Neurological Flashcards
Which pharmacological intervention is used to intervene in an ischaemic stroke?
Thrombolytic therapy aka clotbusters
What does alteplase do?
Acts on fibrin in thrombus, reperfuses occluded vessels in approximately 90 minutes in most patients
Alteplase indication
Acute myocardial infarction and acute ischemic stroke withing 4.5 hours of onset of symptoms
What causes Parkinson’s Disease?
Destruction of the dopaminergic neuronal cells in the basal ganglia of the CNS
What are extrapyramidal effects?
Involuntary movements that you cannot control
When dopamine levels drop which neurotransmitters increase?
Acetylcholine
What are the three classes of drugs used to treat PD?
Medications that raise brain dopamine levels or stimulate dopamine receptors
Medications with central anticholinergic activity
Other medications as adjuncts for symptomatic relief (anti-inflammatory, decongestants, laxatives, antipsychotics)
What medication is the precursor to dopamine which is the first line treatment for PD?
Levodopa
What medication makes sure that levodopa isn’t converted to dopamine in the periphery?
Carbidopa
Which two enzymes convert dopamine?
MAO-B and COMT
How does Selegiline work?
It inhibits the conversion of dopamine by MAO-B leaving more available for the receptors
How does entacapone work?
It inhibits the conversion of dopamine by COMT leaving more available for the receptors
What the side effects of Selegiline?
Nausea, vomiting, dizziness. Inform patients to use caution if using heavy machinery
How do apomorphine and rotigotine work?
They mimic the actions of dopamine as well as stimulate dopamine receptors
When the dopaminergic system deteriorates, which system predominates and causes PD symptoms?
Cholinergic
Which drugs treat PD symptoms of muscle rigidity and tremor directly?
Anticholiergics
How does Benztropine work?
It’s an anticholinergic that blocks central cholinergic pathways and restores balance between dopamine and acetylcholine
What’s the other name for antiepileptics?
Anticonvulsants
How do antiepileptics work?
By inhibiting ionic channels (sodium, calcium) involved in the excitation of the neuron by either enhancing GABA mediated inhibition or by blocking excitatory transmissions
What are the common side effects of antiepileptics?
Excessive sedation, ataxia (abnormal, uncoordinated movements), confusion
What does GABA do?
It’s a neurotransmitter that decreases excitability in the brain
How do benzos treat epilepsy?
They act at the same site as GABA and facilitates its binding, causing decreased brain activity
What are the four ascending stages of analgesia?
Analgesia, Delirium, Surgical, Medullary paralysis
What’s the mechanism of action of General anaesthesia?
They act on the ion channels in the nerve membrane in the central nervous system. They act on GABA receptors which when open, causes a chloride influx into the nerve cell
What is Propofol?
Intravenous anaesthetic with a short half life. Patient resumes consciousness within 10 minutes
How does Ketamine work?
It antagonises NMDA receptors which causes dissociative anaesthesia where not all parts of the brain are depressed and muscle tone and respiration remain normal
How does local anaesthetic work?
Inhibits movement of sodium through the channels in the plasma membranes of a neuron, hence inhibiting the transmission of a nerve impulse
