The key difference between neostigmine and physostigmine is that neostigmine is useful in treating myasthenia gravis, Ogilvie syndrome, and urinary retention without the presence of a blockage whereas physostigmine is useful in treating glaucoma and delayed gastric emptying.
Neostigmine and physostigmine are two types of medications with different treatment applications. These medications are administrated through IV or IM methods.
CONTENTS
1. Overview and Key Difference
2. What is Neostigmine
3. What is Physostigmine
4. Side by Side Comparison – Neostigmine vs Physostigmine in Tabular Form
5. Summary
What is Neostigmine?
Neostigmine is a medication useful in treating myasthenia gravis, Ogilvie syndrome, and urinary retention without the presence of a blockage. We can use this drug in combination with atropine in order to end the effects of neuromuscular blocking medication of the non-depolarizing type.
Figure 01: Chemical Structure of the Drug
We can easily administrate this drug through IM and IV methods or through subcutaneous injection or oral administration. The effect arises after about 30 minutes from the time of administration and may last up to 4 hours.
However, there are some side effects of using this drug. These include nausea, increased saliva, crampy abdominal pain, and slow heart rate. Furthermore, there can be more severe side effects, including low blood pressure, weakness, and allergic reactions.
The drug works by blocking the action of acetylcholinesterase and thereby increasing the levels of acetylcholine. Therefore, this drug is in the cholinergic family of medications. When considering the excretion of this drug, about 70% of the drug is excreted unchanged, and the alcoholic metabolite of this drug (about 30% of the drug) is excreted through urine passing.
The chemical formula of this drug is C12H19N2O2+, and the molar mass is 223.29 g/mol. This substance was named as a member of the World Health Organization’s List of Essential Medicines. The drug was patented in 1931. Moreover, the parent molecule of this drug molecule is physostigmine.
What is Physostigmine?
Physostigmine is a medication useful in treating glaucoma and delayed gastric emptying. This is a highly toxic alkaloid type. We can call it a reversible cholinesterase inhibitor. This substance occurs naturally in the Calabar bean and in the Manchineel tree. The routes of administration for this drug include IV and IM methods.
Figure 02: Chemical Structure pf Physostigmine Drug
The scientist Percy Lavon Julian invented this substance in 1935. In the USA, the trade name of this substance is Antilirium. This substance is most commonly used in the present as a medicine despite its toxicity. However, in early times, this substance was considered an ordeal poison.
The chemical formula of physostigmine is C15H21N3O2. The molar mass of this drug is 275.35 g/mol. The mode of action of this drug is through enhancing the transmission of acetylcholine signals in the brain. Moreover, this substance can cross the blood-brain barrier. We can use this drug to treat reverse neuromuscular blocking.
However, there are some side effects, including cholinergic syndrome, nausea, vomiting, diarrhoea, anorexia, dizziness, etc.
What is the Difference Between Neostigmine and Physostigmine?
Neostigmine is a derivative of physostigmine. In other words, the parent molecule of neostigmine is physostigmine. The key difference between neostigmine and physostigmine is that neostigmine is useful in treating myasthenia gravis, Ogilvie syndrome, and urinary retention without the presence of a blockage whereas physostigmine is useful in treating glaucoma and delayed gastric emptying.
Below is a list of differences between neostigmine and physostigmine in tabular form for side by side comparison.
Summary – Neostigmine vs Physostigmine
Neostigmine and physostigmine are two types of medications. The key difference between neostigmine and physostigmine is that neostigmine is useful in treating myasthenia gravis, Ogilvie syndrome, and urinary retention without the presence of a blockage whereas physostigmine is useful in treating glaucoma and delayed gastric emptying.
Reference:
1. “Physostigmine.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine, Available here.
Image Courtesy:
1. “Neostigmine” (Public Domain) via Commons Wikimedia
2. “Physostigmin” By Ayacop assumed (based on copyright claims). – Own work assumed (based on copyright claims). (Public Domain) via Commons Wikimedia