The Prevalence of Sub Optimal Anti Coagulation

Assiut University

Status: Unknown

Conditions: Poor Drug Response

Treatments: Diagnostic Test: Liver and kidney function tests for patients with chronic liver or kidney diseases; Behavioral: Non compliance of the patient; Drug: Drug or food interactions

Study type: Observational

Funder types: Other

Identifiers

NCT03485300

Sub optimal anti coagulation

Details and patient eligibility

About

A study on warfarin administration to show whether noncompliance of the patient will affect our target (INR) during therapy or not beside its drug and dietary interactions.

The study will show the prevalence of sub optimal anti coagulation among patients with prosthetic cardiac valves that will undergo warfarin therapy.

Full description

Besides the risk of infective endocarditis, thromboembolism from the foreign body structures of the prosthesis remains a major problem, which can be effectively reduced, but not inhibited by the use of oral anticoagulants in patients with prosthetic cardiac valves.

Warfarin as a vitamin k antagonist is widely used to decrease risk of thromboembolism but need strict monitoring for INR to avoid warfarin failure or hemorrhage.

It acts through inhibiting an enzyme called the vitamin K1 2,3 epoxide reductase complex, subunit1 (VKORC1).

All patients with mechanical heart valves need the oral anticoagulation to keep the INR between 2.5:3.5 according to valve type, position and other comorbid conditions.

However some patients need higher than expected doses of warfarin to get their (INR) into the target therapeutic range.

Resistance to warfarin has been described as the inability to prolong the prothrombin time or raise the international normalized ratio (INR) into the therapeutic range when the drug is given at normally prescribed doses.

Resistance is different than warfarin failure ,which is defined as a new thrombotic event despite a therapeutic prothrombin time and INR .

The causes of warfarin resistance can be either acquired from high consumption of vitamin K or C ,decreased absorption or increased clearance of the drug ,dietary or drug interactions or hereditary by genetic factors that result either in faster metabolism of the drug (a form of pharmacokinetic resistance) or in lower activity of the drug (pharmacodynamic resistance).

Enrollment: 50 estimated patients

Sex: All

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

All patients of prosthetic cardiac valves undergo warfarin therapy with sub optimal anti coagulation

Exclusion criteria

• Refusal of the patients
• Patients with target INR (2.5-3.5)
• Patients with hypoalbumenimia and chronic liver diseases

Trial design

50 participants in 3 patient groups

Patients with chronic liver or kidney diseases

Description:

Patients with chronic liver diseases may affect warfarin therapeutic outcome as liver is the site of metabolism of the drug by cytochrome p 450 enzymes so it decrease warfarin absorption Kidney diseases also affect the clearance of the drug these patients will undergo liver function tests and kidney function tests

Treatment:

Diagnostic Test: Liver and kidney function tests for patients with chronic liver or kidney diseases

Non compliance of the patient

Description:

Missed dose of the warfarin or intermittent drug intake may affect drug therapeutic outcome as well as changing time of drug administration during the day

Treatment:

Behavioral: Non compliance of the patient

Drugs or food interactions

Description:

Administration of other drugs beside warfarin may affect its therapeutic outcome either by inhibition or synergism certain food may also interfere with warfarin especially vitamin k and c rich food so patients will be followed up for drug or food interactions

Treatment:

Drug: Drug or food interactions