Neostigmine Methylsulfate

Neostigmine Methylsulfate Injection, a cholinesterase inhibitor, is indicated for reversal of the effects of nondepolarizing neuromuscular blocking agents (NMBA) after surgery. Neostigmine Methylsulfate, a cholinesterase inhibitor, is indicated for reversal of the effects of nondepolarizing neuromuscular blocking agents (NMBA) after surgery ( 1 ).

Injection: 0.5 mg/mL and 1 mg/mL solution in 10 mL multiple-dose vials in package of 10 vials. Injection: 0.5 mg/mL and 1 mg/mL solution in 10 mL multiple dose vial in packages of 10 vials ( 3 )

Neostigmine 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). peritonitis or mechanical obstruction of the urinary or intestinal tracts. Hypersensitivity to neostigmine ( 4 ) Peritonitis or mechanical obstruction of urinary or intestinal tracts ( 4 )

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 ) ].

The most common adverse reactions include bradycardia and nausea and vomiting. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Fresenius Kabi, Vigilance & Medical Affairs at 1-800-551-7176 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

6.1 Clinical Trial Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The following serious adverse reactions are described below and elsewhere in the labeling: Bradycardia [ see Warnings and Precautions ( 5.1 ) ] Cardiovascular Complications [ see Warnings and Precautions ( 5.2 ) ] Hypersensitivity (Anaphylaxis) [ see Warnings and Precautions ( 5.3 ) ] Adverse reactions to neostigmine methylsulfate are most often attributable to exaggerated pharmacological effects, in particular, at muscarinic receptor sites. The use of an anticholinergic agent, e.g., atropine sulfate or glycopyrrolate, may prevent or mitigate these reactions. Quantitative adverse event data are available from trials of neostigmine methylsulfate in which 200 adult patients were exposed to the product. Adverse reactions that occurred with an overall frequency of 1% or greater included the following: Allergic: Allergic reactions and anaphylaxis. Neurological: Dizziness, syncope, weakness, convulsions, loss of consciousness, drowsiness, headache, dysarthria, miosis and visual changes. Cardiovascular: Cardiac arrhythmias including bradycardia, tachycardia, atrioventricular block and nodal rhythm, as well as cardiac arrest, and hypotension. Respiratory: Increased oral, pharyngeal and bronchial secretions, dyspnea, respiratory depression, oxygen desaturation, respiratory arrest and bronchospasm. Dermatologic: Diaphoresis, flushing, rash, pruritus, and urticaria. Gastrointestinal: Dry mouth, nausea, emesis, flatulence and increased peristalsis. Genitourinary: Increased urinary frequency. Musculoskeletal: Muscle cramps and spasm, arthralgia. Psychiatric: Insomnia. General: Incision site complication, pharyngolaryngeal pain, procedural complication, procedural pain.

6.2 Post-Marketing Experience The following adverse reactions have been identified during parenteral use of neostigmine methylsulfate. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Allergic Disorders: Allergic reactions, anaphylaxis Nervous System Disorders: Convulsions, drowsiness, dysarthria, fasciculation, loss of consciousness, miosis, visual changes Cardiovascular Disorders: Cardiac arrest, cardiac arrhythmias (A-V block, nodal rhythm), hypotension, nonspecific EKG changes, syncope Respiratory, Thoracic and Mediastinal Disorders: Bronchospasm; increased oral, pharyngeal and bronchial secretions; respiratory arrest; respiratory depression Skin and Subcutaneous Tissue Disorders: Rash, urticaria diaphoresis, flushing Gastrointestinal Disorders: Bowel cramps, diarrhea, flatulence, increased peristalsis Renal and Urinary Disorders: Urinary frequency Musculoskeletal and Connective Tissue Disorders: Arthralgia, muscle cramps, spasms, weakness

