Effects of renal insufficiency on the pharmacokinetics and pharmacodynamics of opioid analgesics

Iopromide and Iodixanol in the Development of Postoperative Contrast Nephropathy in Patients with Renal Insufficiency: A Meta-Analysis

In order to compare the effects of iopromide and isoxazole on postoperative contrast-induced nephropathy in patients with renal insufficiency, the paper searches for randomized controlled trials and retrospective cohort studies comparing the effects of iopromide and iodixanol on renal function in patients with renal insufficiency after surgery. The data are extracted from eligible studies. We tried to assess the incidence of contrast-agent nephropathy, preoperative and postoperative serum creatinine indicators, and mortality. This paper includes 8 studies with a total of 1243 patients. The incidence of contrast-induced nephropathy in the iopromide group is higher than that in the iodixanol group, and there is no significant difference between the two groups in postoperative mortality and preoperative serum creatinine expression. Sensitivity analysis and funnel chart show that our research is robust and has low publication bias. Our research shows that in patients with renal insufficiency, the incidence of contrast-medium nephropathy in the iopromide group is higher than that in the iodixanol group. Iodixanol is safer and has less effect on patients' serum creatinine levels.

Opioid Safety and Concomitant Benzodiazepine Use in End-Stage Renal Disease Patients

Background

Opioid use is common in end-stage renal disease (ESRD) patients. However, safety of individual opioids and concomitant benzodiazepine use has not been studied.

Objective

To study the epidemiology of opioid and concomitant benzodiazepine use in ESRD population. To study the clinical safety profile of individual opioids in patients on hemodialysis.

Design

Retrospective analysis of the U.S. Renal Data System. A comprehensive review of the current literature was performed to update currently used opioid safety classification.

Participants

ESRD patients ≥18 years on hemodialysis who were enrolled in Medicare A and B and Part D between 2006 and 2012, excluding those with malignancy.

Main Measures

Hospital admission with diagnosis of prescription opioid overdose within 30, 60, and 90 days of prescription; death due to opioid overdose.

Results

Annually, the percentage of patients prescribed any opioid was 52.2%. Overall trend has been increasing except for a small dip in 2011, despite which the admissions due to opioid overdose have been rising. 30% of those who got a prescription for opioids also got a benzodiazepine prescription. 56.5% of these patients received both prescriptions within a week of each other. Benzodiazepine use increased the odds of being on opioids by 3.27 (CI 3.21–3.32) and increased the odds of hospitalization by 50%. Opioids considered safe such as fentanyl and methadone were associated with 3 and 6 folds higher odds of hospitalization within 30 days of prescription. Hydrocodone had the lowest odds ratio (1.9, CI 1.8–2.0).

Conclusions

Concurrent benzodiazepine use is common and associated with higher risk of hospitalization due to opioid overdose. Possible opioid-associated hospital admission rate is 4-5 times bigger in ESRD population than general population. Current safety classification of opioids in these patients is misleading, and even drugs considered safe based on pharmacokinetic data are associated with moderate to very high risk of hospitalization. We propose a risk-stratified classification of opioids and suggest starting to use them in all ESRD patients.

Pharmacokinetic considerations and recommendations in palliative care, with focus on morphine, midazolam and haloperidol

INTRODUCTION

A variety of medications are used for symptom control in palliative care, such as morphine, midazolam and haloperidol. The pharmacokinetics of these drugs may be altered in these patients as a result of physiological changes that occur at the end stage of life.

AREAS COVERED

This review gives an overview of how the pharmacokinetics in terminally ill patients may differ from the average population and discusses the effect of terminal illness on each of the four pharmacokinetic processes absorption, distribution, metabolism, and elimination. Specific considerations are also given for three commonly prescribed drugs in palliative care: morphine, midazolam and haloperidol).

