Essential Pharmacology For Inpatient Care
By Hitinder S Gurm and Matthew Konerman
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Reviews for Essential Pharmacology For Inpatient Care
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- Rating: 5 out of 5 stars5/5Very thorough and detailed approach to almost on drugs and related pharmacology used in contemporary clinical settings. I highly recommend it for clinicians.
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Essential Pharmacology For Inpatient Care - Hitinder S Gurm
adherence.
CARDIAC INTENSIVE CARE
Matthew C. Konerman, Sarah Hanigan, Kristen Pogue, Hitinder S. Gurm,
ANTI-PLATELET AGENTS OVERVIEW
Aspirin
Clopidogrel
Prasugrel
Ticagrelor
GP IIb/IIIa Inhibitors
INOTROPES & VASOPRESSORS OVERVIEW
Dobutamine
Milrinone
Norepinephrine
Dopamine
Phenylephrine
Vasopressin
Epinephrine
ARRHYTHMIA MANAGEMENT
Isoproterenol
Atropine
Adenosine
Esmolol
Diltiazem
Amiodarone
Lidocaine
PULMONARY HYPERTENSION MANAGEMENT OVERVIEW (FIGURE)
Endothelin Receptor Antagonists
Prostanoids
Phosphodiesterase-5 Inhibitors
Riociguat
HYPERTENSIVE EMERGENCY & VASODILATORS OVERVIEW
Nitroprusside
Nicardipine
Clevidipine
Fenoldopam
Nitroglycerin
Nesiritide
SEDATION IN THE CICU
Midazolam
Fentanyl
Propofol
GENERAL CONCEPTS
Extensive evidence, beyond the scope of this text, supports the use of Aspirin in ACS. It should be given ASAP in possible ACS.
AHA/ACC Guidelines do not favor any one P2Y12 inhibitor over another. They are all class I recommendations. Consider patient-specific factors and adverse effects in selection of agent.
12 months of dual-antiplatelet therapy (DAPT) is recommended even for conservatively managed (no PCI) ACS patients.
In patients receiving fibrinolytics, choose Clopidogrel for DAPT.
The data supporting the use of GP IIb/IIIa inhibitors in ACS was gathered prior to routine use of DAPT in ACS. Routine upstream use of GP IIb/IIIa agents pre-PCI is no longer recommended.
Aspirin (Acetylsalicylic Acid, ASA)
By irreversibly inhibiting COX-1 within platelets, Aspirin prevents the formation of thromboxane A2 which leads to diminished platelet aggregation.
Indications/Dosing: Give to all STEMI and UA/NSTEMI patients (Class I). Recommended treatment for pericarditis following STEMI (Class I). Used for CVA prophylaxis in low-risk patients with atrial fibrillation (CHADS2 ≤ 1).
Load with 162-325 mg on presentation and prior to PCI (Class I)
Continue indefinitely at a dose of 81-325 mg daily (Class I)
Preferred maintenance dose is 81 mg daily (Class IIa, see below)
Use non-enteric-coated formulations for more rapid absorption
Load and continue P2Y12 inhibitor if patient cannot tolerate Aspirin (Class I).
Kinetics
Peak concentration: 1-2 hours
*If chewed and swallowed, 1-10 minutes*
Lasts duration of platelet life (∼5 days)
Give loading dose to all suspected ACS pts
Documented mortality benefit in CAD
Maintenance dose of 81 mg is reasonable
Continue in the pre-CABG period
Adverse Effects
Bleeding
PUD/gastritis
Angioedema
Reye’s syndrome
Tinnitus
Precautions: GI symptoms, PUD, severe hepatic disease, bleeding disorders. Avoid use of other NSAIDs as may impair Aspirin effect and/or increase GI side effects
CURRENT-OASIS 7: Evaluation of Clopidogrel and ASA dosing in ACS
All patients received an ASA load followed by 75-100 mg vs. 300-325 mg daily
No difference in CV death, MI, and CVA or major bleeding at 30 days.
ISIS-2: Comparison of ASA vs. placebo in 17,187 patients with acute MI
Significant reduction in vascular death at 35 days (11.8 to 9.4%).
Clopidogrel (Plavix)
A thienopyridine that irreversibly inhibits the platelet P2Y12 ADP receptor. Clopidogrel inhibits platelet activation and aggregation both of which play a role in the pathophysiology of ACS and stent thrombosis.
