Abchlor Eye Drops

Indications

• Bacterial infections
• Typhoid fever
• Severe bacterial eye infections
• Bacterial meningitis

Mechanism of action

Chloramphenicol diffuses through the bacterial cell membrane due to its lipid solubility. It reversibly binds to the L16 protein of the 50S subunit of bacterial ribosomes, inhibiting the transfer of amino acids to growing peptide chains by suppressing peptidyl transferase activity. This action prevents peptide bond formation and thus protein synthesis. In addition, chloramphenicol can inhibit mitochondrial protein synthesis in mammalian cells, as mitochondrial ribosomes resemble bacterial ribosomes more than they do mammalian cytoplasmic ribosomes.

Pharmacodynamics

Chloramphenicol is classified as a bacteriostatic antibiotic, meaning it inhibits the growth of bacteria rather than killing them directly. However, at high concentrations or against particularly susceptible organisms, it can exhibit bactericidal properties. The drug is effective against a variety of pathogens, making it useful for treating serious infections. Due to its side effects, particularly hematologic toxicity, chloramphenicol is used cautiously and is often restricted to life-threatening infections where other treatments are not appropriate.

Pharmacokinetics

Chloramphenicol is well-absorbed after oral administration and can penetrate tissues and body fluids, including the central nervous system, making it effective for treating infections in various sites. It is metabolized in the liver, and its elimination half-life can be prolonged in individuals with hepatic impairment. The drug is also excreted in urine, primarily as metabolites, but some unchanged drug may also be present. Dose adjustments may be necessary in cases of liver and kidney impairment to avoid toxicity.

Contra-indications

• Children under 12 years
• Pregnant women
• Patients with a history of cholestasis

Adverse effects

• Agranulocytosis
• Aplastic anaemia
• Nephritis
• Renal impairment
• Gastrointestinal discomfort
• Decreased appetite
• Diarrhoea
• Dizziness
• Toxic epidermal necrolysis
• Hepatotoxicity
• Stomatitis

Interactions

• Chloramphenicol + Guanfacine: Unknown (increases exposure)
• Chloramphenicol + Iron: Unknown (decreases efficacy)
• Chloramphenicol + Sulfonylureas: Unknown (increases exposure)
• Chloramphenicol + Tacrolimus: Unknown (increases concentration)
• Rifampicin + Chloramphenicol: Unknown (decreases concentration)

Precautions

• Caution in hepatic impairment
• Caution in renal impairment
• Use in high doses with caution due to risk of hepatotoxicity
• Monitor for signs of bone marrow suppression

Pregnancy

Chloramphenicol should not be given to pregnant women due to risks of effects on skeletal development and potential for discoloration of the child's teeth. Use only if potential benefit outweighs risk.

Breast-feeding

Manufacturer advises avoiding use during breastfeeding as it is present in milk and may pose risks to the infant.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Tablet
• Capsule
• Oral solution
• Powder for solution for infusion

Indications

• Topical antifungal treatment
• Treatment of yeast infections
• Disinfectant for minor cuts and abrasions

Dosage

Children: Refer to specific product guidelines or medical literature as dosages can vary based on formulation and indication.

Adults: Refer to specific product guidelines or medical literature as dosages can vary based on formulation and indication.

Mechanism of action

Information regarding the mechanism of action of boric acid in mediating its antibacterial or antifungal actions is limited. Boric acid inhibits biofilm formation and hyphal transformation of Candida albicans, which are critical virulence factors. In addition, arrest of fungal growth was observed with the treatment of boric acid.

Pharmacodynamics

Boric acid exhibits minimal bacteriostatic and antifungal activities. It is likely to mediate antifungal actions at high concentrations over prolonged exposures. The effectiveness of boric acid as a topical agent depends on the concentration and duration of exposure to the target organism.

Pharmacokinetics

The pharmacokinetics of borax are not extensively documented. However, it is known that borax is poorly absorbed when ingested orally, and its effects are primarily local when applied topically. Systemic absorption can occur, but this is generally minimal. Boron, the active component in borax, may accumulate in body tissues with prolonged exposure, although specific details regarding the distribution, metabolism, and excretion of borax remain limited.

