Effect of Herbal Products on Platelet Function and Clotting

November 18, 2015 updated by: Singapore General Hospital

A Randomized, Double Blind, Placebo-controlled Crossover Study on the Effect of Commonly Used Herbal Products on Platelet Function and Coagulation Profile of Healthy Volunteers

This is a research study on the effect of some commonly used "blood activating" herbal products on platelet function and coagulation profile, ie whether it causes an increase in bleeding tendency, either used alone or in combination with Aspirin which is a commonly used anti-platelet drug.

Study Overview

Detailed Description

This study is being conducted because there has not been any proper studies to provide evidence that these commonly used "blood activating" herbal preparations can in fact affect blood clotting by interfering with platelet function or clotting mechanism and potentiate the antiplatelet activity of Aspirin. These are assumptions based on TCM theory, laboratory experiments and animal studies but have led to the general statement in medical literature that these herbs increases bleeding risk in patients taking Aspirin or any other anti-platelet drugs. This has resulted in advice that these herbal products should not be taken by patients on Aspirin, which is a common drug taken by many patients. We hope to prove or disprove this theoretical concern by measurement of platelet and clotting function in healthy volunteers before and after taking the herbal product, alone and in combination with Aspirin. This will help to answer the question of whether it is safe for patients to take these common "blood -activating " herbs alone or together with Aspirin.

Healthy volunteers will be consecutively enrolled into 3 arms, each studying one herbal product for 25 volunteers. The design involves taking all 3 of the following combinations: aspirin + placebo, herb + placebo, aspirin + herb, each for a 3-week period, in a randomized order, with 2 weeks of wash-out in between each 3-week period. Platelet function and coagulation profile will be assayed

Study Type

Interventional

Enrollment (Actual)

75

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Singapore, Singapore, 169856
        • Singapore General Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

14 years to 66 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Males and females between the ages of 18 and 70 years.
  2. Healthy by medical history and physical exam.
  3. Laboratory values within established guidelines for participation in clinical studies: AST less than or equal to 2 times the ULN; SCr less than or equal to ULN; FBC showing normal Hb; WBC and platelet count; normal aPTT/PT
  4. Negative urine pregnancy test for females of child-bearing potential.
  5. Females of child-bearing potential who are able and willing to practice abstinence or use non-hormonal effective methods of birth control during the study, such as condoms or diaphragms.

Exclusion Criteria:

  1. Concomitant therapy (chronic or intermittent) with herbal drugs, aspirin, any other anti-platelet agents, non-steroidal anti-inflammatory medications or warfarin from 14 days prior to study participation and throughout the study period
  2. Inability to obtain venous access for blood sample collection.
  3. The presence of any of the following significant medical conditions:

    1. Diabetes mellitus poorly controlled or requiring insulin
    2. Hypertension poorly controlled
    3. Cardiac disease : heart failure, arrhythmia poorly controlled
    4. Renal disease,
    5. Hepatic impairment
    6. Bleeding disorders including thrombocytopenia and coagulopathy, either congenital or acquired
    7. Peptic ulcer disease
    8. Psychiatric illnesses that may interfere with the subject's ability to participate in the study, or any other condition that may interfere with the interpretation of the study results or not be in the best interest of the subject in the opinion of the investigators.
  4. Plans for elective surgery during the investigation or within 2 weeks following completion of the study.
  5. Positive urine pregnancy test or breastfeeding female.
  6. The presence of persistent diarrhea or malabsorption that would interfere with the subject's ability to absorb drugs.
  7. Drug or alcohol abuse that may impair safety or adherence (more than 3 alcoholic drinks per day, on a daily basis).
  8. History of intolerance or allergic reaction to aspirin or any NSAIDS
  9. Pregnancy or lactation

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Angelica sinensis
Angelica sinensis in capsule form will be given with actual or placebo aspirin, each for a 3 week period. Clotting profile and platelet function test will be done before and after.
Angelicae sinensis in capsule form will be given with actual or placebo aspirin, each for a 3 week period. Clotting profile and platelet function test will be done before and after.
Aspirin (enteric-coated) at 100mg daily will be given one of the actual herb or placebo herb, each for a 3 week period. Clotting profile and platelet function test will be done before and after.
Active Comparator: Curcuma longa
Curcuma longa in capsule form will be given with actual or placebo aspirin, each for a 3 week period. Clotting profile and platelet function test will be done before and after.
Aspirin (enteric-coated) at 100mg daily will be given one of the actual herb or placebo herb, each for a 3 week period. Clotting profile and platelet function test will be done before and after.
Curcuma longa in capsule form will be given with actual or placebo aspirin, each for a 3 week period. Clotting profile and platelet function test will be done before and after.
Active Comparator: Siwu Tang
TCM formulation "Siwu Tang" consisting of 4 herbs ( Ligustici chuangxiong, Angelicae sinensis, Rehmanniae praeparata and Paeoniae alba) in tablet form will be given with actual or placebo aspirin, each for a 3 week period. Clotting profile and platelet function test will be done before and after.
Aspirin (enteric-coated) at 100mg daily will be given one of the actual herb or placebo herb, each for a 3 week period. Clotting profile and platelet function test will be done before and after.
TCM formulation "Siwu Tang" consisting of 4 herbs ( Ligustici chuangxiong, Angelicae sinensis, Rehmanniae praeparata and Paeoniae alba) in tablet form will be given with actual or placebo aspirin, each for a 3 week period. Clotting profile and platelet function test will be done before and after.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
platelet function test and coagulation profile
Time Frame: 3 weeks
Platelet function test and coagulation profile ( aPTT/PT) will be done at baseline and after each phase of 3 weeks of Herb/aspirin or their placebo
3 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

December 1, 2013

Primary Completion (Actual)

April 1, 2014

Study Completion (Actual)

April 1, 2014

Study Registration Dates

First Submitted

December 8, 2013

First Submitted That Met QC Criteria

December 8, 2013

First Posted (Estimate)

December 11, 2013

Study Record Updates

Last Update Posted (Estimate)

November 20, 2015

Last Update Submitted That Met QC Criteria

November 18, 2015

Last Verified

November 1, 2015

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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