LEVOTOP PF

Indications

• Bacterial infections
• Acute exacerbation of chronic obstructive pulmonary disease
• Community-acquired pneumonia
• Hospital-acquired pneumonia
• Urinary tract infections
• Complicated urinary tract infections
• Prostatitis
• Chronic pulmonary infections due to Pseudomonas aeruginosa
• Helicobacter pylori eradication (in combination with other drugs)

Dosage

Adults: 500 mg once daily for 5-14 days depending on the infection type and severity; for intravenous infusion, 500 mg to be given over at least 60 minutes.

Mechanism of action

Levofloxacin exerts its antimicrobial activity through the inhibition of two key bacterial enzymes: DNA gyrase and topoisomerase IV. DNA gyrase introduces negative supercoils into DNA during replication, while topoisomerase IV is essential for unlinking newly replicated chromosomes, allowing cell division. By inhibiting these enzymes, levofloxacin blocks DNA replication, resulting in cell death.

Pharmacodynamics

Levofloxacin is bactericidal and inhibits bacterial DNA replication. It has a longer duration of action than many other antibiotics, allowing for less frequent dosing. The drug may cause QTc-interval prolongation, necessitating caution in patients with risk factors for this condition. Levofloxacin shows in vitro activity against various bacterial pathogens, and while resistance can develop, it typically arises from mutations in target enzymes or drug efflux mechanisms.

Pharmacokinetics

Levofloxacin is well absorbed following oral administration, with peak plasma concentrations occurring within 1-2 hours. It has a volume of distribution of approximately 100 L and is approximately 30-40% protein bound. The drug is primarily excreted unchanged in the urine, with a half-life of about 6-8 hours, allowing for once or twice daily dosing.

Contra-indications

• Hypersensitivity to levofloxacin or other fluoroquinolones
• History of tendon disorders related to fluoroquinolone use
• Patients with a history of myasthenia gravis

Adverse effects

• Nausea
• Diarrhea
• Headache
• Dizziness
• QT interval prolongation
• Tendon rupture
• Clostridioides difficile-associated diarrhea
• Nephritis tubulointerstitial

Interactions

• Concurrent use with other drugs that prolong the QT interval
• Antacids, sucralfate, metal cations (e.g. magnesium, aluminum, calcium) can reduce absorption
• NSAIDs may increase the risk of CNS stimulation
• Warfarin may have increased anticoagulant effects

Precautions

• Use cautiously in patients with a history of seizures or CNS disorders
• Monitor for signs of tendon damage
• Consider risks in patients with electrolyte disturbances
• Use with caution in patients with renal impairment

Pregnancy

Manufacturer advises use only if potential benefit outweighs risk.

Breast-feeding

Manufacturer advises caution; levofloxacin may be excreted in breast milk.

Storage

Store at room temperature, away from moisture and heat. Protect from light.

Formulations

• 500 mg tablet for oral use
• Solution for intravenous infusion
• Nebuliser solution
• Eye drops

Indications

• Solubilization of poorly soluble drugs
• Improving the bioavailability of hydrophobic medications
• Pharmaceutical formulations requiring enhanced drug stability

Dosage

Children: Refer to the BNF for Children for dosage recommendations, as pediatric dosing must be determined based on age, weight, and the specific indication.

Adults: Refer to the specific product information or BNF for dosing guidance, as dosages can vary based on the formulation and the drug being solubilized.

Mechanism of action

Betadex functions primarily by forming inclusion complexes with hydrophobic drugs. The lipophilic drug molecules are encapsulated within the hydrophobic cavity of the betadex molecule, resulting in increased solubility and stability of the drug in solution. This mechanism enhances drug bioavailability, allowing for better therapeutic effects and reduced side effects associated with solubility issues.

Pharmacodynamics

The pharmacodynamics of betadex is largely related to its ability to solubilize and stabilize various drug compounds. By enhancing solubility, it increases the drug's absorption in systemic circulation, thus improving its pharmacological action. The formation of inclusion complexes can also modify the drug's release profile, potentially leading to altered pharmacokinetics and efficacy.

