Usage
This combination drug, primarily found as Plegiocard Injection, is indicated for inducing cardioplegia during open-heart surgical procedures like aortic valve replacement and heart transplantation. It’s also used for local anesthesia during minor surgical procedures.
Pharmacological Classifications:
- Electrolyte replenisher (Magnesium Carbonate and Potassium Chloride)
- Local anesthetic (Procaine)
Mechanism of Action: This combination works through the synergistic action of its components: Magnesium and Potassium replenish electrolyte levels vital for cardiac function, particularly during surgical procedures. Procaine blocks nerve impulse transmission, leading to localized numbness and minimizing pain sensation. Potassium contributes to diastolic arrest, helping preserve myocardial energy, while Magnesium aids in stabilizing the myocardial membrane.
Alternate Names
- Plegiocard Injection
- Cardiplegin Injection
- Sterile Cardioplegia Concentrate
How It Works
Pharmacodynamics:
- Potassium: Induces rapid diastolic arrest of the heart, essential during cardiac surgery.
- Magnesium: Stabilizes the myocardial membrane, protecting the heart muscle.
- Procaine: Reduces myocardial electrical excitability, conduction rate, and force of contraction, leading to local anesthesia.
Pharmacokinetics:
Administered directly into the coronary arteries (for cardioplegia) or locally (for local anesthesia). The components distribute to the target tissues (heart muscle or local nerves) and exert their specific effects. Elimination pathways are not a primary concern for cardioplegia due to the bypassing of systemic circulation during cardiopulmonary bypass. In local anesthesia applications, Procaine is metabolized mainly by plasma cholinesterase.
Mode of Action:
- Procaine: Blocks voltage-gated sodium channels in nerve cell membranes, preventing signal transduction and thus producing local anesthesia. Also interacts with NMDA receptors, nicotinic acetylcholine receptors, and serotonin receptors.
Dosage
Standard Dosage
Adults:
- Cardioplegia: Dosage is patient-specific, calculated based on myocardial mass (2-4 ml/g of myocardium). Administered as an infusion directly into the coronary arteries during cardiopulmonary bypass over at least 30 seconds.
- Local Anesthesia: Dosage varies depending on the area needing anesthetization.
Children:
- Cardioplegia: Safety and efficacy not established for pediatric use.
- Local Anesthesia: Dosage must be adjusted according to the child’s weight and the procedure.
Special Cases:
- Elderly Patients: Begin with a lower dose due to potential age-related organ function decline.
- Patients with Renal Impairment: Careful serum potassium monitoring required due to the risk of hyperkalemia. Dosage adjustments may be necessary.
- Patients with Hepatic Dysfunction: Limited information available. Consult a specialist.
- Patients with Comorbid Conditions: Careful monitoring and dosage adjustment may be necessary, especially for conditions affecting electrolyte balance.
Clinical Use Cases
- Intubation: Not typically used.
- Surgical Procedures: Used for local anesthesia in minor procedures and to induce cardioplegia in open-heart surgeries.
- Mechanical Ventilation: Not typically used.
- Intensive Care Unit (ICU) Use: Used for cardioplegia and electrolyte replenishment in critically ill patients undergoing open-heart surgery.
- Emergency Situations: Not typically used in emergency situations like status epilepticus or cardiac arrest.
Dosage Adjustments
Dose modifications are based on renal/hepatic function, metabolic disorders, and concomitant medications.
Side Effects
Common Side Effects
- Local Anesthesia: Diarrhea, flatulence, stomach cramps, increased urine production.
- Cardioplegia: Temporary ECG changes.
Rare but Serious Side Effects
Allergic reactions (difficulty breathing, facial swelling, hives), methemoglobinemia, seizures, circulatory depression.
Long-Term Effects
Not typically applicable due to acute usage.
Adverse Drug Reactions (ADR)
Severe allergic reactions, methemoglobinemia, cardiovascular complications require immediate intervention.
Contraindications
- Hypersensitivity to procaine or any component of the formulation
- Myocardial infarction (MI)
- ECG abnormalities and arrhythmias, including ventricular fibrillation
Drug Interactions
- Neuromuscular blocking agents: Increased neuromuscular blockade
- Cholinesterase inhibitors: Reduced procaine metabolism
- CYP450 enzyme inducers/inhibitors: Altered procaine metabolism
- Medications affecting potassium levels: Risk of hyperkalemia or hypokalemia
Pregnancy and Breastfeeding
- Pregnancy: Safety not established for cardioplegia. Limited data for local anesthesia suggests caution. Consult a specialist.
- Breastfeeding: No data available on excretion in breast milk. Advise caution or consider alternatives.
Drug Profile Summary
- Mechanism of Action: Potassium induces diastolic arrest. Magnesium stabilizes the myocardial membrane. Procaine provides local anesthesia by blocking sodium channels.
- Side Effects: Diarrhea, flatulence, stomach cramps, ECG changes, allergic reactions, methemoglobinemia, seizures.
- Contraindications: Hypersensitivity, MI, ECG abnormalities, arrhythmias.
- Drug Interactions: Neuromuscular blockers, cholinesterase inhibitors, CYP450 modulators, potassium-altering drugs.
- Pregnancy & Breastfeeding: Caution advised. Consult a specialist.
- Dosage: Cardioplegia: Patient-specific based on myocardial mass; Local anesthesia: Varies by area.
- Monitoring Parameters: ECG, serum potassium, magnesium levels, signs of allergic reaction.
Popular Combinations
This combination is typically used as a standalone formulation for cardioplegia.
Precautions
- General Precautions: Screen for allergies, metabolic disorders, organ dysfunction.
- Pregnant Women: Consult a specialist due to limited safety information.
- Breastfeeding Mothers: Caution advised due to lack of data on breast milk excretion.
- Children & Elderly: Exercise caution with dosage.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Magnesium Carbonate + Potassium Chloride + Procaine for cardioplegia?
A: The dosage is patient-specific, determined by the patient’s myocardial mass (2-4 ml/g of myocardium), and is administered as an infusion into the coronary arteries during cardiopulmonary bypass.
Q2: Can this combination be used in pediatric patients for cardioplegia?
A: No, safety and efficacy have not been established for pediatric cardioplegia.
Q3: What are the primary contraindications for this drug combination?
A: Hypersensitivity to any component, myocardial infarction, and ECG abnormalities/arrhythmias.
Q4: What are the key monitoring parameters during and after administration?
A: ECG, serum potassium and magnesium levels, and vigilance for signs of allergic reactions.
Q5: How does this combination achieve cardioplegia?
A: Potassium induces diastolic arrest, magnesium stabilizes the myocardium, and procaine reduces myocardial excitability.
Q6: What are the potential drug interactions to be aware of?
A: Neuromuscular blockers, cholinesterase inhibitors, CYP450 modulators, and drugs affecting potassium levels can interact with this combination.
Q7: Can this combination be administered to pregnant or breastfeeding women?
A: Caution is advised. Consult a specialist for detailed risk assessment and alternative options.
Q8: What are the common side effects of local anesthesia with this combination?
A: Diarrhea, flatulence, stomach cramps, and increased urine production.
Q9: What should be done in case of a suspected allergic reaction?
A: Immediately discontinue administration and provide supportive care as needed, including managing airway, breathing, and circulation.
