INTERACTIONS The pharmacokinetic interaction between neostigmine methylsulfate and other drugs has not been studied. Neostigmine methylsulfate is metabolized by microsomal enzymes in the liver. Closely monitor patients for a longer period of time when using Neostigmine Methylsulfate Injection with other drugs which may alter the activity of metabolizing enzymes or transporters.
7.1 Depolarizing Muscle Relaxants Use of neostigmine to reverse the effects of depolarizing muscle relaxants such as succinylcholine is not recommended, because it may prolong the phase-1 block.
7.2 Antibiotics Certain antibiotics, particularly neomycin, streptomycin and kanamycin have nondepolarizing neuromuscular blocking action, and therefore, neostigmine dose adjustments may be required to reverse neuromuscular block in patients who have been taking these drugs. There was no effect on neostigmine action on rocuronium reversal by cefuroxime, metronidazole, cefuroxime or metronidazole.
7.1 Depolarizing Muscle Relaxants Use of neostigmine to reverse the effects of depolarizing muscle relaxants such as succinylcholine is not recommended, because it may prolong the phase-1 block.
7.2 Antibiotics Certain antibiotics, particularly neomycin, streptomycin and kanamycin have nondepolarizing neuromuscular blocking action, and therefore, neostigmine dose adjustments may be required to reverse neuromuscular block in patients who have been taking these drugs. There was no effect on neostigmine action on rocuronium reversal by cefuroxime, metronidazole, cefuroxime or metronidazole.
Neostigmine Methylsulfate Injection, USP, is contraindicated in patients with: known hypersensitivity to neostigmine methylsulfate (known hypersensitivity reactions have included urticaria, angioedema, erythema multiforme, generalized rash, facial swelling, peripheral edema, pyrexia, flushing, hypotension, bronchospasm, bradycardia and anaphylaxis). with peritonitis or mechanical obstruction of the intestinal or urinary tract. Hypersensitivity to neostigmine ( 4 ) Peritonitis or mechanical obstruction of the intestinal or urinary tract ( 4 )
AND PRECAUTIONS Bradycardia : Atropine or glycopyrrolate should be administered prior to administration of neostigmine methylsulfate injection to lessen risk of bradycardia ( 5.1 )
Coexisting
Conditions : Patients with known cardiac disease, cardiac arrhythmias, or recent coronary artery occlusion may be particularly sensitive to the hemodynamic effects of neostigmine; their blood pressure and electrocardiogram should be continuously monitored with the initiation of neostigmine treatment and for a duration sufficient to assure hemodynamic stability. ( 5.2 )
Neuromuscular
Dysfunction : Can occur if large doses of neostigmine methylsulfate are administered when there is minimal neuromuscular blockade; reduce the dose if recovery from neuromuscular blockade is nearly complete. ( 5.4 )
5.1 Bradycardia Neostigmine has been associated with bradycardia. An anticholinergic agent, (e.g., atropine sulfate or glycopyrrolate) should be administered prior to Neostigmine Methylsulfate Injection administration to lessen the risk of bradycardia [ see Dosage and Administration ( 2.4 ) ].
5.2 Cardiovascular Complications Cardiac arrhythmias, nonspecific electrocardiogram changes, cardiac arrest, syncope and hypotension have been reported with neostigmine methylsulfate. In patients with certain cardiovascular conditions such as coronary artery disease, cardiac arrhythmias or recent acute coronary syndrome, the risk of blood pressure and heart rate complications may be increased. Risk of these complications may also be increased in patients with myasthenia gravis. Standard antagonism with anticholinergics (e.g., atropine) is generally successful to mitigate the risk of cardiovascular complications.
5.3 Hypersensitivity (Anaphylaxis) Hypersensitivity reactions including anaphylaxis have been reported with neostigmine. Ensure that appropriate medical support measures, including atropine, cardiopulmonary resuscitation equipment, and medications to treat anaphylaxis are readily available.
5.4 Neuromuscular Dysfunction Neuromuscular dysfunction has been associated with administration of large doses of neostigmine when neuromuscular blockade is minimal. To mitigate the risk of neuromuscular dysfunction, consider reducing the dose of neostigmine if recovery from neuromuscular blockade is nearly complete.
5.5 Cholinergic Crisis Overdosage of neostigmine may cause cholinesterase inhibitor toxicity or cholinergic crisis which may be difficult to differentiate from myasthenia crisis since both conditions present with similar symptoms. Both conditions result in extreme muscle weakness but require radically different treatments. Cholinergic crisis requires immediate withdrawal of all anticholinergic medication and immediate use of atropine [ see Overdosage ( 10 ) ].
5.1 Bradycardia Neostigmine has been associated with bradycardia. An anticholinergic agent, (e.g., atropine sulfate or glycopyrrolate) should be administered prior to Neostigmine Methylsulfate Injection administration to lessen the risk of bradycardia [ see Dosage and Administration ( 2.4 ) ].
5.2 Cardiovascular Complications Cardiac arrhythmias, nonspecific electrocardiogram changes, cardiac arrest, syncope and hypotension have been reported with neostigmine methylsulfate. In patients with certain cardiovascular conditions such as coronary artery disease, cardiac arrhythmias or recent acute coronary syndrome, the risk of blood pressure and heart rate complications may be increased. Risk of these complications may also be increased in patients with myasthenia gravis. Standard antagonism with anticholinergics (e.g., atropine) is generally successful to mitigate the risk of cardiovascular complications.
5.3 Hypersensitivity (Anaphylaxis) Hypersensitivity reactions including anaphylaxis have been reported with neostigmine. Ensure that appropriate medical support measures, including atropine, cardiopulmonary resuscitation equipment, and medications to treat anaphylaxis are readily available.
5.4 Neuromuscular Dysfunction Neuromuscular dysfunction has been associated with administration of large doses of neostigmine when neuromuscular blockade is minimal. To mitigate the risk of neuromuscular dysfunction, consider reducing the dose of neostigmine if recovery from neuromuscular blockade is nearly complete.
5.5 Cholinergic Crisis Overdosage of neostigmine may cause cholinesterase inhibitor toxicity or cholinergic crisis which may be difficult to differentiate from myasthenia crisis since both conditions present with similar symptoms. Both conditions result in extreme muscle weakness but require radically different treatments. Cholinergic crisis requires immediate withdrawal of all anticholinergic medication and immediate use of atropine [ see Overdosage ( 10 ) ].