Intravenous paracetamol: a review of efficacy and safety in therapeutic use

Evaluation of efficacy and safety of subcutaneous acetaminophen in geriatrics and palliative care (APAPSUBQ)

Introduction

Subcutaneous infusion (SC) or hypodermoclysis is an old perfusion technique that is often used off-label although it has been shown to be effective. Acetaminophen (paracetamol) subcutaneous injection is performed in some centers despite the lack of conclusive evidence on its effectiveness. This study aims to evaluate the efficacy of subcutaneous infusion of Acetaminophen in the treatment of pain and fever in geriatrics and in palliative care and to determine its safety profile and possible side effects.

Material and methods

This experimental study was conducted between 2018 and 2019 on adult patients in palliative care or in geriatrics in several hospitals and nursing homes in Lebanon. Primary outcomes were change in temperature; change in pain score on the numerical rating scale (NS) or on the Algoplus scale after 60 min from the start of the infusion; and the appearance of local side effects at the infusion site. Changes in the various parameters at 30 min and 180 min were also evaluated as secondary outcomes.

Results

Thirty-one patients were included in the study, with a total of 120 doses of acetaminophen. At 60 min, the mean decrease in pain on the NS was 5.35 points, while the mean decrease in temperature was 0.79 degrees Celsius. At 60 min, 75%, CI = [47.62-92.73] of the patients who received acetaminophen for pain and 66.67%, CI = [38.38-88.17] of those who received it for fever had clinically significant improvement. The overall effect of subcutaneous acetaminophen, defined as any clinically significant effect on pain or fever, was 70.97%, CI = [51.96-85.78]. The overall effect at 30 min and at 180 min was 23.33%, CI = [9.93-42.28] and 87.10%, CI = [70.17-96.37], respectively. The side effects reported 30 min after the injection and observed after at least one of the doses were: local edema in 16 patients (51.61%), induration in one patient (3.23%), local pain in one patient (3.23%) and local heat in one patient (3.23%). At 180 min, only 2 patients (6.45%) still had edema at the infusion site.

Conclusion

Subcutaneous administration of acetaminophen is effective and well tolerated in geriatric and palliative care patients. It is appropriate when no other route is available, especially for home-based care. Comparative studies are needed to allow the expansion of this practice.

Efficacy and safety of intravenous paracetamol in management of labour pains in a low resource setting: a randomized clinical trial

OBJECTIVE

To assess the use of single dose of paracetamol intravenously in management of labour pains.

BACKGROUND

Pain during labour is a complex, subjective and multi-faceted physiological phenomenon that varies in intensity among women and is subjected to many social and cultural modifiers.

SUBJECTS AND METHODS

This randomized clinical study was conducted in Obstetrics and gynecology department from March 2019 to March 2020 including 96 primiparous women randomized into paracetamol group (n = 48) received 1000 mg of paracetamol IV infusion and pethidine group (n = 48) received 50 mg of pethidine given slowly IV. Primary outcome is the change of the intensity of perceived labor pain. Pain score was followed and recorded by visual analogue scale (VAS). Our study protocol was registered at ClinicalTrials.gov; NCT04744727.

RESULTS

VAS score was highly significant improved gradually after 30 min, 1, 2 and 3 h of paracetamol and pethidine taken compared at start study, but participants in paracetamol group had lower pain after 2 and 3 h (3.92 ± 1.42 and 5.69 ± 1.07) than those of the pethidine groups (4.42 ± 1.87 and 5.38 ± 1.34). Also, 2.1% of paracetamol group developed dizziness and 4.2% developed nausea and vomiting, while there was 29.2% of pethidine group developed dizziness and 37.5% developed nausea and vomiting.

CONCLUSIONS

Intravenous paracetamol as labour analgesia is effective, safe, inexpensive, available and with no maternal or fetal side effects as compared to Pethidine. Paracetamol needs to have more chance in comparison to other forms as a labour pain analgesia, especially in our communities.

