Rimantadine (Oral)

Rimantadine is a drug used to prevent the flu infection in younger children and to treat certain flu infections in older patients.


The purpose of Rimantadine is to help prevent flu infection (Type A) in children aged 1 to 16. It is also used to treat or prevent certain flu infections (Type A) in adults who are aged 17 or above. It is worth pointing out that Rimantadine is strictly an antiviral that is effective in treating the above-mentioned flu, as it will not be effective in treating colds or other flu viruses.

You should not try to obtain Rimantadine on your own, as it is only given following a prescription from a doctor.

Conditions treated

  • Treat or prevent flu infections (Type A)

Type of medicine

  • Tablet
  • Syrup

Side effects

As with almost all drugs, taking Rimantadine does have the potential to cause any number of side effects to occur, or none at all. Directly below is a list of more serious side effects. If you experience any of them at any time, then notify your doctor immediately and seek medical attention.

Less common

  • Tightness in the chest
  • Laboured or difficult breathing
  • Wheezing
  • Shortness of breath

The following are a list of symptoms of having overdosed on Rimantadine. If they occur at all, then seek immediate medical assistance.

Symptoms of overdose

  • Feeling, seeing, or hearing things that are not there
  • Dry mouth
  • Fainting
  • Dizziness
  • Irregular heartbeats
  • Irritability
  • Lightheadedness
  • Nervousness
  • Anxiety
  • Shaking
  • Chest discomfort or pain
  • Irregular, fast, or slow heartbeat
  • Hyperventilation
  • Trouble sleeping
  • Rapid or pounding pulse
  • Restlessness

As well as these, there may also be some side effects you experience that don't require you to seek immediate medical help. You can find such a list of possible side effects directly below. If you do experience any of them and they are worrying you, then you can still contact your doctor. They may be able to advise on a way to counteract the effects or to alter your dosage so that you don't experience them.

Less common

  • Loss or lack of strength
  • Sour or acid stomach
  • Hearing loss
  • Stomach or abdominal pain
  • Headache
  • Belching
  • Continuing using or ringing or other unexplained noise in the ears
  • Heartburn
  • Unusual drowsiness sleepiness
  • Diarrhea
  • Difficulty concentrating
  • Impaired concentration
  • Trembling, unsteadiness, or other problems with coordination or muscle control
  • Unsteady or shakiness when walking
  • Vomiting
  • Indigestion
  • Unusual weakness or tiredness
  • Loss of appetite
  • Nausea
  • Rash
  • Stomach pain, upset, or discomfort

Though the above lists are extensive they are not necessarily complete. If you experience any other troubling side effects whilst taking Rimantadine, then notify your doctor as they may be able to suggest a way to resolve or lessen them.


Depending on a number of different things, your dosage of Rimantadine may differ greatly from somebody else's. Below you can find the average such dosages that would be prescribed. However, if you have been advised differently by your doctor, then do not alter how much or how frequently you are taking Rimantadine. Your exact prescription will depend on the dosage prescribed, the length you are supposed to be taking it for, and the exact nature of the condition it is combatting.

For treating the flu:

  • Adults aged 17 and above. 100mg to be taken twice a day for seven days.
  • Older adults. 100mg to be taken just once a day
  • Children aged up to 16 years old. Use of Rimantadine is not recommended.

For prevention of the flu:

  • Adults aged 17 and above. 100mg to be taken twice a day
  • Older adults. 100mg to be taken just once a day
  • Children aged 10 to 16 years old. 100mg to be taken twice a day
  • Children aged 1 to 9 years old. The exact dosage will be decided by your doctor, though is usually around 5 mg per kg of body weight, to be taken once a day. You should not receive more than 150 mg a day.
  • Children less than 1-year-old. Your doctor will decide the dosage.

If you miss a dose of Rimantadine, then take it as soon as you remember. However, if it is almost time for your next dose, then simply skip the missed one and carry on as normal. It is important you do not double dose.

If you are prescribed this in liquid form, then be sure to shake the medicine well before each use. You will have a specially marked spoon with which to measure out the necessary amount, so use this instead of any other household measuring object or spoon you have.

It is recommended that Rimantadine is taken before, or as soon as possible after a patient has been exposed to the flu.

To avoid getting the flu, it is recommended you carry out the full dosage term as prescribed by your doctor and don't miss any doses.

If you have the flu, but feel better after taking this drug, continue taking t for the full length as prescribed by your doctor. Failure to do this may cause the flu to return, and the benefit of taking Rimantadine wasted. Usually, you will need it take Rimantadine for at least five to seven days.

If you are taking two doses a day, then try and keep them evenly spaced at the same time each day. This will ensure there's an even dosage in your blood at all times and boost the benefits it can have.

