Neste estudo padronizamos modelo de dor óssea induzida pela administração de células do tumor de Walker 256 em fêmur de ratos e avaliamos o efeito analgésico da crotalfina, um peptídeo com atividade analgésica. Análises radiográficas, tomográficas e cintilográficas demonstraram a presença de processos osteolíticos difusos, destruição do tecido cortical ósseo e intensa atividade osteogênica. Foi detectado aumento de partes moles adjacentes ao osso, fenômeno observado em pacientes com câncer ósseo. Análises histopatológicas mostraram a presença de células tumorais no pulmão, baço e fígado dos animais, indicando disseminação das células tumorais. Foi detectada a presença de hiperalgesia, alodinia e dor manifesta, a partir do 1º dia após a inoculação das células, persistindo por pelo menos 14 dias. Crotalfina (8 <font face=\"Symbol\">mg/kg, p.o) administrada no 14º dia, bloqueou estes fenômenos. Esse efeito antinociceptivo é de longa duração (48 h) e mediado por receptores opióides do tipo <font face=\"Symbol\">k e <font face=\"Symbol\">d. Não foi observado desenvolvimento de tolerância após o tratamento prolongado com crotalfina. / The aim of the present work was to standardize a new rat model of bone pain induced by the injection of Walker 256 carcinoma cells into the femoral cavity of rats, and to evaluate the analgesic effect of crotalphine, an analgesic peptide. Radiographic, tomographic and scintigraphic analysis showed the presence of diffuse osteolytic processes, destruction of cortical bone tissue and intense osteogenic activity. Increase of soft tissue adjacent to the bone was also detected, being this phenomenon observed in patients with bone cancer. Hystopathological analysis showed the presence of tumor cells in lungs, spleen and liver, indicating the occurrence of metastasis. Tumor cell inoculation induced the presence of hyperalgesia, allodynia and spontaneous pain. Crotalphine (8 <font face=\"Symbol\">mg/kg, p.o.), administered on day 14, blocked these phenomena. This antinociceptive effect is long-lasting effect (2 days) and mediated by peripheral <font face=\"Symbol\">k and <font face=\"Symbol\">d- opioid receptors. Prolonged treatment with crotalphine (14 days) did not cause the development of tolerance to its antinociceptive effect.

A coerência do processo de fabricação, via granulação úmida, de comprimidos de dipirona sódica (500 mg) foi avaliada empregando ferramentas de qualidade e de estatística. No estudo foi desenvolvida base racional-científica objetivando determinar as etapas críticas do processo por meio da técnica de análise de modo e efeito da falha (FMEA). A análise de risco revelou as potenciais falhas do processo: variação da distribuição granulométrica da mistura final com elevado percentual de pó fino e problemas relativos a fluidez; ensaios de peso, espessura, dureza, friabilidade, tempo de desintegração e dissolução fora de especificação; não-uniformidade do conteúdo de dipirona sódica (OS) na mistura final e durante a compressão e ocorrência de laminação, capeamento, porosidade e aderência dos comprimidos às estações da máquina compressora. Os métodos analíticos relativos à determinação de (OS), empregando metodologia espectrofotométrica e de cromatografia líquida de alta eficiência (CLAE), foram previamente validados. As seguintes características de desempenho, em ambas metodologias analíticas, foram determinadas: especificidade, linearidade com coeficiente de correlação (r) &#62; 0,99, repetibilidade aceitável com desvio padrão relativo (OPR) &#60; 2% e precisão intermediária entre analistas e em dias diferentes. Além disso, a robustez e exatidão com percentual de recuperação entre 99,28% e 100,84% foram comprovadas para o método de CLAE. No que se refere às etapas críticas da validação do processo produtivo, foi elaborado plano de amostragem baseado nos critérios estabelecidos em compêndio oficial (FARMACOPÉIA BRASILEIRA, 1988), Guia da FOA (UNITEO STATES, 2003), duração de cada etapa de fabricação e tipo de equipamento utilizado. Além disso, foi empregada a lista Millitary Standard 105E (TAYLOR, ENTERPRISES, 1989). Os resultados relativos à estabilidade estatística do processo revelaram ausência de causas especiais. Os