Neurology Flashcards
Dopaminergics
Name
Levodopa (co-careldopa), pramipexol
Dopaminergics
Mechanism of Action
Levodopa crosses BBB, increasing D in nigrostriatial PW which link substantia nigra to corpus striatum to increased BG inhibition of thalamus to reverse cortical bradykinesia/rigidity
Dopaminergics
Indications
Early parkinson’s, 2^ parkinsonism
Dopaminergics
Contraindications
Pre-existing cognitive/psych conditions, CVD
Dopaminergics
Side effects
Nausea, sedation, hallucination, hypotension, on-off-effect, wearing off effect, dry mouth, anorexia
Dopaminergics
Interactions
Needed with carbidopa - prevent extra-cranial conversion via dopa-decarboxylase
Avoid antipsychotics and metoclopramide - both oppose effect
Anticonvulsants
Name
Phenytoin, carbamazepine, sodium valrpoate, lamotrigine, levitaracetam
Phenytoin
MoA
Reduces neuroexcitability, inhbits spread of seizure activity via Na channel inhibition (causes side effects in heart)
Phenytoin
Indications
Status epilepticus (after benzo), increase seizure threshold
Phenytoin
Contraindications
Zero order liver kinetics, low TPI, in-utero abnx req high dose folic acid
Phenytoin
Side effects
Sedation, cognition change, thick skin, acne, hirsutism, thick gums, haem disorders, osteomalacia, CV collapse, respiratory depression
Phenytoin
Interactions
CYP450 inducer
Reduces: warfarin, oestrogens), also metabolised by CYP450 so inhibitors increase effect (amiodarone, diltiazem, fluconazole)
Carbamazepine
MoA
Inhibits Na channels to reduce neuroexcitability, increases refractory period
Carbamazepine
Indications
Epilepsy, bipolar, trigeminal neuralgia
Carbamazepine
Contraindications
In utero NTDs/cardio/urinary abnx, if pt has had anti-epileptic hypersensitivity syndrome (SJS, TEN)
Carbamazepine
Side effects
GI, neuro (dizzy, ataxia, sedation, diplopia), fever, lymphadenopathy, oedema, hyponatraemia (ADH-like), leucopenia/agranulocytosis
Carbamazepine
Interactions
CYP450 inducer also metabolised by CYP450
Sodium Valproate
MoA
Weakly inhibits Na, stabilises resting membrane potentials, increases GABA
Sodium Valproate
Indications
Epilepsy, bipolar
Sodium valproate
Contraindications
Child-bearing women, conception/T1, foetal abnx in utero
Sodium valproate
Side effects
Gi, neuropsych (tremor, ataxia, behaviour change), low platelets, hairloss/curlier,
Sodium valproate
Interactions
Inhibits CYP450, metabolised by CYP450
Lamotrigine
Summary
MoA - affect many neuronal channels
I - Tonic-clonic dirst line, given with other anti-seizure drugs
C/I - pancytopenia, meningitis
S/E - dizzy, somnolence, headache, N&V rash
Int - CYP breakdown, inducers decrease conc
Levitaracetam
Summary
MoA - slows abnormal impulses I - epilepsy C/I - hypersensitivity S/E - cough, loss of appetite, GI, tired, vomiting Int - paracetamol (acetaminophens)
