Morphine

For an informed discussion with your doctor or pharmacist. This information collection is not a clinically validated interaction checker. Missing data do not establish safety. Do not change or stop prescribed medicines on the basis of this information. The findings apply to the specific conditions studied; laboratory and animal studies cannot be directly extrapolated to humans.

Active substance: Morphine

Examples of brand names: MST Continus [DE]

ATC code: N02AA01

Main use (for orientation): Severe pain

Documented research summary

Direct human pharmacokinetics: Salcedo 2026, morphine 15 mg and CBD 2.5 mg/kg twice daily, cohort initially n=20: acute AUC geometric mean ratio 1.06 (90% CI 0.96–1.16), Cmax 1.19 (1.05–1.35); repeat measurement on day 11 after seven days of CBD pretreatment (nine-day total regimen; n=18), AUC 1.12 (1.00–1.26), Cmax 1.11 (0.94–1.30). Effects on parent morphine were limited. However, AUC∞ of active metabolite M6G increased by 26% after repeated CBD (90% CI 17–36%). Not an absolute null finding or a guarantee for high doses/renal impairment. Abrams 2011, n=21, mixed morphine/oxycodone group with vaporised cannabis: no significant AUC change, pain reduction in an uncontrolled short trial. Naef 2003, n=12, oral THC 20 mg/morphine 30 mg: no consistent analgesic synergy, only slightly additive with electrical stimulation; Roberts 2006, oral THC 5 mg plus intravenous morphine 0.02 mg/kg: synergy only in affective, not sensory pain dimension. Beaulieu 2006, nabilone n=41, postoperative patient-controlled analgesia: no morphine sparing, higher pain scores with nabilone 2 mg every 8 hours. Newer perioperative studies with morphine-equivalent endpoints are not morphine-specific pair studies. Preclinical CBD/THC UGT2B7 inhibition, but PBPK predicts only small exposure change; measured human values take precedence over models. CBG can reduce morphine antinociception in a mouse model; CBDV improves it in preclinical tests. No clinical efficacy/safety proof for rare cannabinoids.

Uncertainties and limitations

Human studies small/short, with different pain models and cannabinoid formulations. A modelled UGT effect is not a clinically proven strong interaction. No direct clinical CBG/CBDV/CBN pair study; older Δ8-THC/CBN withdrawal models partly conflict depending on timing/model. Do not confuse morphine equivalents with actually administered morphine.

Hine 1975 (PMID 1237925) concerns precipitated withdrawal in morphine-dependent rats and CBD or CBN administered in addition to Δ9-THC. Not an isolated morphine–CBD/CBN pair study or proof of analgesic synergy, altered morphine concentrations or safe withdrawal treatment. Original abstract assessed; group sizes, precise exposures and complete statistics unresolved without verified full text.

Separately recorded findings

10 separately recorded findings. Each statement applies to its documented study context.

CBD – clinically studied

Finding ID: B0034

Type of result: No / minor effect under the conditions studied

Observation: Acute CBD co-medication: morphine AUC∞ ratio 1.06 (90% CI 0.96–1.16), Cmax 1.19 (1.05–1.35). Repeated CBD: AUC∞ 1.12 (1.00–1.26), Cmax 1.11 (0.94–1.30). Limited pharmacokinetic effect overall; do not describe as a categorical null finding or exclusion of pharmacodynamic risks. Metabolites separate: after repeated CBD, M6G AUC∞ increased to 1.26 (90% CI 1.17–1.36), M6G AUClast to 1.26 (1.19–1.35), M6G Cmax to 1.11 (1.01–1.21). M3G AUC∞ largely unchanged; acute M3G Cmax increased to 1.12 (1.03–1.21).

Mechanism: UGT probe

Study type: Open-label sequential human pharmacokinetics

Context studied: Healthy adults: 20 enrolled; acute morphine pharmacokinetics n=20, after repeated CBD n=18 (two discontinued early). Morphine 15 mg on days 1, 4 and 11; CBD solution 2.5 mg/kg twice daily (=5 mg/kg/day) on days 4–12, nine days total. Day 4: acute co-medication; day 11: after seven days of pretreatment. Sampling up to 48 hours.

Clinical interpretation: Limited pharmacokinetic signal

Limitations and uncertainties: Limited parent-morphine effects do not exclude pharmacodynamic risks. Active metabolite M6G shows a measurable exposure increase. Do not extrapolate to other opioids, chronic-pain patients or different exposures.

