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Lessons from Pharmacovigilance: Pulmonary Immune-Related Adverse Events After Immune Checkpoint Inhibitor Therapy. Lung 2021; 199:199-211. [PMID: 33616727 DOI: 10.1007/s00408-021-00425-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 02/05/2021] [Indexed: 12/18/2022]
Abstract
PURPOSE To characterize pulmonary toxicities associated with the use of novel immune checkpoint inhibitors METHODS: Adverse event reports from immune checkpoint inhibitors targeting PD-1/L1 and CTLA-4 were captured from the W.H.O pharmacovigilance database (VigiBase) up until Dec. 31st 2019 and were analyzed to evaluate for measures of association between the use of immune checkpoint inhibitors and pulmonary toxicities. Disproportionality analysis using both frequentist and Bayesian approaches were used to detect signals between pulmonary immune-related adverse events and the use of these agents. RESULTS A total of 9202 adverse pulmonary immune checkpoint inhibitor-related events were captured up until 2019. Adverse pulmonary events were compromised of 1305 airway, 18 alveolar, 5491 interstitial, 898 pleural, 560 vascular and 939 non-specific pulmonary events. We found a common association between all immune checkpoint inhibitors studied and pneumonitis, interstitial lung disease, pulmonary embolism and respiratory failure. We also noted other associations between immune checkpoint inhibitors, however not as uniformly across agents. Most of these immune-related adverse drug reactions were noted to be severe and accounted for a significant source of mortality in the reported cases. CONCLUSION Immune checkpoint inhibitors are associated with a spectrum of inflammatory pulmonary toxicities. The breadth of pulmonary complications and prevalence may be underappreciated with the use of these agents.
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Recovery from minimally invasive vs. open surgery in kidney cancer patients: Opioid use and workplace absenteeism. Investig Clin Urol 2020; 62:56-64. [PMID: 33314804 PMCID: PMC7801161 DOI: 10.4111/icu.20200194] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/23/2020] [Accepted: 07/09/2020] [Indexed: 12/25/2022] Open
Abstract
Purpose Does surgical approach (minimally invasive vs. open) and type (radical vs. partial nephrectomy) affects opioid use and workplace absenteeism. Materials and Methods Retrospective multivariable regression analysis of 2,646 opioid-naïve patients between 18 and 64 undergoing radical or partial nephrectomy via either a minimally invasive vs. open approach for kidney cancer in the United States between 2012 and 2017 drawn from the IBM Watson Health Database was performed. Outcomes included: (1) opioid use in opioid-naïve patients as measured by opioid prescriptions in the post-operative setting at early, intermediate and prolonged time periods and (2) workplace absenteeism after surgery. Results Patients undergoing minimally invasive surgery had a lower odds of opioid use in the early and intermediate post-operative periods (early: odds ratio [OR], 0.77; 95% confidence interval [CI], 0.62–0.97; p=0.02, intermediate: OR, 0.60; 95% CI, 0.48–0.75; p<0.01), but not in the prolonged setting (prolonged: OR, 1.00; 95% CI, 0.75–1.34; p=0.98) and had earlier return to work (minimally invasive vs. open: −10.53 days; 95% CI, −17.79 to −3.26; p<0.01). Controlling for approach, patient undergoing partial nephrectomy had lower rates of opioid use across all time periods examined and returned to work earlier than patients undergoing radical nephrectomy (partial vs. radical: −14.41 days; 95% CI, −21.22 to −7.60; p<0.01). Conclusions Patients undergoing various forms of surgery for kidney cancer had lower rates of peri-operative opioid use, fewer days of workplace absenteeism, but no difference in long-term rates of opioid use in patients undergoing minimally invasive as compared to open surgery.
