Gentamicin And Prednisolone

Uses

Blepharitis, blepharoconjunctivitis, conjunctivitis, dacryocystitis, keratitis, keratoconjunctivitis, acute meibomianitis, and corneal ulcers caused by susceptible organisms. Otorrhea associated with external otitis, chronic suppurative otitis media or subacute purulent otitis media; or postoperative otorrhea, such as that following fenestration, mastoidectomy or tympanoplasty.

Gentamicin cream is used for the topical treatment of the primary and secondary bacterial infections of the skin caused by the organisms sensitive to Gentamicin. Gentamicin may clear infections that have not responded to other topical antibiotics.

Prednisolone is a glucocorticoid used to treat adrenocortical insufficiency, inflammatory conditions, and some cancers.

Prednisolone is indicated to treat endocrine, rheumatic, and hematologic disorders; collagen, dermatologic, ophthalmic, respiratory, and gastrointestinal diseases; allergic and edematous states; and other conditions like tuberculous meningitis.

Gentamicin And Prednisolone is also used to associated treatment for these conditions: Bacterial Conjunctivitis, Bacterial Infections, Bacterial Peritonitis, Bacterial dacryocystitis, Blepharoconjunctivitis, Central Nervous System Infections, Conjunctivitis allergic, Corneal infection, Dermatitis infected, Ecthyma, Eczematous dermatitis infected, Folliculitis, Furunculosis, Gram-negative enteric bacilli neonatal sepsis, Impetigo contagious, Inflammation, Keratitis bacterial, Keratoconjunctivitis, Meibomianitis, Meningitis, Bacterial, Ocular Inflammation, Pustular Psoriasis (PP), Pustular acne, Pyoderma Gangrenosum, Seborrheic Dermatitis, Septicemia gram-negative, Skin Infections, Skin Infections, Bacterial, Skin and Subcutaneous Tissue Bacterial Infections, Sycosis barbae, Bacterial blepharitis, Bacterial corneal ulcers, Bacterial dermatoses, Complicated Bacterial Urinary Tract Infections, Complicated Respiratory tract infection bacterial, Corticosteroid-responsive dermatoses, Ocular bacterial infections, Severe Endocarditis enterococcal, Severe Infection Pseudomonas aeruginosa, Severe Staphylococcal infectionAcne Rosacea, Acute Gouty Arthritis, Allergic Bronchopulmonary Aspergillosis, Allergic Contact Dermatitis, Allergic corneal marginal ulcers, Alveolitis, Extrinsic Allergic, Anal Fissures, Ankylosing Spondylitis (AS), Aspiration Pneumonitis, Atopic Dermatitis (AD), Bell's Palsy, Berylliosis, Bullous dermatitis herpetiformis, Burns, Chorioretinitis, Choroiditis, Chronic Obstructive Airways Disease Exacerbated, Congenital Adrenal Hyperplasia (CAH), Congenital Hypoplastic Anemia, Conjunctivitis, Corneal Inflammation, Corneal injuries, Corneal ulceration, Crohn's Disease (CD), Cyclitis, Dermatitis exfoliative generalised, Dermatitis, Contact, Dermatomyositis, Dermatosis of the Ear Canal, Drug hypersensitivity reaction, Edema of the cerebrum, Epicondylitis, Erythroblastopenia, Exacerbation of asthma, Eye inflammation caused by Cataract Surgery, Eye inflammation caused by Infection, Herpes Zoster Keratitis, Hot Water Burns (Scalds), Hypercalcemia of Malignancy, Idiopathic Pulmonary Fibrosis (IPF), Idiopathic Thrombocytopenic Purpura, Inflamed External Hemorrhoid, Inflamed Hemorrhoids, Internal, Inflammatory Reaction caused by susceptible Bacterial Infections, Iridocyclitis, Iritis, Itching caused by susceptible Bacterial Infections, Leukemia, Acute, Loeffler's syndrome, Malignant Lymphomas, Multiple sclerosis exacerbation, Mycosis Fungoides (MF), Ocular Inflammation, Ophthalmia, Sympathetic, Optic Neuritis, Otic Eczema, Pemphigus, Perennial Allergic Rhinitis (PAR), Pericarditis, Pneumocystis Jirovecii Pneumonia, Pneumonia, Aspiration, Polymyalgia Rheumatica, Post-traumatic Osteoarthritis, Proctitis, Proteinuria, Pruritus, Pruritus Ani, Psoriatic Arthritis, Pulmonary Tuberculosis (TB), Pure Red Cell Aplasia, Rash, Rejection, Transplant, Relapsing Polychondritis, Rheumatoid Arthritis, Rheumatoid Arthritis, Juvenile, Seasonal Allergic Conjunctivitis, Seasonal Allergic Rhinitis, Secondary Adrenal Insufficiency, Secondary thrombocytopenia, Serum Sickness, Severe Asthma, Sjögren's Syndrome, Skin Infections, Bacterial, Stevens-Johnson Syndrome, Superficial punctate keratitis, Synovitis, Systemic Lupus Erythematosus (SLE), Trichinosis, Tuberculosis (TB), Tuberculous Meningitis, Ulcerative Colitis, Uveitis, Vasculitis, Acquired immune hemolytic anemia, Acute Bursitis, Acute Rheumatic heart disease, unspecified, Acute Tenosynovitis, Allergic skin manifestations, Anal eczema, Exfoliative erythroderma, Idiopathic Bronchiolitis obliterans with organizing pneumonia, Idiopathic eosinophilic pneumonias, Non-suppurative Thyroiditis, Primary adrenocoritical insufficiency, Severe Psoriasis, Severe Seborrhoeic dermatitis, Severe alcoholic liver disease, Steroid-responsive inflammation of the eye, Subacute Bursitis, Susceptible Bacterial Infections, Symptomatic Sarcoidosis, Varicella-zoster virus acute retinal necrosis

