EPICROM 4% EYE DROPS

Indications

• Seborrhoeic dermatitis
• Dandruff
• Scalp psoriasis
• Bacterial infections affecting the scalp

Dosage

Children: For children, apply 3 times a week for 1 week, then apply twice weekly as needed. Refer to BNF for Children for further details.

Adults: Apply to the affected area as directed, typically 1-3 times weekly depending on the condition being treated. Refer to specific product guidelines for detailed dosing.

Mechanism of action

Benzalkonium chloride exerts its antimicrobial effect by disrupting the cell membrane of microorganisms, leading to leakage of cellular contents and ultimately cell death. This is facilitated by its cationic nature, which allows it to bind to negatively charged bacterial surfaces.

Pharmacodynamics

Benzalkonium chloride demonstrates rapid bactericidal activity, with effectiveness observed against gram-positive and gram-negative bacteria, fungi, and some viruses. Its antiseptic properties may be enhanced in the presence of moisture and are typically influenced by the concentration of the solution used.

Pharmacokinetics

Benzalkonium chloride is poorly absorbed through the skin. After topical application, it remains primarily at the site of application, where it exerts localized effects. Systemic absorption is minimal, and it is primarily eliminated through the skin and urine. However, specific pharmacokinetic data may vary based on formulation and application site.

Pregnancy

Benzalkonium chloride should be used with caution during pregnancy. Refer to specific guidelines or consult a healthcare professional.

Breast-feeding

Benzalkonium chloride should be used with caution while breastfeeding. Refer to specific guidelines or consult a healthcare professional.

Storage

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

Formulations

• Shampoo
• Soap or detergent
• Topical solution

Indications

• Disinfection of surfaces
• Antiseptic for skin
• Preservative in pharmaceuticals
• Treatment of minor cuts and abrasions

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations in pediatric populations.

Adults: Refer to the BNF for specific formulations and concentrations as doses may vary based on the application and preparation.

Mechanism of action

The bactericidal action of benzalkonium chloride is believed to result from the disruption of intermolecular interactions, which leads to the dissociation of cellular membrane lipid bilayers in bacteria. This disruption compromises cellular permeability, causing leakage of vital cellular contents. Moreover, the agent can deactivate important molecular complexes such as enzymes that regulate various respiratory and metabolic activities within the cells. Cationic surfactants like benzalkonium chloride can thus effectively disrupt critical intermolecular interactions and tertiary structures in biochemical systems, impairing bacterial function.

Pharmacodynamics

Benzalkonium chloride is classified as a biocidal agent with a relatively long duration of action. It exhibits a spectrum of activity against various microorganisms, including bacteria, certain viruses, fungi, and protozoa; however, it is ineffective against bacterial spores. The agent tends to demonstrate greater efficacy against gram-positive bacteria compared to gram-negative ones. The mode of action can be bacteriostatic (preventing growth) or bactericidal (killing bacteria), depending on its concentration. The activity of benzalkonium chloride is generally stable across different pH levels but is enhanced at elevated temperatures and with extended exposure.

Pharmacokinetics

The pharmacokinetic properties of benzalkonium chloride, including absorption, distribution, metabolism, and excretion, are not fully characterized. Its topical application limits systemic exposure, and it primarily exerts localized effects at the site of application. The duration of action and efficacy may be influenced by the formulation and concentration used.

Pregnancy

Benzalkonium chloride is generally considered safe for use during pregnancy when applied topically, but systemic absorption should be minimized. Always consult a healthcare provider for use during pregnancy.

Breast-feeding

Benzalkonium chloride is considered safe for topical application during breastfeeding, but care should be taken to avoid exposure to the infant. Consultation with a healthcare provider is recommended.

Storage

Store at room temperature, away from moisture and heat. Keep in a tightly closed container, protected from light.

Formulations

• Topical solution
• Disinfectant wipes
• Liquid antiseptics

Indications

• Asthma
• Allergic rhinitis
• Conjunctivitis
• Systemic mastocytosis
• Ulcerative colitis

Dosage

Children: Refer to the BNF for Children for appropriate paediatric dosing guidelines.

