Absorption, Distribution and Excretion
Neostigmine bromide is poorly absorbed from the gastrointestinal tract following oral administration
NEOSTIGMINE...IS ABSORBED POORLY AFTER ORAL ADMINISTRATION, SUCH THAT MUCH LARGER DOSES ARE NEEDED THAN BY THE PARENTERAL ROUTE. ...THE EFFECTIVE PARENTERAL DOSE OF NEOSTIGMINE IN MAN IS 0.5 TO 2.0 MG, THE EQUIVALENT ORAL DOSE MAY BE 30 MG OR MORE. LARGE ORAL DOSES MAY PROVE TOXIC IF INTESTINAL ABSORPTION IS ENHANCED FOR ANY REASON.
...THE EXCRETION OF NEOSTIGMINE IS RETARDED IN PATIENTS WITH SEVERE KIDNEY DISEASE, MAKING THIS ANTICHOLINESTERASE DRUG AN ACCEPTABLE CHOICE IN PATIENTS WITH RENAL FAILURE.
The pharmacokinetics of neostigmine in patients with normal renal function were determined and compared with those of patients undergoing renal transplantation or bilateral nephrectomy. Ten to 15 min prior to the end of operation and anesthesia, d-tubocurarine infusion was terminated and neostigmine, 0.07 mg/kg and atropine 0.03 mg/kg were given by infusion over a 2-min period. In anephric patients the elimination half-life was prolonged. Total serum clearance was decr from 16.7 ml/kg/min in patients with normal renal function to 7.8 ml/kg/min in anephric patients. Neostigmine pharmacokinetics following renal transplantation were not different from those in patients with normal renal function. Renal excretion accounts for 50% of neostigmine clearance.

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Metabolism / Metabolites
Neostigmine undergoes hydrolysis by cholinesterase and is also metabolized by microsomal enzymes in the liver.
NEOSTIGMINE IS DESTROYED BY PLASMA ESTERASES, AND THE QUATERNARY ALCOHOL AND PARENT COMPOUND ARE EXCRETED IN THE URINE.
NEOSTIGMINE YIELDS 3-HYDROXYPHENYL TRIMETHYLAMMONIUM IN THE RAT. ROBERTS, JB ET AL; BIOCHEM PHARMAC 17: 9 (1968). /FROM TABLE/

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Biological Half-Life
The half-life ranged from 42 to 60 minutes with a mean half-life of 52 minutes.
The pharmacokinetics of neostigmine was evaluated in man after iv and oral admin. The mean plasma T/2 for neostigmine after iv admin was 0.89 hr. Following oral admin peak concn occurred 1-2 hr after intake, but biol availability was only 1-2% of the admin dose. In patients with myasthenia gravis, the decrement of the evoked electric muscle response of repetitive nerve stimulation correlated well with plasma concn of neostigmine.

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Limited data indicate that use of neostigmine to treat myasthenia gravis may be acceptable during breastfeeding, although pyridostigmine may be preferred. Monitor newborns because abdominal cramps after each breastfeeding has been reported. Because of its short half-life, single doses of neostigmine to reverse neuromuscular blockade following surgery are unlikely to adversely affect the breastfed infant more than transiently.
◉ Effects in Breastfed Infants
Six infants of mothers treated with neostigmine for myasthenia gravis were reportedly breastfed successfully. One newborn infant appeared to have abdominal cramps after each breastfeeding, probably caused by neostigmine, although it could not be detected in the breastmilk of the infant's mother.
◉ Effects on Lactation and Breastmilk
Relevant published information in nursing mothers was not found as of the revision date. In animals, cholinergic drugs increase oxytocin release, and have variable effects on serum prolactin. The prolactin level in a mother with established lactation may not affect her ability to breastfeed.

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Protein Binding
Protein binding to human serum albumin ranges from 15 to 25 percent.

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Interactions
ACTIONS OF ANTICHOLINESTERASE AGENTS ON AUTONOMIC EFFECTOR CELLS & ON CORTICAL & SUBCORTICAL SITES IN CNS, WHERE RECEPTORS ARE LARGELY OF MUSCARINIC TYPE, ARE BLOCKED BY ATROPINE. /ANTI-CHE AGENTS/
VARIOUS ACTIONS OF ANTI-CHE AGENTS ON SKELETAL MUSCLE ARE AUGMENTED BY EPINEPHRINE OR EPHEDRINE...& BLOCKED BY D-TUBOCURARINE. /ANTICHOLINESTERASE AGENTS/
QUINIDINE MAY ANTAGONIZE THE EFFECTS OF NEOSTIGMINE (PROSTIGMINE)...IN THE TREATMENT OF MYASTHENIA GRAVIS. ...THE ANTICHOLINERGIC EFFECT OF QUINIDINE MAY ANTAGONIZE THE VAGAL-STIMULATING EFFECT OF CHOLINERGIC DRUGS. QUINIDINE SHOULD BE USED WITH CAUTION IN PATIENTS WITH MYASTHENIA GRAVIS WHO ARE BEING TREATED WITH CHOLINERGIC DRUGS.
Neostigmine failed to modify the development of neuromuscular block in the presence of a high local concn of tubocurarine.
For more Interactions (Complete) data for NEOSTIGMINE (13 total), please visit the HSDB record page.

