The document summarizes key information about dopamine, including its discovery and functions as a neurotransmitter. It describes dopamine's effects at different doses when used intravenously as a drug. Low doses selectively activate dopamine receptors to increase renal and splanchnic blood flow. Intermediate doses stimulate heart rate and contractility through beta-1 receptors. High doses cause systemic and pulmonary vasoconstriction through alpha receptors. The document also discusses dopamine's clinical uses, administration, interactions, and adverse effects.

1. DR ZIKRULLAH

2.  The function of dopamine as a neurotransmitter
was discovered in 1958 by ARVID CARLSSON and
NILS-ÅKE HILLARP at the Laboratory for Chemical
Pharmacology of the National Heart Institute of
Sweden.
 It was named dopamine because it was a
monoamine, and its synthetic precursor was 3,4-
dihydroxyphenylalanine .
 Arvid Carlsson was awarded the 2000 Nobel
prize for physiology or medicine for showing that
dopamine is not just a precursor of
norepinephrine (noradrenaline) and epinephrine
(adrenaline) but a neurotransmitter, as well.

3.  Dopamine is an endogenous catecholamine
that serve as both a neurotransmitter and a
precursor of nor epinephrine synthesis.
 When given as an exogenous drug dopamine
activates a variety of receptors in dose
dependent manner.
 Regulates cardiac, vascular and endocrine
function.

4.  Each ampoule contains
200 mg /5ml

7. o Dopamine acts through D1 , D2 as well
as adrenergic alpha and B1 receptors ( But
not B2)
o D1 and D2 receptors are the most
abundant and widespread in areas receiving
a dopaminergic innervation ( namely the
striatum ,limbic system, thalamus and
hypothalamus) as are D2 receptors, which
also occur in the pituitry gland

8.  AT LOW DOSE (0.5 to 3 mic /kg /min
 Selectively activates dopamine specific
receptors in the renal and splanchnic
circulation.
 Increase blood flow in these region.
 Low dose dopamine also directly affects
renal tubular epithelial cells.
 It causes an increase in urinary Na
excretion

9.  INTERMEDIATE DOSE (3 to 10 mic /kg /min )
 It stimulates B1 receptors in the heart and
peripheral circulation.
 Increases myocardial contractility, increases
heart rate and peripheral vasodilatation
 It increases myocardial oxygen demand, so
when ever dopamine is to be used oxygen must
be supplemented
 Over all increase in cardiac output
 Contractile response to dopamine is modest
when compared to dobutamine

10.  AT HIGH DOSE (> 10 mic /kg / min ):-
Dopamine produces a progressive
activation of alpha receptors in the systemic
and pulmonary circulation resulting in
progressive pulmonary and systemic
vasoconstriction
This vassopressor effect is by virtue of
increasing ventricular afterload

11. Dopamine not effective orally and does not
cross blood brain barrier in sufficient
amounts to cause CNS effects.

12.  Rapid metabolism of dopamine mandates its use
as a continuous infusion. A portion of the
positive inotropic effect of dopamine is due to
stimulation of release of endogenous
norpinephrine which may predispose to
development of cardiac disarrythmias never
theless, dopamine is less disarrythmogenic than
epinephrine
 Dopamine increase cardiac index by 18%
 Microcirculatory flow did not change significantly
 It is used only intravenously .

13.  Dopamine is often used in situation where
both cardiac stimulation and peripheral
vasoconstriction is desired such as
cardiogenic shock
 Also used to correct the hypotension in the
septic shock .But norepinephrine has become
the preferred vassopressor in this condition
 Low dose is often used in an attempt to
prevent or reverse acute renal failure

14.  Drug initially administered at a rate of 2 to 5 mic
/ kg /min . During infusion ,pt require clinical
assessments of myocardial function perfusion of
vitals organs such as the brain , and the
production of urine
 Most pts should receive intensive care with
monitoring of arterial and venous pressures and
ECG
 Reduction in urine flow ,tachycardia or the
development of arrhythmias may be indications
to slow or terminate the infusion