índices de capacidade Cp e Cpk foram calculados após avaliação da distribuição dos dados empregando teste de Anderson-Darling. Todos os dados apresentaram distribuição normal (p &#62; 0,05), exceto àqueles relativos à uniformidade de conteúdo de OS na etapa de compressão. Esses dados foram tratados utilizando método proposto por Box-Cox (Iambda igual a 5) visando sua normalização. Os índices de capacidade Cp e Cpk. revelaram resultados &#62; 1 e, portanto, permitiram determinar a consistência do processo e baixa probabilidade de falha. / The consistency of the metamizol tablets (500 mg) manufacturing process, via wetting granulation, was evaluated by quality and statistical tools. In this study, rational-scientific base was developed aiming determination of the critical steps of this process, using the Failure Mode and Effects Analysis (FMEA) technique. The risk analysis shows the potential failures of the process: variability of particle size distribution, high percentage of fine powder and flowability problems related to the final mixture; weight, thickness, hardness, friability, disintegration time and dissolution percentage of the tablets out-of-specifications; non-uniformity of the metamizol content in the final mixture and during the tabletting steps; laminating, capping, porosity and sticking of the tablets. The analytical methods performed by spectrophotometric and high performance liquid chromatography (HPLC), in order to assay metamizol, were previously validated. The following parameters were evaluated in both analytical methodologies: specificity, linearity with correlation coefficients more than 0.99, acceptable repeatability with relative standard deviation (RSD) less than 2% and intermediate precision between two different analysts and days. Besides that, the system suitability and accuracy were also proved by HPLC method. The recoveries obtained were between 99.28% and 100.84%. The sampling plan was elaborated according to official compendium (FARMACOPEIA BRASILEIRA, 1988), FOA Guidance (UNITED STATES, 2003), Military Standard 105E (TAYLOR ENTERPRISES, 1989), the duration of each step and the type of equipment used. This plan was just applied for critical steps identified by FMEA tool. The results related to the statistical stability of the process show no special cause. The capability indexes, Cp and Cpk, were calculated after the evaluation of the data distribution using Anderson-Darling test. Ali data showed normal distribution (p &#62; 0.05), except for uniformity of metamizol content of the tablets. This data was treated by a method proposed by Box-Cox (Iambda equal -5.0) aimed at obtaining the normality of the data. The capability indexes, Cp and Cpk, obtained were all &#62; 1. Therefore, this process can be considered consistent and with low probability of failures.

Abstract In four prospective clinical trials, 114 parturients used intravenous patient-controlled remifentanil analgesia during the 1st stage of labour. The median effective dose per bolus was ascertained to be 0.4 μg/kg and the pain scores were reduced with this by a median of 2 on a numerical scale (0–10). Compared with nitrous oxide, 15 parturients included in a cross-over study reported a larger reduction in pain scores during remifentanil analgesia (1.5 vs. 0.5, p =  0.001) and better pain relief scores (2.5 vs. 0.5 on a ranked five point scale 0–4, p  &lt;  0.001). In a parallel study including 45 parturients, epidural analgesia (EDA, 20 ml bupivacaine 0.625 mg/ml and fentanyl 2 μg/ml) was associated with lower pain scores (5.2 vs. 7.3 with remifentanil, p =  0.004) but variables related to satisfaction with analgesia (pain relief score, proportion of mothers with desire to continue with the given medication and termination of the study due to inadequate pain relief) were similar. A comparison of two methods for timing the remifentanil bolus during the uterine contraction cycle suggested that delaying the bolus does not improve analgesia. A period effect was noted in the cross-over trial with higher pain scores and increased drug consumption during the second study period suggesting acute hyperalgesia. Side effects of remifentanil analgesia included respiratory depression warranting oxygen supplementation in 33% of parturients. Sedation was experienced by the parturients using remifentanil and this was scored as stronger than sedation during nitrous oxide and EDA. The number of parturients with nausea did not increase during remifentanil analgesia. Other maternal side effects included dizziness, a difficulty in visual focusing and itching. Foetal heart rate tracing abnormalities were noted. The incidence of abnormal tracings and decreased UapH were not different, however, from that observed during nitrous oxide or EDA. Apgar scores at 1 and 5 minute indicated no neonatal depression.