Compare the Difference Between Similar Terms

What is the Difference Between Ephedrine and Pseudoephedrine

The key difference between ephedrine and pseudoephedrine is that ephedrine is a mixed-acting sympathomimetic amine, whereas pseudoephedrine is an indirectly-acting sympathomimetic amine.

Ephedrine and pseudoephedrine are sympathomimetic amine compounds. Both are useful as medication. Ephedrine is a medication and a stimulant that is useful in preventing low blood pressure during spinal anaesthesia. Pseudoephedrine, which is an isomer of ephedrine, is a sympathomimetic drug that belongs to the phenethylamine and amphetamine chemical class.

CONTENTS

1. Overview and Key Difference
2. What is Ephedrine 
3. What is Pseudoephedrine
4. Ephedrine vs Pseudoephedrine in Tabular Form
5. Summary – Ephedrine vs Pseudoephedrine

What is Ephedrine?

Ephedrine is a medication and a stimulant that is used in preventing low blood pressure during spinal anaesthesia. We can also use this drug as a treatment for asthma, narcolepsy, and obesity. The route of administration preferred for this drug is the mouth, but we can take it as an injection into a muscle, vein, or just under the skin as well. The intravenous injection is the fastest route of administration into the body. Taking the medication from the mouth can take hours to give the preferred effect.

Figure 01: The Chemical Structure of Ephedrine in Two Different Spatial Arrangements

Moreover, some common side effects of ephedrine include trouble sleeping, anxiety, headache, hallucinations, high blood pressure, fast heart rate, loss of appetite, and inability to urinate. Moreover, there are some adverse side effects as well, e.g. stroke, heart attack, and abuse.

What is Pseudoephedrine?

Pseudoephedrine is a sympathomimetic drug that belongs to the phenethylamine and amphetamine chemical classes. This drug is useful as a nasal/sinus decongestant, as a stimulant and as a wakefulness-promoting agent when used in higher doses.

Figure 02: The Chemical Structure of Pseudoephedrine

The trade names of this medication include Afrinol, Sudafed, Sinutab, etc. The route of administration for this medication is by mouth. The metabolism of pseudoephedrine occurs in the liver. The elimination half-life of the drug is about 4.3 to 8 hours. The excretion occurs in the kidney. The chemical formula of pseudoephedrine is C10H15NO, and the molar mass is about 165.23 g/mol.

Pseudoephedrine is a well-known drug for shrinking swollen nasal mucous membranes; therefore, it is often useful as a decongestant. Moreover, it can reduce tissue hyperemia, edema, and nasal congestion, which are commonly associated with colds and allergies. Furthermore, we can use this drug as an oral or as a topical decongestant. In addition, this drug is useful as a first-line prophylactic for recurrent priapism.

There can be some side effects of this drug, including central nervous system stimulation, insomnia, nervousness, excitability, dizziness, and anxiety.

What is the Difference Between Ephedrine and Pseudoephedrine?

Ephedrine and pseudoephedrine are sympathomimetic amine compounds. Ephedrine is a medication and a stimulant that is useful in preventing low blood pressure during spinal anaesthesia, while pseudoephedrine is a sympathomimetic drug that belongs to the phenethylamine and amphetamine chemical class. The key difference between ephedrine and pseudoephedrine is that ephedrine is a mixed-acting sympathomimetic amine, whereas pseudoephedrine is an indirectly-acting sympathomimetic amine. In addition, Akovaz, Corphedra, and Emerphed are trade names for ephedrine whereas Afrinol, Sudafed, and Sinutab are trade names for pseudoephedrine.

The following table summarizes the difference between ephedrine and pseudoephedrine.

Summary – Ephedrine vs Pseudoephedrine

Pseudoephedrine is an isomer of ephedrine. Therefore, these two substances differ from each other according to their chemical structure and other properties. The key difference between ephedrine and pseudoephedrine is that ephedrine is a mixed-acting sympathomimetic amine, whereas pseudoephedrine is an indirectly-acting sympathomimetic amine.

Reference:

1. “Pseudoephedrine Uses, Dosage & Side Effects.” Drugs.com.
2. “Ephedrine.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine.

Image Courtesy:

1. “Ephedrine enantiomers” By Vaccinationist – (1R,2S)-(−)-ephedrine on PubChem(1S,2R)-(+)-ephedrine on PubChem (Public Domain) via Commons Wikimedia

2. “Pseudoephedrine S,S ephedrine comparison” By Testem – Own work (CC0) via Commons Wikimedia