EXPERT OPINION

The pharmacokinetics of drugs in terminally ill patients can be complex and limited evidence exists on guided drug use in this population. To improve the quality of life of these patients, more knowledge and more pharmacokinetic/pharmacodynamics studies in terminally ill patients are needed to develop individualised dosing guidelines. Until then knowledge of pharmacokinetics and the physiological changes that occur in the final days of life can provide a base for dosing adjustments that will improve the quality of life of terminally ill patients. As the interaction of drugs with the physiology of dying is complex, pharmacological treatment is probably best assessed in a multi-disciplinary setting and the advice of a pharmacist, or clinical pharmacologist, is highly recommended.

Effects of intermittent hemodialysis on buprenorphine and norbuprenorphine plasma concentrations in chronic pain patients treated with transdermal buprenorphine

The present study was designed to study the impact of intermittent hemodialysis on the disposition of the partial agonist buprenorphine and its metabolite norbuprenorphine during therapy with transdermal buprenorphine in chronic pain patients with end-stage kidney disease. Ten patients (mean age 63 years) who had received transdermal buprenorphine for at least 1 week, were asked to provide blood samples immediately before and after hemodialysis. Blood samples were analysed for buprenorphine and its metabolite norbuprenorphine. The median buprenorphine plasma concentrations were found to be 0.16 ng/ml before and 0.23 ng/ml after hemodialysis. A significant correlation between plasma levels and administered doses was observed (Spearman R=0.74; P<0.05). In three patients norbuprenorphine plasma levels were detected. No differences in pain relief before and after hemodialysis were observed. This investigation shows no elevated buprenorphine and norbuprenorphine plasma levels in patients with renal insufficiency receiving transdermal buprenorphine up to 70 microg/h. Furthermore, hemodialysis did not affect buprenorphine plasma levels, leading to stable analgesic effects during the therapy.

A systematic review of the use of opioid medication for those with moderate to severe cancer pain and renal impairment: a European Palliative Care Research Collaborative opioid guidelines project

BACKGROUND

Opioid use in patients with renal impairment can lead to increased adverse effects. Opioids differ in their effect in renal impairment in both efficacy and tolerability. This systematic literature review forms the basis of guidelines for opioid use in renal impairment and cancer pain as part of the European Palliative Care Research Collaborative's opioid guidelines project.

OBJECTIVE

The objective of this study was to identify and assess the quality of evidence for the safe and effective use of opioids for the relief of cancer pain in patients with renal impairment and to produce guidelines.

SEARCH STRATEGY

The Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, MedLine, EMBASE and CINAHL were systematically searched in addition to hand searching of relevant journals.

SELECTION CRITERIA

Studies were included if they reported a clinical outcome relevant to the use of selected opioids in cancer-related pain and renal impairment. The selected opioids were morphine, diamorphine, codeine, dextropropoxyphene, dihydrocodeine, oxycodone, hydromorphone, buprenorphine, tramadol, alfentanil, fentanyl, sufentanil, remifentanil, pethidine and methadone. No direct comparator was required for inclusion. Studies assessing the long-term efficacy of opioids during dialysis were excluded.

DATA COLLECTION AND ANALYSIS

This is a narrative systematic review and no meta-analysis was performed. The Grading of RECOMMENDATIONS Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of the studies and to formulate guidelines.

MAIN RESULTS

Fifteen original articles were identified. Eight prospective and seven retrospective clinical studies were identified but no randomized controlled trials. No results were found for diamorphine, codeine, dihydrocodeine, buprenorphine, tramadol, dextropropoxyphene, methadone or remifentanil.

CONCLUSIONS

All of the studies identified have a significant risk of bias inherent in the study methodology and there is additional significant risk of publication bias. Overall evidence is of very low quality. The direct clinical evidence in cancer-related pain and renal impairment is insufficient to allow formulation of guidelines but is suggestive of significant differences in risk between opioids.

