plb 1 b 8 rianti novaliana

8/10/2019 Plb 1 B 8 Rianti Novaliana

1/21

Clinical Pharmacokinetics on

Renal Failure Patients

Tugas ke-1 Kel 8 Kelas B :Rianti Novaliana 089

Risnalia 090

Rizki akbar 091

Sri Rahayu Putri 094

Suci Amanda 095


2/21

Pharmacokinetics : What the body does to

drug ! Is the study of absorption,

distribution, metabolism, and excretion of

drug (WHO)

Clinical Pharmacokinetics or AppliedPharmacokinetisc is the process of using

drug concentrations, pharmacokinetics

prinsiples, and pharmcodynamics criteria

to optimize drug therapy in individual

patients


3/21

Pharmacodinamics : What the drugs does

to the body ! The study of biochemical and

physiological effects of the drug and their

mechanism of action

Therapeutic Drug Monitoring and ClinicalPharmacokinetics are used as near

synonyms for this process of using drug

concentration as a guide in therapy


4/21

Pharmacokinetics relates thedoes to the serumconcentration

Pharmacodynamics relates

the serum concentration to thetherapeutic response


5/21

Therapeutic Drug Monitoring

TDM)

TDM telah menjadi suatu pelayanan yang essensialuntuk kondisi pasien yang kronis dan kritis di

rumah sakit. Hal ini bukan hanya karena akibat

pesatnya perkembangan Pharmacology, Analytical

Chemistry dan Clinical medicine tetapi juga akibatmunculnya obat yang memerlukam monitoring

rutin agar dicapai efek terapi optimal.

TDM melibatkan pengukuran serum drugconcentration (SDC) dan clinical

pharmacokinetics. Berbagai golongan obat

mempunyai hubungan yang baik dengan respons

farmakologi


6/21

Commonyly Monitored Drugs

1. Antibiotics :

Aminoglycosides

Immunusuppressive agents (cyclosporine)Chloramphenicol

Vancomycin

Other antiinfective agents

2 Bronchdilator3 Analgesic, Antipyretic, Antiinflammatory Agents

4 Antiepileptics : phenobarbital, phenytoin etc

5 Antineoplastics

6 Cardiac Agents : antiarhytmics (lidocain, propanolol etc)

cardiac glycosides ( digitoxin, digoxin)

7. Psychoactive agents

Tricyclic Antideppressants : amitriptyline, imipramine etc

Lithium


7/21

Gagal Ginjal

Ginjal adalah organ penting dalam

mengatur cairan penghapusan sisa

metabolisme, keseimbangan elektrolit dan

ekskresi obat dari tubuh

Penurunan nilai atau degenerasi fungsi

ginjal farmakokinetik obat


8/21

Cammon Causes of Renal Failure

Hypertension

Diabetes-

Melitus

Nephrotoxicdrugs/metals

Hypovolemia

Nephroallergens


9/21

Effect of renal disease on

pharmacokinetics

Pharmacokinetics processes such as drugdistribution (volume of distribution and

renal excretion), and elimination

(biotransformation and renal excretion) are

altered by renal impairment

Therapeutic and toxic responses may get

altered as a result of changes in drug

sensitivity at the the receptor site


10/21

Absorption

Gastric PH is increased in chronic

renal failure because urea is cleaved,yielding ammonia with acids and

buffers in stomatch

Impaired renal function will result inincreased bioavailability of drugs

exhibiting first-pass metabolism

when the function of drug

metabolizing enzyms is compromised


11/21

Distribution

Impaired renal function is associated

with important changes in thebinding of drugs to plasma proteins.

Protein binding in serum from uremic

patients is decreased Most acidic drugs bind to the

bilirubin site on albumin

The reduced binding occurs whenrenal function is impaired for the

following reasons.


12/21


13/21

Metabolisme

Most drugs are not excreated by the

kidneys unchanged but arebiotransformed to metabolites that

then excreted

Renal failure retard the excretion ofmetabolic clearance of the drug


14/21

Excretion

Many studies shown that there is a

linear relationship between the renalclearance of a drug and Creatinine

clearance in patients with varying

degrees of renal function

A=Drug specific constant

Patients with renal disease alsoexcrete less unchanged drug in the

urine than patients with normal renal

function

Renal clearance + A* Creatinine clearance


15/21

Dose adjustment in renal

disease

In the renal disease, the renal clearanceand elimination rate are reduced, the

elimination half-life is increased and the

volume of distribution is altered

The half-life of some drugs are changed

sufficiently in patiens with impaired renal

function to warrant change in the usual

dosage regimen to prevent accumulationof the drug in the body tp toxic levels


16/21

Generally, one should consider a

possible modest decrease in drugdoses when creatinine clearance is


17/21

Decrease the drug dose and retain the

usual dosage interval

Retain the usual dose and increase the

dosage interval

Decrease the dosage and prolong the

dosage interval. The dosage change is usually proportional

to the relative difference ini half-life

between the patients with renal diisease

and the person with normal renal function


18/21

Patients with renal failure sometimes

need loading doses because the timerequired to reach steady state with a

particularly important when planning

antibiotic or cardiac glycoside

therapy

Adjutsment of mainenance dose

involves either reducing each dose

given or lengthening the timebetween doses


19/21

Special caution is needed when the

patients is hypoproteinaemic and thedrug is usually extensively protein

bounded or in advanced renal

disease when accumulated metabolic

products may compete for protein

binding sites, particular care is

required in early stages of dosing

until response to the drug can begauged


20/21

DAFTAR PUSTAKA

1. Shargel, L. Pong, W. & Yu, A. (2005). Appl ied

Biop harmaceut iccs and Pharmacok inetics. 5th

Ed. Connecticut : Appleton & Lange.2. Related Publication in Journal of Cl in ical

Pharmacokinet ics

3. Setiawati A, Suharto B. Select ion and dosage of

drug s in pat ients w i th renal fai lure. Cermin DuniaKedokteran. 1992 ; No.28 : 32-40


21/21

TH NK YOU

plb 1 b 8 rianti novaliana

Documents