awaiting revascularisation in whom Rx will be < 3 months duration, or,
long term Rx in pt who is unsuitable or unwilling to have revascularisation.
need to measure plasma levels:
Rx range:
0.15-0.6mg/L - adequate for most
0.6-1.2mg/L - for those not responding to above dose range
Toxicity:
> 1.2mg/L ⇒ hepatotoxicity, peripheral neuropathy (if chronic high levels)
adverse effects in Rx range:
60% have some dose dependent adverse effects but most are mild:
dizziness, nausea during loading phase
diabetics may develop hypoglycaemia in 1st few days Rx
relative C/I's:
liver disease
peripheral nerve disease
~10% popn are slow metabolisers of perhexilene & require very low maintenance doses (eg. 50-100mg once weekly).
these pts can be idientified by relatively high plasma concentrations after the initial week's Rx together with absence of detectable circulating metabolite
administration:
200mg orally bd for 3 days, then,
200mg daily after taking a blood sample
further dose adjustments at monthly intervals should be based on plasma levels
usual maintenance dose: 100-400mg daily aiming for plasma level 0.15-0.6mg/L