Esmolol; Indications/Uses, Dosage, Side effects, Drug Interaction ,Pregnancy

Esmolol is a cardioselective beta1 receptor blocker with rapid onset, a very short duration of action, and no significant intrinsic sympathomimetic or membrane stabilizing activity at therapeutic dosages. Esmolol decreases the force and rate of heart contractions by blocking beta-adrenergic receptors of the sympathetic nervous system, which are found in the heart and other organs of the body. Esmolol prevents the action of two naturally occurring substances: epinephrine and norepinephrine.

Esmolol is a cardioselective beta-blocker used in parenteral forms in the treatment of arrhythmias and severe hypertension. Esmolol has not been linked to instances of clinically apparent drug-induced liver injury.

Mechanism of Action of Esmolol

Similar to other beta-blockers, esmolol blocks the agonistic effect of the sympathetic neurotransmitters by competing for receptor binding sites. Because it predominantly blocks the beta-1 receptors in cardiac tissue, it is said to be cardioselective. In general, so-called cardioselective beta-blockers are relatively cardioselective; at lower doses they block beta-1 receptors only but begin to block beta-2 receptors as the dose increases. At therapeutic dosages, esmolol does not have intrinsic sympathomimetic activity (ISA) or membrane-stabilizing (quinidine-like) activity. Antiarrhythmic activity is due to blockade of adrenergic stimulation of cardiac pacemaker potentials. In the Vaughan Williams classification of antiarrhythmics, beta-blockers are considered to be class II agents.

Indications of Esmolol

• High blood pressure
• Postoperative hypertension
• Nonvalvular atrial fibrillation
• Atrial fibrillation
• Atrial flutter
• Intra- or Post-op SVT or hypertension
• Supraventricular tachycardia
• Intraoperative hypertension
• Intraoperative tachycardia
• Noncompensatory sinus tachycardia
• Postoperative tachycardia
• Also for the rapid control of ventricular rate in patients with atrial fibrillation or atrial flutter in perioperative, postoperative, or other emergent circumstances where short term control of ventricular rate with a short-acting agent is desirable. Also used in noncompensatory sinus tachycardia where the rapid heart rate requires specific intervention.

Contra-Indications of Esmolol

Hypersensitivity to the active substance or to any of the excipients or other beta-blockers (cross-sensitivity between beta-blockers is possible)

• Sinus Bradycardia
• Suddenly serious symptoms of heart failure
• Emphysema
• Asthma attack
• Bronchospasm
• Kidney disease with a reduction in kidney function
• Blood circulation failure due to Serious Heart Condition
• Anaphylactic Shock due to Allergy Shots
• Severe sinus bradycardia (less than 50 beats per minute);
• Beta-Blockers (Beta-Adrenergic Blocking Agents)
• Decompensated heart failure;
• Sick sinus syndrome; severe AV-nodal conductance disorders (without pacemaker); 2^nd or 3rd-degree AV-block;
• Cardiogenic shock;
• Concomitant or recent intravenous administration of verapamil.
• Non-treated phaeochromocytoma;
• Pulmonary hypertension;
• Acute asthmatic attack;
• Metabolic acidosis.

Dosage of Esmolol

Strengths: 10 mg/mL; 250 mg/mL; 20 mg/mL

Atrial Fibrillation

Recommended Dosing

• (Step 1) Optional loading dose (500 mcg/kg IV over 1 minute), then 50 mcg/kg/min IV for 4 minutes; if the response is adequate, the infusion may be maintained at 50 mcg/kg/min; if the response is inadequate, see step 2.
• (Step 2) Optional loading dose (500 mcg/kg IV over 1 minute) if necessary, then 100 mcg/kg/min IV for 4 minutes; if the response is adequate, the infusion may be maintained at 100 mcg/kg/min; if the response is inadequate, see step 3.
• (Step 3) Optional loading dose (500 mcg/kg IV over 1 minute) if necessary, then 150 mcg/kg/min IV for 4 minutes; if the response is adequate, the infusion may be maintained at 150 mcg/kg/min; if the response is inadequate, see step 4.
• (Step 4) If necessary, increase the dose to 200 mcg/kg/min IV
• Maintenance dose: 25 to 200 mcg/kg/min IV
• Maximum dose: 200 mcg/kg/min IV
• Duration: Maintenance infusions may be continued for up to 48 hours

Atrial Flutter

Recommended Dosing

• (Step 1) – Optional loading dose (500 mcg/kg IV over 1 minute), then 50 mcg/kg/min IV for 4 minutes; if the response is adequate, the infusion may be maintained at 50 mcg/kg/min; if the response is inadequate, see step 2.
• (Step 2) – Optional loading dose (500 mcg/kg IV over 1 minute) if necessary, then 100 mcg/kg/min IV for 4 minutes; if the response is adequate, the infusion may be maintained at 100 mcg/kg/min; if the response is inadequate, see step 3.
• (Step 3) – Optional loading dose (500 mcg/kg IV over 1 minute) if necessary, then 150 mcg/kg/min IV for 4 minutes; if the response is adequate, the infusion may be maintained at 150 mcg/kg/min; if the response is inadequate, see step 4.
• (Step 4) – If necessary, increase the dose to 200 mcg/kg/min IV
• Maintenance dose: 25 to 200 mcg/kg/min IV
• Maximum dose: 200 mcg/kg/min IV
• Duration: Maintenance infusions may be continued for up to 48 hours

