CARDIOTONIC

DRUGS
SUBTITLE
INTRODUCTION

▪ Cardio stimulatory drugs (also called "cardiotonic drugs")

▪ Enhance cardiac function by
▪ increasing heart rate (chronotropy)
▪ myocardial contractility (inotropy),
▪ May increase electrical conduction (dromotropy) within the
heart
▪ augment relaxation (lusitropy).
CLASS OF CARDIOTONIC DRUGS

I. BETA AGONISTS
II. DIGITALIS COMPOUNDS
III. PHOSPHODIESTERASE
IV. CALCIUM SENSITIZERS
BETA AGONIST

Beta-agonists, also known as beta-adrenergic

agonists, are a class of medications that
stimulate beta-adrenergic receptors in the
body. These receptors are primarily found in
the heart, lungs, and blood vessels. There are
three main types of beta receptors, beta-1 and
beta-2,beta-3 and the effects of beta-agonists
depend on which type they primarily
stimulate.
 BETA 1 RECEPTORS
β1 receptors induces

• positive inotropic,
• chronotropic output(increases heart rate) of the cardiac
muscle, leading to increased heart rate and blood pressure

Primarily affect the heart.

Examples include dobutamine, which is used to

increase heart contractility, and isoproterenol
BETA 2 RECEPTORS

Induces smooth muscle relaxation in the lungs, gastrointestinal tract,

uterus, and various blood vessels

increases heart rate and heart muscle contraction.

Primarily affect the lungs and blood vessels.

Commonly used in the treatment of respiratory conditions such as asthma

and chronic obstructive pulmonary disease (COPD)
 BETA 3 RECEPTORS

β3 • are mainly located in adipose

tissue.
receptors • It induces the metabolism of
induces lipids.
Mechanism of Action:
•Stimulation of beta receptors leads to the activation of the
cyclic AMP (cAMP) pathway, resulting in smooth muscle
relaxation, increased heart rate, and enhanced contractility
▪ Phosphodiesterase inhibitors PDEI

These drugs mimic sympathetic stimulation

and increase cardiac output.
▪ Are used clinically for short-term
treatment of cardiac failure
▪ Examples
Amrinone
Milrinone
Enoximone. Phosphodiesterase
▪ Mechanism of Action:
• PDE inhibitors increase the intracellular levels of inhibitors PDEI
cAMP and cGMP by preventing their breakdown.
• Elevated cAMP and cGMP levels lead to various
cellular responses, including vasodilation,
smooth muscle relaxation, and positive inotropic
effects in the heart.
Digitalis compounds, also known as cardiac glycosides,
are a group of drugs derived from the foxglove plant
(Digitalis species), historically used in the treatment of
various heart conditions.
1. Source:
1. Digitalis compounds are derived from the leaves
of the foxglove plant (Digitalis purpurea).
2. Main Component:
1. The primary active components are digoxin and DIGITALIS
digitoxin.
COMPOUNDS
3. Mechanism of Action:
1. Digitalis compounds increase the force and
efficiency of heart contractions by inhibiting the
sodium-potassium pump in cardiac cells.
2. This leads to an increase in intracellular sodium,
which reduces the activity of the sodium-
calcium exchanger, ultimately raising
intracellular calcium levels. Increased calcium
enhances cardiac muscle contraction.
 Mechanism of Action

Cardiotonic drugs, also known as cardiac glycosides, exert

their effects on the cardiovascular system by increasing the
force and efficiency of cardiac muscle contraction. These
drugs primarily target the sodium-potassium ATPase pump,
which is responsible for maintaining the balance of sodium
and potassium ions in cardiac cells.
 Inhibition of sodium-
Increased Enhanced cardiac
potassium ATPase
Intracellular Calcium contractility
pump

Inhibition of Sodium- Increased Intracellular Enhanced Cardiac Contractility: The

Potassium ATPase Pump: Calcium: The inhibition of increased intracellular calcium
Cardiotonic drugs inhibit the the sodium-potassium concentration triggers a series of
activity of the sodium- ATPase pump results in a events that ultimately lead to
potassium ATPase pump, disruption of the normal ion enhanced cardiac contractility.
leading to an increase in the gradients across the cell Calcium ions bind to troponin C,
intracellular concentration of membrane. This disruption which promotes the interaction
sodium ions and a decrease leads to an increase in the between actin and myosin, resulting
in the concentration of intracellular concentration of in stronger and more forceful
potassium ions. calcium ions contractions of the cardiac muscle.
CALCIUM SENSITIZERS

Calcium sensitizers are a class of drugs that affect the

contractility of the heart muscle by enhancing the sensitivity
of cardiac myofilaments to calcium ions. Calcium plays a
crucial role in the contraction of cardiac muscles, and
calcium sensitizers aim to improve this process.

▪ Mechanism of Action:
• Calcium sensitizers enhance the sensitivity of cardiac
myofilaments to calcium ions.
• They work by improving the interaction between calcium
ions and proteins like troponin and tropomyosin in cardiac
muscle cells.
GENERIC NAME , BRAND NAME , DRUG CLASS

▪ Digoxin (Lanoxin)
• Drug Class: Cardiac Glycoside
▪ Dobutamine (Dobutrex)
• Drug Class: Beta-1 Adrenergic Agonist
▪ Milrinone (Primacor)
• Drug Class: Phosphodiesterase Inhibitor
▪ Levosimendan (Simdax)
• Drug Class: CALCIUM SENSITIZERS
 Dosage and Route

