Influenza Flashcards
(24 cards)
Which type of influenza is most virulent and associated with pandemics?
Influenza A.
How is influenza transmitted?
Via droplets, aerosols, or direct contact with respiratory secretions.
What is the typical incubation period for influenza?
1–3 days.
Name 4 common symptoms of influenza.
Fever, chills, headache, myalgia (muscle aches).
What are some possible respiratory complications of influenza?
Bronchitis, pneumonia, otitis media, exacerbation of asthma/COPD.
How is uncomplicated influenza managed?
Self-limiting, managed in the community; antivirals not usually required.
Who is considered ‘at risk’ for complications from influenza?
Children <6 months
Pregnant/post-partum women
Aged ≥65
Chronic conditions (e.g., heart, lung, kidney, liver, neurological, diabetes, BMI ≥ 40)
Severely immunosuppressed
What conditions must be met to prescribe antivirals to at-risk patients?
Influenza is circulating (confirmed by national surveillance)
Patient is in an at-risk group
Treatment can begin within 48 hours (36 for zanamivir in children)
What are the first-line antivirals for influenza treatment?
Oseltamivir (oral) and Zanamivir (inhaled).
Which group should receive treatment without waiting for test confirmation?
At-risk patients, including pregnant women.
Which influenza strain is more likely to be resistant to oseltamivir?
Influenza A(H1N1)pdm09.
What are the conditions for giving post-exposure prophylaxis with antivirals?
Influenza is circulating
Close contact with symptomatic person
At-risk individual not fully immunised
Can start prophylaxis within 48 hours (oseltamivir) or 36 hours (zanamivir)
Which antiviral is preferred for prophylaxis in at-risk groups?
Oseltamivir.
What is the mechanism of action of oseltamivir?
Neuraminidase inhibitor – prevents release of new influenza virus particles from infected cells.
What is the usual adult dose of oseltamivir for treatment of influenza?
75 mg twice daily for 5 days.
What is the usual adult dose of oseltamivir for post-exposure prophylaxis?
75 mg once daily for 10 days.
How is oseltamivir adjusted in renal impairment?
Dose reduction is required if eGFR <60 mL/min. Refer to BNF renal dosing chart.
Can oseltamivir be used in pregnancy?
Yes, when the benefits outweigh the risks. It is the preferred oral antiviral in pregnancy.
List common side effects of oseltamivir.
Nausea, vomiting, abdominal pain, headache.
How is zanamivir administered?
Inhaled via Diskhaler; IV formulation available for hospital use (unlicensed).
What is the adult treatment dose of zanamivir (inhaled)?
10 mg twice daily for 5 days.
What is the adult prophylactic dose of zanamivir?
10 mg once daily for 10 days.
What are the common side effects of inhaled zanamivir?
Bronchospasm, cough, headache.
Can zanamivir be used in children?
Yes – licensed from age 5 years (treatment) and 5 years (prophylaxis), though BNFc guidance should be followed.
