Urinary cannabinoids in monitoring abstinence in a drug abuse treatment program.

Urine specimens from 162 adolescents entering a drug treatment program were tested for cannabinoids using a photometric immunoassay (EMITst) and thin-layer chromatography (TLC). The EMITst has a cutoff point of detection 25 ng/mL or less of 9-carboxy-tetrahydrocannabinol. When reported as positive, both tests appeared to be reliable. There were two false-positive EMITst results and three false-positive TLC results in the 67 urine specimens that did not contain cannabinoids. When reported as negative, however, the EMITst with its 100 ng/mL cutoff failed to detect almost 40% of all cannabinoid-positive specimens. Of the 65 chronic marijuana smokers in the present study who stated that they had smoked within two days of their admission into the treatment facility, 17 (26%) went undetected by the 100 ng/mL cutoff used by the EMITst method. In clinical settings such as drug treatment programs, tests for urinary cannabinoids should use a detection threshold at 20 ng/mL or less.

Drug testing programs.

Many Federal agencies and private companies are conducting drug tests on job applicants and employees. Although the reasons for testing and the circumstances under which testing is conducted vary considerably, the main intent of these programs is to provide a drug-free environment for other employees and a safe service to the public. The programs that have been most successful usually include a clear communication to all employees and applicants as to the nature of the drug program and the consequences of detected drug use. Also, successful programs usually afford employees some type of assistance and a second chance. Finally, it is essential for successful programs to provide a reasonable and fair approach that includes procedures for due process, that is, a line of review and appeal.

Development of assays for drugs of abuse.

The treatment and prevention of drug abuse has required the development of assays for biological markers to assess an individual's adherence to a treatment regimen or to the prescribed abstinence of drug use. Generally, this requires assays sensitive enough to detect a few nanograms of a particular metabolite per milliliter of urine. Most frequently, the identify of the drug or combination of drugs is not known. This placed a large responsibility on the development of reliable methods. To accomplish this mission, the National Institute on Drug Abuse funded a multiyear, multiple-contract program. This program included the synthesis of reference drugs, their metabolites, and labeled derivatives; the development of several new analytical methods, especially using gas chromatography/mass spectrometry and immunoassay techniques; the establishment of analytical service facilities; animal and human pharmacokinetic studies; and laboratory proficiency testing. Many of the assays are now commercially available and widely used. Assay development requires the consideration of a number of factors, namely, specificity, sensitivity, time, simplicity, and cost. These factors are illustrated in a number of examples.

Evaluation of immunoassays for cannabinoids in urine.

A comparison was made of several cannabinoid urine assays. Two hundred randomly selected urine specimens were initially screened by two enzyme immunoassays (EMIT-st and EMIT-d.a.u.) and a radioimmunoassay (Abuscreen RIA). Selected specimens found positive by any of these methods were further analyzed by gas-liquid chromatography with flame ionization detection (GLC/FID), gas chromatography/mass spectrometry (GC/MS), and an experimental RIA from Research Triangle Institute (RTI RIA). The GLC/FID method gave confirmations in 69 to 92% of the samples, depending on the method used and the cut-off employed. GC/MS confirmed 98% of the EMIT and RIA positives using a low cut-off (20 ng/mL). All RIA positives at 100 ng/mL were confirmed by GC/MS. There was complete agreement between the RTI RIA and the EMIT assays, but not with the Abuscreen RIA at the 100 ng/mL cut-off. The study illustrates that care must be exercised in establishing assay cut-offs and the designation of false positive results.

Inhibition of morphine analgesia by ascorbate.

Oral administration of single doses of ascorbate produced a decrease in the analgesic effect of morphine in mice when assayed by the tail-flick test. Inhibition of analgesia was dose dependent, had a rapid onset (2 hr) and long duration (48 hr). Ascorbate doses over 8 mg/kg also protected mice from lethal doses of morphine. These findings are in accord with recent reports that ascorbate destroys opioid receptor in vitro and indicates that a similar effect occurs in vivo.

Structure-activity studies on narcotic antagonists. 2. N-substituted ethyl 3-(m- or p-hydroxyphenyl) nipecotates.

A number of N-substituted ethyl 3-(n- or p-hydroxyphenyl)nipecotates were synthesized to evaluate the role of a m- or p-hydroxy substituted beta-phenethylamine moiety in narcotic antagonist action. Ethyl m- or p-methoxy-phenylcyanoacetate was alkylated with 1-bromo-3-chloropropane. The resultant chloronitriles were hydrogenated (Raney Ni) to amines and cyclized to yield the N-substituted ethyl 3-(m- or p-methoxyphenyl)nipecotates. These were N-benzylated, O-demethylated using BBr3, N-debenzylated, and then N-alkylated. The following N-substituted derivatives were prepared: methyl, allyl, cyclopropylmethyl, and n-propyl. No significant morphine-like analgesic activity was found in mice by the tail-flick method. The acetic writhing assay showed several compounds to possess analgesic activity. N-n-Propyl and N-(cyclopropylmethyl) m-hydroxy derivatives were marginally active antagonists by the mouse tail-flick method. Surprisingly, the N-methyl m-hydroxy derivative, 11m, was found to be an antagonist.

Piperidine derivatives: synthesis of potential analgesics in 3-substituted 4-phenylpiperidine series.

The syntheses of 1-methyl-3-(3-hydroxy-3-phenylpropyl)-4-phenyl-4-piperidinol and 1-methyl-3(3-hydroxy-3-phenylpropyl)-4-phenyl-4-propanoyloxypiperidine are described. Preliminary pharmacological testing showed these compounds to be weakly active in the writhing test.