Drug Database
MO

morphine (Intramorph / Duramorph / Epimorph)

✓ Approved

Pfizer, Inc. · OPRD1 · Small Molecule

What is morphine?

morphine is a small molecule developed by Pfizer, Inc.. It is approved for therapeutic indications via injectable (others) or intraspinal/intrathecal injection.

Drug Profile

Brand NamesIntramorph, Duramorph, Epimorph
CompanyPfizer, Inc.
Drug ClassSmall Molecule
Molecular TargetOPRD1, OPRK1, OPRM1
RouteInjectable (Others), Intraspinal/Intrathecal Injection
StatusApproved
Sources: ClinicalTrials.gov, Pfizer, Inc.

Mechanism of Action

Molecular Targets

morphine acts on 3 molecular targets:

OPRD1opioid receptor delta 1 (DOR, OPRD)
OPRK1opioid receptor kappa 1 (KOR1, OPRK)
OPRM1opioid receptor mu 1 (MOR1, LMOR)
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Therapeutic Indications

morphine is developed for 1 unique indication across 1 therapeutic area.

Therapeutic AreaConditionPhase
Gastrointestinal disordersAbdominal pain✓ Approved

Related Research Articles

PubMedThe American journal of hospice & palliative care2026-10-16

Rapid-Onset Opioid-Induced Neurotoxicity During Morphine Therapy.

Weilein Erica E, Amoateng Magdelene Doris MD, Bruera Eduardo E

PurposeOpioid therapy is central to cancer pain management and aims to provide effective analgesia while minimizing neurotoxic adverse effects; however, cognitive dysfunction, delirium, and hallucinations continue to be significant complications.SummaryOpioid-induced neurotoxicity (OIN) has been associated with higher opioid doses, poor functional status, and advanced disease burden, and is frequently an underrecognized contributor to delirium. We describe an unusual case of visual and auditory hallucinations shortly after morphine exposure, with prompt reversibility after opioid rotation and recurrence upon rechallenge.ConclusionThis case strengthens the causal association between morphine exposure and hallucinations and emphasizes the importance of early recognition and opioid rotation in reversing opioid-related neurotoxicity.

PMID 42885728
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PubMedJournal of clinical medicine2026-10-16

Comparison of External Oblique Intercostal Plane Block and Subcostal Transversus Abdominis Plane Block for Postoperative Analgesia After Open Radical Gastrectomy: A Single-Blind Randomized Trial.

Mamasaliev Uson U, Taşar Ahmet A, Sönmez Ersin E, Talih Gamze G et al.

Background: Ultrasound-guided fascial plane blocks are increasingly incorporated into multimodal analgesia for upper abdominal surgery. Although both the external oblique intercostal plane (EOIP) block and the subcostal transversus abdominis plane (scTAP) block have been used for postoperative analgesia, evidence directly comparing their efficacy after open radical gastrectomy is lacking. We compared the postoperative analgesic efficacy of bilateral EOIP and bilateral scTAP blocks in patients undergoing open radical gastrectomy. Methods: In this prospective, single-center, randomized, patient-blinded trial, 60 adults undergoing elective open radical gastrectomy were randomly assigned to receive either a bilateral ultrasound-guided EOIP block or a bilateral scTAP block. The primary outcome was cumulative morphine consumption during the first 24 postoperative hours. Secondary outcomes included postoperative Numeric Rating Scale (NRS) scores, rescue analgesic requirements, postoperative nausea and vomiting (PONV), and length of hospital stay. Results: Thirty patients were analyzed in each group. 24 h cumulative morphine consumption did not differ significantly between the EOIP and scTAP groups (24.3 ± 11.4 mg vs. 22.4 ± 8.8 mg, respectively; mean difference 1.9 mg, 95% confidence interval -3.10 to 6.97; p = 0.47). Morphine consumption at 2, 6, and 12 h also showed no statistically significant differences. Postoperative NRS scores showed no significant differences at any time point. Rescue analgesic requirements and the proportion of patients experiencing PONV episodes did not differ significantly between the groups. No complications were observed. Conclusions: Among patients undergoing open radical gastrectomy, no statistically significant differences were detected between bilateral EOIP and bilateral scTAP blocks in postoperative opioid consumption, pain scores, rescue analgesic requirements, or PONV. These findings do not establish equivalence or efficacy relative to standard care without a block and warrant confirmation in larger multicenter trials.

PMID 42882196
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PubMedBalkan medical journal2026-10-16

Anterior Quadratus Lumborum Block for Postoperative Analgesia in Hip Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials with Trial Sequential Analysis.

Dost Burhan B, Karapinar Yunus Emre YE, Turunc Esra E, Turan Engin İhsan Eİ et al.

Postoperative pain following hip surgery remains challenging to manage despite the use of multimodal analgesia. Anterior quadratus lumborum block (aQLB) has been proposed as an effective regional analgesic technique; however, its clinical efficacy remains uncertain. To conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate whether aQLB reduces postoperative opioid consumption and pain following hip surgery. Systematic review and meta-analysis. PubMed, Scopus, Embase, CENTRAL, and Web of Science were systematically searched through March 2026. The primary outcome was 24-hour postoperative opioid consumption. Random-effects models were used for all pooled analyses. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool, and the certainty of evidence was evaluated using the GRADE approach. Subgroup and sensitivity analyses and trial sequential analysis were also performed. Sixteen RCTs involving 994 patients were included in the analysis. aQLB reduced 24-hour postoperative opioid consumption, expressed as morphine milligram equivalents (MME) (mean difference, -6.60 mg; 95% confidence interval, -10.46 to -2.74; p = 0.003; I² = 94%). aQLB also reduced pain scores, postoperative nausea and vomiting (PONV), and rescue analgesic requirements, with no significant differences in time to rescue analgesia, mobilization, or hospital stay. The certainty of evidence was low for 24-hour MME, pain at rest across all assessed time points, and rescue analgesic requirements, and moderate for pain during movement at 6 hours and PONV. aQLB was associated with statistically significant reductions in 24-hour postoperative opioid consumption, early postoperative pain at rest, rescue analgesic requirements, and PONV after hip surgery. However, the magnitude of these benefits was small and did not consistently exceed established thresholds for clinical importance, and the certainty of evidence remained low.

