Pharmacovigilance

Recommendations of the Agency for Medicinal Products and Medical Devices on the use of Tamiflu in children under one year of age and the use of Tamiflu and Relenza in pregnant and breastfeeding women in the influenza A/H1N1 pandemic

09.06.2009

In connection with the recent outbreak of the A/H1N1 influenza, the Committee for Medicinal Products of the Agency for Medicinal Products and Medical Devices, at its 111th session, adopted the recommendations for use of antiviral medicine Tamiflu (oseltamivir) in children under one year of age, and the medicinal products Tamiflu and Relenza (zanamivir) in pregnant and breastfeeding women in the case of a declared influenza A/H1N1 pandemic (The World Health Organization has raised its pandemic alert level for the A/H1N1 influenza virus to phase 6). The recommendations are harmonised with the recommendations of the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMEA).

Tamiflu is a medicinal product approved for treatment and prophylaxis of influenza in adults and children above one year of age. Relenza is a medicinal product approved for treatment and prophylaxis of influenza in adults and children above five years of age. The active substances in these medicinal products (oseltamivir and zanamivir) act by inhibiting neuraminidase (enzyme on the surface of the virus) activity. They block the enzyme by attaching themselves to it, and thus preventing the spread of the virus. Both medicinal products showed efficacy against the new A/H1N1 influenza virus.

Considering the A/H1N1 influenza virus potential for causing a pandemic, the CHMP investigated whether the use of Tamiflu (oseltamivir) in children under one year of age and the use of Tamiflu and Relenza (zanamivir) in pregnant and breastfeeding women would be justified in the event of a pandemic.

Children under one year of age

In this group of children, the data regarding use of the above medicinal products are relatively limited and, since Relenza is approved for use in children above 5 years of age, only Tamiflu, which is approved for use in children above one year of age, has been taken into consideration. In order to judge the efficacy and safety of Tamiflu, the results of a clinical study which is currently under way with children under one year of age as study subjects, as well as two completed clinical studies and one retrospective analysis, have been taken into consideration.
The recommendations are as follows:

  • There is sufficient scientific evidence to support the use of Tamiflu in the treatment of children younger than one year of age in the event of an influenza A/H1N1 pandemic as justifiable.
  • As for the use of Tamiflu in the post-exposition prophylaxis of children younger than one year of age, scientific evidence is scarcer. Therefore, the recommendation is that in case of children younger than one year of age, the prophylaxis with Tamiflu does not last for more than 10 days.
  • It is recommended that, should it be necessary to prescribe Tamiflu to children younger than one year of age, the physician evaluates the benefit/risk ratio associated with the use of this medicinal product for each child individually.
  • If the medicinal product is being used to treat children below 1 year of age, the appropriate dosage is 2 to 3 mg/kg of body weight twice daily during 5 days.
  • Children below 1 year of age should be treated under medical supervision. However in case of pandemic influenza, this recommendation could potentially place huge burden on hospital resources and therefore, it is strongly recommended that at least children below 3 months of age are treated under medical supervision in hospital.

Pregnant and breastfeeding women

The data regarding the use of Tamiflu and Relenza in the treatment or prophylaxis of pregnant and breastfeeding women are also limited. In order to evaluate the safety and efficacy in the event of a pandemic, the post-marketing data on the safe use in patients taking Tamiflu (232 patients) or Relenza (97 patients) during pregnancy or breastfeeding, have been reviewed.
The recommendations are as follows:

  • In the event of a pandemic of the A/H1N1 influenza, there is sufficient scientific evidence to support the justifiability of use of Tamiflu and Relenza in pregnant and breastfeeding women, i.e. to show that the risk of use of these medicinal products is acceptable when compared with the risk of possible complications of the A/H1N1 influenza itself.
  • If Tamiflu is used to treat pregnant or breastfeeding women, the appropriate dosage is 75 mg twice a daily during five days.
  • If Relenza is used to treat pregnant or breastfeeding women, the appropriate dosage is two inhalations per day (2x5 mg) during five days.

Supervised prescribing of Tamiflu to children under one year of age and of Tamiflu and Relenza to pregnant and breastfeeding women during influenza A/H1N1 pandemic

During influenza A/H1N1 pandemic, in order to ensure a safe use of the above medicinal products, the Agency will maintain a Register recording any prescription of such medicines to children younger than one year of age, as well as to pregnant and breastfeeding women, which will enable the Agency to promptly notify health professionals should signals be found in this population. The Agency will be receiving data in the following way:
Every time any of these medicinal products is prescribed to a child younger than one year of age, a pregnant or a breastfeeding woman, the physician concerned shall notify the Agency for Medicinal Products and Medical Devices. For each patient, a Tamiflu or Relenza Prescription Notification Form will have to be completed and sent to the Agency address (Ksaverska cesta 4, 10 000 Zagreb) or fax no.: +385 1 4884 110, or to the e-mail address pandemija@almp.hr. All patients who have received the medicinal product must be registered, whether any adverse reactions have been observed or not.

Monitoring adverse reactions during influenza A/H1N1 pandemic

When suspecting an expected or unexpected adverse reaction to Tamiflu or Relenza in patients who have received such medicinal products, the physician must, in addition to the Tamiflu or Relenza Prescription Notification Form (if the patient concerned is a pregnant or breastfeeding woman or a child younger than one year of age), complete a Tamiflu or Relenza Adverse Reaction Notification Form and send it to the Agency address (Ksaverska cesta 4, 10 000 Zagreb) or fax no.: +385 1 4884 110, or the e-mail address pandemija@almp.hr. If the suspected adverse reactions are observed in patients from other age groups, only the Tamiflu or Relenza Adverse Reaction Notification Form or the Agency's standard adverse reaction notification form should be sent to the above address. It is very important to report in the described manner the potential inefficacy of a medicinal product, which is considered an adverse reaction of F type.

Important: The above recommendations for children younger than one year of age and pregnant or breastfeeding women are valid only during the sixth phase pandemic alert level of the A/H1N1 influenza, as classified by the World Health Organisation. Outside a pandemic, the medicinal products Tamiflu and Relenza must be used only in line with the approved Summary of Product Characteristics. These recommendations, both on the level of the European Medicines Agency and on the level of the Croatian Agency for Medicinal Products and Medical Devices, do not imply amendment to the marketing authorisation for a finished medicinal product for Tamiflu and Relenza, i.e. amendment to already approved indications.

The Agency emphasises that these medicinal products may be obtained solely based on a prescription of a physician.

External links:

The CHMP opinion concerning use of Tamiflu (oseltamivir) and Relenza (zanamivir) in the epidemic of the A/H1N1 influenza of 5 May 2009 (EMEA/H/A-5.3/1172): http://www.emea.europa.eu/humandocs/PDFs/EPAR/tamiflu/27883809en.pdf
The Epidemiology Service for Contagious Diseases at the Croatian Institute of Public Health:
http://www.hzjz.hr/epidemiologija/svinjska_gripa.htm

Forms:

Tamiflu or Relenza Prescription Notification Form (.doc, .pdf)
Tamiflu or Relenza Adverse Reaction Notification Form (.doc, .pdf)

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