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Temporal trends in the incidence of testicular cancer in the United States over the past four decades. EUR UROL SUPPL 2020. [DOI: 10.1016/s2666-1683(20)32832-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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EDITORIAL COMMENT. Urology 2020; 139:42-43. [DOI: 10.1016/j.urology.2019.10.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Minimally invasive cancer surgery is associated with a lower risk of venous thromboembolic events. J Surg Oncol 2020; 121:578-583. [PMID: 31916588 DOI: 10.1002/jso.25832] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 12/21/2019] [Indexed: 11/08/2022]
Abstract
BACKGROUND Venous thromboembolism (VTE) is a significant source of postoperative morbidity and mortality in patients undergoing common oncologic procedures. We sought to estimate the effect of surgical approach on the risk of developing a VTE. METHODS IBM Watson Health Marketscan Database was used to conduct this retrospective study. In total, 12 938 patients who underwent either a radical prostatectomy, partial colectomy, or hysterectomy via a minimally invasive or open approach. We used a propensity-weighted logistic regression analysis to assess the independent effect of surgical approach on VTE. The primary outcome of interest was the 90-day rate of VTE after surgery. RESULTS Patients undergoing minimally invasive surgery across all three surgical procedures were noted to have a lower odds of developing a VTE: (radical prostatectomy, odds ratio [OR]: 0.667, 95% confidence interval [CI]: 0.500-0.891; P = .006 |partial colectomy: OR, 0.620, 95% CI: 0.477-0.805; P < .001| hysterectomy: OR, 0.549 95% CI: 0.353-0.854; P = .008). CONCLUSION We found that a minimally invasive approach was associated with significantly lower odds of VTE compared with undergoing the same open procedure. This study highlights how surgical approach may be an independent risk factor for development of VTE and may elucidate potential risk mitigation strategy.
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Abdominal Radiography With Digital Tomosynthesis: An Alternative to Computed Tomography for Identification of Urinary Calculi? Urology 2018; 120:56-61. [PMID: 30006268 DOI: 10.1016/j.urology.2018.06.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/28/2018] [Accepted: 06/29/2018] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To compare the accuracy of plain abdominal radiography (kidneys, ureter, and bladder [KUB]) with digital tomosynthesis (DT) to noncontrast computed tomography (NCCT), the gold standard imaging modality for urinary stones. Due to radiation and cost concerns, KUB is often used for diagnosis and follow-up of nephrolithiasis. DT, a novel technique that produces high-quality radiographs with less radiation and/or cost than low-dose NCCT, has not been assessed in this situation. MATERIALS AND METHODS Seven fresh tissue cadavers were implanted with stones of known size and/or composition and imaged with KUB, DT, and NCCT. Four blinded readers (2 urologists, 2 radiologists) evaluated KUBs for presence and/or location of calculi. They then re-evaluated with addition of tomograms to assess additional value. After a memory extinction period, readers evaluated NCCT images. Accuracy of detection was determined using nearest-neighbor match with generalized linear mixed modeling. RESULTS Total of 59 stones were identified on reference read. Overall, NCCT and DT were both superior to KUB alone (P < .001) while the difference between DT and NCCT was not significant (P = .06). When evaluating uric acid stones, NCCT and DT outperformed KUB (P < .01 and P < .05, respectively) while DT and NCCT were similar (P = .16). Intrarenal stones were better evaluated on DT and NCCT (P < .001 compared to KUB), while DT and NCCT were similar (P = 1.00). Accuracy was lower than anticipated across modalities due to use of the cadaver model. CONCLUSION Our study demonstrates DT is superior to KUB for identification of intrarenal calculi and could replace routine use of KUB or NCCT for detecting renal stones, even those composed of uric acid.
