U nas zapłacisz kartą
Neomycyna - Skuteczny Lek na Pryszcze?
Skutki uboczne neomycyny
Neomycyna może wywołać objawy niepożądane. Najczęściej obserwowane skutki uboczne to m.in.:
- nudności,
- biegunka,
- wysypka,
- swędzenie skóry,
- osłabienie organizmu,
- spadek masy ciała.
Miejscowo może też dojść do podrażnienia skóry, czyli np. do zaczerwienienia, obrzęku, wyprysku, itp. Jeśli lek jest stosowany w sposób przewlekły, może powodować nadwrażliwość. Natomiast aplikowany na duży obszar skóry lub np. na otwarte rany może przenikać do krwi i uszkadzać słuch oraz czynność nerek.
W przypadku zażywania neomycyny do oczu, może wystąpić przejściowe łzawienie, zaczerwienienie oczu, pieczenie, a nawet problemy z widzeniem.
W razie wystąpienia niepokojących oznak po zażyciu neomycyny należy jak najszybciej skontaktować się z lekarzem oraz w razie konieczności odstawić lek (lekarz prawdopodobnie zmieni antybiotyk na inny lub zaleci odmienną dawkę preparatu).
Neomycyna bez recepty nie jest dostępna, powinno się ją stosować wyłącznie na zlecenie lekarskie.
Side effects [ edit ]
In 2005–06, Neomycin was the fifth-most-prevalent allergen in patch test results (10.0%). [10] It is also a known GABA gamma-Aminobutyric acid antagonist and can be responsible for seizures and psychosis. [11] Like other aminoglycosides, neomycin has been shown to be ototoxic, causing tinnitus, hearing loss, and vestibular problems in a small number of patients. Neomycin affects the cochlea, which is found in the inner ear. [12] Hearing loss is caused by ear hair cell death, which occurs in response to treatment with neomycin. [13] Patients with existing tinnitus or sensorineural hearing loss are advised to speak with a healthcare practitioner about the risks and side effects prior to taking this medication. [ citation needed ]
Activity [ edit ]
Neomycin's antibacterial activity stems from its binding to the 30S subunit of the prokaryotic ribosome, where it inhibits prokaryotic translation of mRNA. [14]
Neomycin also exhibits a high binding affinity for phosphatidylinositol 4,5-bisphosphate (PIP2), a phospholipid component of cell membranes. [15]
Resistance [ edit ]
Neomycin resistance is conferred by either one of two kanamycin kinase genes. [16] Genes conferring neomycin-resistance are commonly included in DNA plasmids used to establish stable mammalian cell lines expressing cloned proteins in culture. Many commercially available protein expression plasmids contain a neo-resistance gene as a selectable marker. Currently, research is being performed to understand if derivatives of neomycin have the same antibiotic effects while still being effective against neomycin-resistant bacteria. [17]
Neomycin
(2RS,3S,4S,5R)-5-Amino-2-(aminomethyl)-6-((2R,3S,4R,5S)-5-((1R,2R,5R,6R)-3,5-diamino-2-((2R,3S,4R,5S)-3-amino-6-(aminomethyl)-4,5-dihydroxytetrahydro-2H-pyran-2-yloxy)-6-hydroxycyclohexyloxy)-4-hydroxy-2-(hydroxymethyl)tetrahydrofuran-3-yloxy)tetrahydro-2H-pyran-3,4-diol
- 1404-04-2 Y
- DB00994 Y
- 8075 Y
- D08260 Y
- CHEBI:7508 Y
- ChEMBL449118 N
InChI=1S/C23H46N6O13/c24-2-7-13(32)15(34)10(28)21(37-7)40-18-6(27)1-5(26)12(31)20(18)42-23-17(36)19(9(4-30)39-23)41-22-11(29)16(35)14(33)8(3-25)38-22/h5-23,30-36H,1-4,24-29H2/t5-,6+,7+,8?,9+,10+,11-,12+,13+,14-,15+,16-,17+,18-,19+,20-,21+,22-,23-/m0/s1 N
Key:PGBHMTALBVVCIT-DPNHOFNISA-N N
Neomycin is an aminoglycoside antibiotic that displays bactericidal activity against Gram-negative aerobic bacilli and some anaerobic bacilli where resistance has not yet arisen. It is generally not effective against Gram-positive bacilli and anaerobic Gram-negative bacilli. Neomycin comes in oral and topical formulations, including creams, ointments, and eyedrops. Neomycin belongs to the aminoglycoside class of antibiotics that contain two or more amino sugars connected by glycosidic bonds. Neomycin was discovered in 1949 by microbiologist Selman Waksman and his student Hubert Lechevalier at Rutgers University. Neomycin received approval for medical use in 1952. [1] Rutgers University was granted the patent for neomycin in 1957. [2]
Biosynthetic pathway [ edit ]
Neomycin was first isolated from the Streptomyces fradiae and Streptomyces albogriseus in 1949 (NBRC 12773). [18] Neomycin is a mixture of neomycin B (framycetin), and its epimer neomycin C, the latter component accounting for some 5–15% of the mixture. It is a basic compound that is most active with an alkaline reaction. [5] It is also thermostable and soluble in water (while insoluble in organic solvents). [5] Neomycin has good activity against Gram-positive and Gram-negative bacteria, but is ototoxic. Its use is thus restricted to the oral treatment of intestinal infections. [19]
Neomycin B is composed of four linked moieties: D-neosamine, 2-deoxystreptamine (2-DOS), D-ribose, and L-neosamine. [ citation needed ]
Next is the attachment of the D-ribose via ribosylation of neamine, using 5-phosphoribosyl-1-diphosphate (PRPP) as the ribosyl donor (BtrL, BtrP), [22] glycosyltransferase (potential homologues RibF, LivF, Parf) gene (Neo15). [23]
Neosamine B (L-neosamine B) is most likely biosynthesized in the same manner as the neosamine C (D-niosamine) in neamine biosynthesis, but with an additional epimerization step required to account for the presence of the epimeric neosamine B in neomycin B. [24]
Neomycin B and C are 23-carbon molecules with a four-ring structure. Three of the rings are six-membered, and one is five-membered. [25] Neomycin B and Neomycin C are stereoisomers of each other and differ by only one stereocenter one giving the R conformation and the other giving the S conformation. [26] Neomycin C can undergo enzymatic synthesis from ribostamycin. [27]