RECOMMENDATIONS

RECOMMENDATIONS regarding opioid use in renal impairment and cancer pain are made on the basis of pharmacokinetic data, extrapolation from non-cancer pain studies and from clinical experience. The risk of opioid use in renal impairment is stratified according to the activity of opioid metabolites, potential for accumulation and reports of successful or harmful use. Fentanyl, alfentanil and methadone are identified, with caveats, as the least likely to cause harm when used appropriately. Morphine may be associated with toxicity in patients with renal impairment. Unwanted side effects with morphine may be satisfactorily dealt with by either increasing the dosing interval or reducing the 24 hour dose or by switching to an alternative opioid.

Increased clearance of morphine in sickle cell disease: implications for pain management

Acute vaso-occlusive painful episodes associated with sickle cell disease (SCD) are frequently treated with morphine. Many SCD individuals require relatively higher doses of morphine to achieve optimal analgesia. We studied pharmacokinetics of morphine in SCD to explore if altered disposition could be a factor contributing to increased requirement of morphine in this population. The study subjects were in steady state of health to avoid the effect of hemodynamic changes associated with vaso-occlusion on morphine disposition. The plasma concentrations of morphine and its major metabolites were measured at timed intervals in 21 SCD subjects after they received a single .1 mg/Kg infusion of morphine sulfate. USCPACK software was used to fit candidate pharmacokinetic models. Noncompartmental pharmacokinetic parameters for morphine were calculated. Morphine clearance was 2.4-3.6 L/h, half-life was .3-.7 hours, AUC(0-∞) was 27.7-42.5 ng∗h/mL, and volume of distribution was .96-3.38 L/kg. Clearance of morphine in the study population was 3-10 folds higher than published estimates in the non-SCD population, with correspondingly lower AUC and half-life. Volume of distribution was similar. This observation suggests that due to increased clearance SCD individuals may require higher dose and frequency of morphine to achieve comparable plasma levels.

PERSPECTIVE

Accelerated clearance of morphine likely related to increased hepatic and renal blood flow may be responsible for increased requirement of morphine in SCD. Although SCD individuals may require higher and more frequent doses of morphine, inter-individual variability of morphine disposition highlights the importance of individualization of the therapy.

Opioid and benzodiazepine use in end-stage renal disease: a systematic review

BACKGROUND AND OBJECTIVES

Chronic pain and psychiatric disorders are common in dialysis patients, but the extent to which opioids and benzodiazepines are used is unclear. We conducted a systematic review to determine the: (1) prevalence of opioid and benzodiazepine use among dialysis patients; (2) reasons for use; (3) effectiveness of symptom control; and (4) incidence of adverse events.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Two authors reviewed all relevant citations in MEDLINE/EMBASE/CINAHL/BIOSIS Previews/Cochrane and hand-searched bibliographies. Studies after 1990 reporting prevalence estimates for opioid and/or benzodiazepine use in ≥50 dialysis patients were included.

RESULTS

We identified 15 studies from 12 countries over 1995 to 2006. Sample size ranged from 75 to 12,782. Prevalence of opioid and benzodiazepine use was variable, ranging from 5 to 36% (95% CI, 4.1 to 45.5%; n=10) and 8 to 26% (95% CI, 7.1 to 27.3%; n=9), respectively. Prevalence was positively correlated with years on dialysis. Five studies reported on the same cohorts but gave different prevalence estimates. One study verified medication use through patient interviews. Reasons for use were reported in one study. Effectiveness of pain control varied from 17 to 38%, and 72 to 84% of patients with significant pain had no analgesia (n=2). No study rigorously examined for adverse events.

CONCLUSIONS

The prevalence of opioid and benzodiazepine use in dialysis patients is highly variable between centers. Further information is needed regarding the appropriateness of these prescriptions, adequacy of symptom control, and incidence of adverse effects in this population.

Pharmacotherapy in the treatment of addiction: methadone

Methadone maintenance treatment (MMT) is the most widely available pharmacotherapy for opioid addiction and has been shown to be an effective and safe treatment over a period of 40 years. Although women comprise approximately 40% of clients currently being treated in MMT programs, comparatively little research geared specifically toward this group has been published. This article begins with an overview of neurobiological studies on opioid addiction, including a discussion of gender differences, followed by a review of the pharmacology of methadone. The authors then examine the particular needs and differences of women being treated in MMTs, including co-dependence with other substances, women's health issues, and psychosocial needs unique to this population. Research shows that women have different substance abuse treatment needs in comparison to their male counterparts. One New York City MMT program that has attempted to address these differences is highlighted.