Current State of Analgesia and Sedation in the Pediatric Intensive Care Unit

Critically ill pediatric patients often require complex medical procedures as well as invasive testing and monitoring which tend to be painful and anxiety-provoking, necessitating the provision of analgesia and sedation to reduce stress response. Achieving the optimal combination of adequate analgesia and appropriate sedation can be quite challenging in a patient population with a wide spectrum of ages, sizes, and developmental stages. The added complexities of critical illness in the pediatric population such as evolving pathophysiology, impaired organ function, as well as altered pharmacodynamics and pharmacokinetics must be considered. Undersedation leaves patients at risk of physical and psychological stress which may have significant long term consequences. Oversedation, on the other hand, leaves the patient at risk of needing prolonged respiratory, specifically mechanical ventilator, support, prolonged ICU stay and hospital admission, and higher risk of untoward effects of analgosedative agents. Both undersedation and oversedation put critically ill pediatric patients at high risk of developing PICU-acquired complications (PACs) like delirium, withdrawal syndrome, neuromuscular atrophy and weakness, post-traumatic stress disorder, and poor rehabilitation. Optimal analgesia and sedation is dependent on continuous patient assessment with appropriately validated tools that help guide the titration of analgosedative agents to effect. Bundled interventions that emphasize minimizing benzodiazepines, screening for delirium frequently, avoiding physical and chemical restraints thereby allowing for greater mobility, and promoting adequate and proper sleep will disrupt the PICU culture of immobility and reduce the incidence of PACs.

Development of a Multimatrix UHPLC-MS/MS Method for the Determination of Paracetamol and Its Metabolites in Animal Tissues

Paracetamol/acetaminophen (APAP) is one of the most popular pharmacologically active substances used as an analgesic and antipyretic agent. The metabolism of this drug occurs in the liver and leads to the formation of two main metabolites-glucuronic acid and sulfate derivate. Despite the wide use of paracetamol in veterinary medicine, a handful of analytical methods were published for the determination of paracetamol residues in animal tissues. In this paper, a multimatrix method has been developed for the determination of paracetamol and two metabolites-paracetamol sulfate (PS) and p-Acetamidophenyl β-D-glucuronide (PG). A validation procedure was conducted to verify method reliability and fit purpose as a tool for analyzing acetaminophen and metabolites in muscle, liver, lung, and kidney samples from different species of animals. Established validation parameters were in agreement with acceptable criteria laid by the European legislation. The initial significant matrix effect was successfully reduced by implementing an internal standard-4-Acetamidophenyl β-D-glucuronide-d3 (PG-d3, IS). The usefulness of the developed method was verified by analyzing samples from an experiment in which paracetamol was administrated to geese.

Intravenous versus oral paracetamol for acute pain in adults in the emergency department setting: a prospective, double-blind, double-dummy, randomised controlled trial

OBJECTIVE

To determine if intravenous paracetamol was superior to oral paracetamol as an adjunct to opioids in the management of moderate to severe pain in the ED setting.

METHODS

A prospective, randomised, double-blind, double-dummy, controlled trial was conducted at a single academic tertiary care ED. Adult patients with moderate to severe pain were randomly assigned to receive either the intravenous paracetamol or oral paracetamol. The primary outcome was Visual Analogue Scale (VAS) pain reduction at 30 min. A clinically significant change in pain was defined as 13 mm.

RESULTS

87 participants were included in the final analysis, with a median age of 43.5 years and 59.8% were female. Overall mean baseline VAS pain score was 67.9 mm (±16.0). Both formulations achieved a clinically significant mean pain score reduction at 30 min, with no significant difference between the groups with 16.0 mm (SD 19.1 mm) in the intravenous group and 14.6 mm (SD 26.4) in the oral group; difference -1.4 mm (95% CI -11.6 to 8.8, P=0.79). Secondary outcomes, including postintervention intravenous opioid administration, patient satisfaction, side effects and length of stay, did not differ between groups.

CONCLUSIONS

Overall, there was a small but clinically significant decrease in pain in each group. No superiority was demonstrated in this trial with intravenous paracetamol compared with oral paracetamol in terms of efficacy of analgesia and no difference in length of stay, patient satisfaction, need for rescue analgesia or side effects.