Adults: Refer to the BNF for specific dosing information according to the condition being treated.

Mechanism of action

Cromoglicate inhibits degranulation of mast cells, preventing the release of histamine and slow-reacting substance of anaphylaxis (SRS-A), which are mediators of type I allergic reactions. It may also reduce the release of inflammatory leukotrienes and acts by inhibiting calcium influx within mast cells. The drug suppresses the activation effects of chemoattractant peptides on human leukocytes, thereby reducing the accumulation of intracellular calcium induced by antigens in sensitized mast cells.

Pharmacodynamics

Cromoglicate inhibits antigen-induced bronchospasms and is effective in treating asthma and allergic rhinitis. It shows efficacy in preventing the symptoms of allergic reactions by stabilizing mast cells and reducing inflammatory responses.

Pharmacokinetics

Cromoglicate is poorly absorbed when taken orally, with systemic effects being minimal. It is primarily used in inhaled or ophthalmic formulations, where local action is desired. Its pharmacokinetic profile suggests a rapid onset of action upon administration, but the duration of effect is relatively short, necessitating multiple doses throughout the day for optimal efficacy.

Adverse effects

• Cough
• Nasal irritation
• Throat irritation
• Dry mouth
• Headache
• Dizziness

Precautions

• Use with caution in patients with known hypersensitivity to cromolyn or any of its components.
• Patients with severe asthma may require additional therapy.
• Monitor patients for any signs of worsening respiratory conditions.

Pregnancy

Cromoglicate should only be used during pregnancy if clearly needed, as safety in human pregnancy has not been established.

Breast-feeding

Cromoglicate is generally considered safe during breastfeeding, but caution is advised.

Storage

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

Formulations

• Ophthalmic solution
• Oral solution
• Inhalation aerosol

Indications

• Electrolyte replacement
• Volume expansion in hypovolemic patients
• Management of hyponatremia
• Support in intravenous fluid therapy

Dosage

Children: Refer to the BNF for Children for appropriate dosing in paediatric patients, as dosages may vary based on the formulation and clinical condition.

Adults: Refer to specific product information or clinical guidelines for dosage recommendations, as disodium is often part of combination products.

Mechanism of action

Disodium compounds often function by providing sodium ions that are essential for various physiological processes. Sodium ions play a critical role in maintaining osmotic balance, nerve impulse transmission, and muscle contraction. In the context of intravenous solutions, disodium helps to restore electrolyte balance in patients.

Pharmacodynamics

The pharmacodynamics of disodium is primarily related to its role in electrolyte balance and fluid homeostasis. Sodium ions are vital for the function of excitable tissues, including neurons and muscle cells. Changes in sodium levels can affect blood pressure, hydration status, and overall cellular function.

Pharmacokinetics

The pharmacokinetics of disodium compounds depend on their specific formulation and route of administration. When administered intravenously, disodium is rapidly distributed in the extracellular fluid, where it helps to maintain osmotic pressure. Sodium is primarily excreted by the kidneys, and its levels can be influenced by fluid intake, dietary sodium, and renal function.

Pregnancy

Use with caution. Consult a healthcare provider for specific guidance.

Breast-feeding

Use with caution. Consult a healthcare provider for specific guidance.

Storage

Store at room temperature, away from moisture and direct sunlight.

Indications

• Lead poisoning
• Mercury poisoning
• Calcium overload
• Certain diagnostic procedures involving heavy metals

Dosage

Children: Refer to the BNF for Children for appropriate dosing information tailored for paediatric patients.

Adults: Refer to the BNF for specific dosing guidelines based on the condition being treated, considering factors such as the severity of metal poisoning and renal function.

Mechanism of action

Edetate functions by forming stable complexes with divalent and trivalent metal ions, including lead and calcium, through its multiple carboxylate and amine groups. This chelation renders the metals more soluble and promotes their renal excretion, thereby reducing their toxic effects in the body.

