neuropharmacology Flashcards
what are primary issues that determine the success of treatment? give examples
• Primary issues – related directly to the disease and its pathology
o Understanding of the pathophysiology of the disease
o Choice of the correct treatment target
what are secondary issues that determine the success of treatment? give examples
• Secondary issues – related directly to the therapeutic regime
o Ensure that drugs reach the target
o Minimise the adverse effects
o Manage any potential drug-resistance
why is it difficult for a disease to be clearly associated with a specific CNS region?
neurological diseases have a much higher level of complexity and involved interconnected circuits.
what is the target of therapeutics?
well-defined entity
what questions are important to ask when looking at CNS diseases?
- Is it possible to identify the CNS structure?
- What is the best target for a disease?
- Can we make drugs to affect the target?
- Will the drugs reach the target?
- Do patients always respond to treatment?
what are the symptoms of parkinson’s?
• Tremor, slow movement, rigidity, slurred speech, affected gait
is parkinson’s reversible?
no
what causes parkinson’s?
• Loss of a specific group of cells (known as substantia nigra –> midbrain, role in reward and movement) in the brain which produce dopamine
deficit in dopamine at the level of receptor
what is the substantia nigra?
group of cells in the midbrain which have a role in reward and movement
what is parkinsonism?
any condition that causes a combination of the movement abnormalities seen in Parkinson’s disease (an umbrella term for any symptoms related to Parkinson’s).
how is dopamine synthesised?
tyrosine –> L-Dopa –> Dopamine
what catalyses the formation of L-Dopa –> Dopamine?
L-aromatic amino acid
what type of chemical is dopamine?
monoamine neurotransmitter
why does supplementing dopamine not work as a treatment for parkinsons?
dopamine doesnt reach the brain after peripheral administration
Systemic oral administration of L-Dopa leads to conversion into dopamine outside the brain
what does conversion of L-Dopa outside the brain lead to?
can trigger intense vomiting, triggered by peripheral formation of dopamine
how is parkinsons treated and how does this work?
L-Dopa combined with an inhibitor of the enzyme L-aromatic amino acid decarboxylase (which doesn’t have access to the brain) L-Dopa is converted into dopamine only in the brain, protected in the periphery.
Another solution is to stimulate dopamine receptors directly with dopamine receptor agonists
what is an agonist?
a compound that stimulates receptors directly
what is schizophrenia?
a significant cognitive disruption
what are symptoms of schizophrenia?
hallucinations, delusions, paranoid behaviour, disruption of social contact, withdrawal from friends and family
what causes schizophrenia?
result of hyperactivity in the ventral striatum which leads to an increased release of dopamine and increased stimulation of receptors
what is the ventral striatum?
major portion of the basal ganglia: functions as reward system
what are the treatment options for schizophrenia?
• Dopamine receptor antagonists (known as antipsychotic or neuroleptic drugs) - these drugs block dopamine receptors
what is another name for dopamine receptor antagonists?
antipsychotics or neuroleptics
why can antipsychotics cause adverse effects?
they block other receptors due to lack of specificity