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190 Low Hanging Fruit: A Simple Surgical Intervention for Chronic Orchialgia Secondary to a Low Hanging Testicle after Varicocelectomy. J Sex Med 2018. [DOI: 10.1016/j.jsxm.2017.11.149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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High Survivorship and Few Complications With Cementless Total Wrist Arthroplasty at a Mean Followup of 9 Years. Clin Orthop Relat Res 2017; 475:3082-3087. [PMID: 28721601 PMCID: PMC5670059 DOI: 10.1007/s11999-017-5445-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 07/07/2017] [Indexed: 01/31/2023]
Abstract
BACKGROUND Total wrist arthroplasty (TWA) has been described as traditionally being performed with fixation in the radius and carpus with cement. The TWA implant used in our series has been associated with promising results in studies with up to 6 years followup; however, studies evaluating survivorship, pain, and function with this implant are limited. QUESTION/PURPOSE: (1) To report ROM and pain scores after wrist reconstruction with cementless fourth-generation TWA at a mean followup of 9 years (range, 4.8-14.7 years). (2) To report complications of a cementless fourth-generation TWA and the cumulative probability of not undergoing a revision at a mean followup of 9 years. METHODS This is a retrospective case series of 69 patients who were treated for pancarpal wrist arthritis between 2002 and 2014. Of those, 31 had inflammatory arthritis (rheumatoid arthritis [n = 29], juvenile rheumatoid arthritis [n = 1], and psoriatic arthritis [n = 1]); all of these patients received TWA with the cementless implant studied in this investigation. Another 38 patients had osteoarthritis or posttraumatic arthritis; in this subgroup, 28 patients were 65 years or younger, and all underwent wrist fusion (none were offered TWA). Ten patients with osteoarthritis were older than 65 years and all were offered TWA; of those, eight underwent TWA, and two declined the procedure and instead preferred and underwent total wrist arthrodesis. The mean age of the 39 patients who had TWA was 56 ± 8.9 years (range, 31-78 years) at the time of surgery; 36 were women and three were men. The patients who underwent TWA were seen at a minimum of 4 years (mean, 9 years; range, 4-15 years), and all had been examined in 2016 as part of this study except for one patient who died 9 years after surgery. The dominant wrist was involved in 60% (25) of the patients. All patients were immobilized for 4 weeks postoperatively and then underwent hand therapy for 4 to 6 weeks. Pain and ROM were gathered before surgery as part of clinical care, and were measured again at latest followup; at latest followup, radiographs were analyzed (by the senior author) for evidence of loosening, defined as any implant migration compared with any previous radiograph with evidence of periimplant osteolysis and bone resorption. Subjective pain score was assessed by a verbal pain scale (0-10) and ROM was measured with a goniometer. Complications were determined by chart review and final examination. Kaplan Meier survival analysis was performed to estimate the cumulative probability of not undergoing a revision. RESULTS The mean preoperative active ROM was 34o ± 18° flexion and 36° ± 18° extension. Postoperatively, the mean active ROM was 37° ± 14° flexion and 29° ± 13° extension. The mean difference between the preoperative pain score (8.6 ± 1.2) and postoperative pain score (0.4 ± 0.8) was 8.1 ± 1.9 (p < 0.001). Implant loosening occurred in three (7.7%) patients. No other complications occurred in this series. Kaplan-Meier survivorship analysis estimated the cumulative probability of remaining free from revision as 78% (95% CI, 62%-91%) at 15 years. CONCLUSION Cementless fourth-generation TWA improves pain while generally preserving the preoperative arc of motion. The cumulative probability of remaining free from revision at 14.7 years after the index procedure is 77.7% (95% CI, 62.0%-91.4%). Future studies should compare alternative approaches for patients with endstage wrist arthritis; such evaluations-which might compare TWA implants, or TWAs with arthrodesis-will almost certainly need to be multicenter, as the problem is relatively uncommon. LEVEL OF EVIDENCE Level IV, therapeutic study.