Indication/Dosing: Class I indication in STEMI and UA/NSTEMI
Indicated in both invasive and conservatively managed patients
Only P2Y12 inhibitor recommended for use with fibrinolytics (Class I)
Class I: Loading dose of 600 mg PO in patients undergoing PCI
Conservatively managed patients should receive at least a 300 mg load
Class I: Maintenance dose of 75 mg PO daily
Kinetics: Requires conversion from prodrug to active metabolite via liver CYP2C19 isoenzyme. Loss of function polymorphisms associated with increased risk of adverse cardiovascular events.
Tmax = 60 minutes; t1/2 = 6 hours. Lasts duration of platelet life (∼5 days).
Avoid use with strong inhibitors of CYP2C19
Monitoring: P2Y12 assay No trial supports altering therapy based on assay. (Class IIb recommendation)
Adverse Effects
Bleeding
Stevens-Johnson’s
TTP
DAPT is essential after coronary stenting
Conservative Treatment: Up to 12 mo. DAPT
Hold for 5 days prior to elective surgery
Benefit of P2Y12 assay unclear
Interaction: Retrospective data suggests Clopidogrel is less effective in setting of PPI use though this has not been confirmed with randomized data. Omeprazole and Lansoprazole inhibit CYP2C19 decreasing response to drug.
COGENT: RCT of 3761 patients on Clopidogrel randomized to Omeprazole vs. Placebo.
Omeprazole use associated with reduced rate of upper gastrointestinal bleeding.
Omeprazole use associated with no difference in composite endpoint of CV death, nonfatal MI, CVA, and revascularization.
CURE: RCT of 12,562 patients with UA/NSTEMI
Reduction in CV death, MI, and CVA when Clopidogrel added to Aspirin.
Increased major/minor but not life-threatening bleeding with Clopidogrel
Prasugrel (Effient)
A thienopyridine that irreversibly inhibits the platelet P2Y12 ADP receptor. Prasugrel inhibits platelet activation and aggregation both of which play a role in the pathophysiology of ACS and stent thrombosis.
Indications: Class I in STEMI patients undergoing PCI. Class I in UA/NSTEMI patients undergoing PCI once coronary anatomy known.
Can give prior to angiography in patients with STEMI
Use discouraged in UA/NSTEMI patients prior to angiography
No evidence for use in medically managed UA/NSTEMI
Dosing: Loading dose of 60 mg PO once (Class I)
Maintenance dose of 10 mg PO daily (Class I)
Consider alternative drug or maintenance dose of 5 mg daily if <60 kg, age >75, or high bleeding risk
Kinetics: Prodrug that requires activation via CYP enzyme system.
Unlike Clopidogrel, genetic polymorphisms do not impact efficacy.
Tmax = 30 minutes
t1/2 = 7-8 hours
Effect lasts duration of platelet life
Monitoring: No role for platelet function testing.
No evidence of benefit without PCI.
Do not use if prior TIA/CVA, CNS bleed
No benefit if age > 75 or weight < 60 kg
Hold for 7 days prior to elective surgery
Adverse Effects: Increased bleeding vs. Clopidogrel
Contraindications
Evidence of harm if prior CVA/TIA, prior CNS bleed, or current bleeding
No evidence of benefit in patients over age 75
No evidence of benefit in patients < 60 kg
TRITON-TIMI 38: Prasugrel vs. Clopidogrel in high-risk ACS treated with PCI
Prasugrel (60 mg → 10 mg daily) vs. Clopidogrel (300 mg → 75 mg daily)
Lower rates of CV death, nonfatal MI/CVA, stent thrombosis with Prasugrel
Increased rates of major bleeding with Prasugrel compared to Clopidogrel
Net clinical benefit with Prasugrel in patients without above risk factors
TRILOGY ACS: Prasugrel vs. Clopidogrel for ACS without revascularization
No benefit of Prasugrel over Clopidogrel with similar risks of bleeding
Ticagrelor (Brilinta)
Ticagrelor is a potent, reversible antagonist of the P2Y12 ADP receptor. Ticagrelor inhibits platelet activation and aggregation both of which play a role in the pathophysiology of ACS and stent thrombosis.
Indications: Class I recommendation for use in STEMI and UA/NSTEMI
Acceptable for use if initial conservative strategy selected
Recommended maintenance Aspirin dose is 81 mg daily
Dosing
Loading dose of 180 mg PO once (Class I)
Maintenance dose of 90 mg PO twice daily (Class I)
Kinetics: Does not require activation via CYP enzyme system.
