Multi Drug Resistant OrganismsNCT07505446
Characterization of the Synergistic Antibacterial Effect of Verapamil on Bacterial Isolates From Cancer Patients
An observational study of Multi Drug Resistant Organisms and Antibiotic Resistance, run by Assiut University.
Trial summary
Multidrug-resistant (MDR) bacteria represent a significant global health challenge, particularly among immunocompromised populations such as cancer patients undergoing chemotherapy. Read more about this study
- Who is it for?
- Ages 18 to 90 years
- Conditions the study is for
- Multi Drug Resistant Organisms, Antibiotic Resistance
- What is being tested?
- verapamil
- How many people
- 100 participants
- Where
- No sites listed yet
- Study dates
- 1 May 2026to 1 Jun 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 90 years
- All sexes
- Adult, Older adult
Study population: The study will be carried out on clinical specimens of cancer patients already withdrawn for routine testing during the study period
Who may be able to join
- Bacterial isolates from clinical samples submitted for the SECI laboratory for culture and sensitivity testing that are:
- MDR: resistant to one or more agent within three or more of antimicrobial classes
- XDR: resistant to one or more agent within all but two antimicrobial classes
- PDR: resistant to all agents within all antimicrobial classes.
Who cannot join
- Bacterial isolates from non-cancer patients.
- Contaminant or non-pathogenic isolates.
- Duplicate isolates from the same patient with identical antibiogram.
- Bacterial isolates that are neither MDR, XDR OR PDR.
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Characterization of the Synergistic Antibacterial Effect of Verapamil on Bacterial Isolates From Patients in South Egypt Cancer Institute
Multidrug-resistant (MDR) bacteria represent a significant global health challenge, particularly among immunocompromised populations such as cancer patients undergoing chemotherapy. These patients are highly susceptible to severe infections due to weakened immune defenses, often necessitating the use of broad-spectrum or combination antibiotic therapy. Combination regimens may enhance treatment efficacy through synergistic effects, helping to overcome bacterial resistance mechanisms and improve clinical outcomes.
In recent years, there has been growing interest in the use of non-antibiotic drugs as adjunctive agents to enhance antimicrobial activity. These agents, often referred to as antibiotic adjuvants or resistance modifiers, may improve antibiotic effectiveness through mechanisms such as inhibition of bacterial efflux pumps, disruption of biofilm formation, or interference with resistance pathways.
Read more
Verapamil, a widely used calcium channel blocker, has demonstrated potential antimicrobial and resistance-modifying properties. Experimental evidence suggests that verapamil can inhibit bacterial efflux pumps, thereby increasing intracellular concentrations of antibiotics and enhancing their activity against resistant organisms.
This study aims to evaluate the in vitro synergistic antibacterial activity of verapamil in combination with selected antibiotics against MDR, extensively drug-resistant (XDR), and pandrug-resistant (PDR) bacterial isolates obtained from cancer patients. Standard microbiological methods will be used to determine antimicrobial susceptibility and minimum inhibitory concentrations, while combination effects will be assessed using established synergy testing approaches.
The findings of this study may contribute to identifying novel, cost-effective strategies to combat antimicrobial resistance through drug repurposing and optimization of existing antibiotic therapies.
Read the detailed description
This study evaluates the potential synergistic antibacterial effect of verapamil in combination with selected antibiotics against multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR) bacterial isolates obtained from cancer patients.
- Study Samples Clinical specimens will be collected as part of routine diagnostic care from cancer patients. Specimen types may include: Blood Urine Respiratory samples Wound swabs Other relevant clinical specimens Only non-duplicate bacterial isolates will be included. Only isolates classified as MDR, XDR, or PDR will be selected for further analysis.
- Isolation of Bacterial Isolates Specimens will be cultured using standard microbiological techniques. Culture media will include: Blood agar MacConkey agar Plates will be incubated under appropriate conditions (temperature and atmosphere) according to standard laboratory protocols.
- Identification of Bacteria Bacterial isolates will be identified using: Colony morphology Gram staining Biochemical tests Where available, automated identification systems will be used. Identification procedures will follow standard microbiological guidelines.
