• Ask yourself if the result is likely to affect patient management
• Appropriate indications
  
  • assist dose adjustment for optimal serum concentrations
  • confirm suspected toxicity
  • monitor effect of drug/drug or drug/disease interactions
  • investigate treatment failure
  • investigate suspected non-adherence

Advice

• Contact your ward’s clinical pharmacist or medicines information with 
  
  • details of the dose regimen, sample time and assay
  • patient's clinical details and drug treatment 
• For advice on optimal use of antimicrobial agents, contact microbiologist

• Unless toxicity suspected, assays usually little value until regular dosing with a steady state
  
  • usually 4-5 half-lives after treatment began or dose was last altered

• Check appropriate forms and tubes on intranet
• Send all samples in tube appropriate for assay required
• Provide the following details
  
  • dose, frequency and duration of treatment with drug
  • time of last dose
  • any impaired organ function (e.g. renal impairment, liver disease, cardiac failure)
  • potentially interacting drugs (see individual drugs and BNF Appendix 1) including dose, frequency and duration of co-prescription 

• Consult local pathology laboratory and/or contact appropriate specialist 

Microbiology

• Gentamicin see Gentamicin guideline
• Vancomycin see Vancomycin guideline