Original sources for this finding: Clinical Study to Evaluate Drug Interactions of Cannabidiol with Citalopram and Morphine in Healthy Adults [CL11]

CBD – laboratory and animal studies

Finding ID: B0107

Type of result: Context-specific finding; read the limitations

Observation: Morphine glucuronidation inhibited in the laboratory; unbound Ki 0.16 µM.

Mechanism: UGT2B7 inhibition

Study type: In vitro plus static modelling

Context studied: Human liver/recombinant microsomes; formation of M3G/M6G.

Clinical interpretation: Clinical significance unresolved

Limitations and uncertainties: Active metabolite M6G also affected; simply equating with stronger analgesia is invalid. Additional context from merged row B0144: laboratory investigation; no corresponding inhibition finding for 7-carboxy-CBD. Human CBD–morphine study shows only a limited effect. Consider total/unbound concentration and model assumptions. Summary row of the same original study as B0107/B0108; do not count as independent evidence.

Original sources for this finding: Cannabinoid-Induced Inhibition of Morphine Glucuronidation and the Potential for In Vivo Drug-Drug Interactions [ME10]

THC – laboratory and animal studies

Finding ID: B0108

Type of result: Context-specific finding; read the limitations

Observation: Morphine glucuronidation inhibited in the laboratory; unbound Ki 0.37 µM.

Mechanism: UGT2B7 inhibition

Study type: In vitro plus static modelling

Context studied: Human liver/recombinant microsomes.

Clinical interpretation: Clinical significance unresolved

Limitations and uncertainties: Static in-vivo prediction not clinically confirmed. Additional context from merged row B0144: laboratory investigation; no corresponding inhibition finding for 7-carboxy-CBD. Human CBD–morphine study shows only a limited effect. Consider total/unbound concentration and model assumptions. Summary row of the same original study as B0107/B0108; do not count as independent evidence.

Original sources for this finding: Cannabinoid-Induced Inhibition of Morphine Glucuronidation and the Potential for In Vivo Drug-Drug Interactions [ME10]

CBD – theoretical plausibility

Finding ID: B0109

Type of result: Context-specific finding; read the limitations

Observation: Modelled morphine AUC increases approximately 5% in healthy people and 10% in cirrhosis, not high clinically measured increases.

Mechanism: UGT2B7 inhibition; dynamic PBPK

Study type: PBPK model

Context studied: Published 2024; model inputs/scenarios limit the conclusion. Virtual healthy and liver-disease populations.

Clinical interpretation: Smaller prediction than the static model; clinical significance unresolved

Limitations and uncertainties: Not a measured combination or evidence of relevant respiratory depression due to this pharmacokinetic change. Not a human experiment; do not confuse with in-vitro/static model findings.

Original sources for this finding: Evaluation of the Drug-Drug Interaction Potential of Cannabidiol Against UGT2B7-Mediated Morphine Metabolism Using Physiologically Based Pharmacokinetic Modeling [ME11]

Oral THC – clinically investigated

Finding ID: B0141

Type of result: Mixed/context-dependent finding

Observation: No general analgesic synergy; combination neutralised THC-induced thermal hyperalgesia, with only a small additive electrical-pain response.

Mechanism: Pharmacodynamic pain processing

Study type: Randomised crossover study

Context studied: n=12 healthy people; oral THC 20 mg and morphine 30 mg.

Clinical interpretation: Model-dependent; no general opioid-sparing evidence

Limitations and uncertainties: Acute experimental pain; mild sedation/other adverse effects. Not chronic clinical pain.

Original sources for this finding: The analgesic effect of oral delta-9-tetrahydrocannabinol (THC), morphine, and a THC-morphine combination in healthy subjects under experimental pain conditions. [CA_P_14499423]

Oral THC – clinically investigated

Finding ID: B0142

Type of result: Mixed/context-dependent finding

Observation: Interaction in the affective pain component (p=0.012), not the sensory component.

Mechanism: Pharmacodynamic

Study type: Human experiment

Context studied: Oral THC 5 mg 90 minutes before intravenous morphine 0.02 mg/kg.

Clinical interpretation: Limited to the endpoint

Limitations and uncertainties: n not stated in the abstract read; no blanket synergy or pharmacokinetic change claimed.

Original sources for this finding: Synergistic affective analgesic interaction between delta-9-tetrahydrocannabinol and morphine. [CA_P_16375890]

Oral nabilone – clinically investigated

Finding ID: B0143

Type of result: No benefit/opposing finding under the investigated conditions

Observation: No difference in morphine consumption; higher pain scores in the nabilone 2 mg group.

