Nimbex

Nimbex - General Information

Nimbex is a nondepolarizing skeletal muscle relaxant for intravenous administration. Nimbex acts on cholinergic receptors, blocking neuromuscular transmission. This action is antagonized by acetylcholinesterase inhibitors such as neostigmine. The neuromuscular block produced by cisatracurium besylate is readily antagonized by anticholinesterase agents once recovery has started. As with other nondepolarizing neuromuscular blocking agents, the more profound the neuromuscular block at the time of reversal, the longer the time required for recovery of neuromuscular function. Compared to other neuromuscular blocking agents, it is intermediate in its onset and duration of action.

Pharmacology of Nimbex

Nimbex is a nondepolarizing skeletal muscle relaxant for intravenous administration. Nimbex acts on cholinergic receptors, blocking neuromuscular transmission. This action is antagonized by acetylcholinesterase inhibitors such as neostigmine. The neuromuscular block produced by cisatracurium besylate is readily antagonized by anticholinesterase agents once recovery has started. As with other nondepolarizing neuromuscular blocking agents, the more profound the neuromuscular block at the time of reversal, the longer the time required for recovery of neuromuscular function. Compared to other neuromuscular blocking agents, it is intermediate in its onset and duration of action.

Nimbex for patients

Nimbex Interactions

NIMBEX has been used safely following varying degrees of recovery from succinylcholine-induced neuromuscular block. Administration of 0.1-mg/kg (2 x ED₉₅) NIMBEX at 10% or 95% recovery following an intubating dose of succinylcholine (1 mg/kg) produced ³95% neuromuscular block. The time to onset of maximum block following NIMBEX is approximately 2 minutes faster with prior administration of succinylcholine. Prior administration of succinylcholine had no effect on the duration of neuromuscular block following initial or maintenance bolus doses of NIMBEX. Infusion requirements of NIMBEX in patients administered succinylcholine prior to infusions of NIMBEX were comparable to or slightly greater than when succinylcholine was not administered.

The use of NIMBEX before succinylcholine to attenuate some of the side effects of succinylcholine has not been studied.

Although not studied systematically in clinical trials, no drug interactions were observed when vecuronium, pancuronium, or atracurium were administered following varying degrees of recovery from single doses or infusions of NIMBEX.

Isoflurane or enflurane administered with nitrous oxide/oxygen to achieve 1.25 MAC [Minimum Alveolar Concentration] may prolong the clinically effective duration of action of initial and maintenance doses of NIMBEX and decrease the required infusion rate of NIMBEX. The magnitude of these effects may depend on the duration of administration of the volatile agents. Fifteen to 30 minutes of exposure to 1.25 MAC isoflurane or enflurane had minimal effects on the duration of action of initial doses of NIMBEX and therefore, no adjustment to the initial dose should be necessary when NIMBEX is administered shortly after initiation of volatile agents. In long surgical procedures during enflurane or isoflurane anesthesia, less frequent maintenance dosing, lower maintenance doses, or reduced infusion rates of NIMBEX may be necessary. The average infusion rate requirement may be decreased by as much as 30% to 40%.

In clinical studies propofol had no effect on the duration of action or dosing requirements for NIMBEX. Other drugs which may enhance the neuromuscular blocking action of nondepolarizing agents such as NIMBEX include certain antibiotics (e. g., aminoglycosides, tetracyclines, bacitracin, polymyxins, lincomycin, clindamycin, colistin, and sodium colistemethate), magnesium salts, lithium, local anesthetics, procainamide, and quinidine. Resistance to the neuromuscular blocking action of nondepolarizing neuromuscular blocking agents has been demonstrated in patients chronically administered phenytoin or carbamazepine. While the effects of chronic phenytoin or carbamazepine therapy on the action of NIMBEX are unknown, slightly shorter durations of neuromuscular block may be anticipated and infusion rate requirements may be higher.

Drug/Laboratory Test Interactions

None known.

Nimbex Contraindications

NIMBEX is contraindicated in patients known to have an allergic hypersensitivity to NIMBEX or other bis-benzylisoquinolinium agents. Use of NIMBEX from vials containing benzyl alcohol as a preservative is contraindicated in patients with a known hypersensitivity to benzyl alcohol.

Additional information about Nimbex

Nimbex Indication: For inpatients and outpatients as an adjunct to general anesthesia, to facilitate tracheal intubation, and to provide skeletal muscle relaxation during surgery or mechanical ventilation in the ICU.
Mechanism Of Action: Nimbex binds to the nicotinic acetycholine (cholinergic) receptors in the motor endplate and blocks access to the receptors. In the process of binding, the receptor is actually activated - causing a process known as depolarization. Since it is not degraded in the neuromuscular junction, the depolarized membrane remains depolarized and unresponsive to any other impulse, causing muscle paralysis.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Cisatracurium Besylate
Synonyms: Not Available
Drug Category: Neuromuscular Blocking Agents
Drug Type: Small Molecule; Approved

Other Brand Names containing Cisatracurium Besylate: Atracurium Besylate; Atracurium Besylate Preservative Free; Nimbex; Tracrium Preservative Free;
Absorption: Not Available
Toxicity (Overdose): Overdosage with neuromuscular blocking agents may result in neuromuscular block beyond the time needed for surgery and anesthesia.
Protein Binding: The binding of cisatracurium to plasma proteins has not been successfully studied due to its rapid degradation at physiologic pH.
Biotransformation: The degradation of cisatracurium is largely independent of liver metabolism. Results from in vitro experiments suggest that cisatracurium undergoes Hofmann elimination (a pH and temperature-dependent chemical process) to form laudanosine and the monoquaternary acrylate metabolite. The monoquaternary acrylate undergoes hydrolysis by non-specific plasma esterases to form the monoquaternary alcohol metabolite. The monoquaternary alcohol metabolite can also undergo Hofmann elimination but at a much slower rate than cisatracurium. Laudanosine is further metabolized to desmethyl metabolites which are conjugated with glucuronic acid and excreted in the urine.
Half Life: Elimination half-life of 22 minutes.
Dosage Forms of Nimbex: Liquid Intravenous
Chemical IUPAC Name: benzenesulfonate; benzenesulfonate; 5-[3-[(1R,2R)-1-[(3,4-dimethoxyphenyl)methyl]-6,7-dimethoxy-2-methyl-3,4-dihydro-1H-isoquinolin-2-ium-2-yl]propanoyloxy]pentyl 3-[(1R,2R)-1-[(3,4-dimethoxyphenyl)methyl]-6,7-dimethoxy-2-methyl-3,4-dihydro-1H-isoquinolin-2-ium-2-yl]propanoate
Chemical Formula: C65H82N2O18S2
Cisatracurium Besylate on Wikipedia: Not Available
Organisms Affected: Humans and other mammals