15.  The sympathomimetic amines
dopamine is potent ionotropic agents
 Used in pulmonary edema
 Forcefully contracts the heart and
thus decreases the pulmonary load

16.  Like dobutamine, dopamine is inactivated by
higher PH So ,alkaline fluids should not be
infused along with dopamine
 D-5-- Yes
 RL -- No
 NS -- yes
 DNS-- No
 HAEMACCEL -- No

17.  Maintaining adequate MAP ,hepatic blood
flow and oxygen exchange with dopamine
required a consequent increased cardiac
output. Which was responsible for increase
global oxygen demand
 Dopamine also impaired hepatic energy
balance
 In vasoplegic septic pt preferrential treatment
with dopamine compared with
norepinephrine had no advantage

18.  The divergent pharmacologic effects of
dopamine and dobutamine make their use in
combination potentially useful.Infusion of the
combination of dopamine and dobutamine
have been noted to produce a greater
improvement in cardiac output, at lower
doses, than can be achieved by either drug
alone.

19.  Low dose simultaneously increases:
Glomerular filtration rate
Renal blood flow
Urine output

20.  Use 5 ml 2 ampoule / vials containing 40 mg
/ml dopamine HCL add to 500 ml isotonic
saline [Final concentration= 40mic /drop ]

21.  No of drops= Body weight ( in Kg)× µ/kg/min
40
 2 amp of dopamine i.e 400 mg in 500 ml of NS
40kg X 10 =10 drop/ min
40
60kg x 10 = 600 = 15 drops/min
40 40
80kg x 10 = 800 = 20 drops/min
40 40

22.  2 amp (200 x 2) in 500 ml NS
 No. of drops = no of µ/ min is valid only for
40 kg body weight
 If body Wt changes  no. of drops will
change

23.  Commercial preparation of dopamine are
concentrated drug solution [Containing 40
mg /80 mg dopamine HCL /ml]
 Provided in small volume vial / ampoule
in 5 ml /10 ml
 THE Preparation must be diluted to prevent
intense vasoconstriction during drug
infusion
 Dopamine solution diluted in isotonic
saline to prepare the infusate
 Always delivered into , large central veins

24.  Weight based
 There are two recommended doses:-
 3 to 10 mic /kg /min is for augmenting
cardiac output thereby increasing BP
 More than 10 mic /kg /min is
recommended to increase the blood pressure
directly

25.  Before dopamine is administered to pt in
shock ,hypovolemia should be corrected by
transfusion of whole blood , plasma or other
appropriate fluid

26. o Tachyarrhythmia's are the most common
adverse effects of dopamine
o Malignant tachyarrhythmia [ Multifocal
ventricular ectopic , ventricular tachycardia ]
o The most feared complication of dopamine
infusion is limb (Fingers /toes ) necrosis
o Extravasations of drug through a peripheral
vein can be treated with local injection of
phentolamine [5 to 10 mg in 15 ml saline ]

27.  Allergic reactions
 Delays gastric emptying which could
predispose to nosocomial pneumonia
 If pt is on dopamine infusion and is to be
anaesthetized , he / she will be treated as a
full stomach pt
 Less dysarrythmogenic than epinephrine

28.  Continuous infusion of dopamine increase
intraocular pressure
 Ventilation effects :-
Infusion of dopamine interferes with the
ventilatory response to arterial hypoxemia
They results in unexpected depression
of ventilation
ABG have been observed to deteriote
during infusion of dopamine

29.  Hyperglycemia that is commonly present in
pts receiving a continuous infusion of
dopamine is likely to reflect drug induced
inhibition of insulin secretion

30.  Cyclopropane
 Bromocriptine
 Dyhydroergotamine
 Entacapone
 Halothane
 Linezolide (antibiotic )
 Phenytoin

31.  Pt receiving MAO inhibitors
 Tricyclic antidepressants agents
 Pheochromocytoma
 Uncorrected tachyarrhythmia
 Ventricular fibrillation

32.  If dopamine liquid falls on floor /cloth it gives
permanent staining if allowed to dry and was
not mopped off wet

33. Thank you…