IV acetaminophen: Efficacy of a single dose for postoperative pain after hip arthroplasty: subset data analysis of 2 unpublished randomized clinical trials

Inadequate control of postoperative pain after orthopedic procedures may trigger complications that increase morbidity. Multimodal analgesia is used to manage pain effectively after surgical procedures and reduce the need for rescue analgesia. Intravenous (IV) acetaminophen (OFIRMEV; Cadence Pharmaceuticals, Inc.), an analgesic that has been studied and used in the multimodal management of acute pain after major orthopedic procedures, combines the safety seen with oral and rectal formulations with a preferred route of administration. Two double-blind, randomized, placebo-controlled clinical trials were conducted (total 130 patients) to determine the efficacy and safety of single-dose IV acetaminophen in patients following total hip arthroplasty. Although both studies were stopped prematurely, overlap in patient populations, study design, and methodologies in the single-dose phase of these studies allowed for analysis of their results to be presented concurrently. Both trials demonstrated IV acetaminophen having greater efficacy than placebo in terms of primary endpoints [pain intensity differences from T0.5 to T3 (P < 0.05 in both studies)]. The use of IV acetaminophen also reduced the need for rescue opioid consumption, with patients receiving IV acetaminophen consuming, on average, less than half the amount of rescue medication as those receiving placebo. IV acetaminophen was effective in treating moderate-to-severe pain after total hip arthroplasty and reduced the need for rescue opioid consumption.

Intravenous paracetamol infusion versus intramuscular tramadol as an intrapartum labor analgesic

OBJECTIVES

To compare intravenous paracetamol and intramuscular tramadol as labor analgesics.

METHODS

This prospective-randomized study conducted in 200 primigravidae in active labor, distributed into two groups of 100 women each with one receiving intravenous 1,000 mg Paracetamol and other 100 mg intramuscular tramadol. Pain intensity is recorded by McGills scale before, one and 3 h after drug administration. Perinatal outcome is recorded.

RESULTS

No difference in pain intensity is seen before drug administration. After 1 h of drug administration, in paracetamol group, 4 % women had horrible pain, and 29 % had distressing pain, while in tramadol group, 30 % women had horrible pain, and 60 % had distressing pain. After 3 h of drug administration, in paracetamol group, 26 % had distressing pain, while in tramadol group, 51 % women had horrible pain, and 35 % had distressing pain. Labor duration in paracetamol and tramadol group was 4.3 and 5.9 h, respectively. In paracetamol group, nausea is seen in 2.2 % and vomiting in 1.1 %, while in tramadol group, nausea is seen in 6.4 % and vomiting in 4.3 %.

CONCLUSIONS

Intravenous paracetamol is more effective labor analgesic with fewer maternal adverse effects and shortens labor as compared to intramuscular tramadol.

The effect of intravenous paracetamol on postoperative pain after lumbar discectomy

Study Design

A randomized, double-blinded controlled trial.

Purpose

Postoperative pain relief especially using analgesic drugs with minimal side effects has considerable clinical importance. This study aimed to examine the effect of intravenous paracetamol on pain relief after lumbar discectomy as a major surgery.

Overview of Literature

Patients undergoing lumbar discectomy experience a high degree of lumbar pain. Some authors emphasize the use of intravenous paracetamol to improve postoperative pain and increase patients' satisfaction following this surgery.

Methods

Fifty-two patients scheduled for lumbar discectomy were randomly allocated into two groups: a group that received intravenous paracetamol (1 g/100 mL normal saline) within the last 20 minutes of surgery as the case group (n=24) and a group that received sodium chloride 0.9% 100 mL as the control group (n=28). Postoperative pain was assessed at 1, 6, 12, 18, and 24 hours after surgery by a visual analogue scale (VAS). The dosage of the administered opioid (morphine), as well as drug-related side effects within the first 24 hours after surgery were also recorded.

Results

The mean VAS score was significantly lower in the paracetamol group than the controls for all of the assessed time points. Although the dose of the administered morphine was numerically lower in the paracetamol group, this difference was not statistically significant (5.53±4.49 mL vs. 7.85±4.17 mL).

