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Clinical Toxicology Testing

Clinical toxicology testing is used to identify and measure drugs or chemicals in human blood specimens in order to guide patient care. This includes testing for drugs of abuse and other chemicals.

Quantitative toxicology testing
Acetaminophen, Salicylate, Ethanol, Iron overdose

Volatile Analysis (Methanol, Acetone, Isopropanol, Ethylene Glycol)
For more information see Volatile Screen

Drugs of Abuse (DOA) testing
DOA testing may be performed to determine compliance with drug rehabilitation programs or to detect drugs of abuse in patients presenting to the hospital. DOA testing is typically performed by immunoassay screening either alone or in combination with more definitive testing such as gas chromatography-mass spectrometry (GC-MS) and/or liquid chromatography-tandem mass spectrometry (LC-MS/MS).
DOA testing is performed in urine which usually contains drug metabolites. This allows for a longer detection windows for the drug as metabolites are present at higher concentrations and longer times than the parent drugs. However, periods of detection are only estimates and depend on the individual user's dose, frequency of the dose, metabolism and elimination.
At CLS DOA testing is performed by immunoassay (qualitative screen) and LC-MS/MS (qualitative, confirmation):

Immunoassay Screen
Immunoassay for DOA testing allows for rapid screening of urine specimens. They are often reported by a drug class (e.g. Amphetamines, opiates, benzodiazepines, barbiturates); however, some are available for a single drug (methadone, oxycodone). The drugs detected by the method used at CLS are shown below. Note: Fentanyl is not detected by the Opiates immunoassay.

 Amphetamines: Reported as a class  Amphetamine
 Methylenedioxyamphetamine (MDA)
 Methylenedioxymethamphetamine (MDMA)
 Barbiturates: Reported as a class  Amobarbital
 Benzodiazepines: Reported as a class   Alprazolam
 Opiates: Reported as a class  Codeine
 Cocaine Metabolites   

Immunoassay results are reported as Presumptive Positive or Negative according to the assay’s established cut-off value. Presumptive positive results indicate that the immunoassay result is above the cut-off and can be caused by the presence of the drug of abuse in the sample or by another drug with a similar structure that cross reacts. Because the immunoassay cannot distinguish between these two scenarios, any positive result is reported as Presumptive Positive. Confirmatory testing is not routinely performed on immunoassay orders.  Negative results reflect concentrations that fall below the cut off and do not necessarily exclude the presence of the drug or metabolite. Adulteration of the urine sample may cause erroneous results.

Two immunoassay screens are available at CLS:

  1. Urine drug screen, STAT (Mnemonic UDS) Includes: barbiturates, benzodiazepines, cocaine metabolite, cannabinoids, opiates and amphetamines. This test is restricted to acute care sites.

  2. Urine drug screen, Routine (Mnemonic UDSR) Includes: barbiturates, benzodiazepines, cocaine metabolite, cannabinoids, opiates, amphetamines, oxycodone, and methadone metabolite.

Mass spectrometry
Mass spectrometry based techniques can detect and differentiate drugs, even within the same class. Although gas chromatography-mass spectrometry (GC-MS) has been used for DOA testing for many years, it is being replaced by liquid chromatography-tandem mass spectrometry (LC-MS/MS), now considered the gold standard.

LC-MS/MS is used for all confirmatory testing at CLS. The drugs include amphetamine, methamphetamine, MDMA, MDA, morphine, codeine, norcodeine, hydrocodone, hydromorphone, fentanyl, norfentanyl, oxycodone, noroxycodone, oxymorphone, heroin, 6-monoacetylmorphine, methadone, EDDP, cocaine, benzoylecgonine, cocaethylene and ∆9-tetrahydrocannabinol (THC).

GC-MS is available to acute care patients only. Requests for GC-MS analysis of specimens from other locations require approval from a clinical biochemist. See below for a list of drugs that are detectable by our GC-MS method.


Full drug screen, Urine (FDSU) – Specimens undergo an immunoassay screen. Presumptive positive opiate or amphetamine screens are automatically reflexed to LC-MS/MS for confirmation. Any other requests for confirmation must be approved by the laboratory director.

All DOA testing performed by CLS is intended for medical purposes (i.e. treatment) only. If drug testing is required for a non-clinical reason (eg. test required by an employer), contact the Lab Information Centre at 403-770-3600.

DOA test requests from Patient Service Centres and Extra-Regional Laboratories are analyzed by the CLS Analytical Toxicology Laboratory.

