Hypoglycemic effects of tramadol analgesia in hospitalized patients: a case-control study

Evaluating the Incidence of Seizures and Its Relationship With Blood Glucose Levels in Tramadol Poisoning Patients Admitted to Imam Reza Hospital in Mashhad (Iran) From 2019 to 2020

Background: Drug poisoning is the most common type of poisoning in the world. The utilization of tramadol for the management of pain has been identified as a significant contributor to the incidence of poisoning cases. Tramadol poisoning can result in a range of neurological complications, including seizures and a decreased level of consciousness. Tramadol-induced seizures are frequently dose independent and manifest as generalized tonic-clonic seizures. The neurotoxic effects of tramadol are primarily manifested within the initial 24 h period following ingestion, with 84.6% of the seizures occurring within the first six hours. In addition, it has been documented that 15%-35% of the patients with tramadol poisoning have experienced seizures. The present study was undertaken to elucidate the clinical and paraclinical signs and symptoms observed in patients with tramadol poisoning and their correlation with the occurrence of seizures. Methods and Materials: All patients hospitalized due to tramadol poisoning from October 2019 to September 2020 in the poisoning department of Imam Reza Hospital if they met the inclusion criteria were studied. The patients were divided into two groups with and without seizures. The occurrence of seizures was substantiated through the documentation of EMS personnel and the direct observation of the attending physician in the emergency room. Following admission, the patient's blood glucose level was quantified via a glucometer. A blood sample was also obtained for subsequent laboratory evaluation. In the event of any aberrations in blood glucose levels, a re-evaluation was conducted at one-hour intervals using a glucometer. All findings were analyzed using SPSS Version 25 statistical software. The level of significance was set at p < 0.05. Results: A total of 163 patients were included in this study. In 94 patients (57.3%), some degree of consciousness loss and seizures occurred in 69 patients (42.1%). There was a significant relationship between the occurrence of seizures and the increase in blood glucose levels of patients (p=0.031). The findings indicated that 60% of the patients with blood glucose levels exceeding 140 mg/dL experienced seizures. Conclusion: Seizures in tramadol poisoning may be related to the patient's blood glucose levels.

Dose-related hypoglycemia in venlafaxine poisoning: a retrospective cohort study

CONTEXT

Several case reports describe hypoglycemia in the context of venlafaxine overdose, while investigations at therapeutic dose suggested a neutral effect on glucose homeostasis. Studies on hypoglycemia in venlafaxine intoxication are lacking.

METHODS

Single-center retrospective cohort study of non-diabetic patients presenting with a laboratory-confirmed antidepressant overdose to the department of clinical toxicology of a tertiary care hospital over a 12-year period. Our main goal was to investigate the association of hypoglycemia as the primary outcome with venlafaxine exposure using multiple logistic regression. Multi-drug exposures were included. We further aimed to describe the association of blood glucose (BG)/hypoglycemia with antidepressant dose, seizures and length of hospital stay.

RESULTS

525 antidepressant intoxications were included, 85 of which involved venlafaxine. Hypoglycemia occurred in 34.1% (29/85) of venlafaxine intoxications and in 10.7% (47/440) of non-venlafaxine antidepressant overdoses. Venlafaxine exposure was significantly associated with hypoglycemia (adjusted odds ratio (OR): 6.6, 95% confidence interval (CI): 3.5-12.6). Venlafaxine-associated hypoglycemia was mainly mild (BG: 51-70 mg/dL), in 75.8% of cases, to moderate (BG: 31-50 mg/dL), in 20.7%, with one case of severe hypoglycemia (BG: 30 mg/dL). BG was significantly inversely correlated with dose in the venlafaxine group (Spearman's correlation coefficient: -0.47, p = 0.002) but not in other commonly prescribed antidepressants. Regardless of venlafaxine exposure, hypoglycemia was associated with seizures (adjusted OR: 5.3, 95% CI: 2.6-10.6) and with a 2.7 day increase in hospital length of stay (95% CI: 1.3-4.2).

CONCLUSION

A dose-related, mild to moderate hypoglycemia occurred in over one-third of venlafaxine poisonings. In overdose of other antidepressants, hypoglycemia was seen less frequently and without significant dose-dependency. Regardless of venlafaxine exposure, hypoglycemia was associated with seizures and prolonged length of stay, although these factors are likely primarily determined by other toxicities. BG monitoring in venlafaxine overdose should be considered.

Hong Kong poison information centre: Annual report 2020

Background:

The Hong Kong Poison Information Centre has provided consultation service to healthcare professionals and collected epidemiological data on poisoning in Hong Kong since 2005.