- Antimicrobial Susceptibility Testing (AST) AST will be performed according to: Clinical and Laboratory Standards Institute (CLSI), 2025 guidelines Methods include: Kirby-Bauer disk diffusion method Automated susceptibility testing systems (if available) Results will be interpreted using CLSI breakpoints. Quality control will be ensured using standard reference strains.
- Preparation of Verapamil Verapamil stock solution will be prepared: Under aseptic conditions Using sterile distilled water or appropriate solvent Serial dilutions will be prepared to achieve required working concentrations.
- Determination of Minimum Inhibitory Concentrations (MICs) MICs for: Selected antibiotics Verapamil Will be determined using: Broth microdilution method Procedures include: Preparation of serial twofold dilutions Standardization of bacterial inoculum (e.g., 0.5 McFarland) Incubation under appropriate conditions MIC values will be recorded as the lowest concentration inhibiting visible growth.
- Assessment of Synergistic Activity Synergy testing will be performed using: Checkerboard assay Interaction between verapamil and antibiotics will be evaluated by calculating: Fractional Inhibitory Concentration Index (FICI) Interpretation of FICI: ≤ 0.5 → Synergistic > 0.5 - 1 → Additive > 1 - 4 → Indifferent > 4 → Antagonistic
- Additional/Confirmatory Testing Where applicable, additional methods may be used: Disk diffusion-based combination testing These methods will support and validate synergy findings.
- Exploratory Analysis If significant synergy is observed: Further analysis may be conducted to investigate resistance mechanisms This may include: Evaluation of changes in resistance patterns Analysis of resistance-related gene expression (if feasible)
- Quality Control and Laboratory Standards
All procedures will follow:
Standard microbiological protocols Institutional biosafety regulations
Quality assurance measures will be applied to ensure:
Accuracy Reproducibility Reliability of results
- Being tested
- verapamil
- Keywords
- Verapamil, Antibiotic Adjuvant, Efflux Pump Inhibitor, Antimicrobial Synergy, Checkerboard Assay, Fractional Inhibitory Concentration Index (FICI), Minimum Inhibitory Concentration (MIC), MDR / XDR / PDR Bacteria, Cancer Patient Isolates
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
verapamilDrug
Intervention Name: Verapamil Other Names: Verapamil hydrochloride Clinical specimens from cancer patients collected for routine testing will be included. Bacterial isolates will be cultured on appropriate media and identified using standard microbiological methods and/or automated systems. Antimicrobial susceptibility testing will be performed using the Kirby-Bauer disk diffusion method or automated systems according to CLSI 2025 guidelines.
A stock solution of verapamil will be prepared under aseptic conditions. The antibacterial activity of selected antibiotics alone and in combination with verapamil will be evaluated. Minimum inhibitory concentrations (MICs) will be determined using the broth microdilution method. Synergistic interactions will be assessed using the checkerboard method and quantified by fractional inhibitory concentration index (FICI).
What is being measured
The primary outcome is the main question the study is designed to answer.
Characterization of the synergistic antibacterial effect of Verapamil on bacterial isolates from patients in South Egypt Cancer Institute
Determination of the antibiotic sensitivity patterns of the bacterial isolates as measured by MIC values
Measured: Baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Apr 2026
- Study start1 May 2026 (estimated)
- Primary completion1 May 2027 (estimated)
- Study completion1 Jun 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (6)Papers the sponsor has linked to this study.
- Other trials for Multi Drug Resistant OrganismsStudies of the same condition, open and under way.
- More trials run by Assiut UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Prospective
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Assiut University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ahmed Ibrahim Khalaf Mohamed, Assiut University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07505446
- Sponsor's protocol ID
- Verapamil use in MDR bacteria
- Status last verified
- Apr 2026
- First submitted
- 26 Mar 2026
- Last updated
- 8 Apr 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Yin Q, Shen J, Zhang Z, Yu H, Li Y. Reversal of multidrug resistance by stimuli-responsive drug delivery systems for therapy of tumor. Adv Drug Deliv Rev. 2013 Nov;65(13-14):1699-715. doi: 10.1016/j.addr.2013.04.011. Epub 2013 Apr 20.
