DIRECT ADRENOMIMETICS

3.2.1.Mixed action Adrenomimetics

List of drugs

Epinephrine hydrochloride

Dopamine hydrochloride

Mechanism of action of epinephrine: direct stimulation of α₁, α₂, β₁, β₂- adrenoreceptors.

Pharmacological effects of epinephrine:

Indications for epinephrine:

1. Bronchospasm (relieving).

Epinephrine → stimulation of β₂- adrenoreceptors → dilation of bronchi → relieving of bronchospasm

2. Hypoglycemic coma

Epinephrine → α₁, α₂, β₁, β₂- adrenoreceptors → increasing of the glucose level in the blood (due to disruption of glycogen in the liver etc.) → relieving of hypoglycemic coma.

3. Anaphylactic (allergic) shock

Epinephrine → stimulation of β₂- adrenoreceptors → inhibition of degranulation of mast cells → relieving of anaphylactic (allergic) shock.

Side effects:

Epinephrine can produce cardiac arrhythmias.

Mechanism of action of dopamine: mostly direct stimulation of D₁-receptors (dopamine receptor type 1) and α₁- adrenoreceptors.

Pharmacological effects of dopamine: iincreasing of heart contractility + dilation of blood vessels.

Indications for dopamine:

1. Shocks of different aetiology (e.g. cardiogenic shock etc.)

3.2.2. Alfa-adrenomimetics

List of drugs

α₁, α₂- adrenomimetics: Norepinephrine bitartrate

α₁- adrenomimetics: phenylephrine hydrochloride

α₂- adrenomimetics: naphazoline hydrochloride

Mechanism of action

Phenylephrine produces direct stimulation of α₁-adrenoreceptors.

Naphazoline produces direct stimulation of α₂-adrenoreceptors

Pharmacological effects:

for phenylephrine:

for naphazoline:

Indications

1. Acute hypotension (circulatory collapse) – relieving

Phenylephrine → stimulation of α₁-adrenoreceptors → constriction of blood vessels → increasing of arterial pressure

2. Rhinitis

Naphazoline → stimulation of α₂-adrenoreceptors → constriction of blood vessels → decreasing of running nose

3.2.3. Beta-adrenomimetics

List of drugs

β₁, β₂- adrenomimetics: isoprenaline sulfate

β₁- adrenomimetics: dobutamine hydrochloride

β₂- adrenomimetics: fenoterol, salbutamol

Mechanism of action

Isoprenaline sulfate produces direct stimulation of β₁, β₂- adrenoreceptors.

Dobutamine produces direct stimulation of β₁- adrenoreceptors.

Fenoterol, salbutamol produce direct stimulation of β₂- adrenoreceptors

Pharmacological effects:

for isopreneline:

for dobutamine:

for fenoterol, salbutamol:

Indications

1. Acute heart failure

Dobutamine → stimulation of β₁- adrenoreceptors → increasing of heart rate, heart contractility, heart conductance and heart excitability → relieving of acute heart failure

1. Bronchospasm (prophylaxy and relieving)

Isopreneline, Fenoterol, Salbutamol → stimulation of β₂- adrenoreceptors → dilation of bronchi → prophylaxy and relieving of bronchospasm

1. Relaxation of uterus to prevent preterm labor (delivery) of child.

Isopreneline, Fenoterol, Salbutamol → stimulation of β₂- adrenoreceptors → relaxation of uterus → prevention of preterm labor (delivery) of child.

Date: 2015-12-18; view: 848