Neostigmine is a quaternary ammonium ion comprising an anilinium ion core having three methyl substituents on the aniline nitrogen, and a 3-[(dimethylcarbamoyl)oxy] substituent at position 3. It is a parasympathomimetic which acts as a reversible acetylcholinesterase inhibitor. It has a role as an EC 3.1.1.7 (acetylcholinesterase) inhibitor and an antidote to curare poisoning.
A cholinesterase inhibitor used in the treatment of myasthenia gravis and to reverse the effects of muscle relaxants such as gallamine and tubocurarine. Neostigmine, unlike physostigmine, does not cross the blood-brain barrier.
Neostigmine is a Cholinesterase Inhibitor. The mechanism of action of neostigmine is as a Cholinesterase Inhibitor.
Neostigmine is a parasympathomimetic agent that acts as a reversible acetylcholinesterase inhibitor.
A cholinesterase inhibitor used in the treatment of myasthenia gravis and to reverse the effects of muscle relaxants such as gallamine and tubocurarine. Neostigmine, unlike PHYSOSTIGMINE, does not cross the blood-brain barrier.
See also: Neostigmine Methylsulfate (has salt form).

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Drug Indication
Neostigmine is used for the symptomatic treatment of myasthenia gravis by improving muscle tone.

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Mechanism of Action
Neostigmine is a parasympathomimetic, specifically, a reversible cholinesterase inhibitor. The drug inhibits acetylcholinesterase which is responsible for the degredation of acetylcholine. So, with acetylcholinesterase inhibited, more acetylcholine is present By interfering with the breakdown of acetylcholine, neostigmine indirectly stimulates both nicotinic and muscarinic receptors which are involved in muscle contraction.. It does not cross the blood-brain barrier.
...PHARMACOLOGICAL EFFECTS OF ANTICHOLINESTERASE AGENTS ARE DUE PRIMARILY TO PREVENTION OF HYDROLYSIS OF ACH /ACETYLCHOLINE/ BY ACHE /ACETYLCHOLINESTERASE/ AT SITES OF CHOLINERGIC TRANSMISSION. TRANSMITTER THUS ACCUMULATES, AND THE ACTION OF ACH /ACETYLCHOLINESTERASE/ THAT IS LIBERATED BY CHOLINERGIC IMPULSES OR THAT LEAKS FROM THE NERVE ENDING IS ENHANCED.
Neostigmine increased both miniature end-plate potential and end-plate potential amplitudes but did not affect quantal content in isolated frog sciatic nerve-Sartorius muscle prepn. This suggests that cholinesterase inhibition was the only effect.
Long term (24-96 hr) treatment of a mouse-derived myogenic cell line (G8) with neostigmine markedly reduced binding of alpha-bungarotoxin (alpha-BuTx) to these cells. Protein synthesis in these cultures was markedly reduced and cell morphology degenerated. Myotubes maintained slightly hyperpolarized resting membrane potentials, and were able to respond to iontophoretic acetylcholine (Ach) application with overshooting action potentials. Degenerative changes at the neuromuscular junction associated with chronic neostigmine treatment in vivo are probably due to a direct action of the anticholinesterase on the muscle, rather than to altered intracleft ACh levels or to presynaptic effects of the anticholinesterase.
The intraluminal probe mounted with 2 electrode-strain gauge pairs, 4 cm apart, was used to study the effect of a neutral interview, a stressful interview, a meal (478.7 cal) and neostigmine (0.5 mg, im) on the contractile electrical complex, continuous electrical response activity and their associated contractions in 17 normal subjects. Neostigmine resulted in an incr in contractile electric complex & continuous electric response activity indexes 5-10 and 25-30 min after the injection, respectively. Both the meal and neostigmine incr the percentage of propagated contractile electric complexes during all of the recording periods.

