Toxicology screens often do not result in information that affects acute treatment but may be valuable in building a case of abuse or neglect and for the determination of ongoing emotional, social, or psychiatric treatment needs. These tests should be considered in children/adolescents with unexplained neurological signs or symptoms or if there is a symptom complex strongly suggestive of a particular toxidrome. A toxicology screen usually consists of urine, blood, and/or gastric contents.
When ordering a toxicology screen, be aware of what the healthcare facility/lab includes on the general screen. Order specialized testing as needed. If there is suspicion of a particular drug ingestion and testing is available for that drug, order that specific drug level. For example, if there is a suspicion of alcohol ingestion, order an alcohol level.
Do not delay treatment while awaiting results. Emergent treatment of a poisoning can usually be guided by the history and physical.
Toxicology Screening in Newborns
Most drugs of high abuse potential tend to cross the placenta and affect the fetus. Detection of drug-exposed newborns requires a high index of suspicion. Inquiry regarding maternal drug use should be a part of the obstetric and newborn evaluations because it is estimated that as many as 10% of all newborns, maybe higher in some urban regions, are exposed to drugs of abuse in utero.
Illicit prenatal drug use should be suspected in the following situations:
Maternal history of sexually transmitted diseases
History of multiple abortions, both spontaneous and elective, and unexplained fetal demise
Late or inadequate prenatal care
History of chaotic living arrangements, such as shelters or homeless
Precipitous labor and delivery and/or placental abruption
Maternal cerebrovascular accidents or myocardial infarctions
Atypical vascular incidents in the otherwise healthy full-term newborn, such as cerebrovascular accidents, myocardial infarction, and necrotizing enterocolitis
Neonatal signs and symptoms consistent with drug exposure or withdrawal
Newborn urine or meconium can be used for screening. Meconium drug testing is more likely to identify infants of drug-abusing mothers than is infant urine testing, but laboratory availability of this test is variable. Urine screening of the newborn will have a high false negative rate because only results for infants with recent exposure will be positive. A positive toxicology screen confirms the diagnosis, but a negative test does not the rule out the possibility of drug use.
No clinical signs should be attributed solely to drug withdrawal without appropriate assessment and diagnostic tests to rule out other causes, including central nervous system irritability as the result of infectious or metabolic disorders, such as hypoglycemia and hypocalcemia.
The American Academy of Pediatrics Committee on Drugs Policy Statement: Neonatal drug withdrawal. Pediatrics June 6, 1988; 101(6):1079-1088 provides further information on intrauterine drug exposure and the subsequent effects on the newborn, such as neonatal narcotic abstinence syndrome, as well as a neonatal drug withdrawal scoring system. See
http://pediatrics.aappublications.org/content/101/6/1079.full.pdf+html .
The following table gives an estimate of expected positive urine tests for mothers who have ingested specific drugs. In general, urine screens in a newborn reflect recent ingestion by the mother, although some drugs are present for longer periods.
Club Drugs
Club drugs refer to a wide variety of potentially dangerous substances being used by young people at fraternities, dance clubs, bars, and all-night dance parties (rave dances). Commonly used drugs include Gamma Hydroxybutyrate (GHB), Flunitrazepam (Rohypnol), and alcohol. Rohypnol and GHB can incapacitate a victim and prevent him or her from resisting sexual assault.
Rohypnol, also called "roofies," is manufactured in tablet form and can be easily crushed and dissolved in liquid. It is tasteless and odorless and can be slipped into a drink without the person knowing it. A single dose of Rohypnol as small as 1 mg. can produce effects for 8 to 12 hours after ingestion. It enhances the effects of alcohol by decreasing inhibition and causing sleepiness and memory loss. Recipients are left open to suggestions, physically weak, and without memory of events that transpire after the drug takes effect. This has made prosecution of "roofie-rape" cases challenging. For example, people report waking up naked and alone in strange hotel rooms without any idea of how they got there and who was involved.
GHB is also known as Grievous Bodily Harm, G, Liquid Ecstasy, and Georgia Home Boy. It is usually abused either for its intoxicating/sedative/euphoria properties or for its growth hormone- releasing effects, which can build muscles. GHB is a central nervous system depressant that can relax or sedate the body. At higher doses it can slow breathing and heart rate to dangerous levels. Overdose of GHB can occur quickly, and the signs are similar to those of other sedatives: drowsiness, nausea, vomiting, headache, loss of consciousness, loss of reflexes, impaired breathing, and ultimately death.
Rohypnol can be detected in urine for up to 72 hours after ingestion. However, the sooner someone is tested, the better. GHB is usually cleared within 6 to 12 hours. The New York State Drug Facilitated Sexual Assault Kit was developed specifically to test the blood and urine of victims suspected of unwittingly ingesting these drugs. A resource for this kit can be found at:
https://www.templateroller.com/template/2151701/new-york-state-sexual-offense-and-drug-facilitated-sexual-assault-evidence-collection-kits-order-form-new-york.html . For more information about these drugs, see www.streetdrugs.org .