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Pain is the most common complaint in the medical field and the identification of compounds that can effectively treat painful states without induction of side-effects remains a major challenge in biomedical research. The aim of the present study was to investigate the antinociceptive effect of a novel compound, 3-(4-fluorophenyl)-5-trifluoromethyl-1H-1-tosylpyrazole (compound A) in several models of pain in mice and compare with those produced by the known trifluoromethyl-containing pyrazole compound celecoxib. Compound A or celecoxib were administrated by oral (78 780 μmol/kg), intrathecal (9 22.5 nmol/site) or intracerebroventricular (9 22.5 nmol/site) routes. Oral administration of either compound A or celecoxib abolished the mechanical allodynia, but not the oedema caused by intraplantar injection of carrageenan. Similarly, compound A reduced the overt nociception, but not the oedema, produced by bradykinin or capsaicin. However, compound A (500 μmol/kg, orally) did not alter nociception nor oedema caused by intraplantar injection of prostaglandin E2 or glutamate, whereas celecoxib reduced only the nociception induced by the former. Moreover, oral and intrathecal administration of compound A or celecoxib also reduced the nociception induced by acetic acid. However, only celecoxib reduced the acetic acid-induced nociception when it was injected by the intracerebroventricular route. Finally, neither compound A nor celecoxib was able to produce antinociceptive effect in the tail-flick test or to alter the motor performance and the body temperature. Besides, compound A or celecoxib did not induce gastric lesion. Thus, compound A seems to be an interesting prototype for the development of novel analgesic drugs. / A dor é uma das maiores queixas na área médica e a identificação de compostos que possam tratar efetivamente os estados dolorosos, sem induzir efeitos colaterais, permanece um grande desafio na pesquisa biomédica. O objetivo do presente estudo foi investigar o efeito antinociceptivo de um novo composto 3-(4-fluorfenil)-5-trifluormetil-1H-1-tosilpirazol (composto A) em diferentes modelos de dor em camundongos e comparar os seus efeitos com aqueles produzidos por um pirazol contendo trifluormetil em sua estrutura, o celecoxibe. O composto A ou o celecoxibe foram administrados por via oral (78 780 μmol/kg), intratecal (9 22,5 nmol/sitio) ou intracerebroventricular (9 22,5 nmol/sitio). A administração oral do composto A ou do celecoxibe aboliram a alodínia mecânica, mas não o edema, causado pela injeção intraplantar de carragenina. Do mesmo modo, a administração do composto A reduziu a nocicepção, mas não o edema, produzido pela bradicinina ou capsaicina. Entretanto, o composto A administrado por via oral (500 μmol/kg) não alterou a nocicepção nem o edema causados pela injeção intraplantar de prostaglandina E2 (PGE2) ou glutamato. Já o celecoxibe, reduziu somente a nocicepção induzida pela PGE2. Além disso, a administração oral ou intratecal do composto A ou celecoxibe também reduziu a nocicepção induzida por ácido acético. Quando administrados por via intracerebroventricular, somente o celecoxibe foi capaz de reduzir a nocicepção induzida por ácido acético. Finalmente, o composto A ou o celecoxibe não alteraram a nocicepção térmica aguda, a performance motora ou a temperatura corporal dos animais, nem produziram lesões gástricas quando administrados por via oral. Consequentemente, o composto A parece ser um interessante protótipo para o desenvolvimento de novas drogas analgésicas.

