Generic Name :  Pancuronium.

Trade Name    : Pavulon.

Drug Class      : Non-depolarizing neuromuscular blocking agent.

Forms of The Drug

  1. Injectable solution: 1mg/mL, 2mg/mL.

Mechanism of Action

Its mechanism of action involves interfering with the transmission of nerve impulses to the muscles at the neuromuscular junction, resulting in temporary paralysis of skeletal muscles. Here’s an overview of the mechanism of action of Pavulon:

  1. Competitive Antagonist: Pavulon acts as a competitive antagonist at the nicotinic acetylcholine receptors (nAChRs) located on the skeletal muscle endplate. These receptors are normally activated by acetylcholine (ACh), leading to muscle contraction.
  2. Blockade of Nicotinic Receptors: When administered, Pavulon binds to the nAChRs on the motor endplate, but instead of activating the receptors like acetylcholine, it blocks them. By occupying these receptors, Pavulon prevents acetylcholine from binding and exerting its normal stimulatory effect.
  3. Prevention of Depolarization: The blockade of nicotinic receptors by Pavulon prevents the depolarization of the muscle membrane, which is necessary for muscle contraction. Without depolarization, the muscle is unable to contract, leading to muscle relaxation and paralysis.
  4. Non-depolarizing Neuromuscular Blockade: Pavulon belongs to the class of non-depolarizing neuromuscular blockers, meaning it does not cause depolarization of the muscle membrane itself but rather blocks the action of acetylcholine.
  5. Reversibility: The effects of Pavulon are reversible. Over time, the drug is metabolized and eliminated from the body, allowing the neuromuscular blockade to dissipate naturally. Additionally, reversal agents such as neostigmine or sugammadex may be administered to accelerate the recovery of neuromuscular function if necessary.

Indications

  1. General Anesthesia: It is particularly useful in surgeries where muscle relaxation is essential for surgical access and precision, such as abdominal surgeries, thoracic surgeries, and neurosurgical procedures.
  2. Endotracheal Intubation.
  3. Balanced Anesthesia.
  4. Muscle Relaxation for Procedures: Pavulon may be used to induce muscle relaxation during various medical procedures that require temporary paralysis or immobilization, such as cardioversion, bronchoscopy, orthopedic manipulations, and certain diagnostic imaging studies.

Contraindications

  1. Hypersensitivity
  2. Preexisting Neuromuscular Disorders: such as myasthenia gravis or Lambert-Eaton syndrome.
  3. Severe Cardiovascular Disease: Pavulon can have cardiovascular effects, including tachycardia and hypertension, particularly during rapid administration or in patients with preexisting cardiovascular disease.
  4. Renal or Hepatic Dysfunction
  5. Electrolyte Imbalance: Patients with significant electrolyte disturbances, such as hypokalemia or hyperkalemia.
  6. Pediatric Patients: While Pavulon can be used in pediatric patients, its safety and efficacy in neonates and premature infants have not been well established.

Side Effects

  1. Respiratory Depression
  2. Hypotension
  3. Tachycardia
  4. Histamine-mediated effects such as flushing, erythema, and hypotension.
  5. Bradycardia
  6. Prolonged Neuromuscular Blockade
  7. Allergic Reactions: While rare, allergic reactions to Pavulon, including rash, urticaria, and anaphylaxis.

Drug Interaction

  1. Anesthetic Agents: such as inhalational anesthetics (e.g., isoflurane, sevoflurane) or intravenous sedatives (e.g., propofol, benzodiazepines.
  2. Antibiotics: (e.g., gentamicin, amikacin) and polymyxins (e.g., colistin). Additionally, antibiotics such as tetracyclines and clindamycin.
  3. Calcium Channel Blockers: (e.g., verapamil, diltiazem).
  4. Magnesium Sulfate.
  5. Corticosteroids
  6. Lithium

Precautions

  1. Pregnancy: Category C.
  2. Lactation: When considering its use in breastfeeding women, there is limited data available regarding the excretion of Pavulon and its metabolites into human breast milk.

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