PENDAHULUAN

FARMAKOLOGI

dr. Dita Hasni, M.Biomed

setiap bahan kimia atau zat biologis,

sintetik atau non-sintetik

yang mempengaruhi kondisi biologis

sel didalam makhluk hidup

•Diagnosis

•Pencegahan penyakit

•Pengobatan (treatment)

•Menentukan prognosis

Overview

Farmakokinetik

Farmakodinamik

Hubungan Dosis-efek Obat

Interaksi Obat

Topik pembahasan

Pharmacokinetics

Movement of drugs in the body

Absorption

Distribution

Metabolism

Excretion

Drug administration

Pharmacokinetics

Bioavailabilitas

mempengaruhi daya terapeutik,

aktivitas klinik, dan aktivitas toksik obat.

Kecepatan dan Jumlah

zat aktif obat yang

diserap dari bentuk farmaseutik dan

tersedia di tempat kerja nya.plasma

Time (hour)

10

20

30

40

1 2 3 4

m.s.c

Therapeutic level

Low therapy

Drug toxicity

m.e.c

Parameter yang digunakan

untuk menentukan

bioavailabilitas obat

T max

C max

Area dibawah Kurva

(AUC)

waktu yang

diperlukan untuk

mencapai kadar

puncak kadar puncak/tertinggi

obat dalam darah

sesungguhnya

Diperoleh dari

hubungan

konsentrasi obat

dalam plasma

dengan waktu

Memberikan ukuran jumlah

obat yang diserap

Grafik kadar obat-waktu pada

berbagai rute pemberian obat

Drug Time Course

Time Course Studies important for

predicting dosages/dosing intervals

maintaining therapeutic levels

determining time to elimination

Elimination Half-Life

time required for drug blood levels to be reduced by 50%

Approx. 6 half-lives to eliminate drug from body

With repeated regular interval dosing, steady-state

concentration reached in approx. 6 x half-life

Pharmacodinamic

The study of the action and effects of

medications on physiologic function

How drug act ?

Paul Ehrlich :

Corpora non agunt nisi fixata

A drug will not work

Unless it is bound

Kecuali : - osmotic diuretic- osmotic purgatives- antasida- heavy metal chelating agents

Drug-Receptor Interactions

Drug

Receptor

Effect

Drug-Receptor

Complex

Ligand-binding

domain

Effector domain

Pharmacodynamics

• Number of drug’s receptor

• Receptor affinity

DOSE EFFECT RELATIONSHIP

The intensity and duration of a drug’s effects

are a function of the drug dose and

drug concentration at the effect site

Dose EffectEffect site

Concentration

Pharmacokinetics Pharmacodynamics

Absorption

Distribution

Metabolism

Excreation

Tissue/organ sensitivity

(receptor status)

DOSE EFFECT RELATIONSHIP

TD50 : the dose of the drug that produces

a toxic effect in half the population

ED50: the dose of the drug that produces

a therapeutic or desired response in half the population

LD50: the dose of the drug that produces

a lethal effect in half of animal experiments

Definition of the dose

Interaksi Obat

Interaksi fisikokimia

Interaksi farmakokinetik

Interaksifarmakodinamik

TERIMAKASIH