Amantadine

Benjamin Clanner-Engelshofen is a freelance writer in the medical department. He studied biochemistry and pharmacy in Munich and Cambridge / Boston (USA) and noticed early on that he particularly enjoyed the interface between medicine and science. That is why he went on to study human medicine.

More about the experts All content is checked by medical journalists.

The active ingredient amantadine is used to prevent and treat influenza and also to treat Parkinson's disease. The dosage is similar, but the mode of action is very different. Here you can read everything you need to know about amantadine, side effects and effects.

This is how amantadine works

The active ingredient amantadine can - in different ways - help with both flu and Parkinson's.

Flu (influenza)

The active ingredient amantadine is used against the so-called "real flu", although it is only effective against type A influenza viruses. Amantadine is not effective against type B influenza viruses.

Influenza viruses enter the body through droplet or smear infection via the mucous membranes. There they penetrate the cells, lose their shell (also known as “uncoating”) and multiply strongly by using the cell's own machinery of genetic reproduction. The new viruses are re-enveloped and released from the cell. In turn, they can attack body cells and force them to produce viruses.

The flu remedy amantadine prevents the “uncoating”, which means that the viruses get into the cell, but cannot get rid of their shell there. This means that no virus replication is possible. This gives the infected person's immune system the chance to bring the infection under control more quickly, which can shorten the acute phase of the disease.

Parkinson's disease

How amantadine can have a positive effect on Parkinson's disease is far less known than how it works in the flu. We know that the active ingredient affects several “messenger networks” in the brain. This is intended to alleviate the symptoms of the disease, above all tremors (tremor), muscle stiffness (rigor) and lack of movement / lack of movement (hypo- / akinesia).

The main effect of amantadine is the influence on the neurotransmitter dopamine. A lack of dopamine in certain areas of the brain is a major aspect of the disease. This deficiency is partially alleviated by amantadine by promoting the release of the messenger substance and inhibiting its re-uptake in the nerve cells (i.e. the inactivation).

Overall, however, the effectiveness of amantadine for the treatment of Parkinson's disease has not been clearly proven. The active ingredient is often used in addition to drug therapy with L-DOPA in Parkinson's patients at an advanced stage.

Amantadine uptake, breakdown and excretion

After ingestion, the active ingredient amantadine is quickly absorbed through the intestines into the bloodstream, where it reaches the highest levels after two to eight hours. After crossing the blood-brain barrier, the active ingredient enters the brain via the blood.

Amantadine is not metabolized in the body and is excreted in the urine. The excretion rate is age-dependent. On average, half of the active ingredient has left the body 15 hours after ingestion; in older patients this time is extended to about 30 hours.

When is amantadine used?

The areas of application of amantadine include:

• the prevention and treatment of virus flu type A

Amantadine is a long-term treatment for Parkinson's disease. To prevent influenza, the active ingredient is taken for up to three months; it is usually used for the acute treatment of influenza for ten days.

This is how amantadine is used

Amantadine is taken in the form of tablets once or twice a day, depending on the dosage. The tablet is taken with a glass of water in the morning and in the afternoon before 4 p.m.

For the prevention and treatment of the flu, adults are given 200 milligrams once a day or 100 milligrams twice a day of amantadine.

The intake to alleviate Parkinson's symptoms must be gradual, that is: It is started with a low dosage, which is then gradually increased until it is optimally effective. The therapy must also be ended gradually, i.e. gradually, as otherwise the symptoms being treated can suddenly worsen significantly.

What are the side effects of amantadine?

Taking amantadine can also result in adverse drug reactions (ADRs). One in ten to one hundred people treated experience side effects such as sleep disorders, restlessness, urinary retention and the skin disease "livedo reticularis" ("marbled skin").

Psychoses can develop particularly in older patients who are treated with other anti-Parkinsonian drugs in addition to amantadine.

Amantadine side effects such as nausea, dizziness, dry mouth, and low blood pressure when standing up from a sitting or lying position are found in 1 in 100 to 1,000 people.

What should be considered when taking amantadine?

The active ingredient amantadine influences the heart rhythm in a certain way - it causes a so-called QT time lengthening. In combination with other active ingredients that have this side effect, severe interactions in the form of cardiac arrhythmias can occur. Examples of such drugs are:

• Active ingredients against cardiac arrhythmias such as quinidine, procainamide, amiodarone
• Active ingredients against depression such as amitriptyline, citalopram, fluoxetine
• Antibiotics like erythromycin, clarithromycin, ciprofloxacin

There are other drugs that can cause QT prolongation. Anyone taking Amantadine should therefore always discuss any additional medication with their doctor or pharmacist.

Amantadine can be combined with other active ingredients to treat Parkinson's symptoms. However, dose adjustments may be necessary to avoid side effects.

Water tablets (diuretics) such as triamterene and hydrochlorothiazide (HCT) can interfere with the elimination of amantadine.This can lead to dangerously high levels of amantadine in the blood.

Alcohol should not be consumed during treatment, as amantadine can lower alcohol tolerance.

Animal studies have shown that amantadine may be harmful to the child during pregnancy. Since it also passes into breast milk, it should not be taken by either pregnant or breastfeeding women.

The active ingredient amantadine is approved for the treatment of children from five years of age and older patients (over 65 years of age). However, due to the lower body weight of the children and the mostly deteriorated kidney function in older patients, the dosage must be reduced in each case.

How to get medicines with amantadine

Preparations with the active ingredient amantadine require a prescription in every dosage.

How long has amantadine been known?

As early as the 1960s it was recognized that amantadine was effective against some flu viruses, whereupon it was approved for this purpose in the USA in 1966. Just three years later, a positive effect on Parkinson's symptoms was recognized, whereupon the approval was extended. There are now numerous generics with the active ingredient amantadine on the German market.

Tags:  digital health baby toddler skin