4 Influenza Medications You Should Know About

Hello. I am City, a pharmacist. Today, I would like to talk about "4 influenza antiviral medications you should know about."

When you or a family member is diagnosed with influenza, you are already feeling unwell, and it can be overwhelming to worry about things like, "Which medicine is best?" or "Is it safe for my child to take?"
Especially when you have small children or elderly family members, I think many people feel that they want to "make them feel better as safely and as quickly as possible."

In this article, I will organize information about the four commonly used anti-influenza medications:
Tamiflu (oral medication)
Inavir (single inhalation)
Relenza (inhalation over several days)
Xofluza (single oral dose)

I will explain "what kind of medicine it is," "who it is suitable for," "conditions for use in prevention," and "points to note regarding side effects and abnormal behavior" in a way that is easy to visualize.💊

First, the common points you should grasp

All influenza medications are "drugs that suppress viral replication" and are not "antipyretics that make a fever disappear instantly."
Regardless of the medication, the following three points are important:

• It is more effective if started within 48 hours of onset

• Even with medication, it is common for "discomfort to persist for 1 to 2 days"

• Basically, any of these medications can be used for both Type A and Type B influenza

Tamiflu: An oral medication easy to use for a wide range of ages

Tamiflu is a representative oral medication and is often chosen as the "first choice."
It comes in capsules and dry syrup, and is used by a wide range of generations from infants to the elderly.

How to use it for treatment (image)

• The standard is to take it "twice a day for 5 days"

• For children, the dosage varies by weight and is adjusted using powder (dry syrup)

• The guideline is to start within 2 days of onset

Since the key is "whether you can continue taking it properly," other agents may be chosen if there is severe vomiting or difficulty swallowing.

When used for prevention

When someone in the family has influenza and you want to "prevent other household members from developing it," Tamiflu is sometimes used for prevention.

A common pattern is

• There are people in your family you absolutely cannot afford to have bedridden, such as the elderly, those with underlying health conditions, or students preparing for exams.

• You want to prevent a cluster infection in facilities, or in medical or nursing care settings.

These are such cases.
For prevention, a method of continuing for fewer doses than treatment, such as "once a day for 10 days," is used.

Side Effects and Precautions

• Gastrointestinal symptoms such as nausea, abdominal pain, and headache

• Rarely, allergic reactions or serious skin symptoms

Tamiflu and "abnormal behavior" are often discussed together, but it is now believed that "abnormal behavior can occur due to influenza itself," so it cannot be said that it is solely the fault of the medication.
In any case, for teenage patients,

• Do not leave them alone for several days after onset

• Keep them away from dangerous places such as balconies, windows, and stairs

Such "supervision" is very important.

Inavir: A medication that is completed with a single inhalation

Inavir is a type of medication where "treatment is completed after one inhalation."
This is a major benefit for busy people or those who find it difficult to continue taking medication properly every time.

How to use for treatment (concept)

• Inhale the required amount for the day in one go and finish

• Adjusted according to age and weight, such as a smaller amount for children and a larger amount for adults

• Use within 48 hours of onset

The point is whether you can properly inhale it deep into your lungs.
If the inhalation is not done well, the effectiveness will inevitably decrease.

How to use for prevention

Inavir is sometimes used for prevention, but in actual daily clinical practice, "use for treatment" is the main focus.
When used for preventive purposes, a doctor will make a judgment by considering the "level of risk" and "whether inhalation can be performed reliably."

Side effects and precautions

• Coughing, throat discomfort, hoarseness, etc.

• Those with underlying conditions such as asthma or COPD should be cautious, as the airways may be irritated, potentially worsening symptoms.

If you have trouble with inhalers, are wheezing, or are a small child with respiratory disease, other options like Tamiflu or Xofluza may be considered.

Relenza: A type that requires several days of inhalation

Relenza is also an inhalation type, but unlike Inavir, it must be taken for 5 days rather than just once.
It is used by setting a medication disk into a special device and inhaling the powder.

