Intravenous drug administration, errors

The following data were obtained as the result of a review on drug error in anesthetic practice The rate of administration errors was 14%, only four of which were pre-errors. The most common errors were inadvertent arterial injection, subcutaneous injection due to tissued intravenous catheter and inadvertent intravenous injection when performing epidural and peripheral nerve blocks. The most common contributing factors cited were fault of technique (19%), haste (16%) and error of judgement (14%). In the same study, the most frequently cited factors to minimize the incident were prior experience or training (32%) and skilled assistance (11%) (18). 

The administration of a drug by a rapid intravenous injection places the drug in the circulatory system where it is distributed (see section 2.7.1) to all the accessible body compartments and tissues. The one compartment model (Figure 8.3(a)) of drug distribution assumes that the administration and distribution of the drug in the plasma and associated tissues is instantaneous. This does not happen in practice and is one of the possible sources of error when using this model to analyse experimental pharmacokinetic data. 

If the clearance is plasma drug concentration-dependent, and either intravenous exposure is limited by blood stream solubility or the drug has very low bioavailability, there could be an error in the estimation of absolute bioavailability. For more on these PK parameters, see Chapter 3. Additionally, extravascular and intravenous administrations are performed at two different time periods any changes of metabolism in the study subject may also affect the calculated absolute bioavailability. 

FIGURE 14.13 Mean urinary ( ), fecal (O), and total ( ) cumulative excretion (168h) of 14C-ixabepilone derived from eight patients after intravenous administration of 70mg (80 nCi) 14C-ixabepilone over 3 h. Error bars represents the standard deviation. (Adapted from Beumer, J.H. et al., Invest. New Drugs, 25, 327, 2007. With permission.)... 

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