LORAPIN 10

Indications

• Seasonal allergic rhinitis
• Chronic idiopathic urticaria

Dosage

Children: Child 6–11 years: 30 mg twice daily. Child 12–17 years: 120 mg once daily for seasonal allergic rhinitis or 180 mg once daily for chronic idiopathic urticaria.

Adults: 120 mg once daily for seasonal allergic rhinitis or chronic idiopathic urticaria. Alternatively, 180 mg once daily may be prescribed depending on clinical judgement.

Mechanism of action

Loratadine exerts its effects by binding to H1 histamine receptors, which are found on various cell types, including epithelial, endothelial, and smooth muscle cells. It acts as an 'inverse agonist', stabilizing the inactive form of the H1 receptor and thereby preventing the actions of histamine, which is a key mediator in allergic responses. This mechanism effectively reduces the severity of symptoms associated with allergies.

Pharmacodynamics

Loratadine is selective for peripheral H1 receptors and does not significantly penetrate the central nervous system, resulting in minimal sedation and CNS depression. This pharmacodynamic profile helps to avoid common side effects associated with first-generation antihistamines, such as drowsiness and impaired psychomotor function.

Pharmacokinetics

Loratadine is well-absorbed after oral administration and undergoes extensive hepatic metabolism, primarily via cytochrome P450 enzymes. It has a long half-life, allowing for once-daily dosing. The drug is mainly excreted through urine and bile, with a small percentage eliminated unchanged. Dose adjustments may be necessary in individuals with renal impairment.

Contra-indications

• Acute porphyrias

Adverse effects

• Dizziness
• Drowsiness
• Headache
• Nausea
• Fatigue
• Abdominal pain
• Aggression
• Agitation
• Angioedema
• Appetite increased
• Arthralgia
• Depression
• Dyspnoea
• Hallucination
• Hepatitis
• Myalgia
• Oedema
• Palpitations
• Paraesthesia
• Seizure
• Skin reactions
• Suicidal ideation
• Syncope
• Tachycardia
• Taste altered
• Tremor
• Urinary disorders
• Vertigo
• Vision disorders
• Vomiting
• Weight increased

Interactions

• Other antihistamines

Precautions

• Patients and their carers should be advised that drowsiness can occur and may affect performance of skilled tasks such as cycling or driving.
• Avoid in patients with renal impairment if eGFR is less than 10 mL/minute/1.73 m2.

Pregnancy

Most manufacturers of antihistamines advise avoiding their use during pregnancy; however, there is no evidence of teratogenicity.

Breast-feeding

Most antihistamines are present in breast milk in varying amounts; although not known to be harmful, most manufacturers advise avoiding their use in mothers who are breast-feeding.

Storage

Store at room temperature, away from excessive heat and moisture.

Formulations

• Oral suspension
• Oral solution
• Tablet

Indications

• Wound healing
• Skin protection
• Drug delivery systems
• Anti-inflammatory treatments

Dosage

Children: Refer to specific product guidelines for paediatric dosage information, as it can vary based on the formulation and intended use.

Adults: Refer to specific product guidelines for dosage information, as it can vary based on the formulation and intended use.

Mechanism of action

Colloidal systems work by providing a surface for drug absorption and enhancing the bioavailability of the therapeutic agent. The small particle size of colloids allows for increased surface area, which can facilitate interactions with biological membranes and improve penetration. The stability of colloids also allows for a controlled release of the active components, prolonging their therapeutic effects.

Pharmacodynamics

The pharmacodynamic properties of colloidal formulations depend on the specific active ingredients and their interactions with biological systems. Generally, colloids can enhance the solubility and absorption of poorly water-soluble drugs. They may also provide a protective effect on tissues, reduce inflammation, and promote healing processes in the body. The efficacy of colloidal systems is influenced by factors such as particle size, concentration, and the nature of the dispersing medium.

Pharmacokinetics

The pharmacokinetics of colloidal systems can vary widely based on the formulation and the active ingredient used. Typically, colloids exhibit prolonged circulation times due to their size, and they may be taken up by cells through endocytosis. The release of the active ingredient is dependent on the stability of the colloidal system and environmental conditions such as pH and temperature. Elimination pathways can include renal excretion or degradation by phagocytic cells.