Pregnancy

Boric acid should be used with caution during pregnancy. Consult a healthcare professional before use.

Breast-feeding

Use of boric acid while breastfeeding is not well established. Consult a healthcare professional.

Storage

Store in a cool, dry place, protected from light. Keep out of reach of children.

Indications

• Vulvovaginal candidiasis
• Fungal infections
• Antiseptic for minor cuts and abrasions
• Ocular antiseptic
• Insecticide in pest control

Dosage

Adults: Refer to specific guidelines for formulations. Commonly used as a 2-3% solution

Mechanism of action

Boric acid exerts its antifungal effects by disrupting the cell membrane integrity of fungi. It interferes with the synthesis of essential cellular components, leading to cell lysis and death. The acid also has mild antibacterial properties, which can help in reducing bacterial load in infected areas. The exact molecular pathways involved in these actions are not fully elucidated, but it is known to alter the pH of the environment, making it less conducive for fungal growth.

Pharmacodynamics

Boric acid demonstrates a low toxicity profile in humans when used appropriately. Its antifungal activity is primarily effective against Candida species, and it can be used as a second-line treatment for vulvovaginal candidiasis, particularly in cases of recurrent infections. The effectiveness of boric acid is also attributed to its ability to maintain an acidic environment, which is unfavorable for the growth of many pathogens. Its antiseptic properties help in reducing inflammation and promoting healing in infected tissues.

Pharmacokinetics

Boric acid is poorly absorbed through the gastrointestinal tract but can be absorbed through the skin and mucous membranes. Once absorbed, it is distributed throughout the body, with a tendency to accumulate in various tissues, including the liver and kidneys. The elimination half-life of boric acid is variable, depending on dosage and route of administration. It is primarily excreted unchanged in the urine. Due to its potential for toxicity with high systemic exposure, it is important to adhere to recommended dosages.

Contra-indications

• Hypersensitivity to boron or any component of the formulation
• Severe renal impairment

Adverse effects

• Skin irritation or rash
• Nausea
• Vomiting
• Diarrhea
• Headache
• Fatigue
• Tremors
• Confusion

Interactions

• May interact with other topical medications
• Caution with nephrotoxic agents

Precautions

• Use with caution in patients with renal insufficiency
• Careful monitoring is advised in long-term use
• Not recommended for use in large areas of broken skin

Pregnancy

Boric acid is classified as category C. Use during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Limited data available. It is advisable to avoid use while breastfeeding.

Storage

Store in a cool, dry place away from light. Keep out of reach of children.

Formulations

• Topical ointment
• Powder
• Solution

Indications

• Topical antimicrobial agent
• Preservative in pharmaceutical formulations
• Control of microbial contamination in cosmetic products

Dosage

Children: Refer to specific product guidelines for appropriate usage and dosing, as phenylmercuric is often used in varying concentrations depending on the formulation.

Adults: Refer to specific product guidelines for appropriate usage and dosing, as phenylmercuric is often used in varying concentrations depending on the formulation.

Mechanism of action

Phenylmercuric acts by binding to sulfhydryl groups in proteins and enzymes, leading to the inhibition of essential biochemical processes in microorganisms. This interference disrupts cellular functions, ultimately resulting in microbial cell death.

Pharmacodynamics

The pharmacodynamic properties of phenylmercuric are characterized by its ability to inhibit the growth of a wide range of bacteria and fungi. Its efficacy is largely attributed to its mercurial structure, which facilitates its interaction with cellular components, particularly proteins, leading to loss of enzymatic function and disruption of cellular integrity.

Pharmacokinetics

Phenylmercuric compounds are poorly absorbed through the gastrointestinal tract when ingested and thus are primarily effective topically. Once absorbed, they can accumulate in body tissues, particularly the kidneys and brain, due to the lipophilic nature of mercury. The elimination half-life can vary significantly depending on the route of exposure and individual metabolic factors, but mercury generally has a long half-life, leading to potential toxicity with prolonged exposure.