Notre recherche concerne les conditions d'acceptabilité de différents moyens de traiter la douleur dans les soins palliatifs, par les professionnels de santé et le grand public. Deux moyens sont étudiés : l’utilisation d’antalgiques, notamment de palier III ; la mise en œuvre d’une sédation. Notre recherche est basée sur la Théorie Fonctionnelle de la cognition de Norman Anderson (1981). Concernant l'étude portant sur l’utilisation des antalgiques : 192 participants ont jugé du degré d'acceptabilité de chacun des 56 scénarios proposés, résultant de la combinaison de quatre facteurs : « concertation du médecin avec l’équipe de soins », « demande de la personne à être soulagée de sa douleur », « niveau de douleur, exprimé grâce à l’échelle numérique de douleur », « décision du médecin en termes de prescription d’antalgique ». Pour l'étude portant sur la sédation : 192 personnes ont jugé du degré d'acceptabilité des 48 scénarios proposés. Ils sont le résultat de la combinaison des quatre facteurs suivants : « demande de la personne », « type de sédation », « espérance de vie », « concertation du médecin avec l’équipe de soins ». Pour l’étude portant sur l’utilisation des antalgiques, notamment de palier III, il ressort que seuls trois des facteurs manipulés ont joué un rôle dans l’acceptabilité de la décision du médecin. Il s’agit par ordre croissant des facteurs « niveau de douleur », « décision du médecin » et « concertation du médecin ». Le facteur le moins influent puisque n’ayant pas eu d’effet significatif est le facteur « demande de la personne ». L’analyse en clusters nous a également permis de discriminer 6 groupes de participants, ayant chacun leur propre politique de jugement. Concernant l’étude sur la sédation, nous retrouvons également que trois des quatre facteurs manipulés ont eu une influence sur le jugement d’acceptabilité. Par ordre croissant, il s’agit des facteurs « demande de la personne », « type de sédation » et « concertation du médecin ». Le facteur « espérance de vie » n’a pas eu d’effet significatif. L’analyse en clusters nous a permis de différencier 4 classes de participants, se regroupant selon leur politique de jugement. L'acceptabilité des différents moyens utilisés pour soulager la douleur en fin de vie est largement influencée par les facteurs intervenant dans les scénarios. / Our research concerns the conditions of acceptance of different ways to treat pain in palliative care by health professionals and laypeople. Two ways are studied: the use of analgesic, including strong opioids ; implementation of sedation. Our research is based on the Functional Theory of Cognition by Norman Anderson (1981). On the study on the use of analgesics : 192 participants rated the degree of acceptability of each of the 56 proposed scenarios, resulting from the combination of four factors: « decision-making process », « request of the person to be relieved of his pain », « pain level, expressed through digital pain scale », « decision of the physician in terms of painkiller prescription ». For the study of sedation : 192 people judged the acceptability of the 48 proposed scenarios. They are the result of four factors combination: « request for sedation », « type of sedation », « life expectancy », « decision-making process ». In the study on the use of painkillers, especially strong opioids, it appears that only three of the manipulated factors played a role in the acceptability of the doctor's decision. The result by ascending order of the factors is: « pain level », « decision » and « decision-making process ». The less influential factor, since having no significant effect, is the factor « request ». The analysis in clusters also allowed us to discriminate 6 groups of participants, each with their own political judgment. Regarding the study on sedation, we also find that three of the four manipulated factors had influenced the judgment of acceptability. In ascending order, these factors are « request », « type of sedation » and « decision-making process ». The « life expectancy » factor had no significant effect. The analysis in clusters enabled us to distinguish 4 classes of participants, coming together according to their political judgment. The acceptability of the various means used to relieve pain in later life is largely influenced by the factors involved in the scenarios.

Magister Scientiae Dentium - MSc(Dent) / The purpose of this study is to evaluate the need for prophylactic antibiotic treatment in third molar surgery and to establish specific guidelines for antibiotic prophylaxis in the department of Maxillo-Facial and Oral Surgery (MFOS) at Tygerberg Academic, Groote Schuur and Mitchells Plain Hospitals.