Renal palliative care

Patients with chronic kidney disease have a shortened life expectancy and carry a high symptom burden. Clinicians need sophisticated expertise in pain and symptom management and skills in communication to meet the many needs of this population. This article reviews the literature and discusses prognosis, ethical and legal considerations, symptoms, treatment, and end-of-life issues. The field of nephrology is shifting from an exclusive focus on increasing survival to one that provides greater attention to quality of life. There is an opportunity to integrate many of the advances of palliative medicine into the comprehensive treatment of these patients.

Use of the case-crossover design to study prolonged drug exposures and insidious outcomes

PURPOSE

The case-crossover design was originally intended to study brief exposures with immediate and transient effects, and acute outcomes with abrupt onsets. We investigated whether case-crossover methods can be used to study prolonged exposures and insidious outcomes.

METHODS

We conducted a case-crossover study of 8220 patients aged > or = 65 years enrolled in several health benefits programs in New Jersey during the period between 1991 and 1995. All had episodes of central nervous system (CNS) adverse events (e.g., delirium). Drug exposures were assessed during case time periods and control time periods lasting 1, 2, 3, or 4 months. Exposures included 3 active regimens with established deleterious CNS effects (corticosteroids, digoxin, and opiates) and 2 inactive regimens without such effects (multivitamins and statins).

RESULTS

In conditional logistic regression models, significantly elevated risks were observed for all three active drugs, regardless of which time windows were used. The magnitude of these risks generally increased with longer time windows. No significantly increased risks were observed for the 2 inactive drugs, regardless of the window duration.

CONCLUSIONS

These results suggest that with lengthened exposure assessment windows, case-crossover methods may be useful for studying exposures with prolonged effects and outcomes with insidious onsets.

Analgesia in patients with ESRD: a review of available evidence

Moderate to severe pain frequently accompanies chronic diseases in general and end-stage renal disease (ESRD) in particular. Several analgesic agents and associated metabolites show altered pharmacokinetics in the presence of reduced glomerular filtration rate. Drug-related side effects may exacerbate symptoms frequently observed in persons with chronic kidney disease (CKD; eg, fatigue, nausea, vomiting, and constipation) or those often attributed to hemodialysis therapy (eg, orthostatic hypotension and impaired cognition). Persons with advanced CKD and ESRD are at increased risk for adverse effects of analgesic agents because of enhanced drug sensitivity, comorbid conditions, and concurrent medication use. Dose adjustment and avoidance of certain analgesics may be required in patients with advanced CKD and ESRD. We review the available evidence on pharmacokinetics and adverse drug effects of various analgesic agents commonly used in patients with advanced CKD and ESRD. Determining an optimal approach to the control of pain in patients with advanced CKD and ESRD will require additional research.

Meperidine: a critical review

Meperidine was initially synthesized as an anticholinergic agent but was soon discovered to have analgesic properties. Although meperidine's anticholinergic effects were demonstrated in vivo, the anticholinergic effects on the biliary and renal tracts have not been demonstrated in vivo. Studies have clearly demonstrated that meperidine is no more efficacious in treating biliary or renal tract spasm than comparative mu opioids. The initial studies demonstrating the analgesic efficacy of meperidine were mostly case reports and not double-blind, randomized, controlled trials in specific populations. Subsequent comparative studies failed to demonstrate any advantages of meperidine over comparable doses of other analgesics. Meperidine was portrayed in practice and teaching as having unique clinical advantages. The analgesic effects of meperidine are not pronounced, and, in addition, meperidine use is complicated by unique side effects including serotonergic crisis and normeperidine toxicity. Meperidine's poor efficacy, toxicity, and multiple drug interactions have resulted in a movement to replace meperidine with more efficacious and less toxic opioid analgesics.

