Toxic urine screen, urine toxicology screen
This is a urine test to screen for a class of medicines called benzodiazepines. Benzodiazepines are central nervous system depressants. They are used to sedate patients, help them sleep, prevent seizures, ease anxiety, and relax muscle spasms. These medicines are often informally called tranquilizers, sleeping pills, and muscle relaxants.
Variations in the molecules of different benzodiazepines give each medicine specific chemical properties and medical uses.
Examples of common antianxiety medicines, muscle relaxants, and antiseizure medicines include:
Examples of common sedative-hypnotic medicines include:
In addition to medical use, benzodiazepines are sometimes used illegally. Chronic abuse of benzodiazepines can lead to addiction, and combining these medicines with other depressants like alcohol can be fatal. Street names for these medicines include "downers," "benzos," "nerve pills," "candy," and "tranks."
Even if you have been prescribed these medicines, you may need this test if you are showing signs of an overdose. Symptoms of overdose include confusion, slurred speech, loss of muscular coordination, stupor, and unconsciousness. Benzodiazepines can also cause low blood pressure, slow or shallow breathing, and cardiac arrest.
You may also have this test if a healthcare provider suspects you are abusing these medicines or using them illegally.
If you appear confused, cannot be roused, have seizures, or lose muscle control, you may also have this test as part of an overall urine toxicology screen to check for other commonly abused drugs. These screens vary at different hospitals, but often include tests for cocaine, opioids, amphetamines, barbiturates, benzodiazepines, and phencyclidine.
If you are conscious, able to talk with healthcare providers, and willing to cooperate, you can provide information that helps providers figure out the best test for your case. For example, if you are a victim of sexual assault, you may have this test to find out whether someone slipped a benzodiazepine date rape drug, such as Rohypnol ("roofie"), into your drink.
You might also be tested if providers think you have taken benzodiazepines accidentally or in a suicide attempt.
If you seem to have an altered mental state, healthcare providers will most likely give you a glucose test to check your blood sugar. If you are brought to a hospital showing symptoms of central nervous system depression, such as confusion, slurred speech, seizure, or coma, you may be tested for a variety of drugs, including benzodiazepines.
A benzodiazepine overdose alone is unlikely to cause coma or severe heart or lung function problems. If you have those symptoms, a healthcare provider may screen for other drugs and test for causes of central nervous system depression that are not drug-related.
In addition to ordering a urine test, a healthcare provider may also order a blood test for benzodiazepines. In some cases, it may be more practical to take a blood sample than a urine sample. Blood tests are also harder for a patient to alter to hide drug abuse.
Exactly which lab tests you have depends on your physical exam and information about your condition that you are willing and able to provide.
Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your health care provider.
A typical benzodiazepine urine test can detect benzodiazepines or their break-down products, called metabolites. But this is a very complex test.
A positive test result means that the test found the medicine's metabolite in your urine at the time the urine sample was taken. The amount found is called the threshold concentration. This means there was enough metabolite to measure. It does not mean the amount was enough to show you are actively using the medicine--or "under the influence." The time it takes for a substance to show up in the urine varies by medicine. It can show up within minutes of taking the medicine, and it can last for days.
The presence of benzodiazepines varies a lot by each medicine's half-life. Half-life means the amount of time it takes for half of the medicine to be eliminated from the body. Diazepam (Valium), for example, can be found for weeks after the last dose.
Although most benzodiazepines show up in standard urine tests, some don't. Alprazolam (Xanax), clonazepam (Klonopin), temazepam (Restoril), and triazolam (Halcion) may not be found in many of the common tests. Many benzodiazepine tests can find whether the medicine is present, but can't give the amount.
Different benzodiazepines have different therapeutic doses, ranging from 0.5 to 50 milligrams (mg). Overdoses of 10 of 20 times the prescribed dose of some benzodiazepines can result in a mild coma, but usually don't cause slow or shallow breathing. Most people recover.
Overdoses of fast-acting benzodiazepines like triazolam (Halcion) are more likely to cause breathing problems and even death.
A medicine called flumazenil (Romazicon) may be used as an antidote to the sedative effects of benzodiazepines. it shouldn't be used in people who have been taking benzodiazepines over a long period to control seizures. In such cases, flumazenil could cause potentially fatal withdrawal.
This test requires a urine sample. Follow your healthcare provider's instructions for collecting and storing the sample. In some cases, you may have to provide a sample in the presence of a lab employee.
This test poses no known risks.
Some other medicines can cause a false positive result in benzodiazepine urine tests. These drugs include:
You do not need to prepare for this test. But be sure the lab technician and your healthcare provider know all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don’t need a prescription and any illicit drugs you may use.