A series of aminotetralones and aminotetralins were synthesized from the common intermediate F, 3-amino-2,2-dimethyl-7-methoxy- 1-tetralone. The final compounds derived from F were simple substituted and/or reduced analogues. The products would allow a progressive structure activity relationship to be drawn based on pharmacological testing. The common intermediate F was synthesized utilizing a six step procedure starting with p-methoxyphenylacetic acid. The overall yield from the precursor to the F:HC1 was 25%. Compound F was either O-demethylated to form 3-amino-2,2-dimethyl-7-hydroxy-l-tetralone (I) or was dimethylated on the amine and subsequently O-demethylated to yield the 3-dimethylamino-7-hydroxy-2,2-dimethyl-l-tetralone (J). The last major modification was the reduction of the carbonyl group in J to a methylene, to produce the 3-dimethylamino-7-hydroxy-2,2-dimethyltetralin (L). These final compounds I, J, and L, as well as the intermediates leading to them (compounds F, II, G, and K), were tested for opioid activity in the isolated guinea pig ileum assay as described by Kosterlitz. All of the compounds exhibited agonist activity. They generally fell into three groups. Compound J was the most potent, giving 1/40 the potency of normorphine (NM). The majority of compounds (F, H, K, and L) were of intermediate potency, ranging in activity from 1/500 to 1/700 the potency of NM. The last two compounds I and G were not only the least potent at 1/2000 to 1/5000 that of NM, but also the least efficacious. In evaluation of the receptor selectivity of the compounds synthesized, a range of selectivity was observed. Compound J was the only compound which appeared to exhibit 100% of its activity through the mu receptor. The other compounds had varying degrees of mixed receptor agonism.

Study Background and Objectives:Excessive perioperative opioid prescribing has been detrimental to public health, contributing to the elevated prevalence of opioid use disorder. Since 2016, rigorous regulation of opioid prescribing has reduced over-prescription, but has also led to opioid-phobia. The 2022 CDC guideline promotes person-centered decisions on pain management by relaxing restrictions on opioid prescription. The determination of opioid requirements for surgical pain management is influenced by various factors and stakeholders. Despite extensive research, the mechanisms underlying perioperative pain management and the persistence of opioid use after surgery remain unclear. Clinicians currently lack tools to guide opioid prescription in clinical settings, and patients often face a dearth of information regarding expected pain levels, proper opioid use, and options for surgical pain management. The main objective of my doctoral project is to disentangle the intricate relationships among patients, healthcare providers, and policy changes in perioperative opioid prescription for pain management and to identify key intervention points to balance the beneficial effects of proper opioids use against the risks of addition. Another objective is to develop a risk score algorithm for perioperative opioid requirements to help with decision-making in clinical practice. Materials and Methods:In chapter 1, I undertook a systematic review and meta-analysis, and investigated the percentage of adult patients scheduled for general surgeries who received opioid analgesia for perioperative pain management, the quantities of opioids prescribed to patients, the actual quantities consumed, the percentage of patients without prior opioid exposure experiencing prolonged opioid use, and the evolution of perioperative opioid prescription patterns since the policy changes. A causal loop diagram was used to visualize the complex conceptual framework of perioperative pain management and post-surgical prolonged use of opioids based on insights derived from the systematic review and meta-analysis. In chapter 2 and 3, data from patients aged 18-64 years undergoing one of 12 commonly performed procedures (e.g., laparoscopic cholecystectomy) from 2015 to 2018 at a single institution were analyzed. Perioperative opioid requirements (none/low, medium, high) were determined based on patients’ self-reported pain scores and opioid prescription/administration from 30 days before to 2 weeks after surgery. Patients’ clinical and procedure-related factors were collected as potential predictors. Random forest, the Least Absolute Shrinkage and Selection Operator (LASSO), and multinomial logistic regression were used to develop prediction models. Models’ performance, including discrimination, calibration, classification measures were evaluated. A nomogram based on multinomial logistic regression was generated as a score tool, and decision curve analysis was used to examine the clinical utility of the final prediction model dichotomizing the opioid prescription as none/sparing versus medium/high requirements. Results: My systematic review and meta-analysis revealed that around 85% of surgical patients received opioids perioperatively. The pooled mean total amount of opioids