Aminoglycoside
70S ribosomal unit, binding to the methylated interface and trapping the ribosome in an intermediate state of translocation with approximately 8° intersubunit rotation. Capreomycin binds to the 70S ribosomal unit, leading to inhibition of protein synthesis. The mechanism is thought to be similar to aminoglycosides, which bind the 30S ribosomal subunit, causing misreading of the mRNA sequence and inhibition of translocation.

The cyclic peptide antibiotics capreomycin and viomycin are generally effective against the bacterial pathogen Mycobacterium tuberculosis. However, recent virulent isolates have become resistant by inactivation of their tlyA gene. We show here that tlyA encodes a 2'-O-methyltransferase that modifies nucleotide C1409 in helix 44 of 16S rRNA and nucleotide C1920 in helix 69 of 23S rRNA. Loss of these previously unidentified rRNA methylations confers resistance to capreomycin and viomycin. Many bacterial genera including enterobacteria lack a tlyA gene and the ensuing methylations and are less susceptible than mycobacteria to capreomycin and viomycin. We show that expression of recombinant tlyA in Escherichia coli markedly increases susceptibility to these drugs. When the ribosomal subunits associate during translation, the two tlyA-encoded methylations are brought into close proximity at interbridge B2a. The location of these methylations indicates the binding site and inhibitory mechanism of capreomycin and viomycin at the ribosome subunit interface[1].
Capreomycin sulfate inhibits protein synthesis by binding to the 70S ribosomal unit and blocking bacterial ribosomal translocation. The drug binds to the methylated interface, trapping the ribosome in an intermediate state of translocation (often described as a hybrid state with ~8° intersubunit rotation). This inhibits phenylalanine synthesis in mycobacterial ribosomal translation. Capreomycin also binds to components in the bacterial cell which result in the production of abnormal proteins. The compound has anti-amyloidogenic and pro-fibrinolytic activities, reducing amyloid-induced cytotoxicity by inhibiting the occurrence of amyloid fibrillation.

Capreomycin is used for the treatment of multidrug-resistant tuberculosis (MDR-TB), but it is limited therapeutically by its severe side effects. The objectives of the present studies were (i) to design low-density porous capreomycin sulfate particles for efficient pulmonary delivery to improve local and systemic drug bioavailability and capacity to reduce the bacillary load in the lungs in a manner similar to that achieved with intramuscular injections; (ii) to determine pharmacokinetic parameters after pulmonary administration of these capreomycin particles; and (iii) to evaluate the efficacy of these particles in treating animals in a small-aerosol-inoculum guinea pig model of TB. Capreomycin particles were manufactured by spray drying and characterized in terms of size and drug content. Pharmacokinetic parameters were determined by noncompartmental methods with healthy guinea pigs after administration of capreomycin particles by insufflation. The efficacy of the particles was evaluated by histopathological analysis and in terms of wet organ weight and bacterial burden in TB-infected animals. Lungs of animals receiving a 14.5-mg/kg dose of capreomycin particles showed significantly lower wet weights and smaller bacterial burdens than those of animals receiving any other treatment. These results were supported by histopathological analysis. The feasibility of inhaling capreomycin in a novel powder form, with the ultimate objective of the treatment of MDR-TB, is demonstrated by pharmacokinetic and pharmacodynamic studies with guinea pigs. If applied to humans with MDR-TB, such a therapeutic approach might simplify drug delivery by eliminating injections and might reduce adverse effects through lowering the dose[3].
In vivo, capreomycin sulfate is primarily used against Mycobacterium tuberculosis and is given in combination with other antibiotics for multidrug-resistant tuberculosis (MDR-TB). The drug is administered by intramuscular or intravenous injection, as it is not absorbed orally. Capreomycin is effective against M. tuberculosis and is one of four injectable agents (along with streptomycin, kanamycin, and viomycin) used for the treatment of drug-resistant tuberculosis. Its major toxicities are auditory and vestibular.

M. tuberculosis wild-type Beijing D3 and rrl mutant C-401 were inoculated in triplicate into 7H9 media without drug and 7H9 media containing 10 μg/ml capreomycin and were grown at 37°C for 21 days. Growth of the cultures was monitored daily at OD600. The MICs of antibiotics were determined for each strain as previously described (Maus et al., 2005a, Maus et al., 2005b).[1]
Overnight cultures of E. coli cells were diluted 105-fold and plated onto Lauria-Bertani agar (Sambrook et al., 1989) containing viomycin, capreomycin, kanamycin, or rifampicin with concentrations increasing in 2-fold steps. The agar plates were incubated at 37°C, and MICs were scored as the lowest concentration at which no growth was observed.[1]
In vitro susceptibility testing for capreomycin sulfate is performed using standard broth microdilution or agar proportion methods against Mycobacterium tuberculosis isolates. Minimum inhibitory concentrations (MICs) are determined according to CLSI guidelines. The drug's mechanism of action can be studied using cell-free translation systems or ribosomal binding assays with radiolabeled capreomycin to measure its affinity for the 70S ribosomal subunit. These assays confirm the binding of capreomycin to the ribosome and its inhibition of protein synthesis.