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MP92-16 QUALITY IMPROVEMENT FOR UROLOGISTS: CURRICULAR KEYS FOR EDUCATING RESIDENTS (QUICKER). J Urol 2017. [DOI: 10.1016/j.juro.2017.02.2877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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047 Recovery of Glans Sensation Following Combined Dorsal and Ventral Onlay with a Glans Splitting Technique for Strictures of the Fossa Navicularis. J Sex Med 2016. [DOI: 10.1016/j.jsxm.2016.02.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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MP46-11 A QUANTITATIVE ASSESSMENT OF THE QUALITY OF RANDOMIZED CONTROLLED TRIAL REPORTING IN UROLOGICAL LITERATURE. J Urol 2016. [DOI: 10.1016/j.juro.2016.02.309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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MP6-19 COST EFFECTIVENESS COMPARISON OF RENAL CALCULI TREATED WITH URETEROSCOPIC LASER LITHOTRIPSY VERSUS SHOCK WAVE LITHOTRIPSY. J Urol 2014. [DOI: 10.1016/j.juro.2014.02.253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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The Posterior Surgical Approach to Robot-Assisted Radical Prostatectomy Facilitates Dissection of Large Glands. J Endourol 2013; 27:740-2. [DOI: 10.1089/end.2012.0596] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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1819 TRIPLE D SCORE IS A REPORTABLE PREDICTOR OF STONE FREE RATES FOLLOWING SHOCKWAVE LITHOTRIPSY. J Urol 2013. [DOI: 10.1016/j.juro.2013.02.2182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Recommendations for toxicological investigations of drug-facilitated sexual assaults. J Forensic Sci 1999; 44:227-30. [PMID: 9987892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
The recent increase in reports of drug-facilitated sexual assaults has caused alarm in the general public and prompted forensic toxicologists from across North America to address the toxicological issues surrounding this matter. The authors have developed recommendations and guidelines to inform law enforcement, medical, and scientific personnel of the requirements for performing successful toxicological examinations in cases of drug-facilitated rape.
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Plasma butyrylcholinesterase activity and cocaine half-life differ significantly in rhesus and squirrel monkeys. Life Sci 1996; 59:939-43. [PMID: 8795705 DOI: 10.1016/0024-3205(96)00392-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In vitro studies have implicated butyrylcholinesterase (BChE, E.C.3.1.1.8) as the major enzyme for metabolizing cocaine in humans, but little is known about endogenous BChE activity in monkeys and other animals often used in preclinical studies of cocaine. We compared BChE activity in 18 rhesus and 11 squirrel monkeys, using the colorimetric method of Ellman with butyrylthiocholine as substrate, and in vitro cocaine half-life in pooled plasma samples measuring cocaine concentrations over 60 minutes by GC-MS. Rhesus monkeys had a significantly higher plasma BChE activity than squirrel monkeys (8.2 +/- 0.5 U/L vs. 2.8 +/- 0.5 U/L), and a three-fold shorter in vitro cocaine half-life (20.1 min vs. 60.2 min). BChE activity in rhesus monkeys was comparable to the activity reported in humans. There was no significant influence of age, weight, or prior cocaine exposure. These results indicate that BChE level can vary between species of non-human primates, a factor that should be taken into account when studying drugs such as cocaine which are metabolized by BChE.
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Simultaneous assay of buprenorphine and norbuprenorphine by negative chemical ionization tandem mass spectrometry. J Anal Toxicol 1996; 20:229-35. [PMID: 8835660 DOI: 10.1093/jat/20.4.229] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
A method for the simultaneous measurement of buprenorphine and its N-dealkylated metabolite, norbuprenorphine, in human plasma was developed with negative chemical ionization tandem mass spectrometry. Buprenorphine and norbuprenorphine were extracted from biological fluids by solid-phase extraction. The samples were derivatized with heptafluorobutyric anhydride and measured with negative chemical ionization tandem mass spectrometry. Buprenorphine formed a heptafluorobutyryl derivative and norbuprenorphine formed a bis-heptafluorobutyryl derivative; consequently, the sensitivity of norbuprenorphine was substantially higher than buprenorphine. The limit of quantitation (LOQ) for buprenorphine was 0.20 ng/mL, and the LOQ for norbuprenorphine was 0.03 ng/mL. Daily calibration curves were prepared. Buprenorphine was linear from 0.15 ng/mL to 20 ng/mL, and norbuprenorphine was linear between 0.016 ng/mL and 5 ng/mL. Between-run and within-run precision for buprenorphine at 0.5 ng/mL were 13.8% and 9.8%, respectively. Between-run and within-run precision for norbuprenorphine at 0.5 ng/mL were 23.1% and 17.9%, respectively. The molecular anion for buprenorphine was used as a precursor ion, whereas the [M-197]- was used as a precursor ion for norbuprenorphine in tandem mass spectrometry. Product ion spectra from collision-induced dissociation resulted principally from dissociations of the heptafluorobutyryl group. Monitoring select precursor to product ion reactions and using qualifier ion ratios increased the method's sensitivity and selectivity. The method was applied to samples collected from a patient who received oral and subcutaneous buprenorphine. Buprenorphine plasma concentrations ranged from less than 0.20 ng/mL to 8.7 ng/mL.
