This document discusses various sympathomimetic drugs and their effects. It covers endogenous catecholamines like adrenaline, noradrenaline, and dopamine. It then discusses direct sympathomimetics, including phenylephrine, midodrine, isoproterenol, and dobutamine. Sympathomimetics with mixed effects like ephedrine are also mentioned. Finally, it discusses direct sympathomimetics like amphetamines and drugs that inhibit catecholamine reuptake, as well as tyramine and its interaction with MAO inhibitors.

1. SYMPATHOMIMETICS
Domina Petric, MD

2. ENDOGENOUS
CATECHOLAMINES
First chapter

3. ADRENALINE
 Adrenaline is agonist of both alfa and beta adrenergic
receptors.
 It is very powerful vasoconstrictor and stimulator of heart.
 Adrenalin has positive inotropic and chronotropic activity on
the heart muscle (predominantly β1-receptors).
 It activates β2-receptors in sceletal muscles where it stimulates
vasodilatation.

4. NORADRENALINE
 Noradrenaline is agonist for α1 and α2 receptors.
 It also stimulates β1 receptors, but less than adrenalin does,
and β2 receptors weakly.
 Noradrenaline increases peripheral resistance, diastolic and
systolic blood pressure.
 It has positive ionotropic and chronotropic effect
(baroreceptor´s reflex fights back and tends to lower heart rate).

5. DOPAMINE
It is a precursor for noradrenaline synthesis.
It is important for regulation of sodium ions
excretion and renal function.
It is very important neurotransmitter in
central nervous system.

6. DIRECT
SYMPATHOMIMETICS
Second chapter

7. PHENYLEPHRINE
It has longer effect than endogenous
catecholamines.
It is used as mydriatic drug and
decongestant.
It can also be used to elevate blood pressure.

8. MIDODRINE
It is a prodrug that hydrolises into
deglymidodrine.
Deglymidodrine is a selective α1-receptors
agonist.
Primary indication is treatment of
orthostatic hypotension.

9. A2-SELECTIVE AGONISTS
They act on the central nervous
system.
Clonidine, methyldopa and others
are used to treat arterial hypertension.

10. XYLOMETAZOLINE,
OXYMETAZOLINE
They are used as nasal
decongestants locally.
Oxymetazoline has significant afinity
for α2A-receptors.

11. ISOPROTERENOL
 It is very potent agonist of β-receptors with little effect on α-receptors.
 It has positive chronotropic and inotropic effect on the heart.
 It is powerful vasodilator.
 Summing effect is significant increase in heart minute
volume, decrease in diastolic and mean arterial blood
pressure with mild decrease or increase in systolic blood
pressure.

12. DOBUTAMINE
 Dobutamine is β1-selective medication prepared as racemic
mixture.
 Right isomer is powerful β1-agonist and α1-antagonist,
whilst left isomer is powerful α1-agonist.
 Summing effect is positive inotropic and chronotropic effect
and less decrease in peripheral resistance than other similar
drugs.

13. B2-SELECTIVE AGONISTS
These are very
important drugs in
treatment of asthma
and premature labour.

14. SYMATHOMIMETICS
WITH MIXED EFFECT
Third chapter

15. EPHEDRINE
It has moderate stimulative effect in
the central nervous system.
Pseudoephedrine is sometime used as
nasal decongestant.

16. DIRECT
SYMPATHOMIMETICS
Fourth chapter

17.  amphetamin
 metamphetamin
 phenmetrazine
 methylphenidate
 modafinil
 atomoxetine (ADHD
treatment)
 reboxetine
 sibutramine (obesity
treatment)
 duloxetine (antidepressant)
 cocain
DIRECT SYMPATHOMIMETICS
Amphetamin and similar drugs Inhibiotors of catecholamine reuptake

18. TYRAMINE
 It is a nusproduct of tyrosine synthesis in the body.
 It can be found in high concentrations in cheese, sousages, dried
fish…
 Monoamine oxidase (MAO) metabolises tyramine in the liver.
 Patients who take MAO-inhibitors should avoid tyrosine rich
foods because high levels of tyrosine can cause severe arterial
hypertension.