NLM2 Neurotransmitters Flashcards
Name 2 drugs used in Parkinson’s and mode of action
Benztropine, hyoscine
Inhibits post synaptic muscarinic receptors
Name 2 drugs used in Alzheimer’s and action
Physostigmine, donepezil
Inhibits AChE so more in cleft
How is NA formed in the axon?
From tyrosine via dopamine-B-hydroxylase
What enzyme degrades NA in the post synaptic membrane?
COMT
How does amphetamine work?
Displaces NA and serotonin from vesicles so huge action potentials
What is mirtazapine?
Antidepressant, inhibits alpha2 receptor which is inhibitory
therefore more NA in cleft
What two antidepressants function like cocaine?
Imipramine, amitriptyline
How does cocaine work?
By inhibiting the reuptake of NA from cleft via inhibition of NET
How does lithium work and what is it?
Antidepressant, inhibits breakdown of NA and serotonin in axon by inhibition of MAO
How is serotonin (5HT) formed in the axon?
From tryptophan via l-aromatic acid decarboxylase
What are imipramine and amitriptaline + action?
Antidepressants that inhibit the reuptake of serotonin and NA from the synaptic cleft via inhibition of NET and SERT
How does LSD work?
Works on postsynaptic 5HT2 receptor
Causes hallucinations
What is ondansetron?
An antiemetic that works on postsynaptic 5HT3 receptor
What is dopamine formed from?
Tyrosine via DOPA decarboxylase
What breaks down dopamine in the synaptic cleft?
COMT
catechol-O-methyl transferase
Name 3 drugs used in Parkinson’s
Levodopa, selegiline, amantadine
What drug is used to treat pituitary tumours?
Bromocriptine
How does amantadine work?
Increases release of neurotransmitter into cleft
Treats Parkinson’s
How does levodopa work?
Increases production of dopamine in axon from tyrosine
Treats Parkinson’s
What is the main excitatory neurotransmitter?
Glutamate
How is glutamate broken down?
Transported into astrocyte by EAAT and broken down to glutamine by glutamine synthetase
What drug improves memory? How?
Cyclothiazide. Acts at NMDA receptors, increases glutamate’s effect
What alzheimer’s drug acts on NMDA glutamate receptors?
Memantine
What anaesthetic works a NMDA receptors?
Ketamine, suppresses action
What anti-epileptic drugs acts at NMDA glutamate receptors?
Felbamate and topiramate
What is Ketamine?
Anaesthetic that inhibits glutamate NMDA channels
What are felbamate and topiramate?
Anti-epileptic drugs that inhibit glutamate NMDA receptors
What is the main inhibitory neurotransmitter?
GABA
How is GABA formed?
From glutamate via glutamic acid decarboxylase
Which sedative drugs act on GABAa ion channels?
Benzodiazipines (eg temazepam and diazepam) Steroid anaesthetics (alphaxolone) and alcohol
What anti-epileptic drug acts on GABA transaminase to stop its breakdown?
Vigabatrin
ACh is the neurotransmitter involved in what?
Movement, memory, nausea and vomiting
NA and adrenaline are the neurotransmitters involved in what?
Mood, reward, pain and BP control
Serotonin is the neurotransmitter involved in what?
Mood, appetite, pain, nausea and vomiting
Dopamine is the neurotransmitter involved in what?
Reward, movement, nausea and vomiting
Glutamate is the neurotransmitter involved in what?
Movement, excitatory
GABA is the neurotransmitter involved in what?
Movement, inhibitory
How do antiepileptic drugs work?
Glutamate Na+ channel blockers or GABA enhancement
Name 4 antiepileptic glutamate Na+ blockers
Phenytoin, carbamazide, lamotrigine, valproate
What are the actions and problems of phenytoin?
Anti-epileptic drug with many side effects
Wide variation in rates of metabolism (cP450), CNS effects (double vision), gum hyperplasia, excessive hair growth and allergy
What is phenytoin given as?
Fosphenytoin
Describe uses and side effects of carbamazepine
Used for partial seizures and tonic-clonic seizures, little sedation at therapeutic dose
SE: P450 induction, rash, nausea, ADH-like activity, jaundice
What drug is first choice to treat petit mal seizures and myoclonic?
Valproate
What is used in status epilepticus?
IV Diazepam
Others include clonazepam and chlomethiazole
Describe uses and SE of lamotrigine
Used for tonic-clonic epilepsy
Rare SE: skin eruptions, toxic epidermal necrolysis and angioedema
Doesn’t affect P450 :)
Describe action and SE of phenobarbitone
Increases duration of GABAa channel opening
SE: Don’t use in petit-mal
P450 induction and causes sedation
Taken once daily
Name GABA related drugs
GABA agonists= clonezepam, diazepam (benzodiazepines)
gabapentin and pregabalin
How does valproate work?
Enhances GABA formation and inhibits GABA breakdown via transamination
Name the antiepileptic that inhibits GABA reuptake
Tiagabine
What is tiagabine?
Antiepileptic drug that inhibits GABA reuptake
What antiepileptic acts by hyperpolarising neurones?
Retigabine, potassium channel opener
Name the antiepileptic that acts by blocking calcium channels in neurones?
Ethosuximide