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Quantitative analysis of THC, 11-OH-THC, and THCCOOH in human hair by negative ion chemical ionization mass spectrometry. J Anal Toxicol 1995; 19:483-91. [PMID: 8926743 DOI: 10.1093/jat/19.6.483] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
A sensitive and specific method was developed for the quantitative analysis of delta9-tetrahydrocannabinol (THC), 11 -hydroxy-THC (11-OH-THC), and 11-nor-9-carboxy-THC (THCCOOH) in human hair. Deuterated internal standards were added to hair samples, and samples were digested overnight in 1 N NaOH at 37 degrees C. Digest solutions were extracted with a liquid-liquid extraction procedure, which was previously developed in our laboratory for the analysis of plasma and whole blood. Derivatized extracts were analyzed on a Finnigan 4500" mass spectrometer in negative ion chemical ionization mode using methane as the reagent gas, hydrogen as the carrier gas, and a Restek Rtx 200-15M-0.25-microm capillary column. The assay was linear up to 50 ng/mg hair (r, 0.99) for all three compounds and was capable of detecting 10 pg THC and THCCOOH and 100 pg 11-OH-THC on column. The intra-assay precision ranged from 2.1 to 11.2% for the three analytes; the interassay precision ranged from 4.4 to 13.0%. The method was used to detect and quantitate the presence of THC, 11-OH-THC, and THCCOOH in human hair obtained from eight regular users of cannabis. THC, but not 11-OH-THC or THCCOOH, was detectable in the hair shaft above the assay limit of quantitation. Four laboratory wash procedures were also evaluated for their effect on the measured concentration of THC in hair. in seven of eight subjects, a methylene chloride wash procedure substantially reduced the measured THC concentration by up to 50%. The gas chromatographic-mass spectrometric assay is currently being used to support pharmacokinetic studies of drug disposition into the hair of humans and animals.
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Abstract
OBJECTIVES To characterize the postmorphine time course of precipitated withdrawal responses in comparison with the time course of opioid agonist effects and of plasma morphine concentrations. BACKGROUND The study provides a more detailed and comprehensive assessment of the postagonist time course of acute dependence effects in humans than previously available. DESIGN Opioid agonist effects, morphine plasma levels, and withdrawal effects precipitated by naloxone (10 mg/70 kg, administered intramuscularly) were examined at 1, 3, 6, 12, 18, 24, 30, 36, and 42 hours after a single dose of morphine (18 mg/70 kg, administered intramuscularly) in 10 nondependent opioid-experienced subjects. RESULTS The intensity of subjectively reported precipitated withdrawal effects was greatest when testing was conducted at 6 hours after morphine administration, whereas peak intensity of agonist effects (pupil constriction and subjective ratings) and highest plasma morphine concentrations (57.3 ng/ml) were observed at the shortest test interval (1 hour) after morphine. Offset time course of naloxone-precipitated effects differed across specific measures, with hot and cold feelings elevated for the longest time after morphine (36 hrs), but significant effects were generally apparent for up to 24 hours after morphine pretreatment. Agonist effects lasted through only 12 hours; trace amounts of morphine were detected in plasma for up to 30 hours after administration. CONCLUSIONS Results show that acute physical dependence engendered by a single dose of morphine peaks later and persists over a longer duration after morphine administration than do other agonist effects. This suggests that neuronal adaptations underlying physical dependence develop and decay gradually over time during a single episode of receptor occupancy. The presence of detectable morphine in plasma is consistent with a competitive displacement mechanism of precipitated effects, although noncompetitive actions of morphine or its metabolites are not ruled out.