Pharmacokinetics of tilidine in terminal renal failure

The aim of the present study was to investigate the pharmacokinetics of tilidine and its metabolites during the dialysis procedure and in the dialysis-free interval. Tilidine is a prodrug that is metabolized presystemically into the active metabolite nortilidine. Nortilidine is degraded thereafter to bisnortilidine and several polar metabolites. Nine patients with a creatinine clearance < 5 ml/min were treated in a crossover design with single oral doses of 1.5 mg/kg on the day of dialysis (dialysis performed from 3 to 6 hours after drug administration) and on a day in the dialysis-free interval. Blood samples were taken frequently and analyzed for tilidine, nortilidine, and bisnortilidine. Drug and metabolite concentrations were also measured in aliquots of dialysate collected during dialysis. Only negligible amounts of tilidine, nortilidine, and bisnortilidine (about 0.9% of the dose) were recovered from the dialysate. The pharmacokinetics of nortilidine and its inactive metabolite bisnortilidine was not affected by dialysis. The presystemic apparent clearance of the prodrug tilidine was decreased significantly during the dialysis-free interval. A significant decrease of the rate of elimination and an increase of the AUC of bisnortilidine were observed if these parameters were compared with data obtained from healthy volunteers. The plasma concentrations of nortilidine were comparable in patients and normal volunteers. Thus, a reduction of the dose of tilidine in patients with severely impaired kidney function seems not to be required. Tilidine and its metabolites cannot be removed from the body by dialysis.

Palliative care and end-of-life issues

As stated, the goal of palliative care is the achievement of the best quality of life for patients and their families. It incorporates many aspects of care: providing physical comfort, psychosocial and spiritual support, and providing various services in order to achieve this goal. The skills described should be a priority in the practice of all types of medicine because the goal of palliative care is among the central tenets of the medical profession.

Pharmacokinetic considerations

Limited studies of the pharmacokinetics of pain medication suggest altered serum elimination when the liver is hypoperfused or affected by severe cirrhosis. Drugs that are eliminated by Phase I oxidation reactions are sensitive to changes in hepatic blood flow, while drugs eliminated by Phase II glucuronidation are more affected by diseased hepatocytes. Additionally, alterations in renal function decrease elimination of both parent drugs and metabolites, resulting in toxicity for selected opioids such as meperidine and morphine. Caution is suggested in drawing general conclusions from pharmacokinetic patterns of opioid elimination discussed in this review. Practitioners should be aware that drugs with short duration of action may have long half-lives and accumulate in end-stage liver and renal disease. While pharmacokinetic differences have been described in various populations, the clinical effects and adverse outcomes are greatly influenced by numerous independent physiologic alterations seen in critical care patients. Patients with severe alterations in liver and renal function should be administered pain medications judiciously because these patients are predisposed to metabolic disarrays. These patients should not be denied pain care, but they may benefit from smaller, less frequently administered doses, rather than continuous infusion of opioid drugs. Titration of doses to clinical effects with careful patient assessment for adverse effects is crucial for achieving desired therapeutic outcomes with analgesic agents in the ICU.

Morphine-6-glucuronide concentrations and opioid-related side effects: a survey in cancer patients

