Table 5.

Examples of potential clinical consequences of phenoconversion

	Examples of potential consequences of phenoconversion
Phenoconversion of CYP isoform	Increased toxicity of parent drug and/or decreased effect of the prodrugs
CYP2C9	Increased sensitivity to warfarin
	Phenytoin-induced neurotoxicity
	Candesartan-induced hypotension
	Decreased efficacy of losartan?
	Sulphonylurea-induced hypoglycaemia?
CYP2C19	Decreased therapeutic effect of clopidogrel
	Diminished antimyeloma efficacy of thalidomide
	Decreased likelihood of antiviral response to nelfinavir
CYP2D6	Decreased analgesic effect from codeine, tramadol and oxycodone
	Perhexiline-induced toxicity (e.g. neuropathy)
	Decreased therapeutic effect of tamoxifen
	Extrapyramidal symptoms from perphenazine
	Increased β-blockade from metoprolol
	Increased risk of dizziness from carvedilol

[Compiled from literature review.]