How Gentamicin And Prednisolone works

There are 3 key phases of aminoglycoside entry into cells. The first “ionic binding phase” occurs when polycationic aminoglycosides bind electrostatically to negatively charged components of bacterial cell membranes including with lipopolysaccharides and phospholipids within the outer membrane of Gram-negative bacteria and to teichoic acids and phospholipids within the cell membrane of Gram-positive bacteria. This binding results in displacement of divalent cations and increased membrane permeability, allowing for aminoglycoside entry. The second “energy-dependent phase I” of aminoglycoside entry into the cytoplasm relies on the proton-motive force and allows a limited amount of aminoglycoside access to its primary intracellular target - the bacterial 30S ribosome. This ultimately results in the mistranslation of proteins and disruption of the cytoplasmic membrane.[A233320] Finally, in the “energy-dependent phase II” stage, concentration-dependent bacterial killing is observed. Aminoglycoside rapidly accumulates in the cell due to the damaged cytoplasmic membrane, and protein mistranslation and synthesis inhibition is amplified. The necessity of oxygen-dependent active transport explains why aminoglycosides are ineffective against anaerobic bacteria. Hence, aminoglycosides have both immediate bactericidal effects through membrane disruption and delayed bactericidal effects through impaired protein synthesis; observed experimental data and mathematical modeling support this two-mechanism model. Inhibition of protein synthesis is a key component of aminoglycoside efficacy. Structural and cell biological studies suggest that aminoglycosides bind to the 16S rRNA in helix 44 (h44), near the A site of the 30S ribosomal subunit, altering interactions between h44 and h45. This binding also displaces two important residues, A1492 and A1493, from h44, mimicking normal conformational changes that occur with successful codon-anticodon pairing in the A site.[A232324, A232329] Overall, aminoglycoside binding has several negative effects including inhibition of translation, initiation, elongation, and ribosome recycling. Recent evidence suggests that the latter effect is due to a cryptic second binding site situated in h69 of the 23S rRNA of the 50S ribosomal subunit.[A232329, A232339] Also, by stabilizing a conformation that mimics correct codon-anticodon pairing, aminoglycosides promote error-prone translation.[A232344] Mistranslated proteins can incorporate into the cell membrane, inducing the damage discussed above.

The short term effects of corticosteroids are decreased vasodilation and permeability of capillaries, as well as decreased leukocyte migration to sites of inflammation. Corticosteroids binding to the glucocorticoid receptor mediates changes in gene expression that lead to multiple downstream effects over hours to days.

Glucocorticoids inhibit neutrophil apoptosis and demargination; they inhibit phospholipase A2, which decreases the formation of arachidonic acid derivatives; they inhibit NF-Kappa B and other inflammatory transcription factors; they promote anti-inflammatory genes like interleukin-10.

Lower doses of corticosteroids provide an anti-inflammatory effect, while higher doses are immunosuppressive. High doses of glucocorticoids for an extended period bind to the mineralocorticoid receptor, raising sodium levels and decreasing potassium levels.

Dosage

Gentamicin And Prednisolone dosage

Eye: 1-2 drops instilled in affected eye up to 6 times a day or more frequently if required (severe infections may require 1-2 drops every 15-20 minutes initially, reducing the frequency of instillation gradually as the infection is controlled).

Ear: The area should be cleaned and 2-3 drops should be instilled every 3-4 times a day and at night, or more frequently if required.

A small amount of Gentamicin should be applied gently to the affected areas three to four times daily. The area treated may be covered with a gauze dressing if desired. Before applying the medication the affected area should be properly cleaned.