The active morphine metabolite, morphine-6-glucuronide (M-6-G), may contribute to both the analgesia and the adverse effects observed during morphine (MOR) therapy. To evaluate the relationship between M-6-G and adverse effects, we measured steady-state plasma concentrations of MOR and M-6-G and concurrently noted the presence or absence of moderate to severe cognitive impairment or myoclonus in 109 cancer patients who were receiving either oral (n = 71) or parenteral (n = 38) morphine. MOR and M-6-G plasma concentrations were determined by HPLC with electrochemical detection. The presence of cognitive impairment or myoclonus was analyzed in relation to molar M-6-G/MOR ratio, age, morphine dose, the use of other centrally acting drugs, renal function (blood urea nitrogen (BUN) and serum creatinine), hepatic function (serum bilirubin, serum glutamic oxalacetic transaminase (SGOT), and alkaline phosphotase) and serum lactate dehydrogenase (LDH). The patient population consisted of 60 women and 49 men. The mean age was 51.5 years (range: 10-85 years). The mean morphine dose (total dose-prior 48 h) was 486 mg (range: 40-4800 mg) for the oral group and 931 mg (range: (10-9062 mg) for the parenteral group. The mean molar M-6-G/MOR ratios were 6.1 (SD: 18.2; range: 0.01-153.3) for the oral treatment group and 2.7 (SD: 4.16; range: 0.05-23.8) for the parenteral treatment group. Overall, the M-6-G/MOR ratio demonstrated a moderate but significant correlation with BUN (r = 0.4; P < 0.001) and creatinine (r = 0.45; P < 0.001) levels, but not with the other clinical variables examined.(ABSTRACT TRUNCATED AT 250 WORDS)

[Pharmacotherapy of cancer pain : 2. Use of opioids.]

The adequate use of opioids in the treatment of chronic cancer pain requires sound knowledge of selection criteria for the various opioids, the routes of administration, dosages, dosing schemes and possible side effects. Drug selection depends on the intensity of pain rather than on the specific pathophysiology. Mild to moderate pain can often be treated effectively by so-called "weak" opioids. These include codeine, dihydrocodeine and dextropropoxyphene. Non-opioid analgesics, like acetylsalicylic acid or paracetamol can be added according to the "analgesic ladder" proposed by the World Health Organization (WHO). If adequate pain relief is not achieved "strong" opioids are required. The route of administration that is the safest and the least invasive for the patient should be chosen. Non-invasive (oral, rectal, sublingual, transdermal and intranasal) and invasive routes (intravenous, subcutaneous, spinal and epidural) are available (Table 8). Noninvasive routes are preferred, and most patients can be maintained on oral opioids. Alternatively, in some patients pain can be managed by the sublingual (buprenorphine) route. A transdermal preparation exists for fentanyl, but has not yet been approved for the German market. If the oral route cannot be used or if large doses are required, it will be necessary to change to an invasive route. Intravenous bolus injections provide the fastest onset of analgesic action. They are mostly used in very severe pain. Repeated injections can be avoided by using intravenous or subcutaneous infusions. Various types of pumps delivering analgesics at constant basal infusion rates with the option of rescue doses in case of breakthrough pain are available (patient-controlled analgesia=PCA). Opioids frequently used for s. c. infusion are morphine and hydromorphone. Adjuvant drugs (antiemetics, anxiolytics) can be added. Epidural or intrathecal administration of opioids should only be used in intractable pain or if severe side effects, such as sedation and confusion, will arise with systemic opioids. Morphine, hydromorphone, fentanyl and sufentanil have been used, as have other additional compounds (e.g. local anaesthetics, clonidine). Intracerebroventricular application of morphine has been used only occasionally. In all cases, opioids should be given on to a fixed time schedule thereby, preventing pain from recurring. Additional rescue doses (approximately 50% of baseline single dose) are given for break-through pain. The most frequent side effect of opioids is constipation, and the administration of laxatives is often recommended (Table 5). Nausea, vomiting, sedation and confusion mostly occur in the beginning of opioid therapy. In contrast to constipation, tolerance to these effects develops within days or weeks. True dependence or psychological addiction rarely occurs in patients with chronic cancer pain. In most cases, progression of the underlying disease associated with increasing tissue damage and increasing pain is found. Fear of dependence and addiction often contributes to undertreatment of patients suffering from chronic cancer pain.

