Nor Q

Indications

Nor Q is utilized as an adjunct to general anesthesia to facilitate endotracheal intubation and ensure skeletal muscle relaxation during surgical procedures or mechanical ventilation.
Consult a registered physician before using this medication.

Pharmacology

Vecuronium Bromide is a lyophilized powder formulated for injection. It serves as a non-depolarizing neuromuscular blocking agent. Vecuronium Bromide disrupts the transmission between motor nerve endings and striated muscle by competitively binding with acetylcholine at the nicotinic receptors situated in the motor end-plate region of striated muscle.

Dosage

For adults, the initial recommended dosage of Vecuronium Bromide is 0.08 to 0.10 mg/kg administered as an IV bolus injection. This dosage is expected to achieve optimal intubation conditions within 2.5 to 3.0 minutes post-injection. For cesarean sections and neonatal surgeries, the dosage should not exceed 0.1 mg/kg.

As with all neuromuscular blocking agents, Vecuronium Bromide should only be administered by experienced clinicians familiar with its effects and usage. Dosages should be individualized for each patient. Adjustments may include smaller maintenance doses at extended intervals or lower infusion rates during prolonged procedures (lasting over 1 hour) under inhalational anesthesia.

Tracheal intubation: The standard dose for routine anesthesia is 0.08 to 0.1 mg/kg, providing adequate intubation conditions within 90 to 120 seconds in most patients.

Surgical procedures following intubation with succinylcholine: If succinylcholine is utilized for intubation, the administration of Vecuronium should be delayed until the effects of succinylcholine have diminished. A recommended dose is 0.03 to 0.05 mg/kg.

Maintenance dosing: The suggested maintenance dose is 0.02 to 0.03 mg/kg, administered once twitch height has returned to 25% of its baseline.

Continuous infusion dosing: When Vecuronium is delivered via continuous infusion, initiate with a loading dose of 0.08 to 0.1 mg/kg. Adjust the infusion rate to maintain twitch response at 10% of control or achieve 1 to 2 responses to a train of four stimuli. In adults, the required infusion rate ranges from 0.8 to 1.4 µg/kg/min. Regular monitoring is essential as individual requirements can vary.

Dosing for elderly patients: The same dosages as younger adults can be used (0.08-0.1 mg/kg for intubation and 0.02-0.03 mg/kg for maintenance). The onset time in elderly patients is comparable to that in younger adults.

Dosing for pediatric patients: For neonates (up to 4 weeks) and children under 4 months, an initial test dose of 0.01 to 0.02 mg/kg followed by incremental doses until 90% to 95% twitch depression is reached is recommended. For neonatal surgeries, do not exceed 0.1 mg/kg. For children aged 5 months to 10 years, the recommended dose is 0.08-0.1 mg/kg (with potentially quicker onset and lower intubation doses for children under 12 months), and maintenance is 0.02-0.03 mg/kg, adjusted according to response. Due to a shorter duration of action in children, maintenance doses are often needed more frequently.

Dosing for overweight and obese patients: For overweight or obese individuals, dosages should be adjusted based on ideal body weight. Initial doses can range from 0.15 to 0.30 mg/kg during surgical procedures under halothane and neuroleptic anesthesia.
Consult a registered physician before using this medication.

Administration

Vecuronium Bromide must be administered after reconstitution. VencurTM can be given intravenously as either a bolus injection or continuous infusion. To achieve a lower concentration solution, 10 mg of Vecuronium Bromide can be reconstituted with up to 10 ml of the following infusion fluids:

• 5% Glucose IV Solution
• 0.9% Sodium Chloride IV Solution
• Lactated Ringer’s Solution
• Lactated Ringer’s and 5% Glucose IV Solution
• 5% Glucose and 0.9% Sodium Chloride IV Solution

Consult a registered physician before using this medication.

Interaction

Succinylcholine: The prior administration of succinylcholine can amplify the neuromuscular blocking effect and duration of action of Nor Q. If succinylcholine is used, wait until its effects start to diminish before administering Nor Q. For intubation using succinylcholine, initial doses of 0.04 to 0.06 mg/kg of Vecuronium may be sufficient for complete neuromuscular block with a clinical duration of 25 to 30 minutes.