Mechanism: Postoperative adjunctive therapy

Study type: Randomised postoperative study

Context studied: n=41; nabilone 1 mg (n=11), 2 mg (n=9), ketoprofen 50 mg (n=11), placebo (n=10) every 8 hours for 24 hours plus morphine patient-controlled analgesia.

Clinical interpretation: No demonstrated opioid-sparing advantage

Limitations and uncertainties: Small groups and a specific postoperative situation; nabilone is not CBD or plant-derived THC.

Original sources for this finding: Effects of nabilone, a synthetic cannabinoid, on postoperative pain. [CA_P_16873343]

CBG – laboratory and animal studies

Finding ID: B0145

Type of result: Mixed preclinical finding

Observation: CBG attenuated acute morphine antinociception in a mouse model; separate withdrawal endpoints instead showed fewer naloxone-induced jumps.

Mechanism: Preclinical pharmacodynamics

Study type: Mouse models

Context studied: CBG/CBD investigation with oxaliplatin and opioid endpoints.

Clinical interpretation: Not a clinical prediction

Limitations and uncertainties: Direction depends on endpoint; no human interaction evidence or general synergy.

Original sources for this finding: Single and Combined Effects of Cannabigerol (CBG) and Cannabidiol (CBD) in Mouse Models of Oxaliplatin-Associated Mechanical Sensitivity, Opioid Antinociception, and Naloxone-Precipitated Opioid Withdrawal. [CA_P_38927352]

CBDV – laboratory and animal studies

Finding ID: B0146

Type of result: Preclinical mechanism

Observation: Morphine antinociception enhanced in the hot-plate model and tolerance development reduced.

Mechanism: Preclinical MD2/TLR4-related signalling modulation

Study type: Preclinical study

Context studied: CBDV, not CBD; published 2022.

Clinical interpretation: Clinical significance unclear

Limitations and uncertainties: No human pharmacokinetics/pharmacodynamics or treatment recommendation.

Original sources for this finding: Cannabidivarin alleviates neuroinflammation by targeting TLR4 co-receptor MD2 and improves morphine-mediated analgesia. [CA_P_36032146]

CBD – laboratory and animal studies

Finding ID: B0147

Type of result: Preclinical null/contrary finding

Observation: CBD 10 mg/kg plus morphine 1 mg/kg showed no synergy in either sex in the mouse formalin model.

Mechanism: Pharmacodynamic combination

Study type: Mouse pain model

Context studied: Sepulveda 2022; model- and dose-dependent finding.

Clinical interpretation: Limited extrapolation

Limitations and uncertainties: Not evidence of absent interaction in other models or humans.

Original sources for this finding: Evaluating the Antinociceptive Efficacy of Cannabidiol Alone or in Combination with Morphine Using the Formalin Test in Male and Female Mice. [CA_P_34846928]

References and access status

[CA_L_D0139] MS CONTIN (MORPHINE SULFATE) TABLET, FILM COATED, EXTENDED RELEASE [RHODES PHARMACEUTICALS LLC]

Original source / bibliographic reference

Authors: Rhodes Pharmaceuticals LLC

Year: 2026

Source type: Current published human-use SPL / product information

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

[CL11] Clinical Study to Evaluate Drug Interactions of Cannabidiol with Citalopram and Morphine in Healthy Adults

Original source / bibliographic reference

Authors: Salcedo P; Volpe DA; Chaturbedi A; Shah A; Krishna A; Hyland PL; Vegesna G; Hsiao CH; De Palma R; Fein M; Rouse R; Florian J

Year: 2026

Source type: Open-label sequential human pharmacokinetic study

DOI: 10.1002/cpt.70219

PMID: 41622700

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_14499423] The analgesic effect of oral delta-9-tetrahydrocannabinol (THC), morphine, and a THC-morphine combination in healthy subjects under experimental pain conditions.

Original source / bibliographic reference

Authors: Naef M, Curatolo M, Petersen-Felix S, Arendt-Nielsen L, Zbinden A, Brenneisen R.

Year: 2003

Source type: Clinical Trial; Research Support, Non-U.S. Gov't; Randomized Controlled Trial; Journal Article

DOI: 10.1016/s0304-3959(03)00163-5

PMID: 14499423

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_16375890] Synergistic affective analgesic interaction between delta-9-tetrahydrocannabinol and morphine.