Pharmacokinetics

Betadex is not significantly absorbed through the gastrointestinal tract when administered orally. Its pharmacokinetics are influenced by its formulation and the nature of the drug it complexes with. Following injection, complexed drugs may exhibit altered distribution and elimination profiles, depending on the characteristics of both betadex and the drug. The excretion of betadex occurs primarily via the kidneys, with minimal metabolism.

Pregnancy

There is limited data on the use of betadex during pregnancy. Caution is advised.

Breast-feeding

Data on the excretion of betadex in human breast milk is not available. Caution is recommended.

Storage

Store at room temperature, away from light and moisture.

Formulations

• {'name': 'Betadex', 'type': 'Powder for solution'}

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

• Adjustment of pH in pharmaceutical formulations
• Facilitation of drug absorption
• Used in sterile preparations

Dosage

Children: Refer to specific product guidelines for dosing information, as hydrochloric acid is typically used in a controlled setting based on formulation requirements.

Adults: Refer to specific product guidelines for dosing information, as hydrochloric acid is typically used in a controlled setting based on formulation requirements.

Mechanism of action

Hydrochloric acid dissociates in aqueous solution to release hydrogen ions (H+), leading to a decrease in pH. This acidic environment promotes the activation of pepsinogen to pepsin, an enzyme essential for protein digestion. Additionally, the acidity aids in the absorption of certain minerals and drugs that require an acidic environment for optimal bioavailability.

Pharmacodynamics

The primary pharmacodynamic action of hydrochloric acid is the maintenance of gastric acidity, which is essential for normal digestive processes. The acidic environment helps in denaturing proteins, activating digestive enzymes, and providing a barrier against pathogenic microorganisms. Its effects can influence the absorption and efficacy of various medications, particularly those that are pH-dependent.

Pharmacokinetics

Hydrochloric acid does not undergo significant systemic absorption when used in its normal contexts, as it acts locally within the gastrointestinal tract. The amount of hydrochloric acid produced by the stomach varies with food intake and physiological needs. It is secreted by parietal cells in the gastric mucosa, and its secretion is regulated by neural, hormonal, and local factors. The half-life of hydrochloric acid is not applicable as it is continuously produced and neutralized within the gastrointestinal tract.

Contra-indications

• Hypersensitivity to hydrochloric acid or any of its components
• Severe renal impairment
• Active gastrointestinal bleeding

Adverse effects

• Abdominal pain
• Diarrhea
• Nausea
• Vomiting
• Esophageal irritation
• Gastric mucosal irritation
• Electrolyte imbalances

Interactions

• May interact with alkaline substances, potentially neutralizing hydrochloric acid
• Caution with antacids as they may affect the efficacy of hydrochloric acid

Precautions

• Use with caution in patients with a history of gastritis or gastric ulcers
• Monitor electrolytes in prolonged use
• Use cautiously in patients with respiratory conditions due to potential aspiration risks

Pregnancy

Hydrochloric acid is classified as a category C drug. Use during pregnancy only if clearly needed and the potential benefits justify the risks to the fetus.

Breast-feeding

There is limited data on the excretion of hydrochloric acid in human milk. Use with caution during breastfeeding.

Storage

Store in a cool, dry place away from direct sunlight and heat. Ensure the container is tightly closed.

Formulations

• Oral solutions
• Injectable forms
• Tablets

Indications

• Used as an excipient in pharmaceutical formulations
• Improves solubility and stability of active ingredients
• Facilitates drug absorption

Dosage

Children: Refer to specific product guidelines as hydroxypropyl is typically used as an excipient and not dosed independently.

Adults: Refer to specific product guidelines as hydroxypropyl is typically used as an excipient and not dosed independently.

Mechanism of action

Hydroxypropyl functions primarily as a solubilizing agent, which aids in the dissolution of poorly soluble drugs. It interacts with water and other solvents to improve the dispersion of pharmaceutical compounds, thereby enhancing their bioavailability. Hydroxypropyl may also facilitate the permeability of drug molecules through biological membranes, contributing to their overall efficacy.