Conclusions

Intravenous paracetamol as a non-opioid analgesic can relieve postoperative pain in patients undergoing lumbar discectomy; however, its use alone may not represent the best regimen for reducing the needed dose of opioids after operation.

Administration of paracetamol versus dipyrone by intravenous patient-controlled analgesia for postoperative pain relief in children after tonsillectomy

BACKGROUND AND OBJECTIVE

We compared the efficacy of intravenous (IV) paracetamol versus dipyrone via patient-controlled analgesia (PCA) for postoperative pain relief in children.

METHODS

The study was composed of 120 children who had undergone elective tonsillectomy after receiving general anesthesia. Patients were divided into 3 groups according to the dosage of postoperative intravenous-patient-controlled analgesia: paracetamol, dipyrone, or placebo. Pain was evaluated using a 0- to 100-mm visual analog scale and 1- to 4-pain relief score at 30 min, 1, 2, 4, 6, 12, and 24h postoperatively. Pethidine (0.25 mg kg(-1)) was administered intravenously to patients requiring rescue analgesia. Pethidine requirements were recorded during the first 24h postoperatively, and treatment related adverse effects were noted.

RESULTS

Postoperative visual analog scale scores were significantly lower with paracetamol group compared with placebo group at 6h (p<0.05), dipyrone group compared with placebo group at 30 min and 6h (p<0.05). No significant differences regarding visual analog scale values at 1, 2, 4, 12, and 24h were found. No significant differences were found between groups with respect to pain relief score (p>0.05). Postoperative pethidine requirements were significantly lower with paracetamol and dipyrone groups compared with placebo group (62.5%, 68.4% vs 90%, p<0.05). No significant differences were found between groups with respect to nausea, vomiting and the any other adverse effects of the drugs (p>0.05).

CONCLUSIONS

Paracetamol and dipyrone have well tolerability profile and effective analgesic properties when administered IV-PCA for postoperative analgesia in children after tonsillectomy.

Intravenous acetaminophen

Acetaminophen has unique analgesic and antipyretic properties. It is globally recommended as a first-line agent for the treatment of fever and pain due to its few contraindications. Acetaminophen lacks the significant gastrointestinal and cardiovascular side effects associated with nonsteroidal anti-inflammatory drugs and narcotics. An intravenous formulation of acetaminophen is available in Europe and is currently undergoing extensive clinical development for use in the United States. This use may have important implications for management of postoperative pain and fever. This review summarizes recent clinical trial experiences with intravenous acetaminophen for the treatment of postoperative pain and fever in adult and pediatric subjects.

Intravenous paracetamol (acetaminophen)

Intravenous paracetamol (rINN)/intravenous acetaminophen (USAN) is an analgesic and antipyretic agent, recommended worldwide as a first-line agent for the treatment of pain and fever in adults and children. In double-blind clinical trials, single or multiple doses of intravenous paracetamol 1 g generally provided significantly better analgesic efficacy than placebo treatment (as determined by primary efficacy endpoints) in adult patients who had undergone dental, orthopaedic or gynaecological surgery. Furthermore, where evaluated, intravenous paracetamol 1 g generally showed similar analgesic efficacy to a bioequivalent dose of propacetamol, and a reduced need for opioid rescue medication. In paediatric surgical patients, recommended doses of intravenous paracetamol 15 mg/kg were not significantly different from propacetamol 30 mg/kg for the treatment of pain, and showed equivocal analgesic efficacy compared with intramuscular pethidine 1 mg/kg in several randomized, active comparator-controlled studies. In a randomized, noninferiority study in paediatric patients with an infection-induced fever, intravenous paracetamol 15 mg/kg treatment was shown to be no less effective than propacetamol 30 mg/kg in terms of antipyretic efficacy. Intravenous paracetamol was well tolerated in clinical trials, having a tolerability profile similar to placebo. Additionally, adverse reactions emerging from the use of the intravenous formulation of paracetamol are extremely rare (<1/10 000). [table: see text].