Original source / bibliographic reference

Authors: Roberts JD, Gennings C, Shih M.

Year: 2006

Source type: Controlled Clinical Trial; Research Support, Non-U.S. Gov't; Journal Article

DOI: 10.1016/j.ejphar.2005.11.036

PMID: 16375890

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_22048225] Cannabinoid-opioid interaction in chronic pain.

Original source / bibliographic reference

Authors: Abrams DI, Couey P, Shade SB, Kelly ME, Benowitz NL.

Year: 2011

Source type: Controlled Clinical Trial; Journal Article; Research Support, N.I.H., Extramural

DOI: 10.1038/clpt.2011.188

PMID: 22048225

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_16873343] Effects of nabilone, a synthetic cannabinoid, on postoperative pain.

Original source / bibliographic reference

Authors: Beaulieu P.

Year: 2006

Source type: Comparative Study; Research Support, Non-U.S. Gov't; Randomized Controlled Trial; Journal Article

DOI: 10.1007/bf03022793

PMID: 16873343

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[ME10] Cannabinoid-Induced Inhibition of Morphine Glucuronidation and the Potential for In Vivo Drug-Drug Interactions

Original source / bibliographic reference

Authors: Coates S; Bardhi K; Lazarus P

Year: 2024

Source type: Original study: in-vitro UGT and static modelling

DOI: 10.3390/pharmaceutics16030418

PMID: 38543313

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[ME11] Evaluation of the Drug-Drug Interaction Potential of Cannabidiol Against UGT2B7-Mediated Morphine Metabolism Using Physiologically Based Pharmacokinetic Modeling

Original source / bibliographic reference

Authors: Coates S; Bardhi K; Prasad B; Lazarus P

Year: 2024

Source type: Original study: PBPK modelling

DOI: 10.3390/pharmaceutics16121599

PMID: 39771577

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

PubMed – bibliographic reference / abstract

[CA_P_38927352] Single and Combined Effects of Cannabigerol (CBG) and Cannabidiol (CBD) in Mouse Models of Oxaliplatin-Associated Mechanical Sensitivity, Opioid Antinociception, and Naloxone-Precipitated Opioid Withdrawal.

Original source / bibliographic reference

Authors: Hayduk SA, Hughes AC, Winter RL, Milton MD, Ward SJ.

Year: 2024

Source type: research-article; Journal Article

DOI: 10.3390/biomedicines12061145

PMID: 38927352

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_36032146] Cannabidivarin alleviates neuroinflammation by targeting TLR4 co-receptor MD2 and improves morphine-mediated analgesia.

Original source / bibliographic reference

Authors: Wang X, Lin C, Wu S, Zhang T, Wang Y, Jiang Y, Wang X.

Year: 2022

Source type: research-article; Journal Article

DOI: 10.3389/fimmu.2022.929222

PMID: 36032146

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_40840120] Effects of Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), and THC:CBD mixtures on behavioral and physiological signs of morphine withdrawal in rhesus monkeys.

Original source / bibliographic reference

Authors: Carey LM, Galbo-Thomma LK, Maguire DR, France CP.

Year: 2025

Source type: research-article; Journal Article

DOI: 10.1016/j.jpet.2025.103671

PMID: 40840120

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_34561365] No antinociceptive synergy between morphine and delta-9-tetrahydrocannabinol in male and female rats with persistent inflammatory pain.

Original source / bibliographic reference

Authors: Britch SC, Craft RM.

Year: 2021

Source type: Research Support, Non-U.S. Gov't; research-article; Journal Article; Research Support, N.I.H., Extramural

DOI: 10.1097/fbp.0000000000000657

PMID: 34561365

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_39718050] Morphine-induced side effects can be differentially modulated by cannabidiol in male and female rats.

Original source / bibliographic reference

Authors: Alves Jesus CH, Volpe J, Sotomaior BB, Barbosa MAR, Ferreira MV, Fiatcoski F, Genaro K, de Souza Crippa JA, Pires Souto DE, Maria da Cunha J.

Year: 2025

Source type: Research Support, Non-U.S. Gov't; Journal Article

DOI: 10.1097/fbp.0000000000000803

PMID: 39718050

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_34846928] Evaluating the Antinociceptive Efficacy of Cannabidiol Alone or in Combination with Morphine Using the Formalin Test in Male and Female Mice.

Original source / bibliographic reference

Authors: Sepulveda DE, Morris DP, Raup-Konsavage WM, Sun D, Vrana KE, Graziane NM.