In vitro cellular assays for capreomycin sulfate are conducted using mycobacterial cell cultures, where the drug's ability to inhibit protein synthesis and cause bacterial cell death is assessed. Mycobacterial cells are treated with various concentrations of capreomycin, and protein synthesis is measured by incorporation of radiolabeled amino acids. Cell viability is assessed by colony counting. These assays demonstrate the concentration-dependent bactericidal activity of capreomycin against M. tuberculosis.

Pharmacokinetic (PK) studies.[3]
Animals were randomly divided into five groups receiving capreomycin as follows: intravenously (i.v.; n = 6) and i.m. (n = 8) in solution at a dose of 20 mg/kg and as dry powder insufflated by the pulmonary route at low (n = 6), medium (n = 6), and high (n = 8) nominal doses of 1.4, 7.2, and 14.5 mg/kg. These doses were based on the dose reduction estimated from direct delivery of antibiotics to the lungs by insufflation (circumventing oropharyngeal deposition) and on the practical limitations of easily delivering large masses of dry powders to the guinea pigs. Blood samples (0.35 ml) were collected from each animal into heparinized tubes at 0, 0.08, 0.25, 0.5, 1.0, 1.5, 2, 3, 4, 5, 6, 8, and 12 h. After collection of the last blood sample, animals were euthanized by exsanguination and bronchoalveolar lavage (BAL) was conducted (5 ml sterile saline).

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Pharmacodynamic studies.3]
Animals were infected via the respiratory route with nebulized suspensions (2 × 105 CFU/ml) of Mycobacterium tuberculosis (strain H37Rv), employing an aerosol exposure chamber. Animals remained untreated until 4 weeks following infection, when the bacterial burden is known to plateau. Animals were then assigned to different groups of six guinea pigs each to receive capreomycin daily for 4 weeks by i.m. injection or by inhalation using a custom-designed dry powder dosing chamber.
In vivo animal studies for capreomycin sulfate typically involve administration to rodent models of tuberculosis infection. Mice are infected with M. tuberculosis via aerosol or intravenous route, and capreomycin is administered at various doses (typically intramuscularly). Efficacy is assessed by measuring bacterial burden in the lungs and spleen after treatment. Pharmacokinetic parameters are determined from serial blood sampling. These studies establish the dose-response relationship and efficacy of capreomycin against tuberculosis in vivo.

Capreomycin sulfate is administered by intramuscular or intravenous injection for the treatment of tuberculosis. The drug is not absorbed orally. Following parenteral administration, capreomycin distributes widely in extracellular fluid. The drug is primarily eliminated by glomerular filtration, and dosage adjustment is required in patients with renal impairment. The elimination half-life is approximately 3-6 hours in patients with normal renal function. Therapeutic drug monitoring is recommended to optimize dosing and minimize toxicity.

The major toxicities of capreomycin sulfate are auditory (hearing loss) and vestibular (balance disturbances) toxicity, which can be irreversible. Nephrotoxicity (renal tubular damage) is also a significant concern, particularly with prolonged therapy or in patients with pre-existing renal impairment. Other adverse effects include electrolyte disturbances (hypokalemia, hypomagnesemia) and neuromuscular blockade. The drug should be used with caution in patients with renal insufficiency or pre-existing hearing loss. Regular monitoring of renal function and audiometry is recommended during therapy.

[1]. Capreomycin binds across the ribosomal subunit interface using tlyA-encoded 2'-O-methylations in 16S and 23S rRNAs. Mol Cell. 2006 Jul 21;23(2):173-82.

[2]. Mutation of tlyA confers capreomycin resistance in Mycobacterium tuberculosis. Antimicrob Agents Chemother. 2005 Feb;49(2):571-7.
[3]. Inhaled large porous particles of capreomycin for treatment of tuberculosis in a guinea pig model. Antimicrob Agents Chemother. 2007 Aug;51(8):2830-6.

