Difference Between Ephedrine vs. Pseudoephedrine

Main Difference

The main difference between Ephedrine and Pseudoephedrine is that Ephedrine is sympathomimetic alkaloid derived from a plant of Genus ephedra while Pseudoephedrine is the isomer of ephedrine with sympathomimetic activity.

Ephedrine vs. Pseudoephedrine

Ephedrine has direct or indirect sympathomimetic activity on both α, and β receptors, on the other hand, Pseudoephedrine has indirect sympathomimetic activity on α receptors and indirect weak sympathomimetic activity on β receptors. Ephedrine increases the release and activity of norepinephrine on adrenergic receptors, whereas Pseudoephedrine increases the release of the endogenous norepinephrine from the storage vesicles. Ephedrine has a structure similar to the amphetamine and methamphetamines, on the other hand, Pseudoephedrine is phenethylamine. Ephedrine is used in low doses to treat the hypotension while Pseudoephedrine is used in higher doses to treat the hypotension. Ephedrine has strong bronchodilatory effect as compared to Pseudoephedrine, on the other hand, Pseudoephedrine has weak bronchodilatory effect as compared to Ephedrine.

Comparison Chart

EphedrinePseudoephedrine
Ephedrine is a natural sympathomimetic alkaloid.Pseudoephedrine is an isomer of Ephedrine with sympathomimetic activity.

Receptors at which Drug Acts

Ephedrine actions are through both Alpha and Beta receptors.Pseudoephedrine actions are mostly through Alpha receptors.

Mode of Action

Ephedrine has both direct and indirect actions on adrenergic receptors.Pseudoephedrine has only indirect actions.

Nasal Decongestant

Ephedrine is used as a nasal decongestant, but its effectiveness is less as compared to Pseudoephedrine,Pseudoephedrine is used as a nasal decongestant, but its effectiveness is more as compared to Ephedrine.

Use in Hypotension

Ephedrine is more effective to treat hypotension.Pseudoephedrine is less effective to treat hypotension.

Effect on CNS

Ephedrine is a potent CNS stimulator.Pseudoephedrine has CNS effects.

Available Dosage Forms

Ephedrine is available as oral, parenteral and topical dosage forms, but orally it is more effective than pseudoephedrine.Pseudoephedrine is available as oral, parenteral, and topical dosage forms.

Contraindications

Closed-angle glaucoma, Phaeochromocytoma, Asymmetric septal hypertrophyType 2 diabetes, High blood pressure, Severe uncontrolled high blood pressure, Severe disease of the arteries of the heart, Enlarged Prostate

Adverse Effects

Palpitation, Headache, Tachycardia, Vertigo, InsomniaFear, Anxiety, Loss of appetite, Sleep problems, Nervousness

What is Ephedrine

Ephedrine is classified as Sympathomimetic agent which acts as an agonist at α and β receptors. Ephedrine is also considered as the mixed-acting sympathomimetic drug because it increases the release of norepinephrine from the sympathetic neurons. Ephedrine has two asymmetrical carbon atoms. Ephedrine lacks a catechol moiety. Ephedrine is effective when given orally. Ephedrine increases heart rate and cardiac output. Ephedrine increases peripheral resistance but invariably. Usually, Ephedrine increases blood pressure. When Ephedrine stimulates α receptors of smooth muscle cells of the bladder, it increases the resistance to outflow of urine. When ephedrine stimulates β receptors in the lungs, it causes bronchodilation. Ephedrine stimulates CNS and is a potent CNS stimulator. When taken orally, the effects of Ephedrine persist for a long time. Elimination of Ephedrine is through urine, and it eliminates as unchanged drug. The half-life of Ephedrine is 3 to 6 hours. Ephedrine is used in the treatment of asthma, and it is used to treat hypotension caused by spinal anesthesia. Adverse effects of Ephedrine are hypertension, especially when Ephedrine is taken through parenteral route or when it is taken in higher than recommended oral doses. CNS adverse effects include insomnia.

Example

Examples of famous brands containing Ephedrine are Bronkaid, Primatene tablets, etc.

What is Pseudoephedrine?

Pseudoephedrine is classified as Sympathomimetic agent which acts as an agonist at α receptors. Pseudoephedrine is phenethylamine that is an isomer of Ephedrine with the sympathomimetic property. Pseudoephedrine has two asymmetric carbon atoms. Pseudoephedrine displaces norepinephrine from its storage sites and released norepinephrine acts as the alpha agonist. Pseudoephedrine has weak agonist activity at beta-adrenergic receptors. Pseudoephedrine has less central nervous system effects. Receptor stimulation causes vasoconstriction and leads to a decrease in nasal and sinus congestion. Pseudoephedrine is used as a nasal decongestant associated with cold and allergies. Pseudoephedrine is used as a wakefulness-promoting agent. Pseudoephedrine is also had antitussive pharmacological action. Pseudoephedrine is also used in the manufacturing of amphetamines. Pseudoephedrine shows anxiety, nervousness, dizziness, and excitability as its adverse effects.

Example

Common brands that contain Pseudoephedrine are Actifed, Allegra, Aleve.

Key Differences

  1. Ephedrine is both direct, and indirect-acting adrenergic drug, whereas Pseudoephedrine is an indirect-acting adrenergic drug.
  2. Ephedrine is both alpha and beta-adrenergic agonist, on the other hand; Pseudoephedrine is mainly alpha-adrenergic agonist.
  3. Ephedrine is sympathomimetic amine, on the other hand, Pseudoephedrine is an isomer of Ephedrine.
  4. The main therapeutic use of Ephedrine is to raise blood pressure in patients of hypotension, whereas the main therapeutic use of pseudoephedrine is in respiratory system decongestion.

Conclusion

The conclusion of the above discussion is that Ephedrine is the prototype mixed-acting sympathomimetic drug and Pseudoephedrine being an isomer of Ephedrine shows approximately all pharmacological actions of Ephedrine and difference lies only in effectiveness of these pharmacological actions.

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