PubMed 23611952Jang J, Kim R, Woo M, Jeong J, Park DE, Kim G, Delorme V. Efflux Attenuates the Antibacterial Activity of Q203 in Mycobacterium tuberculosis. Antimicrob Agents Chemother. 2017 Jun 27;61(7):e02637-16. doi: 10.1128/AAC.02637-16. Print 2017 Jul.
PubMed 28416541Vega-Chacon Y, de Albuquerque MC, Pavarina AC, Goldman GH, Mima EGO. Verapamil inhibits efflux pumps in Candida albicans, exhibits synergism with fluconazole, and increases survival of Galleria mellonella. Virulence. 2021 Dec;12(1):231-243. doi: 10.1080/21505594.2020.1868814.
PubMed 33410730Duckett SG, Ginks M, Shetty AK, Knowles BR, Totman JJ, Chiribiri A, Ma YL, Razavi R, Schaeffter T, Carr-White G, Rhode K, Rinaldi CA. Realtime fusion of cardiac magnetic resonance imaging and computed tomography venography with X-ray fluoroscopy to aid cardiac resynchronisation therapy implantation in patients with persistent left superior vena cava. Europace. 2011 Feb;13(2):285-6. doi: 10.1093/europace/euq383. Epub 2010 Oct 25. No abstract available.
PubMed 20974762Soons JA, Ricci AJ, Steele CR, Puria S. Cytoarchitecture of the mouse organ of corti from base to apex, determined using in situ two-photon imaging. J Assoc Res Otolaryngol. 2015 Feb;16(1):47-66. doi: 10.1007/s10162-014-0497-1. Epub 2014 Oct 28.
PubMed 25348579Enoh J, Orega M, Yao A, Cisse L, Couitchere L, Attimere Y, Niangue M, Andoh J. [Choleriform diarrhea in children in Abdijan]. Arch Pediatr. 2003 Nov;10(11):1009-10. doi: 10.1016/j.arcped.2003.09.026. No abstract available. French.
PubMed 14613700
Study at a glance
From the registry record, last updated by the sponsor on 8 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Characterization of the Synergistic Antibacterial Effect of Verapamil on Bacterial Isolates From Patients in South Egypt Cancer Institute
- ClinicalTrials.gov ID
- NCT07505446
- Acronym / sponsor ID
- Verapamil use in MDR bacteria
- Keywords
- Verapamil, Antibiotic Adjuvant, Efflux Pump Inhibitor, Antimicrobial Synergy, Checkerboard Assay, Fractional Inhibitory Concentration Index (FICI), Minimum Inhibitory Concentration (MIC), MDR / XDR / PDR Bacteria
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Assiut UniversityUniversity, hospital or other
- Study start
- 1 May 2026 (estimated)
- Primary completion
- 1 May 2027 (estimated)
- Study completion
- 1 Jun 2027 (estimated)
- First posted
- 1 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Multidrug-resistant (MDR) bacteria represent a significant global health challenge, particularly among immunocompromised populations such as cancer patients undergoing chemotherapy. These patients are highly susceptible to severe infections due to weakened immune defenses, often necessitating the use of broad-spectrum or combination antibiotic therapy. Combination regimens may enhance treatment efficacy through synergistic effects, helping to overcome bacterial resistance mechanisms and improve clinical outcomes.
In recent years, there has been growing interest in the use of non-antibiotic drugs as adjunctive agents to enhance antimicrobial activity. These agents, often referred to as antibiotic adjuvants or resistance modifiers, may improve antibiotic effectiveness through mechanisms such as inhibition of bacterial efflux pumps, disruption of biofilm formation, or interference with resistance pathways.
Verapamil, a widely used calcium channel blocker, has demonstrated potential antimicrobial and resistance-modifying properties. Experimental evidence suggests that verapamil can inhibit bacterial efflux pumps, thereby increasing intracellular concentrations of antibiotics and enhancing their activity against resistant organisms.