Side Effects

In patients with dermatoses treated with gentamicin, irritation (erythema and pruritus) had been reported in small number of cases. Itching, redness, swelling or other signs of irritation may develop. With the eye/ear drop bacterial and corneal ulcer have developed during treatment with gentamicin. Most frequently reported adverse reactions are ocular burning and irritation upon drug instillation, non specific conjunctivitis, conjunctival epithelial defects, and conjunctival hyperemia.

Gentamicin cream is well tolerated. There has been no evidence of irritation and sensitization after using Gentamicin cream.

Toxicity

As with other aminoglycosides, nephrotoxicity and ototoxicity are associated with gentamicin. Signs of nephrotoxicity include an increase in plasma creatinine and urea, while signs of ototoxicity include issues with balance, nausea, tinnitus, and hearing loss. It is important to note that aminoglycoside-induced nephrotoxicity is typically reversible, while ototoxicity is more likely to be permanent. The risk of both toxicities increases with long-term gentamicin therapy. Gentamicin is considered to be more vestibulotoxic than cochleotoxic compared to other aminoglycosides. Unfortunately, gentamicin-related ototoxicity does not correlate with cumulative dosing, peak and trough levels, or dosing schedule. The unpredictability of ototoxicity supports close monitoring of the patient throughout treatment. In cases of toxicity or overdose, the medication should be discontinued immediately; hemodialysis may be initiated to lower gentamicin serum concentrations.

The intraperitoneal LD₅₀ in rats is 2g/kg and 65mg/kg in mice. The subcutaneous LD₅₀ in rats is 147mg/kg and >3500mg/kg in mice. The oral LD₅₀ in mice is 1680mg/kg. In humans, the oral TDLO in men is 9mg/kg/2W and in women is 14mg/kg/13D.

Patients experiencing an overdose of prednisolone may present with gastrointestinal disturbances, insomnia, and restlessness. Overdose of oral prednisolone may be treated by gastric lavage or inducing vomiting if the overdose was recent, as well as supportive and symptomatic therapy. Chronic overdosage may be treated by dose reduction or treating patients on alternate days. An overdose by the ophthalmic route is not expected to cause problems.

Precaution

If these occurs or if irritation, sensitization develops, treatment with gentamicin should be discontinued and appropriate therapy instituted. Gentamicin ear/eye drops is not for injection. It should never be injected subconjunctivally, nor it should be directly introduced into the anterior chamber of the eye.

Use of topical antibiotics occasionally cause overgrowth of nonsusceptible organisms including fungi. If this occurs or if irritation, sensitisation or super infection develops, treatment with Gentamicin should be discontinued and appropriate therapy should be instituted.

Interaction

None has been reported so far with topical and Eye/Ear drops.

Volume of Distribution

A 0.15mg/kg dose of prednisolone has a volume of distribution of 29.3L, while a 0.30mg/kg dose has a volume of distribution of 44.2L.

Elimination Route

Oral prednisolone reaches a C_max of 113-1343ng/mL with a T_max of 1.0-2.6 hours. Oral prednisolone is approximately 70% bioavailable.

Half Life

One study assessing the pharmacokinetics of gentamicin in children and adults reported a mean half-life of 75 minutes after intravenous administration. The mean half-life associated with intramuscular administration was about 29 minutes longer. Fever and anemia may result in a shorter half-life although dose adjustments are not usually necessary. Severe burns are also associated with a shorter half-life and may result in lower gentamicin serum concentrations.

Prednisolone has a plasma half life of 2.1-3.5 hours. This half life is shorter in children and longer in those with liver disease.

Clearance

The renal clearance of gentamicin is comparable to individual creatinine clearance.

A 0.15mg/kg dose of prednisolone has a clearance of 0.09L/kg/h, while a 0.30mg/kg dose has a clearance of 0.12L/kg/h.

Elimination Route

Gentamicin is excreted primarily by the kidneys. In patients with normal renal function, 70% or more of an initial gentamicin dose can be recovered in the urine within 24 hours. Excretion of gentamicin is significantly reduced in patients with renal impairment.

Prednisolone is over 98% eliminated in urine.

Pregnancy & Breastfeeding use

Consideration should be given the possibility of foetal ototoxicity when gentamicin is applied topically to large denuded areas of skin. For Gentamicin Eye/Ear Drops safety profile in pregnancy is not yet established and should be administered when considered essential.

Contraindication

Gentamicin is contraindicated in individuals with a history of sensitivity reaction to any of its components. Use of topical Gentamicin may occasionally allow overgrowth of nonsusceptible organisms, including fungi.

Storage Condition

To avoid contamination, do not touch the tip of the container to the eye, eyelid or any surface.

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