderly.

Authors' conclusions

AMT was effective in the prophylaxis of influenza A in children. As confounding matters might have affected our findings, caution should be taken when considering which patients should to be given this prophylactic. Our conclusions about effectiveness of both antivirals for the treatment of influenza A in children were limited to a proven benefit of RMT in the abatement of fever on day three of treatment. Due to the small number of available studies we could not reach a definitive conclusion on the safety of AMT or the effectiveness of RMT in preventing influenza in children and the elderly.

Plain language summary

The usefulness of amantadine (Symmetrel®) and rimantadine (Flumadine®) in preventing and treating influenza A in children and the elderly

Influenza A is a respiratory virus in which cough, runny nose, headache and fever are frequent manifestations. Most symptoms usually resolve without treatment within three to seven days. A rare complication of influenza A viruses is that they may develop into a more serious illness leading to hospitalisation, pneumonia and even death, especially among children and the elderly.

This review of trials showed that amantadine can prevent influenza A in children, but it would be necessary to use the drug in up to 14 children during a 14 to 28 weeks period to prevent one case of influenza. New trials are needed to confirm the safety of this drug. We could not reach a conclusion on the use of amantadine in the elderly, as no studies were available.

Although rimantadine was shown to be a safe drug, it cannot be recommended for the prevention of influenza A in children or the elderly as its efficacy has not yet been proven. The only observed benefit of rimantadine in the treatment of children with influenza A was abatement of fever by the third day of treatment, as opposed to four to eight days without this drug. Therefore, rimantadine should be prescribed in selected cases, such as in children with underlying medical conditions in which fever may lead to complications (for example, febrile seizures or dehydration) or in which fever may impair treatment or control of diseases such as diabetes, cardiopulmonary illness, and chronic anemia such as sickle cell disease.

Due to the small number of studies available, we could not reach a definitive conclusion on the safety of amantadine or the effectiveness of rimantadine on preventing influenza in children and the elderly.

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