how do drugs interfere with clinical laboratory testing course hero

by Casimer Weber 9 min read

Antibacterial agents are the drugs most likely to interfere with laboratory tests, with cephalosporins at the forefront. Cephalosporins can cause false positive results in urine glucose and urine ketone tests, as well as in the direct Coombs test (used to detect immune-mediated hemolytic anemia).

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Do drugs interfere with laboratory tests?

 · Antibacterials Antibacterial agents are the drugs most likely to interfere with laboratory tests, with cephalosporins at the forefront. Cephalosporins can cause false positive results in urine glucose and urine ketone tests, as well as in the direct Coombs test (used to detect immune-mediated hemolytic anemia).

What are drug/laboratory test interactions?

Clinical laboratory professionals are vital members of the health care team Up to 70% of physician decisions regarding patient diagnosis and therapy are based on lab test results Modern medicine could not function without clinical laboratory professionals INTRODUCTORY CLINICAL LABORATORY SCIENCE HLB 11103 Careers in healthcare • Although most ...

What is drug/laboratory test interference?

A total of 134 labels were positive, which indicated that the drug interferes with at least one clinical laboratory test. Antibacterial agents, psychotropic drugs and contrast media are the classes of drugs most likely to lead to DLTI. Urine was the clinical sample most frequently affected by DLTI.

Can over-the-counter drugs affect lab test results?

 · This review article describes drug–laboratory test interactions, in which medications can affect test results and impede diagnosis. Although the quality of studies varies, researchers identified a potential benefit of clinical decision support to inform ordering clinicians about these potential interactions.

What is DLTI in medical?

Drug-related laboratory test interference or drug/laboratory test interactions (DLTI) are a major source of laboratory errors. DLTI is of concern with regard to both the clinical diagnosis and the monitoring of patients.

What is the FDA label?

The FDA drug label is a source of information for studies of DLTI, although information is still lacking for most drugs, and additional improvements are needed for many of the existing records. Medical professionals, clinicians and laboratory staff should keep these possible interactions in mind when interpreting the results of laboratory tests, ...

How many lab tests are available?

Lab tests play a key role in clinical decision-making. More than 4000 lab tests are available, and an estimated 70% of clinical decisions are based on their results. Correct interpretation is critical.

Can rifampin cause false positives?

Interacting drugs can cause false-positive and false-negative results. For example, labetalol and ranitidine can cause a false-positive result for amphetamines, and rifampin can cause a false-positive result for opioids. False-positive results usually undergo more sensitive and specific testing. [ 4]

How does a CGM measure glucose?

CGMs measure glucose by converting glucose into an electronic signal, using glucose oxidase, which converts glucose to hydrogen peroxide. The hydroxyl group on acetaminophen is also oxidized at the CGM electrode, causing an error.

What is legal drug testing?

Drug testing for legal purposes primarily aims to detect illegal or banned drug use in a variety of situations. Sample collection procedures for this type of testing are strictly controlled and documented to maintain a legal "chain-of-custody.".

What is the purpose of a drug screen?

To screen for drug abuse, to monitor someone with a substance abuse problem, to monitor compliance with prescribed medications, or to detect and evaluate drug intoxication or overdose.

What is drug abuse testing?

Drugs of abuse testing is the detection of one or more illegal and/or prescribed substances in the urine, blood, saliva, hair, or sweat. Testing detects substances not normally found in the body, with the exception of some hormones and steroids measured as part of sports testing. Drug abuse testing usually involves an initial screening test ...

How long does marijuana stay in urine?

Marijuana and its metabolites, cannabinoids, may be detectable for several weeks. Methadone, barbiturates and benzodiazepines can be detected for about a week.

How long does it take for marijuana to be detected in urine?

Marijuana and its metabolites, cannabinoids, may be detectable for several weeks. Methadone, barbiturates and benzodiazepines can be detected for about a week.

How to collect urine and saliva?