Tmax = 1.5-2 hours
t1/2 = 7 hours
Monitoring: No role for platelet function testing.
Consider patient compliance (BID dosing!)
Maintenance Aspirin dose of 81 mg daily
Hold for 5 days prior to elective surgery
Associated with all-cause mortality benefit
Adverse Effects
Bleeding
Ventricular pauses
Dyspnea
Elevated uric acid
Contraindications
FDA cautions against use in patients with active bleeding
FDA cautions against use if history of intracranial bleeding
Avoid use with concomitant use of strong CYP3A inducers/inhibitors.
Avoid doses of greater than 40 mg of Simvastatin or Lovastatin.
PLATO: Ticagrelor vs. Clopidogrel in patient with STEMI and UA/NSTEMI
Over 60% of patients underwent PCI. Followup of 12 months.
Reduction in vascular death, MI, CVA, stent thrombosis with Ticagrelor
Benefit in both invasive and medically-managed patients
No benefit observed in North America (attributed to high Aspirin dosing)
Reduction in death from any cause observed with Ticagrelor.
No difference in rate of major, fatal, or life-threatening bleeding
Increased non-CABG and fatal intracranial bleeding with Ticagrelor
GP IIb/IIIa Inhibitors
These agents bind to GP IIb/IIIa receptors, preventing binding of fibrinogen, vWF, and other adhesion molecules. Inhibition of platelet aggregation results.
Abciximab: Chimeric human-murine monoclonal antibody Fab
Noncompetitive, irreversible inhibitor of GP IIb/IIIa receptors
Eptifibatide/Tirofiban: Low molecular weight competitive, reversible antagonists.
Indications: ACS (most benefit in high-risk patients with positive biomarkers)
To support PCI in patients not receiving P2Y12 inhibition (Class I)
Chest pain refractory to therapy with ASA, P2Y12 inhibitor, UFH (Class IIa)
Eptifibatide and Tirofiban preferred in this setting
Limited role for upstream use in patients chest pain free with low bleeding risk (Class IIb)
Abciximab should not be used if PCI is not planned (Class III)
Dosing/Kinetics: Should be given with UFH. Infusion duration 12-18 hours.
Eptifibatide (Integrilin): 180 mcg/kg IV bolus, then 2 mcg/kg/min, then a second 180 mcg/kg bolus is given 10 minutes after the first bolus. Half-life = 2.5 hours.
Renal clearance. ↓ infusion by 50% if CrCl < 50 mL/min. Avoid in dialysis pts.
Reversal: Discontinuing drug leads to marked diminution of effect in 2-4 hours.
Tirofiban (Aggrastat): 25 mcg/kg IV bolus then 0.15 mcg/kg/min
Renal Clearance (half-life 2 hrs.). ↓ infusion by 50% if CrCl < 30 mL/min
Reversal: Discontinuing drug leads to marked diminution of effect in 2-4 hours.
Abciximab (ReoPro): 0.25 mg/kg IV then 0125 mcg/kg/min (max 10 mcg/min)
>80% of platelets at two hours. Long infusion half-life of approximately 12 hours.
Reversal: Platelet transfusions
Adverse Effects
Bleeding, intracranial hemorrhage. Alveolar hemorrhage is a rare complication of Abciximab.
Thrombocytopenia (esp. Abciximab). Can occur within hours of starting therapy.
Hypotension
Contraindications
Increased bleeding risk
Recent CVA, prior hemorrhagic CVA
Intracranial malformation/aneurysm
Severe hypertension
Dialysis (Abciximab can be used)
Recent surgery
Thrombocytopenia
Benefit in PCI patients yet to receive P2Y12 inhibition
Limited role for upstream use in ACS
Dose adjustment required in renal disease
EARLY ACS: Compared early vs. delayed (at PCI) Eptifibatide in UA/NSTEMI
Early Eptifibatide did not improve rates of death, MI, recurrent ischemia
No benefit even in absence of Clopidogrel (25% of study population)
Higher rates of non-life-threatening bleeding and transfusion with early use.
INOTROPES AND VASOPRESSORS
α1: vascular smooth muscle contraction → vasoconstriction
β1: inotropy, chronotropy → increased contractility and heart rate
β2: vascular smooth muscle relaxation → vasodilatation
DA: vasodilatation of the renal, splanchnic, and coronary vasculature
GENERAL CONCEPTS
Through their effects on inotropy, afterload, and chronotropy, inotropes and vasopressors increase cardiac demand, potentiate ischemia, and may even have direct toxic effects on myocytes. Therefore, use the lowest necessary dose of these agents!