Year: 2022

Source type: Research Support, Non-U.S. Gov't; research-article; Journal Article

DOI: 10.1089/can.2021.0108

PMID: 34846928

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_33303398] The effect of cannabidiol on sevoflurane minimum alveolar concentration reduction produced by morphine in rats.

Original source / bibliographic reference

Authors: Orden C, Santos M, Ceprian M, Tendillo FJ.

Year: 2021

Source type: Journal Article

DOI: 10.1016/j.vaa.2020.04.017

PMID: 33303398

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_1237925] Differential effect of cannabinol and cannabidiol on THC-induced responses during abstinence in morphine-dependent rats.

Original source / bibliographic reference

Authors: Hine B, Torrelio M, Gershon S.

Year: 1975

Source type: Rat withdrawal-model experiment; original abstract assessed, original full text not verified

PMID: 1237925

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

Unresolved access questions / further review: The official original abstract was scientifically reassessed on 23 October 2026: CBN or CBD in addition to Δ9-THC in a withdrawal model of morphine-dependent rats, not an isolated CBD/CBN–morphine pair study. Europe PMC contains bibliographic data and abstract, not full text. Group sizes, precise exposures and complete statistics remain unassessed; clinical extrapolation not established.

Europe PMC – bibliographic data and abstract (JSON; not full text) – Official bibliographic record successfully checked. The view is machine-readable and is not the original full text.

[CA_P_2994117] The quasi-morphine withdrawal syndrome: effect of cannabinol, cannabidiol and tetrahydrocannabinol.

Original source / bibliographic reference

Authors: Chesher GB, Jackson DM.

Year: 1985

Source type: Comparative Study; Journal Article

DOI: 10.1016/0091-3057(85)90122-4

PMID: 2994117

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_826944] Effect of some cannabinoids on naloxone-precipitated abstinence in morphine-dependent mice.

Original source / bibliographic reference

Authors: Bhargava HN.

Year: 1976

Source type: Journal Article

DOI: 10.1007/bf00426828

PMID: 826944

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_564515] Time course of the effects of naturally occurring cannabinoids on morphine abstinence syndrome.

Original source / bibliographic reference

Authors: Bhargava HN.

Year: 1978

Source type: Journal Article

DOI: 10.1016/0091-3057(78)90115-6

PMID: 564515

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_40839512] The effects of vaped cannabis on the severity of naloxone-precipitated opioid withdrawal.

Original source / bibliographic reference

Authors: Jones JD, Martinez S, Arout C, Haney M, Castillo F, Manubay J, Perez F, Luba RR, Comer SD.

Year: 2026

Source type: research-article; Journal Article

DOI: 10.1037/pha0000796

PMID: 40839512

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_36028000] Cannabidiol enhances the antinociceptive effects of morphine and attenuates opioid-induced tolerance in the chronic constriction injury model.

Original source / bibliographic reference

Authors: Jesus CHA, Ferreira MV, Gasparin AT, Rosa ES, Genaro K, Crippa JAS, Chichorro JG, Cunha JMD.

Year: 2022

Source type: Research Support, Non-U.S. Gov't; Journal Article

DOI: 10.1016/j.bbr.2022.114076

PMID: 36028000

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_25485642] Distinct interactions of cannabidiol and morphine in three nociceptive behavioral models in mice.

Original source / bibliographic reference

Authors: Neelakantan H, Tallarida RJ, Reichenbach ZW, Tuma RF, Ward SJ, Walker EA.

Year: 2015

Source type: Research Support, Non-U.S. Gov't; Journal Article

DOI: 10.1097/fbp.0000000000000119

PMID: 25485642

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_30223868] Cannabidiol enhances morphine antinociception, diminishes NMDA-mediated seizures and reduces stroke damage via the sigma 1 receptor.

Original source / bibliographic reference

Authors: Rodríguez-Muñoz M, Onetti Y, Cortés-Montero E, Garzón J, Sánchez-Blázquez P.

Year: 2018

Source type: Research Support, Non-U.S. Gov't; research-article; Journal Article

DOI: 10.1186/s13041-018-0395-2

PMID: 30223868

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_12604676] Antinociceptive synergy between delta(9)-tetrahydrocannabinol and opioids after oral administration.

Original source / bibliographic reference

Authors: Cichewicz DL, McCarthy EA.

Year: 2003

Source type: Research Support, U.S. Gov't, P.H.S.; Journal Article

DOI: 10.1124/jpet.102.045575

PMID: 12604676

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_29807027] Ventilatory-depressant effects of opioids alone and in combination with cannabinoids in rhesus monkeys.