This study aims to evaluate the in vitro synergistic antibacterial activity of verapamil in combination with selected antibiotics against MDR, extensively drug-resistant (XDR), and pandrug-resistant (PDR) bacterial isolates obtained from cancer patients. Standard microbiological methods will be used to determine antimicrobial susceptibility and minimum inhibitory concentrations, while combination effects will be assessed using established synergy testing approaches.
The findings of this study may contribute to identifying novel, cost-effective strategies to combat antimicrobial resistance through drug repurposing and optimization of existing antibiotic therapies.
Detailed description
This study evaluates the potential synergistic antibacterial effect of verapamil in combination with selected antibiotics against multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR) bacterial isolates obtained from cancer patients.
- Study Samples Clinical specimens will be collected as part of routine diagnostic care from cancer patients. Specimen types may include: Blood Urine Respiratory samples Wound swabs Other relevant clinical specimens Only non-duplicate bacterial isolates will be included. Only isolates classified as MDR, XDR, or PDR will be selected for further analysis.
- Isolation of Bacterial Isolates Specimens will be cultured using standard microbiological techniques. Culture media will include: Blood agar MacConkey agar Plates will be incubated under appropriate conditions (temperature and atmosphere) according to standard laboratory protocols.
- Identification of Bacteria Bacterial isolates will be identified using: Colony morphology Gram staining Biochemical tests Where available, automated identification systems will be used. Identification procedures will follow standard microbiological guidelines.
- Antimicrobial Susceptibility Testing (AST) AST will be performed according to: Clinical and Laboratory Standards Institute (CLSI), 2025 guidelines Methods include: Kirby-Bauer disk diffusion method Automated susceptibility testing systems (if available) Results will be interpreted using CLSI breakpoints. Quality control will be ensured using standard reference strains.
- Preparation of Verapamil Verapamil stock solution will be prepared: Under aseptic conditions Using sterile distilled water or appropriate solvent Serial dilutions will be prepared to achieve required working concentrations.
- Determination of Minimum Inhibitory Concentrations (MICs) MICs for: Selected antibiotics Verapamil Will be determined using: Broth microdilution method Procedures include: Preparation of serial twofold dilutions Standardization of bacterial inoculum (e.g., 0.5 McFarland) Incubation under appropriate conditions MIC values will be recorded as the lowest concentration inhibiting visible growth.
- Assessment of Synergistic Activity Synergy testing will be performed using: Checkerboard assay Interaction between verapamil and antibiotics will be evaluated by calculating: Fractional Inhibitory Concentration Index (FICI) Interpretation of FICI: ≤ 0.5 → Synergistic > 0.5 - 1 → Additive > 1 - 4 → Indifferent > 4 → Antagonistic
- Additional/Confirmatory Testing Where applicable, additional methods may be used: Disk diffusion-based combination testing These methods will support and validate synergy findings.
- Exploratory Analysis If significant synergy is observed: Further analysis may be conducted to investigate resistance mechanisms This may include: Evaluation of changes in resistance patterns Analysis of resistance-related gene expression (if feasible)
- Quality Control and Laboratory Standards
All procedures will follow:
Standard microbiological protocols Institutional biosafety regulations
Quality assurance measures will be applied to ensure:
Accuracy Reproducibility Reliability of results
Study design
- Observational model
- Other
- Time perspective
- Prospective
Who may qualify
- Ages
- 18 to 90 years
- Sex
- All
- Age groups
- Adult, Older adult
- Study population
- The study will be carried out on clinical specimens of cancer patients already withdrawn for routine testing during the study period
Key inclusion criteria (4 listed)
- Bacterial isolates from clinical samples submitted for the SECI laboratory for culture and sensitivity testing that are:
- MDR: resistant to one or more agent within three or more of antimicrobial classes
- XDR: resistant to one or more agent within all but two antimicrobial classes
- PDR: resistant to all agents within all antimicrobial classes.
Key exclusion criteria (4 listed)
- Bacterial isolates from non-cancer patients.
