Drug Investigation

Module details

Title

Drug Investigation

Type

Specialist

Module code

SLS125

Credits

10

Requirement

Compulsory

Aim of this module

This module will provide the trainee with the knowledge and understanding of basic pharmacology and the mechanism of action of drugs. They will understand pharmacokinetics, pharmacogenomics and the criteria for valid therapeutic drug monitoring (TDM). They will optimise the use of commonly prescribed therapeutic drugs. They will be able to investigate the poisoned patient; screen for and confirm the presence of drugs of abuse. In the work-based module they will be expected to apply this knowledge as they learn to perform assays to assess therapeutic and toxic drugs using a range of methods and gain experience of the interpretation of results in a range of acute and chronic clinical conditions.

Competencies

#	Learning outcome	Competency	Action
# 1	Learning outcome 1,2	Competency Perform the analyses to laboratory standard operating procedures for the following drugs: digoxin and other cardioactive drugs lithium anticonvulsants theophylline ciclosporin and other immunosuppressive drugs.	Action View
# 2	Learning outcome 1,3,4	Competency Perform the analyses to laboratory standard operating procedures for drugs of abuse testing, including: screening protocols confirmation tests.	Action View
# 3	Learning outcome 1,3,5	Competency Perform the analyses to laboratory standard operating procedures for drugs/toxins commonly found in overdose: salicylates paracetamol ethanol carbon monoxide.	Action View
# 4	Learning outcome 1,3,5	Competency Assist with two of the following analyses (following observation of a practitioner performing the relevant analysis): toxic metals (Al, Fe, Hg, Pb) ethanol ethylene glycol, methanol and related alcohols paraquat organophosphorus insecticides or nerve agents.	Action View
# 5	Learning outcome 6	Competency Assist with at least one of the following pharmacogenetic assays (following observation of performance by practitioner): cholinesterase variants TPMT CYP variability in drug metabolism Acetylation.	Action View
# 6	Learning outcome 1	Competency Perform review of internal quality control (IQC) and external quality assessment (EQA) performance of a range of TDM and other drug assays.	Action View
# 7	Learning outcome 2,3,4,5,6	Competency Identify cases that require urgent intervention and offer clinical advice on the follow-up and/or further management of the patient.	Action View
# 8	Learning outcome 2,3,4,5,6	Competency Interpret biochemical and toxicological data in light of the clinical details.	Action View
# 9	Learning outcome 2,3,4,5,6	Competency Draft written reports on investigations.	Action View

Assessments

You must complete:

• 2 case-based discussion(s)
• 2 of the following DOPS/ OCEs:

Perform calibration and quality control of an automated analyser assay for a therapeutic drug	DOPS
Perform screening tests for drugs of abuse	DOPS
Refer drugs of abuse samples which test positive for confirmatory testing	DOPS
Perform confirmatory testing for drugs of abuse samples	DOPS
Select the sample type and preanalytical requirements and undertake the measurement of digoxin	DOPS
Select the sample type and preanalytical requirements and undertake the measurement of an immunosuppressives drug	DOPS
Select the sample type and preanalytical requirements and undertake the measurement of an antibiotic.	DOPS
Identify refer and report toxicology samples which require urgent analysis at an external laboratory	DOPS
Interpret an External Quality Assurance Report for an anticonvulsant	DOPS
Interpret an External Quality Assurance Report for an immunosuppressant drug	DOPS
Interpret an External Quality Assurance Report for an antibiotic	DOPS
Perform a paracetamol assay	DOPS
Perform an ethanol assay	DOPS
Discuss an abnormal paracetamol result and the therapeutic intervention with a healthcare professional	OCE

Learning outcomes

1. Perform a range of laboratory techniques used in the workplace to monitor therapeutic drug concentrations.
2. Interpret the results of commonly used therapeutic drug monitoring (TDM) assays in the correct clinical context.
3. Perform a range of laboratory and point-of-care techniques to investigate drugs of abuse and other toxic substances in cases of acute poisoning, and understand the clinical context in which such techniques can be useful.
4. Decide the testing strategy for the investigation of patients taking drugs of abuse in the correct clinical and legal context.
5. Decide the testing strategy for the investigation of the poisoned patient in the correct clinical and forensic context.
6. Perform a range of pharmacogenetic tests.
7. Interpret and report the results of analyses of drug abuse, poisons and pharmacogenetic tests in the correct clinical or forensic context.

Learning outcomes

1. Explain the fundamental principles of pharmacokinetics.
2. Discuss the fate of foreign compounds in the human body and the biochemical basis of their desired and undesired actions.
3. Identify the appropriate sampling time and sample type for a range of therapeutically monitored drugs.
4. Describe the design, operation and performance of appropriate analytical methods for the detection and/or estimation of drugs or poisons.
5. Describe the major toxicity mechanisms in the human and explain the investigation of a suspected drug poisoning and related clinical conditions.
6. Describe and justify the medicolegal status of laboratory samples, including chain of custody principles.
7. Discuss and utilise information on liver and renal function, plus genetic information in the clinical interpretation of drug results.
8. Explain analytical sensitivity and specificity in the context of drug investigation.
9. Describe the partnership of biochemical drug investigation with other clinical specialisms in drug investigation and patient care.

Indicative content

• Basic pharmacology, mechanism of action of drugs, drug metabolism
• Pharmacokinetics: half-life, dosage prediction
• Pharmacogenomics
• Therapeutic drug monitoring: digoxin, lithium, antiepileptics, theophylline, methotrexate, immunosuppressive drugs, antibiotics
• Metabolic effects of ethanol; alcohol excess
• Overdose: salicylate, paracetamol, barbiturate, tricyclic antidepressants
• Drug addiction: alcohol, opiates, amphetamines, benzodiazepines, cocaine, cannabis
• Poisoning: carbon monoxide, lead, mercury, aluminium, iron, paraquat, ethylene glycol, methanol and other organic alcohols, organophosphates
• Laboratory investigation of the unconscious or deceased poisoned patient
• Laboratory methods for the measurement of therapeutic and toxic drugs from screening to confirmation

Activities

• Investigate the role of drug testing in a variety of clinical situations, the importance of correct sampling and the use and validity of target ranges. Report on your review and discuss the benefits and implications in terms of service delivery and patient care.
• Review and report on the importance of medico-legal considerations in the field of drug testing.
• Observe and discuss the preparation of reports, the reporting process for patients undertaking a variety of drug analyses and record case overviews observed. Discuss with your trainer/supervisor and identify the key learning points for your future practice.
• Undertake activities that involve the partnership of Clinical Biochemistry with other clinical specialisms in drug investigation. Review and report on the range of multidisciplinary working required to address issues of drug/poison investigations.
• Visit clinics and other health units at which patients receiving therapeutic drugs and patients abusing drugs are monitored. Report on your visits in terms of both service delivery and patient experience. Examples could include the following:
  • transplantation team
  • pharmacy
  • accident & emergency
  • local community drugs of abuse clinic
  • psychiatry
• Attend a clinical unit where POCT for drug analysis is performed. Discuss the method(s) with trained users.