Product Information
Registration Status: ActiveDEXA-GENTAMICIN EYE OINTMENT is approved to be sold in Singapore with effective from 1998-05-14. It is marketed by PHARMAFORTE SINGAPORE PTE LTD, with the registration number of SIN09755P.
This product contains Dexamethasone 0.3mg/g, and Gentamicin 3mg/g in the form of OINTMENT. It is approved for OPHTHALMIC use.
This product is manufactured by URSAPHARM ARZNEIMITTEL GMBH in GERMANY.
It is a Prescription Only Medicine that can only be obtained from a doctor or a dentist, or a pharmacist with a prescription from a Singapore-registered doctor or dentist.
Description
An anti-inflammatory 9-fluoro-glucocorticoid. [PubChem]
Indication
Injection: for the treatment of endocrine disorders, rheumatic D=disorders, collagen diseases, dermatologic diseases, allergic statesc, ophthalmic diseases, gastrointestinal diseases, respiratory diseases, hematologic disorders, neoplastic diseases, edematous states, cerebral edema.
Ophthalmic ointment and solution: for the treatment of steroid responsive inflammatory conditions of the palpebral and bulbar conjunctiva, cornea, and anterior segment of the globe.
Ophthalmic solution only: for the treatment of steroid responsive inflammatory conditions of the external auditory meatus
Topic cream: for relief of the inflammatory and pruritic manifestations of corticosteroid-responsive dermatoses
Oral aerosol: for the treatment of bronchial asthma and related corticosteroid responsive bronchospastic states intractable to adequate trial of conventional therapy
Intranasal aerosol: for the treatment of allergic ot inflammatory nasal conditions, and nasal polyps
Mechanism of Action
Dexamethasone is a glucocorticoid agonist. Unbound dexamethasone crosses cell membranes and binds with high affinity to specific cytoplasmic glucocorticoid receptors. This complex binds to DNA elements (glucocorticoid response elements) which results in a modification of transcription and, hence, protein synthesis in order to achieve inhibition of leukocyte infiltration at the site of inflammation, interference in the function of mediators of inflammatory response, suppression of humoral immune responses, and reduction in edema or scar tissue. The antiinflammatory actions of dexamethasone are thought to involve phospholipase A2 inhibitory proteins, lipocortins, which control the biosynthesis of potent mediators of inflammation such as prostaglandins and leukotrienes.
Pharmacokinetics
- Absorption
- 80-90%
- Distribution
- Metabolism
- Hepatic.
- Elimination
Toxicity
Oral, rat LD50: >3 gm/kg. Signs of overdose include retinal toxicity, glaucoma, subcapsular cataract, gastrointestinal bleeding, pancreatitis, aseptic bone necrosis, osteoporosis, myopathies, obesity, edemas, hypertension, proteinuria, diabetes, sleep disturbances, psychiatric syndromes, delayed wound healing, atrophy and fragility of the skin, ecchymosis, and pseudotumor cerebri.
Active Ingredient/Synonyms
1-Dehydro-16alpha-methyl-9alpha-fluorohydrocortisone | 1-Dehydro-16α-methyl-9α-fluorohydrocortisone | 16alpha-Methyl-9alpha-fluoro-1-dehydrocortisol | 16α-Methyl-9α-fluoro-1-dehydrocortisol | 9alpha-Fluoro-16alpha-methylprednisolone | 9α-Fluoro-16α-methylprednisolone | Dexametasona | Dexamethasone | Dexamethasonum | Dexamethasone |
Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.
Description
A complex of three different closely related aminoglycoside sulfates, Gentamicins C1, C2, and C1a, obtained from Micromonospora purpurea and related species. They are broad-spectrum antibiotics, but may cause ear and kidney damage. They act to inhibit protein synthesis (genetic translation).
Indication
For treatment of serious infections caused by susceptible strains of the following microorganisms: P. aeruginosa, Proteus species (indole-positive and indole-negative), E. coli, Klebsiella-Enterobactor-Serratia species, Citrobacter species and Staphylococcus species (coagulase-positive and coagulase-negative).
Mechanism of Action
Aminoglycosides like gentamicin "irreversibly" bind to specific 30S-subunit proteins and 16S rRNA. Specifically gentamicin binds to four nucleotides of 16S rRNA and a single amino acid of protein S12. This interferes with decoding site in the vicinity of nucleotide 1400 in 16S rRNA of 30S subunit. This region interacts with the wobble base in the anticodon of tRNA. This leads to interference with the initiation complex, misreading of mRNA so incorrect amino acids are inserted into the polypeptide leading to nonfunctional or toxic peptides and the breakup of polysomes into nonfunctional monosomes.
Pharmacokinetics
- Absorption
- Injections lead to peak serum concentrations in 30-60 minutes. Topical gentamicin is readily absorbed from large burned, denuded, or granulating areas but not through intact skin. Absorption of gentamicin is faster and greater with the cream compared to the ointment. Gentamicin is absorbed in small quantities following topical application to the eye. Gentamicin is also absorbed in small amounts following topical application to the ear (especially if the eardrum is perforated or if tissue damage is present). Gentamicin is very poorly absorbed orally.
- Distribution
- Metabolism
- Elimination
Toxicity
Mild and reversible nephrotoxicity may be observed in 5 - 25% of patients. Gentamicin accumulates in proximal renal tubular cells and causes cell damage. Tubular cell regeneration occurs despite continued drug exposure. Toxicity usually occurs several days following initiation of therapy. May cause irreversible ototoxicity. Otoxocity appears to be correlated to cumulative lifetime exposure. Drug accumulation in the endolymph and perilymph of the inner ear causes irreversible damage to hair cells of the cochlea or summit of ampullar cristae in the vestibular complex. High frequency hearing is lost first with progression leading to loss of low frequency hearing. Further toxicity may lead to retrograde degeneration of the 8th cranial (vestibulocochlear) nerve. Vestibular toxicity may cause vertigo, nausea, vomiting, dizziness and loss of balance. Mouse, intravenous LD50: 52 mg/kg; rat, intravenous LD50: 96 mg/kg.
Active Ingredient/Synonyms
Gentamicin | Gentamicin |
Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.