Pharmacology

1. SYMPATHOMIMETICS- II/
ADRENERGIC AGONISTS-II
(Dr. FOUZIA PERVEEN)

2. NOREPINEPHRINE/NOREADRENALINE
Receptor selectivity α1,α2, β1
It is released from adrenergic nerve endings.
Pharmacological effects:
1-CVS
A- It ↑ blood pressure by causing vasoconstriction of vascular bed.
B- Increase in blood pressure increases the vagal activity leading to
reflex bradycardia by baroreceptor reflex.(↓ HR)

3. NOREPINEPHRINE/NOREADRENALINE
Therapeutic indication:
Shock ( To ↑ BP)
Adverse effects:
Blanching and sloughing of skin along an injected site.
It can cause tissue necrosis.

4. ISOPROTERENOL
1-It is a direct-acting synthetic drug that stimulates both β1- and β2-.
2-It ↑ heart rate, contractility, and cardiac output
4-It also dilates the arterioles of skeletal muscle (β2 effect)
5-It is also a potent bronchodilator
Clinical use:
Atrio-ventricular (AV) block.

5. DOPAMINE
1-It occurs in the CNS and in the adrenal medulla.
2-Dopamine activates α , β and dopamine receptors.
Pharmacological effects:
CVS
↑Force of contraction and heart rate
Renal and visceral blood vessels :
It dilates renal and splanchnic arterioles.
Clinical uses
Cardiogenic and septic shock

6. DOBUTAMINE
Dobutamine is a synthetic, β1 receptor agonist.
Pharmacological effects
It ↑ heart rate and cardiac output
Clinical uses
Cardiogenic shock as a supportive measure
Cardiac surgery –e.g. coronary artery bypass grafting,
To ↑ cardiac output in acute heart failure

7. FENOLDOPAM
It is an agonist of peripheral dopamine D1 receptors.
It is used as a rapid-acting vasodilator.
Clinical uses
Severe hypertension in hospitalized patients
Adverse effects:
Headache, flushing, dizziness,
Nausea, vomiting,
Tachycardia (due to vasodilation)

8. PHENYLEPHRINE
It is synthetic agonist of α1 receptors.
It is a vasoconstrictor
Clinical uses
Hypotension in hospitalized or surgical patients
Nasal decongestant (Topically)
Mydriatic (Ophthalmic solutions)
Adverse effects
Large doses can cause hypertensive headache and cardiac irregularities.

9. INDIRECTLY ACTING SYMPATHOMIMETICS
1- ↑Release of NE
2- Inhibit reuptake of NE
3- Inhibit degradation of NE
Potentiate the effects of EPI or NE, do not directly affect receptors.
Amphetamine
Tyramine
Cocaine

10. 3/11/2023 ANS 10

11. AMPHETAMINE
Mechanism of action:
It produces its effect through release of NE from nerve endings.
Pharmacological effects
1-Stimulatory effect on CNS
2- ↑ in blood pressure
3- ↑ in heart rate
Clinical uses
ADHD
Narcolepsy
It is abused by athletes for performance enhancement.

13. MIXED ACTION ADRENERGIC AGONIST
Ephedrine and Pseudoephedrine :
They not only release stored NE from nerve endings but also directly
stimulate both α and β receptors.
Ephedrine :
↑blood pressure and causes bronchodilation
CNS: ↑ alertness, ↓ fatigue, and prevents sleep
Pseudoephedrine :
Nasal and sinus congestion

14. THERAPEUTIC CLASSIFICATION
Therapeutic classification (uses) of sympathomimetics:
1-Bronchodilators
salbutamol, terbutaline, salmetrol, adrenaline
2- For Anaphylaxis
Adrenaline
3-For Hypotensive Shock
Dopamine
Methoxamine
Phenylephrine

15. THERAPEUTIC CLASSIFICATION
4- As Cardiac stimulants
Adrenaline
Isoprenaline
Dopamine
Dobutamine
5- As Nasal decongestants
Phenylephrine,
Xylometazoline
Naphazoline

16. THERAPEUTIC CLASSIFICATION
6- To prolong the effect of local anesthetics
Adrenaline
Phenylephrine
7- As Uterine relaxants
Salbutamol
Ritodrine
8- In Narcolepsy
Amphetamines,
Methyl amphetamine
Ephedrine

17. THERAPEUTIC CLASSIFICATION
9- As Mydriatic
Adrenaline
Phenylephrine
10- In Open angle glaucoma
Adrenaline
Apraclonidine
11- In Attention deficit hyperkinetic disorder (ADHD)
Amphetamines