For further detailed information, see
Characteristics of the Urine Drug Screening Tests used by Calgary Laboratory Services.

Following is a list of drugs, which can be identified by GC-MS at CLS. This list is not all inclusive.Please note that our method is highly selective and optimized for neutral and basic drugs.

 Abacavir  Fentanyl  Oxymetazoline
 Acetaminophen  Fenfluramine  Paroxetine
 Allocryptopine  Fluconazole  Pentazocine
 Amantadine  Flunitrazepam  Pentobarbital
 Amitriptyline  Fluoxetine  Pentoxyphylline
 Amobarbital  Flurazepam  Perphanizine
 Amoxapine  Fluvoxamine  Pethidine
 Amephetamine  Gabapentin  Phencyclidine
 Atomoxetine  Glutethimide  Pheniramine
 Anileridine  Guaifenesin  Phenobarbital
 Articaine  Haloperidol  Phentermine
 Atracurium  Heroin  Phenylpropanolamine
 Atropine  Hydrocodone  Phenytoin
 Benzocaine  Hydrocortisone  Prednisolone
 Benzoylecgonine  Hydromorphone  Primidone
 Benztropine  Hydroxyzine  Procainamide
 Benzydamine  Ibuprofen  Procaine
 Benzylpiperazine  Imipramine  Prochlorperazine
 Biperiden  Irbesartan  Procyclidine
 Bromazepam  Ketamine  Promethazine
 Brompheniramine  Lamotrigine  Propofol
 Bupivacaine  Levamisole  Propoxyphene
 Bupropion  Levetiracetam  Propranolol
 Buspirone  Lidocaine  Psilocin
 Butacaine  Loratidine  Pseudoephedrine
 Butalbital  Lorazepam  Pyrilamine
 Butorphanol  Loxapine  Quetiapine
 Caffeine  Maprotiline  Quinapril
 Canrenone  MDA  Quinidine
 Carbamazepine  MDEA  Quinine
 Carisoprodol  MDMA  Ramipril
 Chlorcyclizine  Meclizine  Ranitidine
 Chlordiazepoxide  Melatonin  Rofecoxib
 Chlorpheniramine  Memantine  Ropivacaine
 Chlorophenylpiperazine  Meperidine  Scopolamine
 Chloroquine  Mepivacaine  Secobarbital
 Chlorpromazine  Meprobamate  Seroquel
 Citalopram  Methadone  Sertraline
 Clindamycin  Methamphetamine  Sildenafil
 Clobazam  Methaqualone  Spironolactone
 Clomipramine  Methocarbamol  Starnoc
 Clonazepam  Methotrimeprazine  Strychnine
 Clonidine  Methylphenidate  Sumatriptan
 Clozapine  Methyprylon  Temazepam
 Cocaethylene  Metoclopramide  TFMPP
 Cocaine  Metoprolol  Thebaine
 Codeine  Metronidazole  Theophylline
 Cotinine  Midazolam  Thiopental
 Cyclobenzaprine  Mirtazepine  Thioridazine
 Desethylchloroquine  Moclobemide  Thymol
 Desipramine  Modafinil  Ticlopidine
 Desvenlafaxine  6-Monoacetylmorphine  Topiramate
 Dextromethorphan  Morphine  Tramadol
 Diacetylmorphine  Naloxone  Tranylcypromine
 Diazepam  Naltrexone  Trazodone
 Diclofenac  Naproxen  Triamterene
 Diethylpropion  Naratriptan  Triazolam
 Diltiazem  Nefazodone  Trifluoperazine
 Diphenhydramine  Nevirapine  Trihexyphenidyl
 Dilantin  Nicotine  Trimeprazine
 Disopyramide  Nitrazepam  Trimethoprim
 Doxepin  Nizatidine  Trimipramine
 Doxylamine  Nordiazepam  Tripelennamine
 Duloxetine  Nortriptyline  Tripolidine
 Ecgonine methyl ester  Olanzapine  Venlafaxine
 EDDP  Ondansetron  Verapamil
 Emetine  Orphenadrine  Xylometazoline
 Enalapril  Oxazepam  Yohimbine
 Ephedrine/Pseudoephedrine  Oxprenolol  Zaleplon
 Erythromycin  Oxybenzone  Zimelidine
 Ethosuximide  Oxycarbazepine  Zolpidem
 Eugenol  Oxycodone  Zopiclone