Objective:

To analyse and report the poisoning data of Hong Kong Poison Information Centre in 2020 during the COVID-19 pandemic.

Methods:

A retrospective review of all poisoning cases recorded in the Poison Information and Clinical Management System of Hong Kong Poison Information Centre in 2020.

Results:

A total of 3633 poisoning cases were analysed. Compared to 2019 (pre-COVID era), there was a reduction of ~10% of total poisoning cases recorded (383 cases), with a majority (> 90%) of reduction from poisoning cases with no clinical effect (353 cases). A greater proportion of reduction was observed among the children (0–12 years), patients with general unintentional poisoning, poisoning due to therapeutic error and food poisoning. An increased number of cases was noted from abusive use, adverse herb/proprietary Chinese medicine reaction and poisoning related to household bleaches. Teenage (13–19 years) poisoning seemed to be unaffected by the COVID-19 pandemic and the previously observed increasing trend continued (up to 11.8% of total poisoning cases this year). Despite a total reduction in poisoning cases recorded, the number of deaths increased by 37% from 35 in 2019 to 48 in 2020 (mortality rate 1.5%). A total of seven interesting cases were discussed.

Conclusion:

This 15th annual report provides updated epidemiological information on poisoning patterns in Hong Kong during the COVID-19 pandemic. It also highlighted important changes and possible effects of the COVID-19 pandemic on poisoning in Hong Kong in comparison with our previous reports.

Association between Non-Steroidal Anti-Inflammatory Drugs Use and the Risk of Type 2 Diabetes Mellitus: A Nationwide Retrospective Cohort Study

Background: Although the link between non-steroidal anti-inflammatory drugs (NSAIDs) and tramadol and symptomatic hypoglycemia has been documented, there is a limited understanding of the associations of NSAIDs and tramadol with the risk of type 2 diabetes mellitus (T2DM). This study was established to evaluate the association between the clinical use of NSAIDs and the risk of T2DM. Patients and methods: A historical cohort study was conducted using the National Health Insurance Research Database in Taiwan dated from 2000 to 2013. Patients who received NSAIDs for at least 3 prescription orders and without co-treatment of tramadol in the exposure period (from 2000 to 2005) were considered as the exposed cohort (n = 3047). In comparison, patients who received tramadol for at least 3 prescription orders and without concomitant use of NSAIDs in the exposure period were considered as the comparison cohort (n = 9141). The primary outcome was the occurrence of T2DM. Multivariable hazard ratios (HRs) with 95% confidence intervals (CIs) derived from the Cox proportional hazard models were applied to determine the association between NSAIDs use and the risk of T2DM. Results: In the average follow-up period of 9.56 years, there were 159 newly diagnosed T2DM, with an incidence rate of 56.96 per 10,000 person years in the exposed cohort. Comparatively, there were 1737 incident T2DM cases, with an incidence rate of 161.23 per 10,000 person years in the comparison cohort. Compared to the comparison cohort, the NSAIDs cohort showed a significantly reduced risk of T2DM with an adjusted HR of 0.31 (95% CI, 0.26–0.36). Conclusions: Our cohort study provides longitudinal evidence that the use of NSAIDs was associated with a reduced risk of T2DM.

The Effect of Different Opioids on Acid-Base Balance and Blood Gas Analysis in Hospitalized Dogs

Pain management is central to veterinary practice, contributing to successful case outcomes and enhancement of the veterinarian-client-patient relationship. Analgesic drugs represent one of the pillars of the multimodal approach to acute and chronic pain management. In dogs, the most used opioids are methadone, buprenorphine and tramadol. Several episodes of hypoglycemia in people treated with tramadol and methadone have recently been described. The aim of this work is to evaluate the changes in the glycemic and acid-base balance induced by tramadol, methadone and buprenorphine in hospitalized dogs. A retrospective review of the medical records of dogs hospitalized for both medical and surgical reasons was performed. During 2018-2020, a total of 876 canine patients were treated with opioids, including 228 with tramadol, 273 with methadone and 375 with buprenorphine. Of all these dogs, only a small percentage met the inclusion criteria presented in the initial design. All the hospitalized animals were monitored daily through clinical examination and blood sampling. Blood samples were obtained before opioid administration (T0), and 24 h (T1) and 48 h (T2) after °pioid administration. The following parameters were evaluated: blood gas value (pH, pCO₂), acid-base state (cHCO₃), oxymetric values (ctHb, haematocrit), electrolyte values (K+, Na+, iCa, Cl-) and metabolic values (glucose, lactate, anion GAP K+c). The glycemic value in enrolled dogs showed a decrease over time, regardless of the type of opioid used, but remained within the physiological range. The highest average glycemic drop was recorded for methadone, between T0 and T1, followed by tramadol between T1 and T2, while buprenorphine recorded the highest overall glycemic drop between T0-T2 when compared to the other two opioids. Female dogs showed the greatest drop in glycemic value. Lactate concentration always presented values beyond the physiological range at an early stage, which then normalized quickly. Measurement of electrolyte concentrations showed a consistent increase in the values of iCa, Na and Cl. In hospitalized dogs treated with opioids monitoring of gas analytic parameters is important and more attention should be paid to patients hospitalized with certain metabolic and endocrine diseases.