Rectal administration of nicomorphine in patients improves biological availability of morphine and its glucuronide conjugates

The pharmacokinetics of 30 mg nicomorphine after rectal administration with a suppository are described in 8 patients under combined general and epidural anaesthesia. No nicomorphine or 6-mononicotinoylmorphine could be detected in the serum. Morphine appeared almost instantaneously with a lag-time of 8 min and had a final elimination half-life of 1.48 +/- 0.48 h. Morphine was metabolized to morphine-3-glucuronide and morphine-6-glucuronide. These glucuronide conjugates appeared after a lag-time of 12 min and the half-life of these two glucuronide conjugates was similar: about 2.8 h (P > 0.8). The glucuronide conjugate of 6-mononicotinoylmorphine was not detected. In the urine only morphine and its glucuronides were found. The renal clearance value for morphine was 162 ml.min-1 and for the glucuronides 81 ml.min-1. This study shows that administration of a suppository with 30 mg nicomorphine gives an excellent absolute bioavailability of morphine and its metabolites of 88%. The lipid-soluble prodrug nicomorphine is quickly absorbed and immediately hydrolysed to morphine.

Difficulties in diagnosing narcotic overdoses in hospitalized patients

OBJECTIVE

To describe the clinical presentation of narcotic overdose in hospitalized patients and to differentiate this circumstance from other conditions often misdiagnosed as overdose.

DESIGN

Case series.

SETTING

Two acute-care teaching hospitals.

PATIENTS

Forty-three hospitalized patients who received naloxone for a clinically suspected narcotic overdose.

INTERVENTIONS

Two investigators independently evaluated each incident to determine whether the patient had a narcotic overdose. The patients were judged to have had an overdose if caregivers documented an immediate improvement in mental status, respiratory rate, or blood pressure after naloxone administration.

MEASUREMENTS

The clinical presentation of a narcotic overdose in hospitalized patients was defined. Conditions misdiagnosed as an overdose were determined.

MAIN RESULTS

Symptoms improved rapidly with the administration of naloxone in 28 incidents (65 percent) and were designated overdose. In 15 other instances there was no improvement in symptoms; these patients were designated nonoverdose. Only half of the overdose patients had a respiratory rate < 8 breaths/min immediately prior to naloxone administration. Only two of the overdose patients had the classic triad of symptoms (respiratory depression, coma, and pinpoint pupils). Other overdose patients had only one or two of the classic signs. The clinical presentation of narcotic overdoses in hospitalized patients did not include respiratory depression, hypotension, or coma in the majority of patients. All overdose patients showed a decrease in mental status. The majority of nonoverdose patients had pulmonary conditions that were misdiagnosed as a narcotic overdose.

CONCLUSIONS

Narcotic overdoses in hospitalized patients seldom fit the classic description. The lack of respiratory depression does not mean the absence of a narcotic overdose. Patients who receive narcotics and develop a significant decrease in mental status should be evaluated for a possible overdose. Pulmonary, neurologic, cardiovascular, and electrolyte abnormalities often are misdiagnosed as a narcotic overdose in hospitalized patients.

Cancer pain management. Current strategy

Pain is among the most prevalent symptoms experienced by cancer patients. A strategy for the management of cancer pain is now widely accepted, and when well implemented, is usually effective. Unfortunately, many oncologists are ill-prepared for the task of pain assessment and management, and the outcomes achieved in clinical practice are often suboptimal. The various elements in the pain management strategy are described. Patient assessment, the use of primary therapies and systemically administered nonopioid and opioid analgesics are pivotal to the strategy. Practical aspects of opioid pharmacotherapy encompass drug selection and dosing considerations including selection of an appropriate route of administration, dose titration, and the management of side effects. Specific approaches are described for the treatment of patients for whom an acceptable balance between relief and side effects of opioids is not achieved. These comprise noninvasive interventions, including the use of adjuvant analgesics, psychological therapies, and physiatric techniques, and invasive interventions, such as the use of intraspinal opioids, neural blockade, and neuroablative techniques. Finally, the use of sedation in the treatment of patients with pain that is refractory to other interventions is addressed. The skilled application of this strategy can provide adequate relief to the vast majority of patients, most of whom will respond to systemic pharmacotherapy alone. Patients with refractory pain should see specialists in pain management or palliative medicine who can address these difficult problems.

