Medications for Bradycardia Quiz

Bradycardia Medications

Medications include Atropine Sulfate, Dopamine, Epinephrine HCL, and Isoproterenol HCL.

Atropine Sulfate

Classification: Parasympatholytic (Anticholinergic)
Mechanism of Action:
- Blocks acetylcholine receptors, inhibiting parasympathetic stimulation.
- Decreases vagal tone, which may increase heart rate and AV conduction.
- Dilates bronchioles and reduces respiratory secretions.
- Suppresses sweating, lacrimation, and salivation.
Indications:
- Used for symptomatic bradycardia, organophosphate poisoning, and prior to RSI in pediatrics.
Contraindications: No absolute contraindications noted.
Side Effects:
- Cardiovascular: Tachycardia, ventricular tachycardia/fibrillation, atrial fibrillation.
- Neurological: Seizures, dizziness, irritability, hallucinations.
- Respiratory: Mucus plugs.
- Other: Increased intraocular pressure, worsened glaucoma, blurred vision.
Precautions:
- May cause paradoxical bradycardia if underdosed or administered too slowly.
- Not recommended for asymptomatic bradycardia due to potential myocardial infarction risk.
- Can exacerbate AV blocks.
Interactions: Potentiated by tricyclic antidepressants, antihistamines, and procainamide.
Routes of Administration: IVP, IO, IM.
Onset and Duration: Onset is 2-5 minutes; duration lasts 20 minutes.
Adult Dosages:
- Bradycardia: 0.5 mg IVP/IO, may repeat every 3-5 minutes, max 3 mg.
- Pesticides: 2 mg IVP/IO/IM, may repeat every 5 minutes until asymptomatic.
Pediatric Dosages:
- RSI: 0.01-0.02 mg/kg IVP/IO (min 0.1 mg, max 0.5 mg).
- Cardiac: 0.02 mg/kg IVP/IO (min 0.1 mg, max 0.5 mg).
- Pesticides: 0.02-0.05 mg/kg IVP/IO/IM (administer based on age criteria).
Notes: Signs of atropinization include blind as a bat, mad as a hatter, red as a beet, dry as a bone, hot as hell.

Dopamine (Intropin)

Classification: Sympathomimetic, catecholamine, vasopressor.
Mechanisms of Action:
- Low Dose (1-5 mcg/kg/min): Dilates renal and mesenteric arteries, increasing urine output.
- Moderate Dose (5-10 mcg/kg/min): Increases inotropy without raising chronotropy.
- High Dose (10-20 mcg/kg/min): Causes vasoconstriction (alpha) and raises inotropy and chronotropy (beta 1).
Indications: Used in cardiogenic shock, distributive shock after fluids, significant hypotension, and symptomatic bradycardia as a second-line agent.
Contraindications: Hypovolemia, tachydysrhythmias, hyperthermia.
Side Effects:
- Cardiovascular: Tachycardia, hypertension/hypotension, chest pain, ventricular irritability.
- Respiratory: Dyspnea.
Precautions:
- Use the largest vein possible; ensure IV patency to avoid necrotic complications.
- Start a second IV for additional medications, avoid interruption of dopamine infusion.
Interactions: Flushing with Sodium Bicarbonate and caution with antidepressants and phenytoin.
Routes: IVPB.
Onset and Duration: Onset is 5 minutes; duration of effects is 3-5 minutes.
Dosages:
- Low dose: 1-5 mcg/kg/min IVPB.
- Moderate dose: 5-10 mcg/kg/min IVPB.
- High dose: 10-20 mcg/kg/min IVPB.
Notes:
- Flow rate determines receptor site stimulation; frequent vital sign monitoring is necessary.
- Infusion may need to slow but not stopped once blood pressure is achieved.

Epinephrine HCL (Adrenalin)

Classification: Sympathomimetic, catecholamine, vasopressor.
Mechanism of Action:
- Increases cardiac output and blood pressure by enhancing inotropy, chronotropy, and dromotropy (beta1).
- Vasoconstriction raises systolic blood pressure (alpha).
- Dilation of bronchioles improves respiratory function (beta2).
- Enhances coronary perfusion during CPR by raising aortic diastolic pressure.
Indications: Effective in cardiac arrest, asthma, allergic reactions, symptomatic bradycardia in pediatrics, and beta blocker overdose in pediatrics.
Contraindications: Hypovolemia and hypertension.
Side Effects:
- Cardiovascular: Tachycardia, hypertension, palpitations, chest pain, ventricular fibrillation.
- Neurological: Tremors, seizures.
- Respiratory: Paradoxical bronchospasms with excessive inhaler use.
Precautions:
- Administer slowly to conscious patients to prevent hearing loss.
- Monitor blood pressure and ECG closely post-administration, especially in older patients.
Interactions: Sodium Bicarbonate can inactivate Epinephrine; flush tubing before and after administration.
Routes of Administration: IVP, IO, IVPB, IM, SQ.
Onset and Duration:
- Onset is 1-2 minutes IVP/IO and 5-10 minutes SQ.
- Duration lasts 3-5 minutes IVP/IO; 20 minutes SQ.
Adult Dosages:
- Cardiac Arrest: 1 mg (1:10,000) IVP/IO every 3-5 minutes.
- Asthma/Allergic Reaction: 0.3-0.5 mg (1:1,000) SQ/IM every 20 minutes (x2).
- Anaphylaxis: 0.1-0.5 mg (1:10,000) slow IVP/IO (over 1-5 minutes), repeat every 3-5 minutes.
- Vasopressor: 1-4 mcg/min IVPB.
Pediatric Dosages:
- Cardiac Arrest: 0.01 mg/kg (1:10,000) IVP/IO, repeat every 3-5 minutes.
- Asthma/Allergic Reaction: 0.01 mg/kg (1:1,000) IM/SQ, max single dose 0.3 mg, repeat every 20 minutes (x2).
- Anaphylaxis with Shock: 0.01 mg/kg slow IVP/IO (over 1 minute), max single dose 0.1 mg, repeat every 3-5 minutes.