Autopsy case of fatal hypoglycemia following ingestion of a therapeutic dose of tramadol

An 86-year-old female was found unconscious the day after taking a prescribed tablet containing a combination of tramadol and acetaminophen. At admission to the hospital, marked hypoglycemia (blood glucose: 4 mg/dL) was confirmed, but serum insulin and C-peptide were within the normal range, which suggested that neither endogenous hyperinsulinemia nor exogenous insulin administration was responsible for the hypoglycemia. Despite resuscitation efforts, the woman subsequently died. At autopsy, there was renal disorder, but any pathological abnormalities that could have caused hypoglycemia were not observed. Blood tramadol and acetaminophen were in the therapeutic range. We speculate that the cause of fatal hypoglycemia was tramadol intake at the therapeutic dose. Older age and renal insufficiency are factors that could have potentially caused the fatal hypoglycemia in this case despite tramadol having been taken at a therapeutic dose. This is the first case report of fatal hypoglycemia following ingestion of a therapeutic dose of tramadol.

The effect of tramadol on blood glucose concentrations: a systematic review

INTRODUCTION

Studies comprehensively summarizing the impact of tramadol use on glucose homeostasis are very sparse. Thus, the present study was performed to collect and summarize the latest information about this issue in a systematic way.

AREAS COVERED

An exhaustive literature search was carried out using relevant keywords. Web of Sciences, PubMed, Scopus, and Google scholar were interrogated until 30 June 2019. Case-control, cohort, cross-sectional, clinical trial, case report, and animal studies that focused on the objective of the study were retrieved. This review summarizes the results of 761 papers on glycemic changes due to tramadol exposure. Thirty-six publications reported hypoglycemia and 17 hyperglycemia during tramadol use. Twenty-two studies either reported normal blood glucose concentrations, or did not observe any difference in the blood glucose levels following tramadol use. Finally, hypoglycemia was reported in diabetic individuals exposed to tramadol in 12 studies.

EXPERT OPINION

The data suggest that primarily hypoglycemia but some degree of hyperglycemia has been reported with tramadol use. Importantly, all studies on tramadol use in diabetes reported hypoglycemia. Tramadol-induced hypoglycemia may be severe in some cases. The risk of alterations in glucose homeostasis accompanying tramadol exposure indicates time importance of careful blood glucose monitoring during tramadol use.

An unconscious man with profound drug-induced hypoglycaemia

Introduction

Hypoglycaemia has been reported as an unusual complication of tramadol use and in a few cases of tramadol poisoning, but the exact mechanism is not known.

Case description

An ambulance crew was dispatched to an unconscious 46-year old man. A glucometer point-of-care measurement revealed a profound hypoglycaemia (1.9 mmol/L). Treatment with intravenous glucose was started and the patient was transported to the hospital. The patient had several episodes of pulseless electrical activity requiring cardiopulmonary resuscitation in the ambulance and upon arrival in the hospital. Despite continuous glucose infusion the hypoglycaemia was difficult to correct during the next few hours and the patient developed hypokalaemia. Further investigation to identify the cause of hypoglycaemia revealed that insulin and C-peptide were inappropriately raised. A toxicological investigation revealed the presence of tramadol and its metabolites in lethal concentrations. Also acetaminophen, ibuprofen and lormetazepam were present. Ethanol screening was negative (< 0.1 g/L) and no sulfonylurea were detected. The patient developed multiple organ failure, but eventually recovered.

What happened

The hypoglycaemia was caused by inappropriate stimulation of insulin secretion in a patient intoxicated with tramadol. The sudden hypokalaemia was caused by a massive intracellular shift of potassium in response to the hyperinsulinemia, triggered by the intravenous administration of glucose.