Death from a morphine infusion during a sickle cell crisis

A 15-year-old boy died during a vaso-occlusive sickle cell crisis after having received a prolonged infusion of morphine. Even in therapeutic doses, narcotics may cause significant respiratory acidosis and hypoxemia, enhancing polymerization of hemoglobin SS and thereby promoting sickling and vaso-occlusion. When narcotics are used during a sickle cell crisis, the best method is pharmacokinetically based patient-controlled analgesia.

Iatrogenesis in the elderly. Drug-related problems

Drug reactions are generally related to the influence of age, toxicity, side effects, immunologic reactions, idiosyncratic reactions, drug-drug interactions, and drug-disease interactions. In addition to age-related changes, the elderly are susceptible to the incidence of adverse drug reactions because of polypharmacy, incorrect self-administration of drugs, omission of drugs, taking another's prescriptions, use of over-the-counter drugs, and medication errors by health-care personnel. To prevent or predict adverse drug reactions, the gerontologic nurse can obtain thorough drug histories, educate clients and health-care providers, use nursing measures to alleviate symptoms, and be astute for the potential for problems through drug review.

The Senior Care Study. The optimal use of medications in acutely ill older patients

Geriatric assessment units have improved pharmacotherapy for their patients by decreasing the number of medications prescribed. The Senior Care Study, a randomized controlled trial, compared a multidisciplinary-team approach to patient care to the standard medical practice of the institution. As a part of the trial, the effectiveness of an interdisciplinary team intervention in improving the use of medications was studied. Study goals were to decrease medications used, decrease unnecessary medications, and improve medication choices in our acutely ill inpatient population. A pharmacist interviewed all experimental patients and patient records, and presented medication concerns and recommendations at a team conference. MEDICATIONs were counted on admission and on the third day, sixth week, and third month after randomization. MEDICATIONs were paired with patient problems.

MEDICATION

problem pairs were judged as inappropriate choices if there were potential side effects that would affect patient function, and if better alternatives were available. The 215 control and 221 experimental patients in the study were similar in age, sex, place of origin, and number of medications on admission. Experimental patients took fewer medications than controls on the third day (5.3 versus 5.9, P less than .05). Experimental patients received fewer multiple unpaired medications (11% versus 19%, P less than .025) and fewer inappropriate medication choices (20% versus 37%, P less than .005). The results suggest that the team intervention was effective in improving pharmacotherapy in the acute-care setting.

Clinical features and management of intoxication due to hallucinogenic drugs

Hallucinogenic drugs are unique in that they produce the desired hallucinogenic effects at what are considered non-toxic doses. The hallucinogenic drugs can be categorised into 4 basic groups: indole alkaloid derivatives, piperidine derivatives, phenylethylamines and the cannabinols. The drugs reviewed include lysergic acid diethylamide (LSD), phencyclidine (PCP), cocaine, amphetamines, opiates, marijuana, psilocybin, mescaline, and 'designer drugs.' Particularly noteworthy is that each hallucinogen produces characteristic behavioural effects which are related to its serotonergic, dopaminergic or adrenergic activity. Cocaine produces simple hallucinations, PCP can produce complex hallucinations analogous to a paranoid psychosis, while LSD produces a combination of hallucinations, pseudohallucinations and illusions. Dose relationships with changes in the quality of the hallucinatory experience have been described with amphetamines and, to some extent, LSD. Flashbacks have been described with LSD and alcohol. Management of the intoxicated patient is dependent on the specific behavioural manifestation elicited by the drug. The principles involve differentiating the patient's symptoms from organic (medical or toxicological) and psychiatric aetiologies and identifying the symptom complex associated with the particular drug. Panic reactions may require treatment with a benzodiazepine or haloperidol. Patients with LSD psychosis may require an antipsychotic. Patients exhibiting prolonged drug-induced psychosis may require a variety of treatments including ECT, lithium and l-5-hydroxytryptophan.