lithium, benzos, Z drugs Flashcards
GI SE lithium
N+V+D
nephrotoxic SE lithium
polyuria, diabetes insipidus
neuro SE lithium
fine tremor, idiopathic intracranial hypertension
endocrine SE lithium
hypothyroid // hyperparathyroid –> hypercalcaemia
ECG + FBC changes lithium
ECG = flattened T wave // leucocytosis (raised WBC)
therapeutic index lithium
v narrow
when should lithium samples be taken
12 hours post dose
how often do lithium levels need to be checked
starting or a change in dose = weekly until stable level, then every 3 months
how often does kidney + thyroid function need to be checked lithium
6 months
when does lithium toxicity occur
> 1.5 mmol/L
what can precipitate toxicity to lithium
dehydration // renal failure // meds
what meds can precipitate toxicity to lithium
diuretics (thiazides) // ACEi , ARBs // NSAIDs // metronidazole
symptoms lithium toxicity
coarse tremor (as opposed to fine) // hyprereflex // polyuria // confusion, seizure
mx lithium toxicity
mild = saline // severe = haemdialysis
mechanism benzo
enhance GABA (the inhibitory neurotransmittor) –> increased frequency of chloride channels
indication benzos
sedation // hypotic // anxiety // anticonvulsant // muscle relaxant
how long should benzos be prescribed for
2-4 weeks
how to withdraw benzos
switch to diazepam // reduce every 2-3 weeks by 2-2.5mg
symptoms of too quick withdrawal benzos
insomnia, irritable, anxious, tremor, tinnitus, perception altered, loss of appetite
mechanism of benzo vs barbiturates
benzos increase frequency chloride channel // barbiturates increase duration chloride channel
mechanism of Z drugs
V similar to benzo // act on a2 GABA subunit
indication Z drugs
mainly insomnia
examples Z drugs
zopiclone, zaleplon
