Six questions and answers about "Oseltamivir"

As non-professionals, parents may not be familiar with the drugs that children use daily, but few parents do not know "oseltamivir". This is because it is one of our most powerful weapons to defeat the influenza virus. Look, the pharmacist at the Children's Hospital is introducing the antiviral drug "oseltamivir". I believe you also want to know more about this weapon and use it better, come and listen~

1. Is oseltamivir effective for all colds?

The "common cold" is a general term for acute inflammation of the nasal cavity, pharynx or larynx, most of which are caused by viruses, including rhinovirus, coronavirus, parainfluenza virus, respiratory syncytial virus, etc. There is no specific antiviral drug for the common cold, and its treatment is mainly symptomatic. "Influenza" (abbreviated as "flu") is caused by influenza viruses. Oseltamivir is effective against both influenza A and B viruses, but not against viruses that cause the common cold.

2. How old can children take oseltamivir?

According to the instructions, oseltamivir can be used to treat and prevent influenza in children over 1 year old [1]. The Expert Consensus on Diagnosis and Treatment of Influenza in Children (2020 Edition) provides dosage recommendations for the use of oseltamivir to treat influenza in children of all ages. However, except in emergency situations where it must be used after clinical evaluation, the preventive use of oseltamivir in children aged 0 to 3 months is not recommended. See Table 1 for specific usage and dosage.

Table 1 Recommended doses of oseltamivir for the treatment and prevention of influenza in children[1, 2]

3. How to choose between granules and capsules?

Oseltamivir is only available in oral dosage form, and most of the oseltamivir currently on the market are granules and capsules. The specifications of oseltamivir granules are generally 15 mg/bag, and the specifications of oseltamivir capsules are generally 75 mg/capsule. In other words, the dosage of one capsule is equivalent to the dosage of 5 bags of granules. Please look at Table 1 below with me. You may find that children weighing less than 40 kg will face the problem of breaking the capsule apart when using oseltamivir capsules, which may lead to improper storage of the drug, waste, or refusal of the child to take the drug. If granules are used, children weighing more than 5 kg generally do not need to be divided into doses. In the actual medication process, parents should take the correct method according to the advice of the doctor or pharmacist to give their children appropriate medications.

4. When should I start taking oseltamivir? When should I stop taking it?

Treatment of influenza: Treatment should be started on the first or second day (ideally within 36 hours) of the onset of influenza symptoms. Studies have shown that antiviral treatment (using antiviral drugs such as oseltamivir) within 48 hours of onset can significantly reduce complications [3]. For children with severe influenza, oseltamivir is still effective after more than 48 hours. The general course of treatment is 5 days, and the duration of use can be appropriately extended for severe cases.

Prevention of influenza: It is recommended to take the drug early (if possible within 48 hours after exposure) and continue for 7 to 10 days after the last exposure. For those who are unable to take the drug within 48 hours after exposure, preventive medication is still recommended [2].

5. Can I still take oseltamivir after getting the flu vaccine?

Oseltamivir should not be used within two weeks of receiving live attenuated influenza vaccine; live attenuated influenza vaccine should not be used within 48 hours after using oseltamivir[1]. Inactivated influenza vaccine can be administered at any time before or after using oseltamivir[1].

6. How safe is oseltamivir?

Most children tolerate oseltamivir well, but a small number of children may experience nausea and vomiting. If you are taking granules, you generally need to take another dose if you vomit right after taking them. If you vomit half an hour after taking them, you generally do not need to take another dose. If you are taking capsules, you need to take another dose if you vomit the entire capsule shell. Otherwise, you generally do not need to take another dose. Children with severe gastrointestinal reactions can try taking oseltamivir with food.

Finally, the pharmacist reminds you that oseltamivir is a prescription drug and can only be used after a doctor's diagnosis, evaluation and prescription. Abuse and blind use are not advisable. It can be used under the guidance of a doctor or pharmacist when necessary. I hope all parents can correctly use our powerful weapon to fight against influenza, and I hope all children can safely and smoothly get through the flu season!

References

[1] Oseltamivir Phosphate Capsules Drug Instructions

[2] National Clinical Research Center for Respiratory Diseases, Chinese Medical Association Pediatrics Branch Respiratory Group. Expert consensus on diagnosis and treatment of influenza in children (2020 edition)[J]. Chinese Journal of Practical Pediatrics, 2020, 35(17): 1281-1288.

[3] National Health Commission of the People's Republic of China, State Administration of Traditional Chinese Medicine. Diagnosis and treatment plan for influenza (2020 edition)[J]. Chinese Journal of Clinical Infectious Diseases, 2020, 13(6): 401-405.

(Li Rongrong, Tianjin Children's Hospital)