These agents commonly trigger arrhythmias. Monitor closely.
Randomized data supporting the use of one inotrope or vasopressor over another is lacking. Agents are typically selected based on the patient’s hemodynamic profile, underlying comorbidities, and potential for adverse effects with particular agents.
Recent data support use of nor-epinephrine over Dopamine as the first line agent for shock.
Dobutamine (Dobutrex)
Dobutamine is a synthetic catecholamine that activates beta receptors.
β1 Stimulation: Potent ↑ inotropy with weaker ↑ chronotropy.
β2 Stimulation: Mild systemic vasodilatation (↓ SVR) at lower doses
Increased vasoconstriction (↑ SVR) at higher infusion rates (α1 matches β2 stimulation).
Indications: Decompensated HF, Cardiogenic Shock, Symptomatic Bradycardia
ACC/AHA 2004 Guidelines: First-line if low output, no shock, SBP 70-100
Preferred inotrope in setting of hypotension (less ↓ in SVR vs. Milrinone)
Preferred inotrope in the setting of renal insufficiency
Preferred agent in the setting of acute RV infarction
Dosing: 2.5 – 20 mcg/kg/min. Can titrate every 5 minutes by 2.5 mcg/kg/min
Half-Life: 2 minutes
Adverse Effects
Tachycardia
Ventricular arrhythmia
Cardiac ischemia
Tachyphylaxis
Nausea, vomiting
Headache
First-line agent for RV infarction
Monitor for arrhythmias!
Agent utilized in stress-testing.
Option for palliation in end-stage HF
Randomized data associate inotropic agent use with ↑ mortality.
PROMISE: Increased mortality with oral Milrinone
FIRST: Increased mortality with Dobutamine
These findings have been corroborated in registry studies where use of inotropes has been associated with increased mortality.
Milrinone (Primacor)
Milrinone exerts its effect via inhibition of phosphodiesterase III within cardiac myocytes. Increased levels of cAMP result leading to increased cardiac contractility. In addition to potent inotropy, this agent decreases afterload via systemic vasodilatation. It also decreases preload via improved lusitropy.
The net effect is increased contractility, decreased afterload, and preload. Milrinone also has a vasodilatory effect on the pulmonary vasculature.
Indications: Decompensated Heart Failure
Beneficial in end-stage HF as β-adrenergic receptor response is often blunted
More potent ↓SVR compared to Dobutamine (use caution if borderline BP)
Greater effect on lowering filling pressures than Dobutamine
Provides RV afterload reduction → consider in RV failure
Dosing: 0.125 – 0.50 mcg/kg/min (dose-adjust for renal impairment!). Maximum dose 0.75 mcg/kg/min
Loading dose of 50 mcg/kg can be given if immediate inotropy needed
Maintains effect despite concurrent beta-blockade
Kinetics
Renal clearance
t1/2 = 3 hours
Dose carefully in renal insufficiency
Monitor BP closely (↓↓ SVR)
Option for palliation in end-stage HF
Provides RV and LV afterload reduction
Adverse Effects
Ventricular arrhythmia
Cardiac ischemia
Hypotension
PROMISE: Milrinone PO in 1,088 HF with reduced EF patients (NYHA III/IV)
Increased all-cause (28%), CV (34%) mortality with Milrinone (6 mo. FU)
Milrinone associated with ↑ hospitalizations, hypotension, syncope
OPTIME-CHF: No role in ADHF with preserved end-organ perfusion
Randomized to 48-hr Milrinone vs. Placebo. Followup of 60 days.
No difference in length of hospitalization or mortality with Milrinone.
Increased rates of atrial arrhythmias and hypotension with Milrinone
Norepinephrine (Levophed)
Norepinephrine is an endogenous neurotransmitter with potent α1-adrenergic activity along with moderate β-receptor activity.
Results in ↑ SBP/DBP/PP with less net impact on CO and HR.
Indications: Vasodilatory Shock, Cardiogenic Shock
ACC/AHA 2004 Guidelines: First-line for cardiogenic shock if SBP < 70
Dosing: Start at 0.1 mcg/kg/min. Titrate by 0.01 - 0.05 mcg/kg/min every 5 minutes.
