Dopamine is a chemical precursor of norepinephrine that stimulates alpha, beta, and dopaminergic receptors. At low doses, it causes vasodilation and increased renal blood flow. At intermediate doses, it increases heart rate and cardiac output. At high doses, it increases blood pressure through alpha receptor stimulation. Dobutamine is a synthetic catecholamine that stimulates beta1 and beta2 receptors, causing increased contractility and cardiac output without affecting renal blood flow. Nitroglycerin dilates coronary arteries to improve blood flow and reduces preload, helping to lower blood pressure and myocardial oxygen demand in conditions like hypertension and heart failure.

1.  DOPAMINE
 DOBUTAMINE
 Dr.PRAVEEN

4. DOPAMINE
(200mg/5ml ampule).
A chemical precursor of nor epinephrine.
 Possessing alpha , beta and dopaminergic receptor –
simulating actions.
The specific effects are related to the dose delivered.

5. LOW DOSE
0.5- 2mcg/kg/minute (Dopaminergic effect).
Vasodilation of renal and mesenteric arteries
Promote blood flow
increased GFR
Urine output may increase
Small beta 1 and alpha effect-tacycardia
Beta 2effect –decreased SVR and BP

6. INTERMEDIATE DOSE
2 to 10 mcg/kg/minute
 Beta1-adrenergic receptor activity is increased in the heart.
 Partial antagonism of alpha – adrenergic receptors will mediate
vasoconstriction.
 Modest increase in systemic vascular resistance increases cardiac
output & CVP

7. HIGH DOSE
more than 10mcg
 increased inotropic effect
 alpha effect –NE release
 increased SVR ,BP,FILLING PRESSURES
 Affects myocardial oxygen consumption

8. Indication:-
 Renal protection.
 Hypotention/haemodynamic
compromise due to MI, trauma,
sepsis, CCF.
Mesenteric ischaemia.
Contraindication: -
 Pregnancy.
 Phaeochromocytoma.
 Tachyarrhythmias.
 Occlusive vascular disease.

9. WARNING:
.
 Do not infuse peripherally.
 Extravasations can cause severe tissue necrosis.
 Monitor the patient carefully for decreased
circulation in the extremities.
If extravasates into tissues-
 The infusion should be immediately stopped.
 Infiltrate with 0-15ml 0.9% Sodium Chloride containing 5-
10mg Phentolalmine.

10. ADVERSE EFFECTS:
 Tachycardia
 Supraventricular tachycardia
 Ventricular arrhythmias
 Pulmonary congestion
 Nausea
 Vomiting
 Headache.
 Increased myocardial oxygen demand.

11. DOBUTAMINE
 Drug class:-
Catecholamine.(synthetic)
 Mechanism of action:-
 Chemically related to dopamine.
 Stimulates Beta 1 and beta 2 mild vasodilatory effect ,
Alpha-adrenergic receptors.
 Increases myocardial contractility, stoke volume and
cardiac output.
 Produces mild chronotropic, hypotensive and
arrhythmogenic effects.
 Increase renal and mesenteric blood flow by increasing
cardiac output.
 Does not affect renal blood flow like dopamine.

12.  Initial dose: -
2 to 3 mcg/kg/minute.
 Usual dose: -
2.5 to 10 mcg/kg/minute.
 Maximum dose: -
20 mcg/kg/minute.

13. Monitor
for hypertension, tachycardia, chest pain, and
premature ventricular contractions
Monitor cardiac output, pulmonary artery pressure
ECG
Patient with atrial fibrillation should be digitalized
before giving this drug to prevent ventricular
tachycardia.

14. Adverse effects:-
 Tachycardia
 Arrhythmias
 Blood pressure fluctuation
 Myocardial ischemia
 Headache
 Nausea
 Tremors
 Hypokalemia

16.  NTG

17.  Nitroglycerin (glyceryl trinitrate) is the prototype of
therapeutically active nitrates.
 Nitrates
dilation of the coronary artery,
improve oxygen supply to the myocardium
reduction of the end-diastolic pressure
reduce the myocardial oxygen requirements (dilation
of the peripheral arteries, lowering of the systemic blood
pressure).
Reduction of venous return is a particular benefit
(reduction of preload) in the event of heart failure.

18.  . In the presence of hypovolemia or a marginal cardiac
output, NTG should be avoided, because it will
lower cardiac output further and produce a reflex
tachycardia.
NTG dilates coronary conductance vessels and improves
blood flow to ischemic zones.
NTG is rapid-acting .onset of action of 2–5 minutes
duration of action of 10–20 minutes.

22. Indications
 Hypertension in association with myocardial ischemia or high
filling pressures
 Prior to surgery in conjunction with phenylephrine to maintain
coronary perfusion pressures.
 Coronary spasm
 Pulmonary hypertension, to reduce right ventricular afterload and
improve RV function
Nitroglycerin infusion during rewarming corrects systemic
ischemic stress and facilitates heparin neutralization in cardiac
surgery.

23.  Starting dose is 0.1 mcg/kg/min with a mix of 50
mg/250mL. The dose can be titrated up to 10
mcg/kg/min.
 The dose used prophylactically to prevent radial artery
spasm is only 5–10 mcg/min.
• NTG must be administered through non-polyvinyl
chloride (PVC) tubing because PVC tubing absorbs up to
80% of the NTG.

24. Adverse effects
 . Methemoglobinemia
. The diagnosis is suggested by
the presence of chocolate-brown blood and a lower
oxygen saturation measured by oximetry . It can be
confirmed by an elevated metHb level (>1% of total
hemoglobin).
Symptoms (cyanosis, progressive weakness, and acidosis) are
usually not noted until the metHb level exceeds 15–20%.
The treatment is intravenous methylene blue 1 mg/kg of a
1% solution.

25.  Nitroglycerin: Adverse Reactions
 headaches,
 suddenly flushed skin,
 orthostatic problems, or
 reflectory tachycardia in approximately 5% of the treated
subjects.
 Paradoxical bradycardia and severe hypotension with
collapse are not as common.
 Contact dermatitis is possible when skin patches are
applied.
 Nitrate tolerance with almost total loss of efficacy develops
very quickly when there is continuous administration (e.g.
with skin patches). A therapy-free interval of about 10
hours daily is therefore of great importance (combination
with other drugs!).

26.  THANK YOU