Rocuronium Disease Interactions

Patients with burns may develop resistance to non-depolarizing neuromuscular blocking agents. These patients may experience a shorter duration of action and/or require higher dosages of the drugs. The extent of altered response depends on the duration since and the size of the burn.

Severe acid-base and/or electrolyte abnormalities may potentiate or cause resistance to the neuromuscular blocking action neuromuscular blocking agents. The potency of these agents may be mixed in metabolic acidosis and alkalosis, and in respiratory alkalosis. Since electrolyte imbalance and acid-base imbalance are usually mixed, either enhancement or inhibition may occur. Caution should be taken when using these agents in predisposed patients.

Some neuromuscular blocking agents stimulate the release of histamine, which can cause wheezing, bronchospasm, increased bronchial secretions, hypotension, tachycardia, and circulatory collapse. Hypotension may also occur due to ganglionic blockade or as a complication of positive pressure respiration. Tubocurarine appears to be the most potent inducer of histamine, followed by metocurine (no longer commercially available in the U.S.) and succinylcholine. Other agents with varying but lesser degrees of histamine-releasing properties include atracurium, mivacurium, and pancuronium (at excessive dosages). Therapy with these neuromuscular blocking agents should be administered cautiously in patients with clinically significant cardiovascular disease and/or a history of asthma or severe allergic reactions. Certain agents may prolong the QTc interval, especially during general anesthesia in pediatric patients. The initial dosage and rate of administration may need to be reduced, and hemodynamic and respiratory status carefully monitored. Neuromuscular blocking agents that appear to have little or no histamine-inducing effects include cisatracurium, doxacurium, pipecuronium, rocuronium, and vecuronium.

Neuromuscular blocking agents undergo metabolism by the liver. Elimination and effects may be prolonged in patients with liver disease. Therapy with neuromuscular blocking agents should be administered cautiously in patients with liver disease.

The use of neuromuscular blocking agents may cause prolonged respiratory paralysis. Therapy with neuromuscular blocking agents should be administered cautiously in patients with myasthenia gravis. Use of a peripheral nerve stimulator may be helpful in evaluating the level of neuromuscular blockade.

Patients with hemiparesis or paraparesis may require higher dosages of non-depolarizing neuromuscular blocking agents in the affected limbs. Neuromuscular monitoring should be performed on a non-paretic limb to avoid inaccurate dosing.

Neuromuscular blocking agents can cause respiratory depression and paralysis. Therapy with neuromuscular blocking agents should be administered cautiously in patients with pulmonary impairment. Treatment of respiratory paralysis consists of positive-pressure artificial respiration with oxygen and maintenance of a patent airway until the recovery of normal respiration is assured.

Nondepolarizing neuromuscular blocking agents have been found to exhibit profound neuromuscular blocking effects in cachectic or debilitated patients, patients with neuromuscular diseases, and patients with carcinomatosis. In these or other patients in whom potentiation of neuromuscular block or difficulty with reversal may be anticipated, a decrease from the recommended initial dose of should be considered.

Resistance to nondepolarizing agents, consistent with up-regulation of skeletal muscle acetylcholine receptors, is associated with burns, disuse atrophy, denervation, and direct muscle trauma. Receptor up-regulation may also contribute to the resistance to nondepolarizing muscle relaxants which sometimes develops in patients with cerebral palsy, patients chronically receiving anticonvulsant agents. When a neuromuscular blocking agent is administered to these patients, shorter durations of neuromuscular block may occur, and infusion rates may be higher due to the development of resistance to nondepolarizing muscle relaxants. Caution is advisable when using these agents.

Because rocuronium bromide is always used with other agents, and the occurrence of malignant hyperthermia during anesthesia is possible even in the absence of known triggering agents, clinicians should be familiar with early signs, confirmatory diagnosis, and treatment of malignant hyperthermia prior to the start of any anesthetic agent. Care should be taken when using this agent.