Pharmacodynamics

The pharmacodynamics of hydroxypropyl relate to its role in improving the physicochemical properties of drug formulations. By increasing solubility and stability, hydroxypropyl can enhance the absorption of drugs administered via various routes, including oral and topical. Its non-toxic nature allows for safe incorporation into formulations, making it suitable for a wide range of applications.

Pharmacokinetics

The pharmacokinetics of hydroxypropyl have not been extensively studied as it primarily acts as an excipient rather than an active pharmaceutical ingredient. When used in formulations, it is typically not absorbed into systemic circulation in significant amounts, thereby minimizing potential systemic effects. Hydroxypropyl is generally regarded as safe when used in appropriate amounts in drug formulations.

Pregnancy

Hydroxypropyl is not classified for use during pregnancy, and its safety has not been established. Caution is advised.

Breast-feeding

There is limited information on the excretion of hydroxypropyl in human milk. Caution is advised when administering to breastfeeding women.

Storage

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

Mechanism of action

Levofloxacin, like other fluoroquinolone antibiotics, exerts its antimicrobial activity via the inhibition of two key bacterial enzymes: DNA gyrase and topoisomerase IV. Both targets are type II topoisomerases, but have unique functions within the bacterial cell. DNA gyrase is an enzyme found only in bacteria that introduces negative supercoils into DNA during replication - this helps to relieve torsional strain caused by the introduction of positive supercoils during replication, and these negative supercoils are essential for chromosome condensation and the promotion of transcription initiation. It is comprised of four subunits (two A subunits and two B subunits) of which the A subunits appear to be the target of fluoroquinolone antibiotics. Bacterial topoisomerase IV, in addition to contributing to the relaxation of positive supercoils, is essential at the terminal stages of DNA replication and functions to “unlink” newly replicated chromosomes to allow for the completion of cell division. Inhibition of these enzymes by levofloxacin likely occurs via complexation with the topoisomerase enzymes. The end result is a blockade of DNA replication, thus inhibiting cell division and resulting in cell death. Levofloxacin is the L-isomer of the racemate, ofloxacin, a quinolone antimicrobial agent. The antibacterial activity of ofloxacin resides primarily in the L-isomer. The mechanism of action of levofloxacin and other fluoroquinolone antimicrobials involves inhibition of bacterial topoisomerase IV and DNA gyrase (both of which are type II topoisomerases), enzymes required for DNA replication, transcription, repair and recombination. Fluoroquinolones prolong the QT interval by blocking voltage-gated potassium channels, especially the rapid component of the delayed rectifier potassium current I(Kr), expressed by HERG (the human ether-a-go-go-related gene). According to the available case reports and clinical studies, moxifloxacin carries the greatest risk of QT prolongation from all available quinolones in clinical practice and it should be used with caution in patients with predisposing factors for Torsades de pointes (TdP).

Pharmacodynamics

Levofloxacin is bactericidal and exerts its antimicrobial effects via inhibition of bacterial DNA replication. It has a relatively long duration of action in comparison with other antibiotics that allows for once or twice daily dosing. Levofloxacin is associated with QTc-interval prolongation and should be used with caution in patients with other risk factors for prolongation (e.g. hypokalemia, concomitant medications). Levofloxacin has demonstrated _in vitro_ activity against a number of aerobic gram-positive and gram-negative bacteria and may carry some activity against certain species of anaerobic bacteria and other pathogens such as _Chlamydia_ and _Legionella_. Resistance to levofloxacin may develop, and is generally due to mutations in DNA gyrase or topoisomerase IV, or via alterations to drug efflux. Cross-resistance may occur between levofloxacin and other fluoroquinolones, but is unlikely to develop between levofloxacin and other antibiotic classes (e.g. macrolides) due to significant differences in chemical structure and mechanism of action. As antimicrobial susceptibility patterns are geographically distinct, local antibiograms should be consulted to ensure adequate coverage of relevant pathogens prior to use.

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.