Table 1.

Terms used by the four sources to phrase recommendations. The terms are not defined in any of the sources

Category	British National Formulary	Martindale	AHFS Drug Information 2004	Drug Prescribing in Renal Failure
Q: Quantitative recommendations:	Initial dose	Initial dose	Initial dose	Initial dose
	Maximal dose	Maximal dose	Maximal dose	Maximal dose
	Specific dose	Loading dose	Specific dose	Specific dose
		Specific dose
NQ: Non-quantitative recommendations:	Start with small doses	May require reduced doses	Reduced dosage may be considered
	Avoid or use small dose	Should be used with caution or in reduced doses	Adjust dosage carefully
	Reduce dose
	Use lowest effective dose	The dosage may need to be adjusted
	May need low/high doses
V: Avoid	Avoid	Avoid	Avoid	Avoid
	Avoid if possible	Do not give	Do not use
	Avoid routine use	Should not be used	Contraindicated
	Avoid or reduce dose	Considered by some contraindicated
C: Use with caution	Caution	Caution	Caution	Metabolites can accumulate
	Manufacturer - caution	Use with care	Manufacturer—caution
	Risk of adverse effects increased	Use with considerable care	Extreme caution
		Use with caution or not at all	Use with extreme caution if at all
			Monitor parameters
			Excessive adverse effects