How to use for treatment (overview)

• Usually inhaled twice a day for 5 days

• Used with similar frequency for both children and adults

• Like other drugs, it must be started within 2 days of symptom onset

Since the inhalation procedure is a bit unique,

• Be sure to receive instructions from a pharmacist the first time

• If possible, practice inhaling on the spot

This will help prevent misuse.

How to use for prevention

While there are cases abroad where it has been used to prevent infection when a family member has influenza,
in Japan, it is my impression that Tamiflu or Xofluza are more often chosen for preventative purposes.

Therefore, it is best to consider 'prevention with Relenza' as a very limited case.

Side effects and precautions

• Throat irritation, cough, headache, dizziness

• For those with sensitive airways, such as those with bronchial asthma, there is a risk of breathing difficulties after inhalation.

Similar to Inavir, it is easy to visualize this as being intended for people who can inhale properly.
If there is a possibility that you cannot inhale, consult your doctor about switching to another medication.

Xofluza: A new type that you only take once

Xofluza is a relatively new type of anti-influenza medication that is a pill you take just once.
It is characterized by its ability to easily lower viral load quickly by stopping the influenza virus at a very early stage of replication.

How it is used in treatment (concept)

• Take a fixed dose just once, depending on your body weight

• As long as you do not forget to take it, the treatment itself is completed that day

• Start taking it within 2 days of the onset of symptoms

For people who are not confident about taking medication continuously or who are too busy to visit the clinic again, this can be a less burdensome option.

How it is used for prevention

Xofluza is approved for post-exposure prophylaxis when there is an influenza patient in the family.

• Family members living together

• People who spend a long time in the same room

These are potential candidates, but it does not mean that anyone can be prescribed it.

• Having underlying medical conditions

• Being elderly and at high risk of severe illness

• Having circumstances where you absolutely cannot afford to be bedridden

In situations like these, a doctor will weigh the benefits and risks to consider a prescription.

Side effects and precautions

• Gastrointestinal symptoms such as diarrhea, nausea, and headache

• Very rare cases of serious allergic reactions or skin disorders

Also, with Xofluza, "resistant viruses (viruses that are harder to treat)" can sometimes be an issue,

• children

• people with weakened immune systems

are considered to require particularly careful use. It is not a "cure-all just because it only takes one dose," but rather a medication chosen while balancing it against other options.

How should you choose between the four medications?

Here is a rough overview of how they compare.

• Tamiflu
  → The most standard option. It is an oral medication that is easy to use for a wide range of ages. It is used for both treatment and prevention.

• Inavir
  → Completed with a single inhalation. If you are able to perform the inhalation, it reduces the burden of taking medication.

• Relenza
  → A type that requires inhalation for 5 days. Suitable for those who are accustomed to using inhalers.

• Xofluza
  → An oral medication taken only once. It is an option for both treatment and household prevention, but caution is needed regarding resistance and the target age group.

When you are unsure,

• whether it is for a child or an adult

• whether you are good at taking oral medication or if you can manage an inhaler

• whether you have underlying conditions (asthma, heart disease, kidney function issues, etc.)

• whether there is anyone in the family at high risk of severe illness

if you can convey points like these during your consultation, it will be easier for the doctor to choose the most appropriate medication.

That is all for this article.
Thank you very much for reading this far.

If you felt this was "even a little helpful" or "would like to read more,"
supporting me with a like and a follow would be a great encouragement.

I will continue to share easy-to-understand "information you can use starting tomorrow" about hospitals and medicine,
so please check out my next article if you would like.

This article is intended for general information purposes as a practicing pharmacist and does not recommend any specific medication or treatment.
While the content of this article is based on the most accurate information available, we do not guarantee its completeness, accuracy, or currency.
Please take full responsibility for any actions or decisions you make based on the content of this article.
For specific consultations, diagnoses, or treatments regarding poor health or medication, please be sure to consult a medical professional such as a doctor or pharmacist.