dispensed was 210 MME per patient per surgical procedure. Notably, only approximately 44% of the prescribed opioids were consumed. Among opioid-naïve patients who initiated opioid use perioperatively, 7.1% persisted in opioid use beyond the conventional three-month postoperative recovery timeframe. Intervention programs (such as setting up maximum limits of opioids prescription, providing trainings to health providers, monitoring opioids prescription behaviors, providing health education to patients, etcetera) reduced perioperative opioid prescription by 38% and opioid consumption by 63.2%. The causal loop diagram illustrates a balancing feedback loop between policy and over-prescription, highlighting the pivotal role of a decision tool in reducing the over-prescription of perioperative opioids while ensuring the fulfillment of opioid needs for effective perioperative pain management. To develop a decision-aid tool based on prediction models, I included 2733 patients in the training dataset and 1081 in the testing dataset, all of whom underwent general surgeries. All prediction models demonstrated moderate discrimination in the testing dataset. The null hypothesis of perfect calibration intercepts and calibration slopes was rejected. In analyses restricted to patients undergoing laparoscopic cholecystectomy, model discrimination remained similar while model calibration improved. The revised LASSO model had an accuracy of around 65% in the testing dataset, classifying future cases correctly into opioid requirements groups in laparoscopic cholecystectomy cohort. Features in the final laparoscopic cholecystectomy model included the use of opioid/NSAID/anti-depressant before surgery, emergency surgery, anesthesia type, and surgical indication for cholelithiasis/cholecystitis. A nomogram was created to guide perioperative opioids use among laparoscopic cholecystectomy patients, and the decision curve analysis demonstrated the clinical utility of the prediction model; it generated higher net benefits than the strategy of prescribing no opioids or opioid sparing to surgical patients and the strategy of prescribing medium or high opioids doses to all patients, with a broad threshold probability from 18% to 92%. Conclusions:In summary, this dissertation described the historically high levels of perioperative opioid prescriptions and highlighted their adverse impacts: persistent opioid use and community diversion. Although the implementation of guidance and policies has significantly reduced nationwide over-prescriptions of opioids, it is essential to recognize the potential benefits of appropriate opioid use in perioperative pain management. The incorporation of a machine-learning approach with subject-matter knowledge may achieve more accurate predictions of opioid requirements than employing machine-learning techniques alone and increase the interpretability of the prediction model. Notably, the surgery-specific model demonstrated superior performance than the model for general surgeries. Future studies should further validate the conceptual model of perioperative opioid prescription and misuse in real-world scenarios, enhance model discrimination, extend external validation efforts, and develop electronic applications tailored to contemporary medical practices.

This thesis presents the design and optimization of a dendrimer-based cationic nanoparticle system tailored for versatile applications, ranging from anti-inflammatory scavenging to targeted pain relief through endosomal delivery. By harnessing the unique attributes of this platform, various strategies were devised to overcome hurdles in drug delivery, offering promising avenues for nanomedicine in anti-inflammatory and nociceptive treatments. In our scavenging screening project, we rigorously screened various materials to find the best universal anti-inflammatory carrier. We started by exploring the potential of dendrimer-based materials as scavengers of inflammatory signals and studied how they could be used to develop therapeutic carriers. With intrinsic therapeutic properties and the ability to create tunable nanocarriers, dendrimer-based delivery systems are powerful multimodal delivery systems. The dendrimer base of our delivery system, cationic PAMAM Generation 3 dendrimer (PAMAM-G3), was selected due to its efficient scavenging ability and low biotoxicity. Conjugation with cholesterol facilitated the formation of polymeric micelles, exhibiting a cationic and hydrophilic exterior coupled with a hydrophobic interior, resulting in a high drug-loading capacity. Among the developed scavengers, PAMAM-Cholesterol (PAMAM-Chol) nanoparticles demonstrated a potent reduction in toll-like receptor activation with minimal toxicity and extended endosomal retention. We then exploited the endosomal retention of PAMAM-Chol nanoparticles to target the activated PAR2 receptor within endosomes of relevant cancer cells, aiming to alleviate oral cancer-induced nociception. Extensive characterization confirmed the platform's stability, physical attributes, and ability to