6.1 Clinical Trial Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The following serious adverse reactions are described below and elsewhere in the labeling: Bradycardia [ see Warnings and Precautions ( 5.1 ) ] Cardiovascular Complications [ see Warnings and Precautions ( 5.2 ) ] Hypersensitivity (Anaphylaxis) [ see Warnings and Precautions ( 5.3 ) ] Adverse reactions to neostigmine methylsulfate are most often attributable to exaggerated pharmacological effects, in particular, at muscarinic receptor sites. The use of an anticholinergic agent, e.g., atropine sulfate or glycopyrrolate, may prevent or mitigate these reactions. Quantitative adverse event data are available from trials of neostigmine methylsulfate in which 200 adult patients were exposed to the product. Adverse reactions that occurred with an overall frequency of 1% or greater included the following: Allergic: Allergic reactions and anaphylaxis. Neurological: Dizziness, syncope, weakness, convulsions, loss of consciousness, drowsiness, headache, dysarthria, miosis and visual changes. Cardiovascular: Cardiac arrhythmias including bradycardia, tachycardia, atrioventricular block and nodal rhythm, as well as cardiac arrest, and hypotension. Respiratory: Increased oral, pharyngeal and bronchial secretions, dyspnea, respiratory depression, oxygen desaturation, respiratory arrest and bronchospasm. Dermatologic: Diaphoresis, flushing, rash, pruritus, and urticaria. Gastrointestinal: Dry mouth, nausea, emesis, flatulence and increased peristalsis. Genitourinary: Increased urinary frequency. Musculoskeletal: Muscle cramps and spasm, arthralgia. Psychiatric: Insomnia. General: Incision site complication, pharyngolaryngeal pain, procedural complication, procedural pain.

6.2 Post-Marketing Experience The following adverse reactions have been identified during parenteral use of neostigmine methylsulfate. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Allergic Disorders: Allergic reactions, anaphylaxis Nervous System Disorders: Convulsions, drowsiness, dysarthria, fasciculation, loss of consciousness, miosis, visual changes Cardiovascular Disorders: Cardiac arrest, cardiac arrhythmias (A-V block, nodal rhythm), hypotension, nonspecific EKG changes, syncope Respiratory, Thoracic and Mediastinal Disorders: Bronchospasm; increased oral, pharyngeal and bronchial secretions; respiratory arrest; respiratory depression Skin and Subcutaneous Tissue Disorders: Rash, urticaria diaphoresis, flushing Gastrointestinal Disorders: Bowel cramps, diarrhea, flatulence, increased peristalsis Renal and Urinary Disorders: Urinary frequency Musculoskeletal and Connective Tissue Disorders: Arthralgia, muscle cramps, spasms, weakness

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.

Pregnancy: No human data and limited animal exist. Use only if clearly needed.

8.1 Pregnancy Risk Summary There are no adequate or well-controlled studies of Neostigmine Methylsulfate Injection in pregnant women. It is not known whether Neostigmine Methylsulfate Injection can cause fetal harm when administered to a pregnant woman or can affect reproductive capacity. The incidence of malformations in human pregnancies has not been established for neostigmine as the data are limited. All pregnancies, regardless of drug exposure, have a background risk of 2 to 4% for major birth defects, and 15 to 20% for pregnancy loss. No adverse effects were noted in rats or rabbits treated with human equivalent doses of neostigmine methylsulfate doses up to 8.1 and 13 mcg/kg/day, respectively, during organogenesis (0.1 to 0.2-times the maximum recommended human dose of 5 mg/60 kg person/day based on body surface area comparisons). Anticholinesterase drugs, including neostigmine may cause uterine irritability and induce premature labor when administered to pregnant women near term. Neostigmine Methylsulfate Injection should be given to a pregnant woman only if clearly needed. Data Animal Data In embryofetal development studies, rats and rabbits were administered neostigmine methylsulfate at human equivalent doses (HED, on a mg/m 2 basis) of 1.6, 4 and 8.1 mcg/kg/day 3.2, 8.1, and 13 mcg/kg/day, respectively, during the period of organogenesis (Gestation Days 6 through 17 for rats and Gestation Days 6 through 18 for rabbits). There was no evidence for a teratogenic effect in rats and rabbits up to HED 8.1 and 13 mcg/kg/day, which are approximately 0.097-times and 0.16-times the MRHD of 5 mg/60 kg, respectively in the presence of minimal maternal toxicity (tremors, ataxia, and prostration). The studies resulted in exposures in the animals well below predicted exposures in humans. In a pre- and postnatal development study in rats, neostigmine methylsulfate was administered to pregnant female rats at human equivalent doses (HED) of 1.6, 4 and 8.1 mcg/kg/day from Day 6 of gestation through Day 20 of lactation, with weaning on Day 21. There were no adverse effects on physical development, behavior, learning ability, or fertility in the offspring occurred at HED doses up 8.1 mcg/kg/day which is 0.097-times the MRHD of 5 mg/60 kg on a mg/m 2 basis in the presence of minimal maternal toxicity (tremors, ataxia, and prostration). The studies resulted in exposures in the animals well below predicted exposures in humans.