Maximum dose 1 mcg/kg/minute
Kinetics
Onset: 1-2 minutes
t1/2 = 2 minutes
First-line agent for cardiogenic shock if SBP < 70
First-line agent for septic shock
Delivery via central access preferred
May be less arrhythmogenic than Dopamine
Monitoring: Consider arterial line for BP monitoring
Adverse Effects
Arrhythmias
Tissue necrosis (limit with central line delivery)
Increased doses cause more α1 stimulation and may decrease renal perfusion.
Precautions: Concomitant use with TCA, SSRI, and MAO inhibitors may increase the alpha-adrenergic effects of the drug.
De Backer NEJM Norepinephrine vs. Dopamine in shock
RCT including 1679 patients requiring initiation of vasopressor for shock
No difference in primary outcome of death at 28 days
Significant increase in rates of arrhythmia with Dopamine
Cardiogenic shock subgroup → increased mortality with Dopamine
Dopamine (Intropin)
Dopamine, the precursor to norepinephrine in catecholamine synthesis, exerts dose-dependent effects on both dopaminergic and adrenergic receptors. It also causes release of norepinephrine at nerve terminals.
Indications: Cardiogenic/Septic Shock, Symptomatic Bradycardia, Diuresis
ACC/AHA 2004 Guidelines: First-line for cardiogenic shock if SBP 70-100
ACC/AHA 2013 HF Guidelines: Class IIb to facilitate diuresis.
Dosing: Start at 2 – 5 mcg/kg/min. Titrate by 1 – 5 mcg/kg/min every 5 min. Maximum 20 mcg/kg/min.
Half-Life: 2 minutes
Monitoring: Consider arterial line for BP monitoring
Adverse Effects
Tachycardia
Ventricular arrhythmia
Tissue necrosis
Cardiac ischemia
Nausea, vomiting
Recognize dose-dependent effects
Temporizing measure for bradycardia
Monitor for arrhythmias!
Low-dose may facilitate diuresis in HF
Havel Cochrane Review (2011): Vasopressors for hypotensive shock
Review of 23 RCTs evaluating vasopressors in shock
No evidence to prove one vasopressor is superior in regards to mortality.
Dopamine appears to increase the risk of arrhythmia
Phenylephrine (Neo-Synephrine)
Phenylephrine is a synthetic agent that activates α1-receptors without any stimulation of beta receptors.
Indications: Hypotension (medication-induced, vagally-mediated), shock
Consider for treatment of hypotension with concomitant severe AS
Consider for pressor support in setting of tachyarrhythmias.
Theoretical benefit in pulmonary hypertension – increased afterload can facilitate LV filling against high RV pressures.
Reduces LVOT gradient in obstructive hypertrophic cardiomyopathy
Dosing
Bolus: 50 – 200 mcg bolus
Infusion: 50 – 300 mcg/min
Titration: 20 mcg/min every 5 min.
Use as bolus for rapid BP improvement
Consider in pulmonary hypertension, AS
Monitor for peripheral ischemia!
Provides ↑ afterload without ↑ inotropy
Reflex bradycardia can lower CO
Half-Life: 2-3 hours
Duration of Action: 15-20 min.
Monitoring: Consider arterial line for BP monitoring
Adverse Effects: Phenylephrine may cause reflex bradycardia which may decrease cardiac output as it has no inotropic effect. Phenylephrine also may cause narrowing of the pulse pressure. It is also associated with tissue necrosis.
Vasopressin (Pitressin)
Vasopressin is an endogenous hormone stored primarily in the posterior pituitary gland. At greater than physiologic doses, it exerts circulatory effects.
V1A Stimulation: Constriction of vascular smooth muscle (↑ SVR)
V2 Stimulation: Increases water reabsorption at renal collecting ducts.
Indications: Shock, Cardiac Arrest
Increases vascular sensitivity to Norepinephrine (enhances pressor effect)
ACLS: Can replace first or second dose of Epinephrine (give IV/IO).
Dosing
Bolus: 40 units IV
Infusion: Fixed at 0.04 units/min
Can be given via endotracheal tube
ACLS agent for cardiac arrest
Do NOT titrate this vasopressor infusion
Potentiates the effect of Norepinephrine
Remains effective in acidosis and hypoxia
Catecholamine-sparing
pressor support
Half-Life: 10-20 minutes
Adverse Effects:
Arrhythmias
Cardiac/peripheral ischemia
Tissue necrosis.