Main lesson

To our knowledge, we are the first to document a significant rise in endogenous insulin production in a hypoglycaemic patient presenting with tramadol intoxication. Our observation suggests that hyperinsulinemia could be the cause of the hypoglycaemia associated with tramadol use.

A Review of the Food and Drug Administration Adverse Event Reporting System for Tramadol-Related Hypoglycemia

Background: Hypoglycemia is a rare adverse effect of tramadol that is described in the medical literature and package insert. Objective: The purpose of this study was to review reports of tramadol and hypoglycemia in the Food and Drug Administration Adverse Event Reporting System (FAERS) database to determine a potential association. Methods: Disproportionality analysis with Bayesian correction was used to compare tramadol and hypoglycemia with other medications in FAERS. The results were considered significant if the fifth percentile of the Empirical Bayesian geometric mean distribution (EB05) >2. Logistic regression odds ratios was used to determine if age, diabetes medications, and renal insufficiency masked the disproportionality of hypoglycemia, with the fifth percentile of the logistic regression odds ratio (LR05) >2 indicating a potential signal. The Interaction Signal Score (INTSS) was computed to determine the influence of predisposing risk factors on the signal. Results: A total of 605 cases of tramadol-associated hypoglycemia were reported, but our results were not significant (EB05: 1.590). Tramadol-associated hypoglycemia was significant in patients who did not take diabetes medications (EB05: 2.256; LR05: 2.2104). Renal insufficiency was not found to increase the risk of tramadol-associated hypoglycemia (INTSS: 0.865). There was a significant signal for tramadol-associated hypoglycemia in patients aged 0 to 1 year (LR05: 3.0240) and 2 to 4 years (LR05: 2.6853). Conclusion and Relevance: Results of our analysis suggest a potential signal between hypoglycemia and tramadol use in patients not taking diabetes medications. Our results do not support a predisposition for tramadol-associated hypoglycemia in patients with renal insufficiency, increasing age, and/or diabetes as noted in the tramadol package insert.

Retrospective analysis reveals significant association of hypoglycemia with tramadol and methadone in contrast to other opioids

Tramadol is one of the most commonly used analgesics worldwide, classified as having a low abuse potential by U.S. Drug Enforcement Agency, and often recommended in pain management guidelines. Its pain-relieving mechanism of action is attributed to mild μ-opioid receptor agonism, serotonin and norepinephrine mediated nociception modulation, and N-methyl-D-aspartate receptor, NMDAR, antagonism. However, recent case reports and case-control studies have shown an association between tramadol use and hypoglycemia. The growing concern over increasing tramadol use and unexpected side effects warranted a further comparative and quantitative analysis of tramadol adverse reactions. In this study we analyzed over twelve million reports from United States Food and Drug Administration Adverse Event Reporting System and provided evidence of increased propensity for hypoglycemia in patients taking tramadol when compared to patients taking other opioids, serotonin-norepinephrine reuptake inhibitors, and drugs affecting NMDAR activity. Additionally, we identified that only methadone from the opioid cohort behaves similarly to tramadol and has an association with hypoglycemia.

Comparative study of hypoglycaemia induced by opioids. Is it a class effect?

Objective: Drug-induced hypoglycaemia has been described with the use of tramadol and methadone. The authors aimed to determine if drug-induced hypoglycaemia could be a class effect for opioids. Methods: The authors performed a disproportionality analysis in VigiBase®, the WHO global individual case safety report database with nine opioids (codeine, fentanyl, hydromorphone, methadone, morphine, oxycodone, tramadol, buprenorphine and nalbuphine) using the broad Standardised MedDRA Query for hypoglycaemia. The authors also carried out a descriptive study of opioid-induced hypoglycaemia in the French PharmacoVigilance DataBase (FPVDB) using the MedDRA Preferred Term 'hypoglycaemia'. Results: The global adjusted Reporting Odds Ratio (aROR) value for the 9 opioids was 1.53 (95% CI 1.52-1.54). The aROR ranged from 1.09 to 1.97 depending on the opioid, but all were statistically significant. A sex ratio of 0.74 was found for the reports of opioid-induced hypoglycaemia in Vigibase®. The authors also found 133 reports of hypoglycaemia in the FPVDB related to opioids. Among the reports, 55 were glycaemic imbalances in diabetics occurring shortly after the start of opioid treatment. Conclusion: This work highlighted a significant association between all opioids and hypoglycaemia, thereby indicating that opioid-induced hypoglycaemia is probably a class effect. Women and/or diabetics seem to be more at risk for developing opioid-induced hypoglycaemia.