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Abstract
The pupillary effects of intravenous buprenorphine were studied in eight nondependent male subjects who reported previous opiate use. Buprenorphine (0.3, 0.6, and 1.2 mg) decreased pupil size, the amplitude of the light reflex, and the velocities of constriction and dilation. Significant pupillary effects occurred within 15 min of the injection and persisted for 24 hr. At 48 hr most measures returned to baseline levels. Generally the magnitude of the effect was not dose related although recovery occurred sooner after the lower dose. The time course of the pupillary effects of buprenorphine exceeds duration of its analgesic and subjective effects. Previous studies have reported that pupillary measures are especially sensitive to the acute effects of full opiate agonists. The results of the present study indicate that buprenorphine, a partial opiate agonist, causes profound and persistent effects on pupillary size and dynamic measures.
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Abstract
The effects of subcutaneous doses of morphine and verapamil on respiratory and cardiovascular parameters have been assessed in conscious rats. Verapamil (10 mg kg-1) was injected simultaneously with morphine (16 mg kg-1) or at 10, 30, or 60 min before morphine administration. Morphine induced respiratory depression, as indicated by marked hypercapnia, hypoxia and acidosis, and caused marked tachycardia. Although morphine produced only a minor and inconsistent (but statistically significant, P less than 0.01) reduction of mean arterial blood pressure, morphine potentiated verapamil-induced hypotension. Verapamil suppressed morphine-induced hypercapnia only when injected simultaneously with morphine. Verapamil alone did not affect arterial blood gases or pH, but decreased heart rate and mean arterial blood pressure. Verapamil attenuated and delayed the maximum positive chronotropic effects of morphine at all times tested. Antagonism by verapamil of respiratory depression and tachycardia produced by morphine was unrelated to morphine levels in plasma. Thus, the explanation of verapamil-morphine interactions on respiration and cardiovascular function is not pharmacokinetic.
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Abstract
The relationship between the subjective effects induced by IV cocaine injection(s) and cocaine plasma concentrations is complex and difficult to interpret. We designed a study in which bolus loading doses of cocaine followed by 4-hr placebo infusions were compared with the same bolus loading doses of cocaine followed by 4-hr infusions of cocaine calculated to maintain the peak plasma concentrations produced by the bolus. Seven cocaine-using volunteers were successfully studied using a randomized double-blind design, in which self- and observer-rating scales were used to measure drug effects. After the cocaine bolus loading doses, scores for most subjective measures remained elevated when the bolus was followed by a cocaine infusion. In contrast, the subjective responses returned to baseline when the bolus was followed by a placebo infusion. However, self-estimates of the intensity of the cocaine "rush" were not altered by the presence of active cocaine infusions and returned rapidly to baseline.
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Abstract
Acute tolerance to the cardiovascular effects of cocaine has been hypothesized from experiments in which the plasma concentrations of cocaine were rapidly changing. We studied the cardiovascular responses of 8 male human subjects for 4 hours following intravenous bolus doses of cocaine, and compared these to responses in the same subjects after intravenous bolus doses of cocaine followed by continuous intravenous infusions of cocaine designed to maintain steady state plasma levels of cocaine. We found little evidence of tolerance to the tachycardia and hypertensive effects of cocaine during a four hour exposure. Lack of tolerance to the cardiovascular effects of cocaine may be a factor in some types of cocaine related toxicity among cocaine abusers.
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A structure activity relationship study of the cyclohexyl and aromatic rings of phencyclidine (PCP). NIDA RESEARCH MONOGRAPH 1982; 41:126-33. [PMID: 6811905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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