Urine and saliva are collected in clean containers. A blood sample is obtained by inserting a needle into a vein in the arm. Hair is cut close to the scalp to collect a sample. A sweat sample is typically collected by applying a patch to the skin for a specified period of time.

Can a drug test result be false?

A concern for anyone undergoing drug testing is the possibility of a false positive result. Initial screening drugs tests may infrequently result in false positive results, although confirmatory (GC-MS) testing greatly lessens the chances of a false positive - reducing the risk to close to zero.

When is drug testing done?

Drug testing is often done when applying for employment, especially for positions that may involve federal transportation, airline industries and pilots, bus drivers, trucker drivers, railways, hospitals, and other workplaces where public safety is of the utmost importance.

What is the purpose of drug testing?

Drug testing is the evaluation of urine, blood or another type of biological sample to determine if the subject has been using the drug or drugs in question. There are many circumstances that may require drug testing:

What is post accident drug testing?

Post-accident drug testing - a vehicular or on-the-job accident which may have involved human error and resulted in casualties or property damage. Safety-related drug testing - if an employee's job could lead to safety issues if judgement or physical ability were impaired.

How much does drug abuse cost the US economy?

The Surgeon General, as reported by NIDA, states that alcohol and drug abuse, including tobacco, costs the economy over $740 billion per year. Costs are related to crime, lost work productivity and health care.

What is a preemployment drug test?

A pre-employment drug test is primarily limited to drugs with the potential for abuse, including some prescription drugs, and alcohol. In addition, sports drug testing may be required for college-level, professional and Olympic athletes. Illegal recreational drugs, performance-enhancing drugs such as. anabolic steroids.

Do you have to give a urine sample for a drug test?

Pre-employment workplace drug testing usually requires the applicant to give a urine sample, but may also infrequently require blood, saliva, sweat, or hair. In certain jobs, especially those that require a high level of safety, employees may be subject to random drug testing, as well.

Why is gas chromatography used for drug testing?

Because drugs tend to be small-molecule structures, gas-chromatography-MS ( GC-MS) serves as confirmation both for alcohol level and for most drugs. “There is still an advantage in terms of comfort level compared with liquid chromatography–based methods,” says Lisa Thomas, senior director for vertical marketing for clinical and forensic toxicology at Thermo Fisher Scientific (Sunnyvale, CA). Thomas describes GC-MS as the “Swiss army knife” of forensics, because in addition to drug testing it serves investigations of arson, explosives, and seized drugs, as well as the characterization of common substances such as inks.

What is GC-MS in forensics?

Thomas describes GC-MS as the “Swiss army knife” of forensics, because in addition to drug testing it serves investigations of arson, explosives, and seized drugs, as well as the characterization of common substances such as inks.

What is a drug test in the workplace?

Workplace drug-testing programs are designed to detect the presence of alcohol, illicit drugs, or certain prescription drugs. Drug testing is a prevention and deterrent method that is often part of a comprehensive drug-free ...

What is an MRO in drug testing?

Ensuring the accuracy of drug-testing results is critical. Using an HHS-certified laboratory to test the specimens and a Medical Review Officer (MRO) to interpret the test results will help prevent inaccurate testing. MROs are licensed physicians who receive laboratory results and have knowledge of substance use disorders and federal drug-testing regulations. MROs are trained to interpret and evaluate test results together with the employee’s medical history and other relevant information.

What is a drug test?

Drug testing is a prevention and deterrent method that is often part of a comprehensive drug-free workplace program. Both federal and non-federal workplaces may have drug testing programs in place. Any workplace drug-testing program should comply with applicable local, state, and federal laws. Learn more about questions to ask when determining ...

Can you test for alcohol and other drug use?

You can test your employees for alcohol and other drug use as part of an annual physical examination. Be sure to inform employees that drug-testing will be part of the exam. Failure to provide prior notification is a violation of the employee's constitutional rights.

What drugs are tested for in a urine test?

Tests are commonly used for five categories of drugs: Amphetamines. Cocaine.

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