Drugs Treating Cognitive Symptoms
- Cholinesterase Inhibitors
Cholinesterase inhibitors are drugs which can lessen the cognitive symptoms of Alzheimer’s disease for some people. They may improve memory and thinking for a time. They work by increasing the levels of a brain chemical that is important for memory called acetylcholine. Three cholinesterase inhibitors (donepezil, galantamine and rivastigmine) are available for use by people with a diagnosis of Alzheimer’s disease.
Memantine (meh-MAN-teen) is a different drug that works on a brain chemical called glutamate that is present in high levels when someone has Alzheimer’s disease. This drug can help improve thinking and daily functions for a time. Memantine is currently available for use by people with moderately severe Alzheimer’s disease.
Treating the Accompanying Symptoms of Dementia
People with dementia often experience behavioural and psychological symptoms which can be very distressing. These may include depression, anxiety, sleeplessness, hallucinations, ideas of persecution, agitation and aggression. These symptoms may respond to reassurance, a change in the environment or removal of the source of any distress such as pain. It is important to determine the causes or triggers of behavioural disturbances and deal with these. Medication should be used as a last resort, but is sometimes necessary.
Antipsychotics are drugs used to treat severe psychotic symptoms including delusions or hallucinations. In dementia, they may also be used to treat agitation or aggression. The newer antipsychotics such as risperidone and olanzapine have fewer side effects and are more commonly used. Antipsychotics will not always be helpful, and may be associated with an increased risk of stroke. If an antipsychotic drug is used, it is important to regularly and carefully monitor the person.
Symptoms of depression are extremely common in people with dementia. Significant depression should be treated as it can make cognitive problems worse and diminish the person’s quality of life. Depression can usually be effectively treated with antidepressant drugs, but care must be taken to ensure that this is done with a minimum of side effects.
Anxiety, panic attacks and unreasonable fearfulness can be distressing for a person with dementia, their family and carers. Mild symptoms are often helped by reassurance, adjustments to the environment or an improved daily routine. More severe and persistent anxiety is often related to underlying depression and will usually improve with antidepressants. Antipsychotics and another group of drugs called benzodiazapines are sometimes used to treat anxiety, but both should usually be avoided as a treatment for anxiety in people with dementia.
- Drugs for treating sleep disturbance
Persistent waking at night and night time wandering can cause a lot of difficulties. Some drugs commonly prescribed for dementia can cause sedation during the day, leading to an inability to sleep at night. Increased stimulation during the day can reduce the need for sleep inducing medications at night. Medication to treat sleep disturbance should be a last resort, as people may become dependent on these and withdrawal of the medication may be followed by rebound sleeplessness and anxiety.
Points to Remember
- All drugs can have side effects, some of which may make the person’s symptoms worse
- Always ask the doctor why the drug is being prescribed and what side effects might occur
- A drug which is useful may not continue to be effective indefinitely because of the progressive changes to the brain caused by dementia
- Do not expect immediate results. Benefits may take several weeks to appear particularly with antidepressants. Discuss this with the doctor.
- It is important that treatment is reviewed regularly
- Keep a record of all medications, including alternative medications and vitamin supplements. Take this record to all medical appointments.
- Many people with dementia take a number of medications for different symptoms. It is important to discuss with the doctor any impact that medications may have on each other.