Capreomycin is an important drug for treating multidrug-resistant tuberculosis. It is a macrocyclic peptide antibiotic produced by Saccharothrix mutabolis subspecies capreolus. This study investigated the resistance mechanism of capreomycin by isolating and identifying capreomycin-resistant strains of Mycobacterium smegmatis and Mycobacterium tuberculosis. Capreomycin-resistant colonies were screened from a transposon-mutated Mycobacterium smegmatis library. The transposon insertion site of one mutant was located in an incomplete open reading frame (OPF) in the Mycobacterium smegmatis genome, corresponding to the tlyA gene (Rv1694) in the Mycobacterium tuberculosis H37Rv genome. In spontaneously generated capreomycin-resistant mutants of Mycobacterium smegmatis, the tlyA gene was disrupted by one of three different natural insertion elements. Using primers targeting the tlyA gene and transposons, genomic DNA of Mycobacterium tuberculosis H37Rv transposon mutants was screened by PCR to detect tlyA gene insertion mutants. A capreomycin-resistant mutant strain was isolated in which a transposon was inserted at position 644 of the tlyA gene. Complementation with the wild-type tlyA gene restored the sensitivity of Mycobacterium smegmatis and Mycobacterium tuberculosis tlyA transposon mutants to capreomycin. Mutations were found in the tlyA gene of 28 spontaneous capreomycin-resistant mutants from three different Mycobacterium tuberculosis strains and capreomycin-resistant clinical isolates. In vitro transcription-translation experiments showed that the ribosomes of the tlyA mutant strain (but not the tlyA(+) strain) were resistant to the inhibitory effect of capreomycin on transcription-translation. Therefore, TlyA appears to affect the ribosomes, and the mutation of tlyA confers capreomycin resistance to the strains [2].
Capreomycin sulfate is a cyclic peptide antibiotic used in combination with other antibiotics for the treatment of multidrug-resistant tuberculosis (MDR-TB). It was first approved in 1971 and is one of four injectable agents available for the treatment of drug-resistant tuberculosis. The drug's mechanism of action involves binding to the 70S ribosomal unit and inhibiting protein synthesis. Its use is limited by its significant toxicities, particularly auditory and vestibular toxicity. Capreomycin remains an important component of MDR-TB treatment regimens in settings where newer agents are not available.

C25H48N14O16S2

864.861

752.298

C, 39.57; H, 6.11; N, 25.84; O, 24.25; S, 4.23

1405-37-4

Capreomycin;11003-38-6

134071939

White to off-white solid powder

1376.7ºC at 760mmHg

786.4ºC

0mmHg at 25°C

16

16

9

51

1310

3

S(=O)(=O)(O[H])O[H].O=C1C([H])(C2([H])C([H])([H])C([H])([H])N=C(N([H])[H])N2[H])N([H])C(/C(=C(\[H])/N([H])C(N([H])[H])=O)/N([H])C([C@]([H])(C([H])([H])N([H])C([C@]([H])(C([H])([H])C([H])([H])C([H])([H])N([H])[H])N([H])[H])=O)N([H])C(C([H])(C([H])([H])O[H])N([H])C([C@]([H])(C([H])([H])N1[H])N([H])[H])=O)=O)=O)=O

TUATYNXRYJTQTQ-RIQUSILOSA-N

InChI=1S/C25H44N14O8.C25H44N14O7.2H2O4S/c26-4-1-2-11(27)6-17(41)32-8-14-20(43)35-15(9-34-25(30)47)21(44)39-18(13-3-5-31-24(29)38-13)23(46)33-7-12(28)19(42)37-16(10-40)22(45)36-14;1-11-19(41)36-15(9-32-17(40)7-12(27)3-2-5-26)21(43)37-16(10-34-25(30)46)22(44)39-18(14-4-6-31-24(29)38-14)23(45)33-8-13(28)20(42)35-11;2*1-5(2,3)4/h9,11-14,16,18,40H,1-8,10,26-28H2,(H,32,41)(H,33,46)(H,35,43)(H,36,45)(H,37,42)(H,39,44)(H3,29,31,38)(H3,30,34,47);10-15,18H,2-9,26-28H2,1H3,(H,32,40)(H,33,45)(H,35,42)(H,36,41)(H,37,43)(H,39,44)(H3,29,31,38)(H3,30,34,46);2*(H2,1,2,3,4)/b15-9+;16-10+;;/t11-,12-,13+,14-,16-,18-;11-,12-,13-,14+,15-,18-;;/m00../s1

sulfuric acid compound with (S)-3,6-diamino-N-(((2S,5S,11S,15S,E)-15-amino-11-((R)-2-amino-3,4,5,6-tetrahydropyrimidin-4-yl)-2-(hydroxymethyl)-3,6,9,12,16-pentaoxo-8-(ureidomethylene)-1,4,7,10,13-pentaazacyclohexadecan-5-yl)methyl)hexanamide and (S)-3,6-diamino-N-(((2S,5S,11S,15S,E)-15-amino-11-((R)-2-amino-3,4,5,6-tetrahydropyrimidin-4-yl)-2-methyl-3,6,9,12,16-pentaoxo-8-(ureidomethylene)-1,4,7,10,13-pentaazacyclohexadecan-5-yl)methyl)hexanamide (1:1:1)

Capreomycin Sulfate; Kapreomycin; Capostatin;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : ≥ 37 mg/mL (~49.28 mM)

Solubility in Formulation 1: 100 mg/mL (133.19 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.

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 (Please use freshly prepared in vivo formulations for optimal results.)