Contra-indications

• Hypersensitivity to phenylmercuric compounds
• Renal impairment
• Pregnancy

Adverse effects

• Nephrotoxicity
• Neurotoxicity
• Dermatitis
• Gastrointestinal disturbances
• Allergic reactions

Interactions

• Other nephrotoxic drugs may enhance the risk of kidney damage
• Mercury exposure may potentiate the effects of chelating agents

Precautions

• Use with caution in patients with pre-existing renal conditions
• Periodic monitoring of renal function is recommended during treatment
• Avoid prolonged exposure due to potential accumulation and toxicity

Pregnancy

Phenylmercuric compounds should be avoided during pregnancy due to potential teratogenic effects and risks to fetal development.

Breast-feeding

There is limited information on the excretion of phenylmercuric compounds in human milk; caution is advised when administering to nursing mothers.

Storage

Store in a cool, dry place, away from light and moisture. Keep out of reach of children.

Formulations

• Phenylmercuric acetate
• Phenylmercuric nitrate
• Topical ointments and solutions

Mechanism of action

Information regarding the mechanism of action of boric acid in mediating its antibacterial or antifungal actions is limited. Boric acid inhibits biofilm formation and hyphal transformation of _Candida albicans_, which are critical virulence factors. In addition, arrest of fungal growth was observed with the treatment of boric acid.

Pharmacodynamics

Boric acid exhibits minimal bacteriostatic and antifungal activities. Boric acid is likely to mediate antifungal actions at high concentrations over prolonged exposures.

Mechanism of action

Chloramphenicol is lipid-soluble, allowing it to diffuse through the bacterial cell membrane. It then reversibly binds to the L16 protein of the 50S subunit of bacterial ribosomes, where transfer of amino acids to growing peptide chains is prevented (perhaps by suppression of peptidyl transferase activity), thus inhibiting peptide bond formation and subsequent protein synthesis. Chloramphenicol inhibits protein synthesis in bacteria, and to a lesser extent, in eukaryotic cells. The drug readily penetrates bacterial cells, probably by facilitated diffusion. Chloramphenicol acts primarily by binding reversibly to the 50S ribosomal subunit (near the binding site for the macrolide antibiotics and clindamycin, which chloramphenicol inhibits competitively). Although binding of tRNA at the codon recognition site on the 30S ribosomal subunit is undisturbed, the drug apparently prevents the binding of the amino acid-containing end of the aminoacyl tRNA to the acceptor site on the 50S ribosomal subunit. The interaction between peptidyltransferase and its amino acid substrate cannot occur, and peptide bond formation is inhibited. Chloramphenicol ... can inhibit mitochondrial protein synthesis in mammalian cells, perhaps because mitochondrial ribosomes resemble bacterial ribosomes (both are 70S) more than they do the 80S cytoplasmic ribosomes of mammalian cells. The peptidyltransferase of mitochondrial ribosomes, but not of cytoplasmic ribosomes, is inhibited by chloramphenicol. Mammalian erythropoietic cells are particularly sensitive to the drug. /Chloramphenicol/ inhibits bacterial protein synthesis by interfering with the transfer of activated amino acids from soluble RNA to ribosomes. In vitro, chloramphenicol exerts mainly a bacteriostatic effect on a wide range of gram-negative and gram-positive bacteria. /Chloramphenicol/ acts by inhibition of protein synthesis by interfering with the transfer of activated amino acids from soluble RNA to ribosomes. For more Mechanism of Action (Complete) data for Chloramphenicol (9 total), please visit the HSDB record page.

Pharmacodynamics

Chloramphenicol is a broad-spectrum antibiotic that was derived from the bacterium Streptomyces venezuelae and is now produced synthetically. Chloramphenicol is effective against a wide variety of microorganisms, but due to serious side-effects (e.g., damage to the bone marrow, including aplastic anemia) in humans, it is usually reserved for the treatment of serious and life-threatening infections (e.g., typhoid fever). Chloramphenicol is bacteriostatic but may be bactericidal in high concentrations or when used against highly susceptible organisms. Chloramphenicol stops bacterial growth by binding to the bacterial ribosome (blocking peptidyl transferase) and inhibiting protein synthesis.