Original source / bibliographic reference

Authors: Weed PF, Gerak LR, France CP.

Year: 2018

Source type: research-article; Journal Article

DOI: 10.1016/j.ejphar.2018.05.041

PMID: 29807027

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_36937502] High-CBD Cannabis Vapor Attenuates Opioid Reward and Partially Modulates Nociception in Female Rats.

Original source / bibliographic reference

Authors: Rivera-Garcia MT, Rose RM, Wilson-Poe AR.

Year: 2023

Source type: research-article; Journal Article

DOI: 10.1016/j.addicn.2022.100050

PMID: 36937502

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_41525358] Effects of oral cannabidiol (CBD) on spontaneous opioid withdrawal in male and female rats.

Original source / bibliographic reference

Authors: Jenkins BW, Pang C, Kuang RY, Weerts EM, Moore CF.

Year: 2026

Source type: Journal Article

DOI: 10.1037/pha0000826

PMID: 41525358

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_41747636] Potential effects of cannabidiol on formalin-induced inflammatory pain in morphine-dependent rats.

Original source / bibliographic reference

Authors: Aalidaeijavadi Z, Khodagholi F, Haghparast A.

Year: 2026

Source type: Research Support, Non-U.S. Gov't; Journal Article

DOI: 10.1016/j.jpsychires.2026.02.042

PMID: 41747636

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_41874946] Cannabidiol (CBD) modulates the serotonin-kynurenine metabolic balance in the brain of morphine-tolerant neuropathic rats.

Original source / bibliographic reference

Authors: Nasini S, Pearl-Dowler L, Lopez-Canul M, Posa L, Bertazzo A, Gobbi G, Comai S.

Year: 2026

Source type: research-article; Journal Article

DOI: 10.1007/s43440-026-00850-w

PMID: 41874946

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_34676322] Effects of Cannabidiol and a Novel Cannabidiol Analog against Tactile Allodynia in a Murine Model of Cisplatin-Induced Neuropathy: Enhanced Effects of Sub-Analgesic Doses of Morphine.

Original source / bibliographic reference

Authors: Harris HM, Gul W, ElSohly MA, Sufka KJ.

Year: 2018

Source type: research-article; Journal Article

DOI: 10.1159/000489077

PMID: 34676322

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_28793355] Effects of Cannabidiol on Morphine Conditioned Place Preference in Mice.

Original source / bibliographic reference

Authors: Markos JR, Harris HM, Gul W, ElSohly MA, Sufka KJ.

Year: 2018

Source type: Journal Article

DOI: 10.1055/s-0043-117838

PMID: 28793355

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_26833888] Cannabidiol disrupts the reconsolidation of contextual drug-associated memories in Wistar rats.

Original source / bibliographic reference

Authors: de Carvalho CR, Takahashi RN.

Year: 2017

Source type: Journal Article

DOI: 10.1111/adb.12366

PMID: 26833888

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_22862835] Cannabidiol inhibits the reward-facilitating effect of morphine: involvement of 5-HT1A receptors in the dorsal raphe nucleus.

Original source / bibliographic reference

Authors: Katsidoni V, Anagnostou I, Panagis G.

Year: 2013

Source type: Research Support, Non-U.S. Gov't; Journal Article

DOI: 10.1111/j.1369-1600.2012.00483.x

PMID: 22862835

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_17498686] Synergy between delta9-tetrahydrocannabinol and morphine in the arthritic rat.

Original source / bibliographic reference

Authors: Cox ML, Haller VL, Welch SP.

Year: 2007

Source type: Journal Article; Research Support, N.I.H., Extramural

DOI: 10.1016/j.ejphar.2007.04.010

PMID: 17498686

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_11331071] Cannabinoid-induced alterations in brain disposition of drugs of abuse.

Original source / bibliographic reference

Authors: Reid MJ, Bornheim LM.

Year: 2001

Source type: Research Support, U.S. Gov't, P.H.S.; Journal Article

DOI: 10.1016/s0006-2952(01)00616-5

PMID: 11331071

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

Research as of 23 October 2026. Not all original full texts could be reviewed in full. Source accessibility and the strength of scientific evidence must be assessed separately. An accessible link does not establish medical approval; a bibliographic record with an abstract does not replace the original full text.

Drug search and explanation of the evidence · Guide: cannabinoids and medicines · Author and responsibility