- Contaminant or non-pathogenic isolates.
- Duplicate isolates from the same patient with identical antibiogram.
- Bacterial isolates that are neither MDR, XDR OR PDR.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| verapamilIntervention Name: Verapamil Other Names: Verapamil hydrochloride Clinical specimens from cancer patients collected for routine testing will be included. Bacterial isolates will be cultured on appropriate media and identified using standard microbiological methods and/or automated systems. Antimicrobial susceptibility testing will be performed using the Kirby-Bauer disk diffusion method or automated systems according to CLSI 2025 guidelines. A stock solution of verapamil will be prepared under aseptic conditions. The antibacterial activity of selected antibiotics alone and in combination with verapamil will be evaluated. Minimum inhibitory concentrations (MICs) will be determined using the broth microdilution method. Synergistic interactions will be assessed using the checkerboard method and quantified by fractional inhibitory concentration index (FICI). | Drug | – |
Primary outcome
Characterization of the synergistic antibacterial effect of Verapamil on bacterial isolates from patients in South Egypt Cancer Institute
Time frame: Baseline
Determination of the antibiotic sensitivity patterns of the bacterial isolates as measured by MIC values
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Apr 2026.
- Background: PubMed 23611952Yin Q, Shen J, Zhang Z, Yu H, Li Y. Reversal of multidrug resistance by stimuli-responsive drug delivery systems for therapy of tumor. Adv Drug Deliv Rev. 2013 Nov;65(13-14):1699-715. doi: 10.1016/j.addr.2013.04.011. Epub 2013 Apr 20.
- Background: PubMed 28416541Jang J, Kim R, Woo M, Jeong J, Park DE, Kim G, Delorme V. Efflux Attenuates the Antibacterial Activity of Q203 in Mycobacterium tuberculosis. Antimicrob Agents Chemother. 2017 Jun 27;61(7):e02637-16. doi: 10.1128/AAC.02637-16. Print 2017 Jul.
- Background: PubMed 33410730Vega-Chacon Y, de Albuquerque MC, Pavarina AC, Goldman GH, Mima EGO. Verapamil inhibits efflux pumps in Candida albicans, exhibits synergism with fluconazole, and increases survival of Galleria mellonella. Virulence. 2021 Dec;12(1):231-243. doi: 10.1080/21505594.2020.1868814.
- Background: PubMed 20974762Duckett SG, Ginks M, Shetty AK, Knowles BR, Totman JJ, Chiribiri A, Ma YL, Razavi R, Schaeffter T, Carr-White G, Rhode K, Rinaldi CA. Realtime fusion of cardiac magnetic resonance imaging and computed tomography venography with X-ray fluoroscopy to aid cardiac resynchronisation therapy implantation in patients with persistent left superior vena cava. Europace. 2011 Feb;13(2):285-6. doi: 10.1093/europace/euq383. Epub 2010 Oct 25. No abstract available.
- Background: PubMed 25348579Soons JA, Ricci AJ, Steele CR, Puria S. Cytoarchitecture of the mouse organ of corti from base to apex, determined using in situ two-photon imaging. J Assoc Res Otolaryngol. 2015 Feb;16(1):47-66. doi: 10.1007/s10162-014-0497-1. Epub 2014 Oct 28.
- Background: PubMed 14613700Enoh J, Orega M, Yao A, Cisse L, Couitchere L, Attimere Y, Niangue M, Andoh J. [Choleriform diarrhea in children in Abdijan]. Arch Pediatr. 2003 Nov;10(11):1009-10. doi: 10.1016/j.arcped.2003.09.026. No abstract available. French.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Questions about this trial
What is this clinical trial studying?
An observational study of Multi Drug Resistant Organisms and Antibiotic Resistance, run by Assiut University.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 8 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Ahmed I Khalaf Mohamed, Demonstrator (+201144427816, drahmednafady0794@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Characterization of the synergistic antibacterial effect of Verapamil on bacterial isolates from patients in South Egypt Cancer Institute (time frame: Baseline). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07505446, which also lists 6 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Apr 2026.