PMID 42885165
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PubMedJournal of clinical medicine2026-10-16

Risk Factors Associated with Spinal Cord Stimulation Failure in Patients with Chronic Pain: A Single-Center Retrospective Cohort Study.

Osailan Ahmed A, Najjar Ahmed A, Fournier-Gosselin Marie-Pierre MP, Fugere Francois F

Background/Objectives: Spinal cord stimulation (SCS) can provide long-term relief for selected patients with refractory chronic pain, but treatment failure may occur without device explantation. This study examined patient-, clinical-, and device-related factors associated with SCS failure after permanent implantation. Methods: This retrospective, single-center cohort study included 108 adults who underwent permanent SCS implantation at the Centre Hospitalier de l'Université de Montréal between 2007 and 2022. Failure was defined as completed or planned explantation, inadequate pain relief accompanied by a desire or plan for removal, or documented device non-use. Associations were evaluated using univariable categorical tests. Paired pain intensity and morphine milligram equivalent (MME) doses were compared using Wilcoxon signed-rank tests. Results: At the most recent documented assessment, composite SCS failure occurred in 40/108 patients (37.0%), and completed explantation occurred in 25/108 (23.1%); these proportions were not adjusted for unequal follow-up duration. The leading reasons for explantation were loss of efficacy (36.0%), paresthesia or dysesthesia (28.0%), and patient request (24.0%). In exploratory univariable analysis, smoking was associated with documented failure (RR = 1.70, 95% CI 1.05-2.75; p = 0.032). Failure differed across comorbidity-count categories (Cramér's V = 0.34, 95% CI 0.00-0.48; p = 0.019), although the pattern was nonmonotonic. Neither association remained statistically significant after Benjamini-Hochberg correction across 26 comparisons (both q = 0.416). Sex, psychiatric history, pain duration, implantation approach, generator type, and generator location were not significantly associated with failure. The median within-patient reduction in pain intensity was 2.50 points (IQR, 1.00-5.00; p < 0.001), whereas the median paired MME change was 0 MME/day (IQR, -60 to 40; p = 0.649). Conclusions: A composite outcome identified a higher prevalence of clinically unsuccessful SCS treatment than completed explantation alone. Smoking showed an unadjusted association with documented failure; however, this finding may reflect confounding or chance arising from multiple comparisons and should be considered hypothesis-generating. Pain intensity improved without a corresponding significant reduction in opioid exposure. These findings require confirmation through prospective, prespecified multivariable and time-to-event analyses.

PMID 42882142
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PubMedAnaesthesia and intensive care2026-10-15

Combined intrathecal and epidural morphine for major abdominal surgery: A two-centre feasibility randomised controlled trial.

Pirie Katrina P KP, Traer Emily A EA, Winter Noam B NB, Brown Wendy A WA et al.

Epidural analgesia using continuous local anaesthetic infusions has declined in popularity, while single-shot intrathecal hydrophilic opioids are increasingly utilised. However, intrathecal opioids have a finite duration of action, which may be insufficient to provide adequate analgesia following major open abdominal surgery. This two-centre randomised controlled trial aimed to determine the feasibility of a strategy combining a single preoperative intrathecal morphine (ITM) injection with postoperative epidural morphine boluses (intervention), compared to ITM alone (control), in terms of recruitment and protocol adherence. Feasibility criteria were met for both recruitment (68%) and protocol adherence (80%). However, the scalability of this study is limited by its resource requirements. Marginal mean pain scores at rest and with movement (dynamic) were similar between groups at all timepoints. Total opioid consumption was comparable between groups, except on postoperative day 1, when consumption was lower in the intervention group (20 mg (IQR 4-36; range 0-220)) compared with the control group (48 mg (IQR 6-94; range 0-212); P=0.04). The number of pruritus events was similar across groups (n = 46), although a greater proportion of patients in the epidural group required treatment with naloxone (14 vs. 5). One patient in the control group received naloxone for sedation; no patients required naloxone for respiratory depression. Further research is required to improve postoperative analgesia and enhance quality of recovery following major abdominal surgery.

PMID 42875999
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PubMedCell2026-10-15

An opioid efficacy switch for reversible optical control of analgesia.

Posa Luca L, Romano Giovanna R GR, Ji Xiang X, Khan Saif S et al.

The mu-opioid receptor (MOR) is a major target for pain treatment, but its effectiveness is limited by dangerous side effects. However, the systemic administration of opioids makes it difficult both to decipher their underlying mechanisms of action and to limit drug action to specific receptor subpopulations to isolate therapeutic effects from adverse effects. Here, we develop a reversibly photoswitchable morphinan agonist termed "azo-morphine-3" (AM-3) that interconverts from low to high efficacy in response to light to enable optical control of MOR signaling. Structural analysis of the low ("trans") and high ("cis") efficacy states of AM-3 bound to the MOR reveals distinct binding modes, with each state driving unique ligand, receptor, and G protein dynamics. In mice, AM-3 drives reversible and repeatable optical control of antinociception across pain models with a reduced side effect profile owing to its limited brain accumulation and its ability to be locally activated.

PMID 42880283
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