Jolly Am J Cardiology (2005): Vasopressin in cardiogenic shock
Retrospective study of 36 patients with cardiogenic shock post-MI
Vasopressin ↑ MAP without affecting PCWP, CI, UOP, or inotrope needs
VASST: Vasopressin vs. Norepinephrine in Septic Shock
Included 778 pts with septic shock. Primary endpoint 28-day mortality.
Vasopressin (max 0.03 U/min) vs. Norepinephrine (max 15 μg/min)
Patients received other open-label vasopressors to maintain goal MAP.
No significant difference in mortality rate between the two groups.
Epinephrine
Epinephrine is an endogenous neurotransmitter with activity at β1, β2, and α1-receptors. At lower doses, beta receptors are mostly affected; as dose increases, activity at the α1 receptor dominates leading to peripheral vasoconstriction. B2 activity relaxes smooth muscle of the bronchi.
Indications:
Utilized in ACLS protocols for cardiac arrest
Can administer for hypotension and shock
Bradycardia unresponsive to atropine
Anaphylactic reactions and severe bronchospasm
Dosing
Bolus (ACLS): 1 mg IV or intraosseously every 3-5 minutes
IM Injection (Anaphylaxis): 0.1 – 0.5 mg (max 1 mg)
Infusion (Shock): Start at 0.1 mcg/kg/min. Titrate by 0.01 - 0.05 mcg/kg/min every 5 minutes.
Maximum dose 1 mcg/kg/minute
May be administered via an endotracheal tube (2 – 2.5 mg).
Half-Life: 2 minutes Monitoring: Arterial Line.
Adverse Effects
Arrhythmias
Cardiac ischemia
Splanchnic vasoconstriction
Tissue necrosis
ACLS agent for cardiac arrest, bradycardia
Most potent alpha-receptor activator
Preferred agent in Anaphylaxis
Precautions: Concomitant use with TCA, SSRI, and MAO inhibitors may increase the alpha-adrenergic effects of the drug.
Lin Circulation (1995): Effect of Epinephrine on coronary thrombosis
In canine models, epinephrine use associated with increased coronary thrombosis; norepinephrine inhibited coronary thrombosis.
Isoproterenol (Isuprel)
Isoproterenol is a synthetic, potent agonist of β1 and β2 receptors. This agent has significant chronotropic and inotropic activity. β2 stimulation results in systemic and pulmonary vasodilatation that can lead to hypotension. It can increase pulse pressure due to reductions in diastolic blood pressure.
Indications: Bradyarrhythmias, AV Block, refractory torsades de pointes
Temporizing agent while awaiting pacing for bradyarrhythmias, heart block
Class IIa: Temporary treatment in patients with recurrent pause-depended torsades de pointes who do not have congenital Long QT syndrome.
Class IIa: Treatment of torsades de pointes due to QT prolonging agents
Class IIa: Treatment of VT storm in the Brugada syndrome
Dosing: 0.5 – 10 mcg/min
Kinetics
Onset: Immediate.
t1/2 = 2.5 – 5 min.
Temporizing measure for bradycardia
Consider in recurrent torsades de pointes
Hypotension is a potential adverse effect
Adverse Effects
Arrhythmias
Palpitations
Cardiac ischemia
Hypotension.
Atropine
Atropine is a competitive antagonist of acetylcholine at muscarinic receptors. Acetylcholine is the main neurotransmitter of the parasympathetic nervous system. Atropine blocks vagal stimulation of the heart; this results in increased firing of the SA and increased AV node conduction (increased HR).
Indications
Class IIa: Acute, symptomatic bradycardia including symptomatic sinus bradycardia, conduction block at the AV node, and sinus arrest.
Less effective if location of heart block is below the AV node (Mobitz II second-degree block, third-degree AV block, wide QRS).
Serves as a temporizing measure while preparing for pacing
Dosing: Give 0.5 mg IV every 3-5 minutes (maximum dose 3 mg)
Can be administered via endotracheal tube.
Kinetics
Onset: Rapid.
t1/2 = 2-3 hours
Adverse Effects
Dysrhythmia
Tachyarrhythmia
Constipation
Dry mouth
Flushing
Blurred vision (dilated pupils)
Disorientation
*Antidote: Physostigmine*
ACLS agent for bradycardia with a pulse
No longer in PEA/Asystole ACLS algorithm
Less effective if block below AV node
Precautions
Atropine can exacerbate cardiac ischemia in ACS