Pregnancy

There is limited data on the safety of colloidal solutions during pregnancy. They should only be used if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Caution is advised when using colloidal solutions during breastfeeding. It is recommended to consult a healthcare professional before use.

Storage

Store in a cool, dry place away from direct sunlight. Ensure that the container is tightly closed to prevent contamination.

Indications

• Hypovolemic shock
• Severe burns
• Postoperative fluid replacement
• Sepsis
• Trauma management

Dosage

Children: Refer to established guidelines for specific dosing, as it varies based on the type of colloidal solution used and the clinical condition being treated.

Adults: Refer to established guidelines for specific dosing, as it varies based on the type of colloidal solution used and the clinical condition being treated.

Mechanism of action

Colloidal solutions work by maintaining oncotic pressure in the blood, thus helping to retain fluid within the vascular system. This is primarily due to the large molecular weight of the colloidal particles, which cannot easily pass through capillary walls. The presence of colloids in the blood helps to draw water into the circulation, increasing blood volume and improving tissue perfusion.

Pharmacodynamics

The pharmacodynamics of colloidal solutions are centered on their ability to exert osmotic pressure, which helps maintain blood volume and pressure. This effect is particularly important in conditions such as hypovolemia and shock, where fluid replacement is necessary to restore hemodynamic stability. The efficacy of colloidal solutions can vary depending on the type of colloid used, as well as the underlying clinical condition being treated.

Pharmacokinetics

Colloidal solutions are typically administered intravenously and their pharmacokinetics can vary based on the specific formulation. Generally, colloids are distributed throughout the vascular compartment and have a longer duration of action compared to crystalloids, as they remain in circulation longer. The elimination of colloids is primarily through the reticuloendothelial system, where they are metabolized or eliminated by the liver and spleen. Factors such as particle size and composition can influence their distribution and clearance.

Adverse effects

• Allergic reactions
• Injection site reactions
• Nausea
• Vomiting
• Headache
• Fever

Precautions

• Use with caution in patients with known allergies to any component of the formulation
• Monitor for signs of hypersensitivity during administration
• Consider volume overload in patients with cardiac or renal impairment

Pregnancy

The safety of colloidal solutions during pregnancy has not been established. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

It is not known whether colloidal solutions are excreted in human milk. Caution should be exercised when administering to breastfeeding mothers.

Storage

Store at room temperature, protect from light, and do not freeze. Keep out of reach of children.

Formulations

• Colloidal silver
• Colloidal gold
• Colloidal iron
• Other metal colloids

Indications

• Used as a disintegrant in tablet formulations
• Enhances the bioavailability of active pharmaceutical ingredients

Dosage

Children: Refer to the specific formulation guidelines, as dosage will vary based on the active ingredient and formulation type.

Adults: Refer to the specific formulation guidelines, as dosage will vary based on the active ingredient and formulation type.

Mechanism of action

Croscarmellose sodium works by swelling and absorbing water when it comes into contact with gastrointestinal fluids. This swelling leads to the rapid disintegration of the tablet or capsule matrix, facilitating the release and absorption of the active pharmaceutical ingredients.

Pharmacodynamics

Croscarmellose sodium is classified as a superdisintegrant. Its ability to rapidly disintegrate solid dosage forms can significantly enhance the dissolution rate of the active ingredient, which is crucial for achieving therapeutic effects in a timely manner.

Pharmacokinetics

Croscarmellose sodium is not absorbed in the gastrointestinal tract and does not exert pharmacological effects in the body. It is considered non-toxic and is excreted unchanged. Its main role is as an excipient, influencing the formulation's characteristics rather than the pharmacokinetics of the active ingredients.

Precautions

• Use with caution in patients with known hypersensitivity to croscarmellose or its components.

Pregnancy

Safety in pregnancy has not been established. Use only if clearly needed.

Breast-feeding

Caution is advised when using during breastfeeding, as safety has not been established.