encapsulate PAR2 inhibitor, AZ3451. The platform exhibited high drug loading capacity and sustained release profiles across various pHs. Cellular uptake studies demonstrated efficient endosomal targeting, with subsequent modulation of PAR2 signaling pathways. Preclinical studies in oral cancer pain models revealed a significant and prolonged reduction in nociception for over 24 hours, surpassing the efficacy of free drugs. Further diversification of the PAMAM-Chol platform explored its potential as a "Push" chemotherapy carrier and a "Pull" cfDNA scavenger against chemotherapy-induced neurological and neuropathic side effects. Evaluation in wild-type mice demonstrated the platform's effectiveness in mitigating chemobrain and chemotherapy-induced peripheral neuropathy, highlighting its translational potential for multimodal cancer therapy. We found that NPs loaded with chemotherapy significantly reduced the painful effects of chemotherapy-induced peripheral neuropathy and decreased recovery times. Collectively, this body of work underscores the potential of PAMAM-Chol as a versatile tool in drug delivery and endosome-localized pain therapeutics. It contributes to the evolving landscape of precision medicine through tailored therapeutic approaches for minimizing side effects and enhancing patient well-being. The innate therapeutic properties coupled with efficient and sustained drug delivery mechanisms position the PAMAM-Chol platform as a foundational element for the development and delivery of next-generation therapeutics.

Nursing homes are an essential yet understudied provider of cancer-related care for those with complex health needs. Nine percent of nursing home residents have a cancer diagnosis at admission, and it is estimated that one-third of them experience pain on a daily basis. Although pain management is an essential component of disease treatment, few studies have evaluated analgesic medication use among adults with cancer in this setting. Use of opioids, which are the mainstay of pain management in older adults because of their effectiveness in controlling moderate to severe pain, may be significantly related to coverage by the Medicare Part D prescription drug benefit. However, little is known about Medicare Part D’s effects on opioid use in this patient population. A limited body of evidence also suggests that despite known risks of overdose and respiratory depression in opioid-naïve patients treated with long-acting opioids, use of these agents may be common in nursing homes. This dissertation examined access to appropriate and effective pain-related health care services among US nursing home residents, with a special focus on those with cancer. Objectives of this dissertation were to: 1) estimate the prevalence, and identify resident-level correlates, of pain and receipt of analgesic medications; 2) use a quasi-experimental research design to examine the relationship between implementation of Medicare Part D and changes in the use of fentanyl patches and other opioids; and 3) to estimate the prevalence, and identify resident-level correlates, of naïve initiation of long-acting opioids. Data on residents’ health status from the Resident Assessment Instrument/Minimum Data Set (versions 2.0 and 3.0) were linked with prescription drug transaction data from a nationwide long-term care pharmacy (January 2005–June 2007) and the Centers for Medicare and Medicaid Services (January–December 2011). From 2006 to 2007, more than 65% of residents of nursing homes throughout the US with cancer experienced pain (28.3% on a daily basis), among whom 13.5% reported severe pain. More than 17% of these residents who experienced daily pain received no analgesics (95% confidence interval [CI]: 16.0–19.1%), and treatment was negatively associated among those with advanced age, cognitive impairment, feeding tubes, and restraints. These findings coincided with changing patterns in opioid use among residents with cancer, including relatively abrupt 10% and 21% decreases in use of fentanyl patches and other strong opioids, respectively, after the 2006 implementation of Medicare Part D. In the years since Medicare Part D was introduced, some treatment practices in nursing homes have not been concordant with clinical guidelines for pain management among older adults. Among a contemporary population of long-stay nursing home residents with and without cancer, 10.0% (95% CI: 9.4–10.6%) of those who began receiving a long-acting opioid after nursing home admission had not previously received opioid therapy. Odds of naïve initiation of these potent opioids were increased among residents with terminal prognosis, functional impairment, feeding tubes, and cancer. This dissertation provides new evidence on pharmaceutical management of pain and on Medicare Part D’s impact on opioid use in nursing home residents. Results from this dissertation shed light on nursing home residents’ access to pain-related health care services and provide initial directions for targeted efforts to improve the quality of pain treatment in nursing homes.