Recommended Dosage Routes of Administration

• The dosage of cardiotonic drugs • Cardiotonic drugs can be administered via different
varies depending on the specific routes, including oral, intravenous (IV), and
medication and the patient's subcutaneous (SC) routes.
condition. • The choice of route depends on the specific
• It is important to follow the medication, the patient's condition, and the desired
prescribing physician's onset and duration of action.
instructions and guidelines for • Oral administration is commonly used for chronic
dosage. management, while IV administration is often used
• Dosage may be adjusted based for acute cases or when rapid onset of action is
on the patient's response to the required.
medication and any potential • SC administration may be used in certain situations
side effects. where IV access is not readily available.
Indications and Contraindications for
Cardiotonic Drugs
Indications for Cardiotonic Drugs Contraindications

• Cardiotonic drugs are contraindicated in

• Cardiotonic drugs are commonly used to patients with known hypersensitivity to
treat heart failure, a condition in which the medication or any of its
the heart is unable to pump enough components.
blood to meet the body's needs. • They should not be used in patients
• They are also used to manage certain with certain types of arrhythmias, such
types of arrhythmias, such as atrial as ventricular tachycardia or ventricular
fibrillation. fibrillation.
• Cardiotonic drugs may be prescribed to • Cardiotonic drugs should be used with
improve cardiac output and increase the caution in patients with pre-existing
strength of the heart's contractions. cardiac conditions, such as severe
• Paroxysmal supraventricular tachycardia aortic stenosis or hypertrophic
obstructive cardiomyopathy.
 DRUG INTERACTIONS

• Anticoagulants
Cardiotonic drugs may interact with anticoagulants, increasing the risk of
bleeding. Close monitoring of clotting factors and adjustment of
anticoagulant dosage may be necessary.
• Beta-blockers
Combining cardiotonic drugs with beta-blockers may lead to additive
effects on heart rate and blood pressure. Dose adjustment and careful
monitoring are recommended.
• Calcium Channel Blockers
Cardiotonic drugs and calcium channel blockers may have synergistic
effects on heart rate and blood pressure. Dose adjustment and close
monitoring are advised.
• Diuretics
Combining cardiotonic drugs with diuretics may increase the risk of
electrolyte imbalances, such as hypokalemia. Regular monitoring of
electrolyte levels is recommended.
• Nonsteroidal Anti-inflammatory Drugs (NSAIDs)
NSAIDs may reduce the effectiveness of cardiotonic drugs and
increase the risk of fluid retention. Caution is advised when using
these medications together.
• P-glycoprotein Inhibitors
Cardiotonic drugs are substrates of P-glycoprotein. Co-administration
with P-glycoprotein inhibitors may increase cardiotonic drug levels.
Dose adjustment may be necessary.
Side Effects

▪ Common Side Effects ▪ Serious Side Effects

• Nausea and vomiting • Irregular heart rhythm
• Headache • Chest pain

• Dizziness • Difficulty breathing

• Fatigue • Fainting

• Loss of appetite • Swelling of the legs, ankles, or feet

• Diarrhea • Unusual bleeding or bruising

• Severe allergic reaction
• Abdominal discomfort
• Mental or mood changes
• Muscle cramps
• Yellowing of the skin or eyes
• Rash
 ADVERSE EFFECTS
1.EXTRACARDIAC 2. CARDIAC EFFECTS
• All types of arrythmia
ON GI TRACT ( increases automaticity in
• Anorexia high dose)
• Nausea • Slowing AV nodal conduction-
• Vomiting Bradycardia Heart Block
• Weakness
• Diarrhoea
Neurological problems
• Blurring of vision
• Confusion
 Due to steroid nucleus- gynaecomastia in
males
 Toxicity
1.NARROW THERAPEUTIC INDEX:
1. Cardiotonic drugs have a narrow therapeutic index, meaning a small margin between
a therapeutic and toxic dose.
2.SYMPTOMS OF TOXICITY:
1. Symptoms include nausea, vomiting, confusion, visual disturbances, and cardiac
arrhythmias.
2. Severe toxicity can lead to life-threatening conditions such as ventricular tachycardia
or fibrillation.
▪ Nursing Responsibility
▪ When administering cardiotonic drugs, nurses have
the following responsibilities:
• Verify the patient's identity and confirm the correct
medication and dosage.
• Assess the patient's vital signs, including heart rate,
blood pressure, and oxygen saturation, before and
after administration.
• Monitor the patient for signs of adverse reactions or
complications, such as arrhythmias or hypotension.
• Educate the patient about the medication, including
its purpose, potential side effects, and any
necessary precautions.
• Document the administration of the medication,
including the date, time, dosage, route, and any
observed effects or patient responses.
SUMMARY AND
COCLUSION
Drug Class Mechanism of action Specific Uses

Inhibit the sodium-potassium pump,

leading to increased intracellular Used to treat heart failure and atrial
Digitalis Glycosides
calcium levels and improved fibrillation.
contractility.
Inhibit the breakdown of cyclic
adenosine monophosphate (cAMP), Used for short-term treatment of acute
Phosphodiesterase Inhibitors
leading to increased calcium levels and heart failure.
improved contractility.
Stimulate beta-adrenergic receptors,
leading to increased intracellular Used for short-term treatment of acute
Beta-Adrenergic Agonists
calcium levels and improved heart failure.
contractility.
Calcium sensitizers enhance the Reduces the workload on the heart by
sensitivity of cardiac myofilaments to relaxing blood vessels.
calcium ions.
CALCIUM SENSITIZERS They work by improving the interaction
between calcium ions and proteins like
troponin and tropomyosin in cardiac
muscle cells.
REFRENCES

• https://slideplayer.com/amp/13602540
• https://www.slideshare.net/
binuenchappanal/cardiotonics-
248826799