What is the Difference Between Tobramycin and Terramycin

The key difference between Tobramycin and Terramycin is that tobramycin is an aminoglycoside antibiotic that impairs the bacterial protein translation by binding to the 16S rRNA in helix 44 (h44) near the A site of the 30S ribosomal subunit. At the same time, Terramycin is a brand name of oxytetracycline that impairs protein translation by preventing amino-acyl tRNA binding in the 30S ribosome.

Tobramycin and Terramycin are broad-spectrum antibiotics used to treat gram-negative and gram-positive bacterial infections with similar mechanisms of action. Both antibiotics impair bacterial protein synthesis by targeting different binding sites of the 30S ribosome. Tobramycin is an aminoglycoside, while Terramycin is a brand name for oxytetracycline, which belongs to the tetracycline antibiotic class. Tobramycin is commonly used for severe infections caused by organisms like Pseudomonas aeruginosa. In contrast, Terramycin is primarily used in ophthalmic formulations for treating eye infections such as conjunctivitis and corneal ulcers.

CONTENTS

1. Overview and Key Difference
2. What is Tobramycin  
3. What is Terramycin
4. Similarities – Tobramycin and Terramycin
5. Tobramycin vs Terramycin in Tabular Form
6. Summary – Tobramycin vs Terramycin

What is Tobramycin?

Tobramycin is an aminoglycoside antibiotic to treat bacterial infections in the lower respiratory tract, urinary tract, skin structures, and cystic fibrosis associated with bacteria. It is mainly derived from Streptomyces spp and displays a broad spectrum of antibacterial activity against gram-positive and gram-negative bacteria. Most importantly, inherently antibiotic-resistant bacterial species such as Pseudomonas aeruginosa, which causes chronic cystic fibrosis, is notably cured by inhaled tobramycin. Tobramycin was approved by FDA in 1975, and in addition to the inhaled formulation, ophthalmic and intravenous formulations are available to treat various bacterial infections.

Tobramycin is a 4,6-disubstituted 2-deoxytreptamine ring-containing antibiotic tightly binding with the bacterial membrane. The membrane permeability increases upon binding, and additional tobramycin enters the cytoplasm, targeting 30S ribosomes. Consequently, mistranslated proteins are produced and integrated into the plasma membrane, allowing more tobramycin to enter the cells and possess bactericidal activities. Tobramycin is inhaled in cystic fibrosis patients and distributed to the central compartments of 85.1 L. The drug neither binds to the serum proteins nor is metabolized, and the unchanged drug is primarily excreted in the urine.

What is Terramycin?

Terramycin is a brand name for the antibiotic ophthalmic ointment containing the active ingredient of oxytetracycline, which belongs to the tetracycline class. This antibiotic is prescribed for a broad spectrum of gram-positive and gram-negative bacteria. Terramycin easily passes through the plasma membrane due to its lipophilic nature and reversibly binds with the 30S ribosomes. This interaction inhibits protein translation by preventing amino-acyl tRNA binding in the 30S ribosome, consequently inhibiting bacterial cell growth.

Terramycin is primarily used in ophthalmic formulations as ointments and eyedrops for treating eye infections. In addition to ophthalmic use, Terramycin can be found in various oral or topical formulations to treat respiratory, urinary, skin, and soft tissue infections.

What are the Similarities Between Tobramycin and Terramycin?

• Tobramycin and Terramycin are antibiotics used to treat bacterial infections targeting bacterial growth by interfering with protein synthesis.
• Both antibiotics have a broad activity spectrum against Gram-positive and Gram-negative bacteria.
• They are available in different formulations for administration.
• Both tobramycin and Terramycin require medical supervision and prescription and should be used under the guidance of a healthcare professional.

What is the Difference Between Tobramycin and Terramycin?

Tobramycin and Terramycin are two antibiotics used to treat a broad spectrum of bacteria with notable differences. Tobramycin is an aminoglycoside antibiotic used mainly for severe systemic infections. In contrast, Terramycin contains oxytetracycline, a tetracycline antibiotic with a broader spectrum of activity against gram-positive and gram-negative bacteria. Tobramycin impairs bacterial protein synthesis by binding to the 30S rRNA, while Terramycin prevents amino-acyl tRNA binding. Tobramycin is administered systemically, while Terramycin is often formulated as an ophthalmic ointment. This difference between Tobramycin and Terramycin is crucial for understanding their appropriate usage in different clinical scenarios.

Below is a summary of the difference between Tobramycin and Terramycin in tabular form for side by side comparison.

Summary – Tobramycin vs. Terramycin

Tobramycin and Terramycin are two antibiotics that treat a broad spectrum of bacteria. Tobramycin is an aminoglycoside antibiotic that impairs bacterial protein translation by binding to the 16S rRNA in helix 44 (h44) near the A site of the 30S ribosomal subunit. In contrast, Terramycin, a brand name for oxytetracycline, prevents amino-acyl tRNA binding in the 30S ribosome to inhibit protein translation. Tobramycin targets specific bacterial species, such as Pseudomonas aeruginosa and Escherichia coli. At the same time, Terramycin has a broader spectrum of activity and is effective against both gram-positive and gram-negative bacteria. Tobramycin is commonly used for severe systemic infections, including respiratory tract infections, while Terramycin is mainly used for eye infections, such as bacterial conjunctivitis and corneal ulcers. Therefore, the difference between Tobramycin and Terramycin should be considered when selecting the correct antibiotic for bacterial infections.

Reference:

1. Pickens, Lauren B., and Yi Tang. “Oxytetracycline Biosynthesis.” Journal of Biological Chemistry, vol. 285, no. 36, 2010, pp. 27509–27515.
2. “Tobramycin Uses, Interactions, Mechanism of Action.” DrugBank Online.

Image Courtesy:

1. “Tobramycin” By Fvasconcellos (talk · contribs) – Own work, after KEGG D00063. Image:Kanamycin B.svg by NEUROtiker (talk · contribs). (Public Domain) via Commons Wikimedia
2. “Oxytetracycline” By Vaccinationist – Own work, based on PubChem (Public Domain) via Commons Wikimedia