Rifamycin sodium salt
[CAS# 14897-39-3]

Identification

• Classification: API >> Antibiotics >> Rifamycin
• Name: Rifamycin sodium salt
• Synonyms: sodium (7S,9E,11S,12R,13S,14R,15R,16R,17S,18S,19E,21Z)-13-acetyloxy-2,15,17,29-tetrahydroxy-11-methoxy-3,7,12,14,16,18,22-heptamethyl-6,23-dioxo-8,30-dioxa-24-azatetracyclo[23.3.1.14,7.05,28]triaconta-1(29),2,4,9,19,21,25,27-octaen-27-olate
• Molecular Formula: C₃₇H₄₆NNaO₁₂
• Molecular Weight: 719.75
• CAS Registry Number: 14897-39-3
• EC Number: 238-965-7
• SMILES: C[C@H]1/C=C/C=C(C(=O)NC2=CC(=C3C(=C2O)C(=C(C4=C3C(=O)[C@](O4)(O/C=C/[C@@H]([C@H]([C@H]([C@@H]([C@@H]([C@@H]([C@H]1O)C)O)C)OC(=O)C)C)OC)C)C)O)[O-])/C.[Na+]

Properties

• Solubility: 50 mg/mL (ethanol)

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin irritation	Skin Irrit.	2	H315

Discovery and Applications

Rifamycin sodium salt is an antibiotic derived from the fermentation of *Amycolatopsis rifamycinica*, a species of actinobacteria. It was first discovered in the 1950s and has since become an essential drug in the treatment of several bacterial infections, particularly those caused by Mycobacterium species. The compound is part of the rifamycin class, which is known for its ability to inhibit bacterial RNA synthesis by binding to the bacterial RNA polymerase enzyme.

Rifamycin sodium salt is primarily used for the treatment of tuberculosis (TB) and other mycobacterial infections. It is highly effective against *Mycobacterium tuberculosis*, the causative agent of TB, and is often used in combination with other antitubercular drugs to prevent the development of drug-resistant strains. Rifamycin's mechanism of action involves binding to the beta subunit of the bacterial RNA polymerase, which prevents the synthesis of RNA and thus inhibits bacterial growth.

In addition to its use in treating tuberculosis, rifamycin sodium salt is also employed in the treatment of leprosy, a chronic infectious disease caused by *Mycobacterium leprae*. The drug is typically included in multidrug regimens to ensure effective treatment and reduce the emergence of resistant bacterial strains.

Rifamycin sodium salt is also used in the prevention and treatment of certain types of bacterial infections such as those caused by *Staphylococcus aureus*, including infections of the respiratory tract, soft tissues, and bones. Its broad-spectrum antibacterial activity extends to some Gram-positive and Gram-negative bacteria, although it is particularly known for its effectiveness against mycobacteria.

Due to the potential for bacterial resistance, rifamycin sodium salt is usually used in combination with other antimicrobial agents. This combination therapy is particularly important in the treatment of tuberculosis, where resistance to single drugs can quickly emerge if only one agent is used. In addition to its clinical applications, rifamycin sodium salt has been used in research to investigate the mechanisms of bacterial transcription and RNA polymerase function.

Rifamycin sodium salt is generally well-tolerated, but it can have side effects, including hepatotoxicity (liver toxicity) and gastrointestinal disturbances. Regular monitoring of liver function is recommended during treatment, especially for prolonged courses of therapy. The drug can also interact with other medications, particularly those metabolized by the liver, due to its effects on liver enzymes that metabolize drugs.

In summary, rifamycin sodium salt is a critical antibiotic in the treatment of tuberculosis and other mycobacterial infections. Its discovery and development have had a significant impact on global public health, particularly in the management of TB, which remains a major infectious disease worldwide. However, its use requires careful monitoring to avoid side effects and the development of drug resistance.

References

2024. The RIVET RCT: Rifamycin SV MMX improves muscle mass, physical function, and ammonia in cirrhosis and minimal encephalopathy. Hepatology Communications, 8(2).
DOI: 10.1097/hc9.0000000000000384

2019. Rifamycin SV MMX®: A Review in the Treatment of Traveller’s Diarrhoea. Clinical Drug Investigation, 39(7).
DOI: 10.1007/s40261-019-00808-2

2019. Rifamycin SV exhibits strong anti-inflammatory in vitro activity through pregnane X receptor stimulation and NFκB inhibition. Drug Metabolism and Pharmacokinetics, 34(3).
DOI: 10.1016/j.dmpk.2019.01.002