8.2 Lactation It is not known whether Neostigmine Methylsulfate Injection is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions from Neostigmine Methylsulfate Injection in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

8.4 Pediatric Use Data from published literature support the intravenous use of neostigmine methylsulfate for reversal of nondepolarizing neuromuscular blocking agents in all pediatric age groups. Recovery of neuromuscular activity occurs more rapidly with smaller doses of cholinesterase inhibitors in infants and children than in adults. However, infants and small children may be at greater risk of complications from incomplete reversal of neuromuscular blockade due to decreased respiratory reserve. The risks associated with incomplete reversal outweigh any risk from giving higher doses of Neostigmine Methylsulfate (up to 0.07 mg/kg or up to a total of 5 mg, whichever is lower). The dose of Neostigmine Methylsulfate required to reverse neuromuscular blockade in children varies between 0.03 mg to 0.07 mg/kg, the same dose range shown to be effective in adults, and should be selected using the same criteria as used for adult patients [ see Clinical Pharmacology ( 12.3 ) ]. Since the blood pressure in pediatric patients, particularly infants and neonates is sensitive to changes in heart rate, the effects of an anticholinergic agent (e.g., atropine) should be observed prior to administration of neostigmine to lessen the probability of bradycardia and hypotension.

8.5 Geriatric Use Elderly patients are likely to have decreased renal function, which may prolong the duration of action of neostigmine methylsulfate. However, elderly patients also experience slower spontaneous recovery from neuromuscular blocking agents. Therefore, dosage adjustments are generally not needed in geriatric patients; however, they should be monitored for longer periods than younger adults to assure additional doses of Neostigmine Methylsulfate Injection are not required. The duration of monitoring should be predicated on the anticipated duration of action for the neuromuscular blocking agents used on the patient.

8.6 Renal Impairment Elimination half-life of neostigmine was prolonged in anephric patients compared to normal subjects, so neostigmine concentration may increase in patients with impaired renal functions. Although no adjustments to Neostigmine Methylsulfate Injection dosing appear to be warranted in patients with impaired renal function, they should be closely monitored for a longer period of time. To assure the effects of the neuromuscular blocking agent, particularly one cleared by the kidneys, do not persist beyond those of Neostigmine Methylsulfate Injection, the interval for re‐dosing the neuromuscular blocking agent during the surgical procedure may be useful in determining whether, and to what extent, post‐operative monitoring needs to be extended.

8.7 Hepatic Impairment The pharmacokinetics of neostigmine methylsulfate in patients with hepatic impairment have not been studied. Neostigmine is metabolized by microsomal enzymes in the liver so neostigmine concentration may increase in patients with impaired hepatic functions. Although no adjustments to the dosing of Neostigmine Methylsulfate Injection appear to be warranted in patients with hepatic insufficiency, patients should be carefully monitored for a longer period of time. If hepatically cleared neuromuscular blocking agents were used during the surgical procedure, their duration of action may also be prolonged by hepatic insufficiency. This could result in the effects of the neuromuscular blocking agent outlasting those of Neostigmine Methylsulfate Injection. In this regard, the interval for re-dosing the neuromuscular blocking agent during the surgical procedure may be useful in determining whether, and to what extent, post-operative monitoring needs to be extended.

8.6 Renal Impairment Elimination half-life of neostigmine was prolonged in anephric patients compared to normal subjects, so neostigmine concentration may increase in patients with impaired renal functions. Although no adjustments to Neostigmine Methylsulfate Injection dosing appear to be warranted in patients with impaired renal function, they should be closely monitored for a longer period of time. To assure the effects of the neuromuscular blocking agent, particularly one cleared by the kidneys, do not persist beyond those of Neostigmine Methylsulfate Injection, the interval for re‐dosing the neuromuscular blocking agent during the surgical procedure may be useful in determining whether, and to what extent, post‐operative monitoring needs to be extended.

8.7 Hepatic Impairment The pharmacokinetics of neostigmine methylsulfate in patients with hepatic impairment have not been studied. Neostigmine is metabolized by microsomal enzymes in the liver so neostigmine concentration may increase in patients with impaired hepatic functions. Although no adjustments to the dosing of Neostigmine Methylsulfate Injection appear to be warranted in patients with hepatic insufficiency, patients should be carefully monitored for a longer period of time. […]

Neostigmine methylsulfate is a competitive cholinesterase inhibitor. By reducing the breakdown of acetylcholine, neostigmine methylsulfate induces an increase in acetylcholine in the synaptic cleft which competes for the same binding site as nondepolarizing neuromuscular blocking agents, and reverses the neuromuscular blockade.