Gerfree

Uses

Higher concentrations of Benzalkonium chloride is used as an antiseptic and disinfectant. This is also widely used as a preservative in eye-drops.

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.

Gerfree is also used to associated treatment for these conditions: Diaper Dermatitis, Dry Eye Syndrome (DES), Eye and eyelid infections, Gingivitis, Hemorrhoids, Infantile Eczema, Mouth irritation, Pruritus Ani, Tonsillitis, Throat inflammation, Antisepsis, Disinfection therapy, Eye disinfection, Eye lubrication, Hand Hygiene, Skin disinfection, Wound treatmentBacterial 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 infection

How Gerfree works

Although not entirely elucidated, the bactericidal action of benzalkonium chloride is believed to be due to the disruption of intermolecular interactions. Such disruption can cause the dissociation of cellular membrane lipid bilayers of bacteria, resulting in compromised cellular permeability control and the leakage of important cellular contents. Additionally, other important molecular complexes like enzymes which control the maintenance of a great range of respiratory and metabolic cellular activities, are also susceptible to such deactivation. Consequently, a variety of critical intermolecular interactions and tertiary structures in very highly specific biochemical systems that allow bacterial agents to function normally can be readily disrupted or deactivated by cationic surfactants like benzalkonium chloride. .

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.

Dosage

Gerfree dosage

• Tincture of benzalkonium chloride 1:750 is used for the preoperative disinfection of unbroken skin or treatment of superficial injuries.
• For preoperative disinfection of mucous membranes and denuded skin, benzalkonium chloride solution in concentrations of 1:10000 to 1:2000 is used.
• For irrigation of the eye, a solution of 1:10000 to 1:5000 is used.
• For urinary bladder and urethral irrigation, a solution 1:5000 to 1:20000 is used.
• For vaginal douche and irrigation, benzalkonium chloride solution 1:5000 to 1:20000.

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

Repeated application may cause hypersensitivity reactions. May cause nausea and vomiting if ingested.

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

An oral dose of 100-400 mg/kg or a parenteral dose of 5-15 mg/kg is believed to be fatal in humans .

A potential concern for larger concentrations of benzalkonium chloride to possibly cause corneal damage when implemented as an excipient ingredient in aqueous eye products is an issue that should be discussed between potential patents and their health care providers . Since decreased regular blinking and tear generation in patients experiencing dry eyes due to any number of eye conditions can result in reduced dilution of applied eye drops containing the benzalkonium chloride preservative , alternative options including benzalkonium chloride-free products should be considered.

Additionally, benzalkonium chloride has been reported to cause punctate keratopathy and/or toxic ulcerative keratopathy. In addition, benzalkonium chloride may cause eye irritation and is known to discolour soft contact lenses . There may also be the possibility of benzalkonium chloride containing eye drops to cause some stinging and pain .

There is the possibility of ototoxicity occurring when benzalkonium chloride containing ear drops are applied to the ear .

Benzalkonium chloride used as a preservative in nebulised solutions of anti-asthma drugs has been reported to cause dose-related bronchoconstriction especially in asthmatic patients and has been associated with the precipitation of respiratory arrest .

Despite the fairly widespread cutaneous use of benzalkonium chloride, only limited human evidence of sensitization in relatively small populations of individuals have been reported . Nevertheless, the main adverse effect for topical formulations of benzalkonium chloride is usually the warning 'may cause local irritation' .

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.

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

Disinfectants containing quaternary ammonium salts should not be used for skin preparation before injections of viscoelastic solutions. Hyaluronic acid will precipitate in the presence of these salts.

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

Volume of Distribution

When applied as a topical antibacterial, antiseptic, disinfectant, or sanitizer it is believed that molecules of benzalkonium chloride are poorly absorbed (perhaps due to their large, positively charged nature ), especially considering expectations for such topical applications to keep their biocidal agents available for action at the topical level and to not be absorbed significantly beyond it.

When benzalkonium chloride is implemented as an excipient preservative ingredient in various eye, nose, and ear aqueous products, such products will always have other active pharmacological agents whose volume of distribution will be of greater importance. In these cases the excipients will only ever be present at the minimal levels necessary to maintain the integrity of the product substance.

Moreover, Benzalkonium chloride is currently listed as a Category III ingredient by the United States Food and Drug Administration . Ingredients are listed in the FDA Category III when the data available about them are insufficient to classify as safe and effective, requiring further testing to determine more formal details about elements like human pharmacokinetic studies, and studies on the ingredients' absorption, distribution, metabolism, and excretion.

Elimination Route

Percutaneous absorption is considered to be insignificant .

In one study, benzalkonium chloride absorption was evaluated in women using tampons containing the agent. Venous blood samples were drawn 15 minutes before the tampon application and then again at 15 min, 1 h, 3 h, and 24 h after application. Benzalkonium chloride was not detected in any of the blood samples at any time tested.

Similarly, in another study, benzalkonium chloride absorption was tested in women using tampons containing the agent. Venous blood and breast milk samples were taken 15 minutes before application and 3 h and 24 h after tampon administration. Benzalkonium chloride was not found in any of the subjects' samples. .

Moreover, in a study where benzalkonium chloride solution was placed on the corneal surface of rabbit subjects, at various intervals after administration, the rabbits' eyes would be washed with 1 mL saline and the following tissues and fluids were removed: bulbar and palpebral conjunctiva, aqueous humour, corneal epithelium, endothelium and stroma, iris-ciliary body, lens, vitreous, retina, and choroid. Plasma samples were obtained with direct cardiac punctures. After administration of one drop, benzalkonium chloride was found in the corneal epithelium, endothelium, and stroma, and in the bulbar and palpebral conjunctivae. Benzalkonium chloride loss from ocular tissues was such that about one-third to two thirds of its concentration (depending on the tissue) at 30 min remained after 24 hr; measurable values existed for as long as 120 hr. The administration of multiple drops led to continued accumulation of benzalkonium chloride. .

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.

Clearance

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

Elimination Route

Administered benzalkonium chloride is likely eliminated largely in faeces, similar to other quaternary ammonium compounds .

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.

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

Incompatible with soaps and other anionic surfactants, citrates, iodides, nitrates, permanganates, salicylates, silver salts, tartrates, and zinc oxide and sulfate.

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

Keep below 30°C temperature, away from light & moisture. Keep out of the reach of children.

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

Innovators Monograph

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