If you have not yet had the flu shot, you should talk to your doctor about getting it.


Rimantadine has the potential to react with a wide number of different medicines. In some instances, such interactions must be avoided, though in others they aren't as troubling. Either way, be sure to make your doctor aware of all drugs you are currently taking, including prescriptions, non-prescriptions, herbal drugs, and supplements. They can advise you whether an interaction will occur and the appropriate means to avoid either one. If you go on any new drugs whilst taking Rimantadine, make your doctor aware that you are using this drug as they may need to alter one dose or the other.

It may also be that Rimantadine could interact with one aspect of your diet, including something you eat, drink or smoke. Your doctor can advise you whether your diet is suitable, or whether you may need to alter it somehow. Be upfront and honest with your doctor about exactly how much of certain things you consume.

Finally, there is the potential for Rimantadine to also interact with other medical conditions you currently have. Though you should make your doctor aware of your full medical history, be particularly clear in clarifying any of the below, as the interactions may be much more severe:

  • Severe kidney disease
  • A history of seizures or epilepsy
  • Severe liver disease (This will cause Rimantadine to be more slowly released from your body, and so heighten the effects it has)


As mentioned, Rimantadine is a drug that is strictly only obtained following a doctor's prescription. This is because they must first sit down and undertake a full inspection of your physical condition to see if it is appropriate. One thing they will need to look at and understand are any allergies you face. Such allergies are in regards to foods, dyes, animals, preservatives and, of course, other drugs. You should be honest with your doctor as there is a chance that Rimantadine could have unpleasant side effects on those facing certain allergies.

Any appropriate studies carried out in the usefulness of Rimantadine in pediatric patients have not shown any negative conclusions. However, no efficacy or safety have, as of writing, been established on Rimantadine and children younger than one year old. Your doctor is best placed to decide whether this is the appropriate drug for your child.

Similarly to geriatric patients, no studies to date have yet demonstrated any geriatric-specific problems with regards to Rimantadine. However, you must be aware that elderly patients do tend to be more susceptible to a number of the side effects, such as nausea, vomiting, stomach pain or dizziness. If you are elderly and experience any such effects at any time, then inform your doctor. They may be able to alter the dose or recommend other means to reduce the unwanted effects.

It is not clear as to the effects of Rimantadine on pregnant patients, as a lack of such studies have been carried out. Your doctor is most up-to-date with such tests and can come to an informed decision as to whether this is safe for you if pregnant. However, if you do fall pregnant at any time whilst taking this or other drugs, then inform your doctor immediately.

Similarly, if you are breastfeeding, then your doctor will need to make an informed decision. They will weigh the benefits against any potential risks it may bring.

Your doctor will likely schedule regular meetings whilst you are taking Rimantadine. Be sure to attend all of these so they can properly track your health and alter your dosage based on any side effects that may be occurring.

You should not attempt to drive, operate machinery or do anything else dangerous unless you are fully aware of how Rimantadine affects you. It can cause some people to become confused, dizzy, or develop difficulty concentrating. If you find such effects are occurring to you, then notify your doctor as they may be able to alter your prescription.

If your child is taking this medication and their condition starts to worsen, or at least does not get better after a few days, then notify your doctor.

Unless otherwise instructed by your prescribing doctor, do not have any other immunizations whilst you are taking Rimantadine. Similarly, once you stop taking Rimantadine, do not have any live virus vaccines. Finally, if you have received any other live vaccines within the last two weeks, then you should not be taking Rimantadine.

Unless you are told to do so by your doctor, do not start on any other medications or drugs whilst you are currently taking Rimantadine.


You should store your medication is a sealed container, in a space which is at room temperature and away from direct light, moisture or heat. You should avoid it becoming frozen, and should keep it safely away from children, as it can be harmful. Once you are finished on your prescription, or if you have any out-of-date medication, ask your doctor for the safest way to dispose of it. Usually, the oral liquid should be stored at room temperature for no more than 14 days.


If you are suffering from, or are trying to prevent yourself from getting the flu, then Rimantadine could be a very useful drug for you to take. However, do be aware that it is known to interact with a wide variety of drugs and foods, and can lead to potential side effects. For this reason, it is available by prescription only and you should never try and access it on your own.

Though you can find lots of advice here regarding dosages and best practices, you should follow any guidelines as laid out by your doctor. Do not attempt to alter them in any way based on what you have read here. If you are worried at all about the drug or have any disconcerting side effects, then do contact your doctor immediately. They can best advise you on any necessary alterations.


Last Reviewed:
January 31, 2018
Last Updated:
April 05, 2018