Clinical Pharmacokinetics and Drug Dosage Adjustment in Patients with Heart Failure

Table of Contents

HEART

The heart is one of the human organs that play a role in the circulatory system At the heart of oxygen-rich blood coming from the lungs to the tissues throughout the body pumped.

Basic Function Heart

Is pumping red blood rich in oxygen and nutrients through the large vessels throughout the body and holds back once cleared by the lungs.

Congestive Heart Failure (CHF) / Gagal Jantung

Is a condition in which the heart is unable to pump blood throughout the body to meet the metabolic needs

Disease risk factors Congestive Heart Failure (CHF) / Heart Failure

1.   Dynamic risk factors:
a. dyslipidemia
b. Hypertension
c. Physical activity
d. Diabetes mellitus
e. smokea.

2. The absolute risk factors
a. History of illness in the family / descent
b. Gender

Classification System Disorders Cardiovascular

1.     Class I (Asymptomatic) No limitations on physical activity
There are no symptoms of heart disease with regular activity

2.     2. Class II (Light) Slight limitation of physical activity
At rest no complaints
Ordinary activity causes the heart isufisiensi symptoms such as fatigue, palpitations (cordis palpitations), shortness of breath or angina pectoris

3.     . Class III (Medium)
a. Many restrictions on physical activity
b. At rest no complaints
c. Activities with less intensity than usual can d. cause symptoms of heart isufisiensi

4.     4. Class IV (Heavy)
a. Inability to perform any physical activity
b. Symptoms occur at rest

Pharmacokinetics of heart problems

ABSORBSI

}  Absorption mainly occurs in the small intestine through the process nonsaturable possibility. Delay gastric emptying or the food may slow the absorption of the drug but did not reduce the rate of absorption. 

}  Plasma concentrations vary on each individual with a certain dose can result in a therapeutic effect on a person, but can also produce toxic effects on others.

}  In the oral administration of drugs will produce the onset after 0.5-2 hours after dosing with maximum effect is achieved after 2-6 hours after administration, while the IM administration, onset produced after 30 minutes with a maximum effect at 4-6 hours after administration. In the IV administration in a single dose produces onset in 5-30 minutes and the maximum effect occurs in 1-4 hours. Digoxin effects may persist for 3-4 days

DISTRIBUSI

}  At therapeutic plasma concentrations, approximately 20-30% of drug bound to the protein plasma.Pasien with complications of severe renal function impairment have smaller distribution volume compared to patients with normal renal function.

METABOLISME

}  A fraction of metabolism occurs in the hearts and metabolism can also occur by bacteria dilumen gut after oral administration or after the elimination of bile on IV administration.

ELIMINASI

}  Prolonged elimination half-life would occur in patients with impaired renal function.

}  Percentage of daily elimination medications for heart failure can be calculated by the equation:

}  % eliminasi =  14 + Clearens Kreatinin (ml/minute/5)

  
Management

•       Stage A.

Patients who have a high risk of heart failure, for example hipertansi patients, coronary artery disease, diabetes. Treatment : ACE Inhibitor (Captopril)

•      Stage B.

Patients with heart disease but do not have symptoms of heart failure, for example: patients with myocardial infarction, hipertropi right ventricular systole disorders.  Treatment : ACE inhibitor + Beta bloker.

•      Stage C.

Patients with heart damage and have symptoms of heart failure, for example: Dyspenea, fatigue, fluid retention.Treatment : ACE inhibitor + Beta bloker + Digoksin, bila tejadi udema beri diuretik.

•      Stage D.

Patients with symptoms of heart failure in addition to maximal medical therapy. Examples: Patients with severe, and hospitalization, treatment after relapse. Treatment  : Perlu tindakan operasi

Dose adjustments
The principle of the drug in patients with heart failure:

1.     Lower starting dose and dose support.

2.     Adjust the dose based on clinical response of the patient.

3.   Adjust dose based on measurement of the drug in plasma.