Pharmacodynamics

The chelation of metals by edetate decreases the free metal concentration in the bloodstream, which mitigates the toxic effects associated with heavy metal accumulation. The efficacy of edetate in removing metals such as lead has been well documented, and its ability to bind calcium can influence calcium homeostasis in certain clinical scenarios.

Pharmacokinetics

Edetate is administered intravenously, with rapid distribution throughout the extracellular fluid. It is primarily excreted unchanged by the kidneys. The onset of action occurs quickly after administration, and the duration depends on the dose and the patient's renal function. The elimination half-life is approximately 1 hour but may vary based on renal clearance.

Contra-indications

• Hypersensitivity to edetate or any component of the formulation
• Severe renal impairment
• Active bleeding disorders

Adverse effects

• Hypocalcemia
• Nausea
• Vomiting
• Diarrhea
• Abdominal pain
• Headache
• Rash
• Fever

Interactions

• May enhance the effects of anticoagulants
• Concurrent use with calcium supplements may reduce effectiveness
• May interfere with the absorption of certain medications due to changes in gastrointestinal motility

Precautions

• Use with caution in patients with renal impairment
• Monitor electrolyte levels, particularly calcium, during treatment
• Assess the patient's hydration status before administration

Pregnancy

Limited data on the use of edetate in pregnancy. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Caution is advised as it is not known whether edetate is excreted in human milk. Weigh the risks and benefits before use.

Storage

Store in a cool, dry place, protected from light. Do not freeze.

Formulations

• Edetate disodium injection
• Edetate calcium disodium injection

Mechanism of action

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..

Pharmacodynamics

Benzalkonium chloride solutions are generally categorized as biocidal agents with relative long durations of action. Their spectrum of activity has been demonstrated against bacteria, to some viruses, fungi, and protozoa, although bacterial spores are treated as being resistant to the agent. Additionally, the agent generally shows more activity against gram-positive than gram-negative bacteria. Finally, solutions of benzalkonium chloride are bacteriostatic or bactericidal based on their concentration. Bacteriostatic agents act to prevent further growth of bacterial organisms that are present while bactericidal agents function to kill bacteria that are present. In general, the activity of the agent is not largely affected by pH, but such activity does increase substantially at higher temperatures and prolonged exposure times.

Mechanism of action

Cromoglicate inhibits degranulation of mast cells, subsequently preventing the release of histamine and slow-reacting substance of anaphylaxis (SRS-A), mediators of type I allergic reactions. Cromoglicate also may reduce the release of inflammatory leukotrienes. Cromoglicate may act by inhibiting calcium influx. One important action of cromolyn is believed to be the inhibition of pulmonary mast cell degranulation in response to a variety of stimuli, including the interaction between cell-bound IgE and specific antigen. ... The release of histamine and other granular contents, as well as the production of leukotrienes, can be shown to be markedly reduced in vitro by cromolyn. However, its efficacy and potency are highly dependent on the source of the mast cells. ... Attention has been focused on the ability of cromolyn to reverse various functional changes in leukocytes obtained from the blood of asthmatic subjects undergoing allergen challenge, such as increased expression of membrane-bound receptors. ... Low concentrations (100 nM) of cromolyn can suppress completely the activation effects of chemoattractant peptides of human neutrophils, eosinophils, or monocytes. The mechanisms of action of cromolyn remain relatively poorly defined. Most attention has been focused on the ability of cromolyn to reduce the accumulation of intracellular Ca +2 induced by antigen in sensitized mast cells. One biochemical correlate of the reduction of histamine release from mast cells by cromolyn is the enhanced phosphorylation of a 78,000-dalton protein. Unfortunately, these observations have been made using rather high concn of cromolyn (50 to 200 uM), and their relationship to therapeutic response has yet to be established. For more Mechanism of Action (Complete) data for CROMOLYN (6 total), please visit the HSDB record page.

Pharmacodynamics

Cromoglicate or cromolyn (USAN), a synthetic compound, inhibits antigen-induced bronchospasms and, hence, is used to treat asthma and allergic rhinitis. Cromoglicate is used as an ophthalmic solution to treat conjunctivitis and is taken orally to treat systemic mastocytosis and ulcerative colitis.