Laboratory monitoring of OxyContin (oxycodone): clinical pitfalls

Some patients have headaches that are refractory to standard treatments, and they require chronic administration of opioid analgesics. The use of opioids in a clinical setting must be closely monitored due to the medications' potential for addiction, abuse, and fatal interactions. Limited access to opioids and the demand for them outside the clinical setting leads to another danger. Patients can mislead their providers into prescribing opioids, intending to sell the medications instead of using them to alleviate their own pain. For protection of the patient, as well as the community, it is vital that such activity be prevented. We recently encountered a patient we suspected of abusing or misusing OxyContin (oxycodone). In order to determine whether the patient was taking the medication as prescribed, we ordered a urine-based immunoassay drug screen. The results were negative; the patient appeared to not have oxycodone in his system. Based on these results, we dismissed the patient from our practice. At the patient's request, a second test was performed, this time using gas chromatography-mass spectrometry. It indicated that the patient did indeed have sufficiently high levels of oxycodone in the urine. The minimum level threshold was too high to detect the presence of oxycodone in the immunoassay. We would like to help prevent future misunderstandings such as we experienced. To do so, we will first present the case of our patient, followed by a discussion of the actions taken. Finally, we will provide an overview of analgesic monitoring systems.     

Isolation of the gene and hypothalamic cDNA for the common precursor of gonadotropin-releasing hormone and prolactin release-inhibiting factor in human and rat.

Cloned cDNAs encoding the precursor protein for gonadotropin-releasing hormone (Gn-RH) and prolactin release-inhibiting factor (PIF) were isolated from libraries derived from human and rat hypothalamic mRNA. Nucleotide sequence analyses predict precursor proteins of 92 amino acids for both species and show identity between the human placental and human hypothalamic precursor proteins. Whereas the Gn-RH peptide structure is completely conserved in human and rat, the PIF domain of the precursor displays 70% interspecies homology. Genomic analyses revealed the presence of a single Gn-RH-PIF gene in human and rat containing sequences corresponding to the cDNA distributed across four exons.     

Cataract formation after initial trabeculectomy in young patients

OBJECTIVE: To evaluate the risk of cataract formation in young patients after initial trabeculectomy. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Thirty-four eyes from 27 patients undergoing initial trabeculectomy at the Glaucoma Consultation Service, Massachusetts Eye and Ear Infirmary (mean age, 43.7 years; range, 12-54 years). INTERVENTION: Follow-up averaged 42.6 months (range, 11-90 months). METHODS: Lens status was observed before surgery and at 3 months; 6 months; and 1, 2, 3, 4, 5, and 6 years after initial trabeculectomy. MAIN OUTCOME MEASURE: The main outcome measure was defined as cataract extraction for visually significant lenticular opacifications that developed after trabeculectomy. RESULTS: The rate of cataract extraction after initial trabeculectomy was 24% (n = 8). The average time from trabeculectomy to cataract extraction was 26 months (range, 5-58 months). Progression of lenticular opacities occurred throughout the follow-up period. There was no increased rate of cataract formation in subjects with uveitic and steroid-induced glaucoma when compared with all other types of glaucoma. In the patients with both eyes in the study, the first eye was a predictor of cataract progression in the fellow eye. CONCLUSIONS: Cataract is a common complication after trabeculectomy in young patients. The 24% rate of cataract extraction after trabeculectomy reported in this study is a significant risk of which young patients contemplating surgery should be aware.     

Typhlitis in childhood cancer

BACKGROUND: Typhlitis is increasingly recognized in children undergoing chemotherapy but is poorly characterized. The authors investigated the demographic, clinical, and imaging (ultrasonography and computed tomography [CT] scans) variables related to the diagnosis, risk, and outcome of typhlitis. METHODS: The authors reviewed the records of patients who had typhlitis (bowel wall thickness > or = 0.3 cm plus clinical findings) during treatment at St. Jude Children's Research Hospital (Memphis, TN) between 1990 and 2001. They assessed whether duration of typhlitis was related to bowel wall thickness, extent of colonic involvement, ascites, demographics, primary diagnosis, symptoms of typhlitis, or duration of neutropenia. To identify risk factors for typhlitis, the authors compared the demographic data and previous drug therapy of 78 patients who had typhlitis and 1231 identically treated children who did not. RESULTS: Of 3171 children, 83 (2.6%) developed typhlitis. Frequent symptoms were abdominal pain (91%), fever (84%), abdominal tenderness (82%), and diarrhea (72%). Twelve percent of the patients were not neutropenic. Duration of typhlitis was associated with bowel wall thickness measured by ultrasonography (n = 68; P = 0.05) but not CT scan (n = 48; P = 0.67) and was associated with duration of neutropenia (P = 0.02), fever (P = 0.01), and abdominal tenderness (P = 0.04). Age >16 years at cancer diagnosis was the only demographic factor associated with typhlitis (P = 0.03). Two patients died of typhlitis. CONCLUSIONS: Ultrasonography was a useful imaging modality for children with suspected typhlitis. The classic triad of abdominal pain, fever, and neutropenia may be absent. The severity of typhlitis was related to the duration of neutropenia and the presence of fever or abdominal tenderness.     

Laser in situ keratomileusis outcomes following radial keratotomy, astigmatic keratotomy, photorefractive keratectomy, and penetrating keratoplasty

PURPOSE: To evaluate the safety and efficacy of laser in situ keratomileusis (LASIK) to enhance refractive status following other corneal surgical procedures. SETTING: Clinical office-based practice. METHODS: Seventy-one eyes of 57 patients had LASIK for refractive errors following radial keratotomy (n = 22), astigmatic keratotomy (n = 13), photorefractive keratectomy (n = 18), and penetrating keratoplasty (n = 18). A Moria LSK-1 microkeratome was used with a Visx S2 or Wavelight Allegretto excimer laser. Data were acquired by retrospective chart review of all appropriately qualified patients. RESULTS: The mean preoperative manifest refractive spherical equivalent (MRSE) was -3.93 diopters (D) +/- 2.83 (SD) in myopic eyes and +1.43 +/- 1.79 D in hyperopic eyes. The mean time from the initial corneal surgical procedure to LASIK was 65.0 months. The mean post-LASIK follow-up was 9.40 months (range 1 to 42 months). Postoperatively, the mean MRSE was -0.85 +/- 1.42 D in myopic eyes (P<.0001) and -0.16 +/- 1.09 D in hyperopic eyes (P<.0001). Enhancement by LASIK was required in 14% of eyes. CONCLUSION: In eyes that have had a variety of previous corneal surgeries, LASIK offers a safe and predictable method for enhancing refractive results.