Cerebral Activators (Cognition Enhancers)
While the use of CNS stimulants has declined due to non-specific nature of their actions, a new class of drugs called ‘Cerebral Activators’ has been introduced. It is claimed that these drugs improve the brain functions particularly in dementia – a condition of brain characterized by loss of intellect and memory, and may have a role in the treatment of Alzheimer’s disease. However their use is limited and the claims regarding their efficacy are not always fully substantiated.
Piracetam (Normabrain, Neurocetam, Nootropil)
This drug is supposed to directly improve the efficiency of the higher functions of the brain such as learning, memory, thought, and consciousness, both in normal and deficient situations. It does not have a sedative or psychostimulant effect. These changes are brought about by increase in nerve-to-nerve message activity and energy supply to nerve or those parts of brain which are involved in learning and memory. It variably improves brain function in senile dementia and mental retardation in children. The drug should be taken with caution in kidney or liver disease, and during pregnancy.
Dosage: The recommended dose for adults is 800 mg, three times a day and for children, it is 50 mg/kg of body weight in 3 divided doses.
This improves disturbed cerebral metabolism and activates glucose metabolism. It also improves cerebral micro-circulation. It has been tried in cerebro-vascular accidents, disturbed cerebral development in children and adolescents, in post-anaesthetic recovery, and alcohol withdrawal state. Its efficacy is doubtfu1.The prescribed dose is 200 mg, three times a day for 6 to 8 weeks.
Adverse Effects: It may cause disturbances, increased excitability, loss of appetite, headache, tiredness, nausea, vomiting, and diarrhoea.
Other drugs of this group are dihydroergotoxine which is used in loss of memory, nimodipine which is useful in subarchnoid haemorrhage, nicergoline (SERMION), glutamic acid and piribedil.
Ginkocer (Ginkocer, Bilovas)
This is a dried extract of Ginkgo biloba. Besides bringing about some action like piracetam and pyritinol, the drug causes inhibition of the platelet-activating factor. It has been tried in the treatment of multi-infarct dementia (repeated minor strokes lead to dementia) because it improves blood supply in small brain vessels in the stroke area.
Alzheimer’s disease is a condition that occurs when there is a breakdown in the brain, in particular when there is a loss of communication among brain cells. Clear communication among brain cells is vital for the brain to function properly. If brain’s networking capabilities deteriorate, cognitive skills (ability to think, reason and remember) are affected or lost.
This drug increases levels of a chemical (Acetylcholine) which is needed for nerve to nerve message transfer in the brain. It has strown improvement of brain function in Alzheimer’s disease. Cognition, apathy, delusions and hallucinations improve with its use. Its usual doses is 1.5 to 3 mg twice a day.
It also improves cognitive functions by increasing acetylcholine levels in remaining nerves in the brains of Alzheimer’s patient. It has a longer duration of action, so it is given once in 5 to 10 mg daily at night.
Other drugs tried are Tacrine, galantamine and antioxidant vitamins (vitamin E, C). Interestingly, Ibuprofen a pain reliever has been shown to slow the course of disease. A new class of pain relievers (COX-2 inhibitors) are also being evaluated to treat this otherwise incurable disease.