Inhalation Anesthetics: The use of volatile inhalational anesthetics, such as enflurane, isoflurane, and halothane, can enhance the neuromuscular blockade effect of Nor Q.

Antibiotics: The intravenous or intraperitoneal administration of high doses of certain antibiotics may lead to intensified neuromuscular block. Antibiotics such as aminoglycosides, tetracyclines, bacitracin, polymyxin B, colistin, and sodium colistimethate are associated with varying degrees of paralysis. When used with Vecuronium during surgery, they may lead to unexpected prolongation of neuromuscular block.

Other Considerations: The injection of quinidine during recovery from other muscle relaxants has been associated with recurrent paralysis. Similar precautions apply to Vecuronium. Neuromuscular blockade induced by Nor Q can be affected by factors like alkalosis and acidosis. Electrolyte imbalances and related diseases can also modify the neuromuscular response, with potential for either enhancement or inhibition. Magnesium salts used for managing pregnancy toxemia may enhance neuromuscular blockade.

Contraindications

Hypersensitivity to Vecuronium Bromide or any of its excipients.

Side Effects

As a non-depolarizing muscle relaxant with an intermediate duration of action, Nor Q typically does not cause histamine release or cardiovascular effects. Common side effects associated with non-depolarizing muscle relaxants may include skin flushing, hypotension, tachycardia, bronchospasm, and in rare cases, anaphylactoid reactions. Prolonged use in intensive care settings may lead to acute myopathy.

Pregnancy & Lactation

Insufficient data are available regarding the use of Vecuronium in pregnant or lactating women to ascertain potential risks to the fetus. This medication should only be administered during pregnancy when the physician determines that the benefits outweigh the risks. No human data are available for lactation; therefore, it should only be given if the physician considers the benefits to outweigh the risks.

Cesarean Sections: Studies indicate the safety of Vecuronium in cesarean sections when administered in doses up to 0.1 mg/kg. Clinical trials have shown no adverse effects on Apgar scores, fetal muscle tone, or cardiopulmonary adaptation. Minimal placental transfer of Vecuronium has been observed, with no significant clinical effects reported in newborns.

Precautions & Warnings

Allergic cross-reactivity among neuromuscular blocking agents has been documented; caution is advised for those with hypersensitivity. Patients with myasthenia gravis or hypothermia may experience prolonged activity and may require lower doses. Non-depolarizing muscle relaxants should be used with caution in patients with neuromuscular disorders or fluid and electrolyte disturbances, as their responses can be unpredictable. Increased doses may be necessary for burn patients due to the development of resistance.

General Precautions: Nor Q should only be administered in precisely adjusted doses by or under the supervision of qualified clinicians familiar with its effects and potential complications. Immediate access to intubation facilities, artificial respiration, oxygen therapy, and reversal agents is essential. Clinicians must be prepared to assist or control respiration and should utilize a peripheral nerve stimulator to monitor the drug’s response and recovery.

Intensive Care Unit: To minimize the risk of prolonged neuromuscular blockade and other complications from long-term use, Nor Q should be administered with careful dose adjustments by experienced clinicians utilizing appropriate monitoring techniques.

Neuromuscular Disease: Patients with known myasthenia gravis or related syndromes may experience profound effects from small doses of Nor Q. A peripheral nerve stimulator and small test doses are beneficial for monitoring dosage requirements in such cases.

Overdose Effects

In cases of overdose resulting in prolonged neuromuscular block, patients should receive ongoing ventilatory support and sedation. Upon the onset of spontaneous recovery, administering an acetylcholinesterase inhibitor (e.g., neostigmine, edrophonium, pyridostigmine) in adequate doses is advisable. If the acetylcholinesterase inhibitor fails to reverse the effects of Nor Q, ventilation must continue until spontaneous breathing resumes. Caution is warranted, as repeated doses of an acetylcholinesterase inhibitor can pose risks.

Therapeutic Class

Non-depolarizing muscle relaxants.

Storage Conditions

Store in a cool, dry place away from light. Keep out of reach of children.