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Therapeutic Uses
Cholinesterase Inhibitors; Parasympathomimetics
...ANTI-CHE /ANTICHOLINESTERASE/ AGENTS ARE OF GREAT VALUE IN MGMNT OF PRIMARY /GLAUCOMA/ AS WELL AS OF CERTAIN CATEGORIES OF SECONDARY TYPE (EG APHAKIC GLAUCOMA, FOLLOWING CATARACT EXTRACTION); THE CONGENITAL TYPE RARELY RESPONDS TO OTHER THAN SURGICAL TREATMENT. PRIMARY GLAUCOMA IS SUBDIVIDED INTO NARROW-ANGLE (ACUTE CONGESTIVE) AND WIDE-ANGLE (CHRONIC SIMPLE) TYPES... ANTI-CHE AGENTS PRODUCE A FALL IN INTRAOCULAR PRESSURE IN BOTH TYPES...BY LOWERING THE RESISTANCE TO OUTFLOW OF THE AQAEOUS HUMOR. ... /IN/ ACUTE CONGESTIVE GLAUCOMA...AN ANTI-CHE AGENT IS INSTILLED IN THE CONJUNCTIVAL SAC IN COMBINATION WITH PARASYMPATHOMIMETIC AGENT... CHRONIC SIMPLE...AND SECONDARY GLAUCOMA REQUIRE CAREFUL CONSIDERATION OF THE NEEDS OF THE INDIVIDUAL PT IN SELECTING DRUG OR COMBINATION OF DRUGS... CHOICES AVAIL INCL...ANTICHOLINESTERASE AGENTS...
...IS USED FOR THE RELIEF OF ABDOMINAL DISTENTION FROM A VARIETY OF MEDICAL AND SURGICAL CAUSES. ...IS TO BE VIEWED MAINLY AS ADJUVANT AGENT IN THE TREATMENT OF DISTENTION. ...WHEN NEOSTIGMINE IS EMPLOYED FOR THE TREATMENT OF ATONY OF THE DETRUSOR MUSCLE OF THE URINARY BLADDER, POSTOPERATIVE DYSURIA IS RELIEVED AND THE TIME INTERVAL BETWEEN OPERATION AND SPONTANEOUS URINATION IS SHORTENED.
...NEOSTIGMINE IS USED IN THE DIFFERENTIAL DIAGNOSIS OF MYASTHENIC CRISIS, IN WHICH CASE IT WILL IMPROVE MUSCLE FUNCTION, AND CHOLINERGIC CRISES, IN WHICH CASE IT WILL WORSEN FUNCTION, AND TO DIAGNOSE MYOTONIA CONGENITA.
For more Therapeutic Uses (Complete) data for NEOSTIGMINE (9 total), please visit the HSDB record page.

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Drug Warnings
...NEOSTIGMINE, MUST BE USED CAUTIOUSLY IN PATIENTS WITH CARDIAC DYSRHYTHMIAS OR BRONCHIAL ASTHMA.
THE DRUG SHOULD NOT BE USED WHEN THERE IS MECHANICAL OBSTRUCTION OF THE INTESTINE OR URINARY BLADDER, WHEN PERITONITIS IS PRESENT, OR WHEN THE VIABILITY OF THE BOWEL IS DOUBTFUL.
The type of reaction to neostigmine in patients with neuromuscular disease is unpredictable. Long-lasting muscle weakness was produced in a 57-yr-old female with dystrophia myotonica. A 50-yr-old male with a 30-yr history of progressive muscle dystrophy exhibited a tonic response to neostigmine during recovery from partial neuromuscular block.
Neostigmine in clinical doses can produce an acetylcholine-induced block which can be a potential hazard in anesthetic practice. Study reveals effects of neostigmine in 26 patients anesthetized with thiopentone and nitrous oxide.
For more Drug Warnings (Complete) data for NEOSTIGMINE (6 total), please visit the HSDB record page.

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Pharmacodynamics
Neostigmine is a cholinesterase inhibitor used in the treatment of myasthenia gravis and to reverse the effects of muscle relaxants such as gallamine and tubocurarine. Neostigmine, unlike physostigmine, does not cross the blood-brain barrier. By inhibiting acetylcholinesterase, more acetylcholine is available in the synapse, therefore, more of it can bind to the fewer receptors present in myasthenia gravis and can better trigger muscular contraction.

C12H19N2O2+

223.29

223.145

59-99-4

114-80-7 (bromide);51-60-5 (methyl sulfate)

4456

Typically exists as solid at room temperature

1.943

0

2

3

16

246

0

CN(C)C(=O)OC1=CC=CC(=C1)[N+](C)(C)C

ALWKGYPQUAPLQC-UHFFFAOYSA-N

InChI=1S/C12H19N2O2/c1-13(2)12(15)16-11-8-6-7-10(9-11)14(3,4)5/h6-9H,1-5H3/q+1

[3-(dimethylcarbamoyloxy)phenyl]-trimethylazanium

Neostigmine Juvastigmin CCRIS 3079

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)