Workplace drug testing, different matrices different objectives.

Drug testing is used by employers to detect drug use by employees or job candidates. It can identify recent use of alcohol, prescription drugs, and illicit drugs as a screening tool for potential health and safety and performance issues. Urine is the most commonly used sample for illicit drugs. It detects the use of a drug within the last few days and as such is evidence of recent use; but a positive test does not necessarily mean that the individual was impaired at the time of the test. Abstention from use for three days will often produce a negative test result. Analysis of hair provides a much longer window of detection, typically 1 to 3 months. Hence the likelihood of a falsely negative test using hair is very much less than with a urine test. Conversely, a negative hair test is a substantially stronger indicator of a non-drug user than a negative urine test. Oral fluid (saliva) is also easy to collect. Drugs remain in oral fluid for a similar time as in blood. The method is a good way of detecting current use and is more likely to reflect current impairment. It offers promise as a test in post-accident, for cause, and on-duty situations. Studies have shown that within the same industrial settings, hair testing can detect twice as many drug users as urine testing.

Doses-carga de carbamazepina e difenil-hidantoína: utilizaçäo em pacientes de alto risco / Carbamazepine and phenytoin loading-doses: utilization in high-risk patients

Doses-carga de difenil-hidantoína (1000mg) e carbamazepina (600mg) foram administradas oralmente a respectivamente 10 e 6 pacientes com crises epilépticas secundárias a doença aguda neurológica ou síndrome de abstinência alcoólica. No grupo da difenil-hidantoína a idade variou de 12 a 73 anos e as concentraçöes séricas 2, 4, 6, 8, 12 e 18 horas após a administraçäo foram 7,6, 8,8 8,7, 7,2 e 6,5 micrograma/ml (média). Näo foram anotados efeitos colaterais importantes por um método quantitativo. No grupo da carbamazepina a idade variou de 25 a 56 anos e as concentraçöes séricas nas mesmas horas foram 3,9, 5,3 6,5, 7,5 7,4 e 8,2 micrograma/ml. Efeitos colaterais foram discretos. Näo foi necessária medicaçäo suplementar durante as 24 horas após a administraçäo das doses-carga. Embora ambos os esquemas tenham controlado a situaçäo clínica sem efeitos colaterais relevantes, as concentraçöes séricas foram sub-terapêuticas no caso da difenil-hidantoína. Sugerimos que a dose-carga ideal de difenil-hidantoína é 1500mg. A dose-carga de carbamazepina foi eficaz e produziu níveis séricos terapêuticos. A estabilidade dos níveis séricos durante o período de estudo torna este esquema útil no controle subagudo de crises epilépticas frequentes, no tratamento de manutençäo de estado de mal epiléptico e na síndrome de retirada alcoólica