Neurological Drugs Flashcards
why isn’t dopamine itself a suitable treatment for Parkinson’s disease
it doesn’t cross the blood brain barrier
Levodopa is a precursor, which can enter via membrane transporter
what is the wearing off effect of L-Dopa
towards the end of dosage interval, symptoms seem to worsen
what is always prescribed alongside levodopa
Carbidopa, prevents conversion of levodopa to dopamine outside of the brain, reducing nausea
how does phenytoin work?
binds to neural Na+ channels in their inactive state, reducing excitability
has similar effects on cardiac Purkinje fibres
which neurological drugs are contraindicated in pregnancy due to foetal abnormality?
Phenytoin Carbamazepine Sodium Valproate Lamotrigine Levetiracetam
what are some side effects of phenytoin
long term use can cause change in appearance - acne, hirsutism, gum growth
dose related cerebellar toxicity
overdose can be lethal
what effect do anti-convulsant drugs have on CyP450 enzymes?
enzyme inducer
reduces plasma concentrations and efficacy of drugs metabolised by this system
how do carbamazepine and sodium valproate work?
Inhibit neuronal sodium channels, inhibits seizure spread
Valproate is a weaker inhibitor
indications for carbamazepine
1st line for focal seizures, primary generalised seizures
trigeminal neuralgia
bipolar disorder
indications for sodium valproate
Epilepsy - 1st line for generalised and absence seizures
bipolar disorder
how does lamotrigine work?
inhibits sodium channels
enhances action of GABA
suppresses glutamate release
inhibits serotonin reuptake
how does Levetiracetam work?
inhibits presynaptic calcium channels
impedes impulse conduction along synapses
indications for levetiracetam
partial, myoclonic, tonic clonic seizures
status epilepticus
Tourette’s, Alzheimer’s
