Clinical experience has long indicated that the drug amantadine can accelerate the waking-up phase for patients with brain damage, but this is the first time that researchers have scientific proof of the theory. The study is also beneficial for the patient’s relatives, who need reassurance and need to be able to communicate with the patient as soon as possible. (Photo: Colourbox)

Flu drug helps severely brain damaged patients recover

A drug used for treating influenza reduces the length of the waking-up phase for patients with severe brain damage.

Severe brain damage after a fall or road traffic accident is sometimes so traumatic that the patient does not regain consciousness properly in one to three months.

This situation is problematic because the patient’s chances for full recovery depend on the length of the awakening phase.

But an international study with Danish participation is bringing good news to such patients and their relatives. The study shows that amantadine, a drug used to treat influenza, can speed up the awakening process (see: Factbox).

“The study’s results indicate that, in time, the medical profession can help this patient group,” says Annette Mosbæk Nordenbo, a consultant at Glostrup Hospital’s Department of Highly Specialised Neuro-rehabilitation/Traumatic Brain Damage; she is the co-ordinator of the Danish research group.

The patients given amantadine showed no signs of side-effects compared with the placebo patients. This indicates that amantadine is a safe drug.

Annette Mosbæk Nordenbo

“Patients don’t wake up and say, ‘Hi!’ from one day to the next – that only happens in films. But the study’s results are important because a shorter wakening phase can improve the patient’s chances of getting better and quickly start rehabilitation.”

Trialled patients had difficulties in waking up

There were 184 patients from the USA, Germany and Denmark in the study’s trial.

They were all patients with very low levels of consciousness – they had not woken up properly within one to three months of severe, traumatic brain damage resulting from blows, a fall or a traffic accident.

The patients were either:

In the study, the researchers used different scales to measure the improvements in the patients’ level of consciousness:

Disability Rating Scale (DRS) is used objectively to assess patients’ degree of wakefulness, degree of consciousness and everyday abilities.

Coma Recovery Scale Revised (CRS-R) is a clinical measure made by a neuro-psychologist, building on the specialist’s professional assessments.

  • In a vegetative state – a condition where doctors believe patients are not conscious of themselves or where they are. At times, the patients can have open eyes and reflex-like movements, but they are not able to communicate or interact with their surroundings.


  • In a condition with minimal consciousness, where the conscious state varies. Sometimes they are able to follow simple orders, e.g. blink or lift an arm, but this does not happen every time.

All the patients were treated for four weeks, some with amantadine, while a control group was given a non-active placebo, after which the researchers observed them for two weeks.

Data from a total of 11 research groups were subsequently collated in a coordination centre, where objective staff, not connected with the study, assessed the results.

Patients on amantadine woke up sooner

The results showed that more patients who were given the placebo remained in the severest condition after four weeks compared with the patients given amantadine (31.6 percent and 18.6 percent respectively).

The placebo group also recovered without amantadine, but not nearly as quickly as the patients given amantadine.

Forty percent of the amantadine patients regained their ability to follow simple orders in the course of four weeks, while the figure for the placebo group was 32 percent.

The results also showed that the improvements reversed slightly for the patients during the two-week observation period. According to Nordenbo this strengthens the theory that the waking process is speeded up by amantadine.

No side effects

The results of the study also indicated that amantadine had no major side effects.

“The patients given amantadine showed no signs of side-effects compared with the placebo patients,” says Nordenbo. “This indicates that amantadine is a safe drug.”

Further studies

Previous pilot studies have suggested that amantadine speeds up the waking up phase, but this is the first time that a study has gathered sufficient data for researchers to draw a definite conclusion, says Nordenbo.

The researchers are still analysing the data, and the next step will be follow-up studies in which patients will be examined over a longer period.

“The studies could be expanded to include patients that are vegetative or with minimal consciousness for reasons other than injury following a fall or traffic accident,” says Nordenbo. “These are costly scientific studies, but now we have proof that makes it worthwhile carrying out further studies.”

Read this article in Danish at

Translated by: Michael de Laine

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