Intra- or Post-op SVT or Hypertension

Immediate Control

• Administer 1 mg/kg IV as a bolus dose over 30 seconds followed by 150 mcg/kg/min if needed
• Adjust the infusion rate as required to maintain desired heart rate and blood pressure (refer to maximum recommended doses)

Gradual Control

• Administer 500 mcg/kg IV as a bolus dose over 1 minute followed by a maintenance infusion of 50 mcg/kg/min IV for 4 minutes
• Infusion may be continued at 50 mcg/kg/min or, if the response is inadequate, titrated upward in 50 mcg/kg/min increments (increased no more frequently than every 4 minutes) to a maximum of 300 mcg/kg/min; may administer an optional loading dose equal to the initial bolus (500 mcg/kg over 1 minute) prior to each increase in infusion rate

Maximum Recommended Doses

• For the treatment of tachycardia, maintenance infusion dosages greater than 200 mcg/kg/min IV are not recommended; dosages greater than 200 mcg/kg/min IV provide little additional heart-rate-lowering effect and the rate of adverse reactions increases.
• For the treatment of hypertension, higher maintenance infusion dosages (250 to 300 mcg/kg/min) may be required; the safety of doses above 300 mcg/kg/min has not been studied.

Side Effects of Esmolol

The most common 

• Dizziness
• Blurred vision
• confusion
• faintness, or lightheadedness when getting up from a lying or sitting position suddenly
• Orthostatic hypotension
• Xerostomia (dry mouth)
• A headache 
• Fatigue
• Skin reactions 
• Hypotension
• Anxiety
• Constipation
• Sedation (dose-dependent)
• Nausea/vomiting
• Weight gain/loss
• Pain below the ear (from salivary gland)
• Erectile dysfunction

More common

• Abdominal or stomach pain, discomfort, or tenderness
• chills or fever
• difficulty with moving
• a headache, severe and throbbing
• joint or back pain
• muscle aching or cramping
• muscle pains or stiffness
• chest pressure or squeezing pain in the chest
• discomfort in arms, shoulders, neck or upper back
• excessive sweating
• feeling of heaviness, pain, warmth and/or swelling in a leg or in the pelvis
• sudden tingling or coldness in an arm or leg
• sudden slow or difficult speech
• sudden drowsiness or need to sleep
• fast breathing
• sharp pain when taking a deep breath
• fast or slow heartbeat
• coughing up blood
• rust colored urine
• decreased amount of urine

Rare

• Anxiety
• change in vision
• chest pain or tightness
• confusion
• a cough
• Agitation
• arm, back, or jaw pain
• blurred vision
• chest pain or discomfort
• convulsions
• extra heartbeats
• fainting
• hallucinations
• a headache
• irritability
• lightheadedness
• mood or mental changes
• muscle pain or cramps
• muscle spasm or jerking of all extremities
• nervousness

Drug Interactions of Esmolol

Esmolol  may interact with the following drug, supplements, & may change the efficacy of the drug

• alpha-1 blockers (e.g., doxazosin, prazosin, tamsulosin)
• alpha-2 blockers (e.g., clonidine, dexmedetomidine, methyldopa)
• angiotensin-converting enzyme inhibitors (ACEIs; e.g., captopril, ramipril)
• angiotensin II receptor blockers (i.e., irbesartan, losartan, valsartan)
• anti-psychotics (e.g., clozapine, olanzapine, quetiapine, risperidone)
• atorvastatin
• azole antifungals (e.g., itraconazole, ketoconazole, posaconazole)
• barbiturates (e.g., phenobarbital)
• benzodiazepines (e.g., alprazolam, diazepam, lorazepam)
• beta-agonists (e.g., formoterol, salbutamol, salmeterol)
• other beta-blockers (e.g., propanolol, metoprolol)
• calcium channel blockers (e.g., amlodipine, diltiazem, nifedipine, verapamil)
• carbamazepine
• cyclosporine
• dexamethasone
• diuretics (water pills; e.g., furosemide, hydrochlorothiazide)
• duloxetine
• lapatinib
• levodopa
• lidocaine
• MAO inhibitors (e.g., phenelzine, moclobemide, selegiline)
• macrolide antibiotics (e.g., azithromycin, clarithromycin, erythromycin)
• nilotinib
• nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., ibuprofen, naproxen)
• other beta-blockers (e.g., atenolol, metoprolol, propranolol)
• pentoxifylline
• phosphodiesterase-5-inhibitors (e.g., sildenafil, tadalafil)
• selective serotonin reuptake inhibitors (SSRI; e.g., fluoxetine, paroxetine, sertraline)
• sunitinib
• theophyllines (e.g., aminophylline, oxtriphylline, theophylline)

Pregnancy Catagory of Esmolol

FDA Pregnancy Category C 

Pregnancy