Storage

Store in a cool, dry place, away from moisture and heat.

Formulations

• Powder
• Granules

Dosage

Children: Refer to specific clinical guidelines for dosing in children, as no standard paediatric dosage is specified in the provided resources.

Adults: Refer to specific clinical guidelines for dosing, as no standard adult dosage is specified in the provided resources.

Mechanism of action

Ethylene glycol toxicity results from its metabolism to glycolic acid and other toxic metabolites. Glycolate accumulates in the body and is eliminated more slowly than ethylene glycol itself. The renal excretion of both compounds plays a crucial role in their elimination, accounting for a significant portion of the administered dose.

Pharmacodynamics

The pharmacodynamics of glycolate are closely tied to its role as a metabolite of ethylene glycol. Its accumulation can lead to metabolic acidosis, although minimal clinical effects have been observed at low doses. The relationship between glycolate and ethylene glycol indicates that glycolate may contribute to the overall toxic effects of ethylene glycol ingestion.

Pharmacokinetics

The pharmacokinetics of glycolate indicate that it reaches peak plasma levels between 4-6 hours after the administration of ethylene glycol. The elimination half-life of ethylene glycol is approximately 1.7 hours in rats and 3.4 hours in dogs. Glycolate is predominantly eliminated through renal excretion, with about 5% of the dose being excreted unchanged.

Pregnancy

There is limited data on the safety of glycolate in pregnancy. Caution is advised.

Breast-feeding

Data on the excretion of glycolate in human milk is not available. Caution is advised.

Storage

Store at room temperature, away from light and moisture.

Indications

• Lactose intolerance
• As a filler or excipient in pharmaceutical formulations

Dosage

Children: Refer to the BNF for Children for specific dosing information based on age and clinical context.

Adults: Refer to the BNF for specific dosing information based on clinical context.

Mechanism of action

Lactose is metabolized in the intestine by the enzyme lactase into its constituent monosaccharides, glucose and galactose. In individuals with lactase deficiency, unabsorbed lactose passes into the colon, where it is fermented by bacteria, leading to gas production and osmotic effects that contribute to diarrhea.

Pharmacodynamics

The pharmacodynamics of lactose are primarily related to its effects on gastrointestinal function. In healthy individuals, lactose is effectively broken down into glucose and galactose, which are absorbed and utilized for energy. In individuals with lactose intolerance, the unabsorbed lactose can cause osmotic diarrhea and colonic fermentation, leading to discomfort and symptoms associated with lactose intolerance.

Pharmacokinetics

Lactose is not absorbed in the gastrointestinal tract until it is hydrolyzed into glucose and galactose by lactase. The absorption of glucose and galactose occurs in the small intestine. The half-life is not applicable as lactose is not typically administered as a medication but is rather ingested as a natural component of food. Its metabolism primarily occurs in the intestine.

Adverse effects

• Bloating
• Diarrhea
• Abdominal pain
• Flatulence

Precautions

• Use with caution in patients with lactose intolerance.
• Consider potential for gastrointestinal upset in sensitive individuals.

Pregnancy

Lactose is generally considered safe for use during pregnancy. However, consult a healthcare professional for individual advice.

Breast-feeding

Lactose is safe to use while breastfeeding, as it is a natural sugar present in breast milk.

Storage

Store in a cool, dry place, away from direct sunlight.

Formulations

• Powder
• Granules
• Tablets
• Syrup

Indications

• Nutritional support
• Source of carbohydrates
• Dietary fiber source
• Animal feed

Dosage

Children: As with adults, there are no specific dosing recommendations for maize for children. It can be introduced into the diet in age-appropriate forms and quantities, keeping in mind the overall dietary balance.

Adults: There are no specific dosing recommendations for maize as it is typically consumed as part of a balanced diet. It can be included in daily meals in various forms such as whole kernels, flour, or as part of dishes.

Mechanism of action

Maize primarily acts as a source of energy due to its high carbohydrate content. The complex carbohydrates in maize are broken down into glucose, which is then utilized by the body for energy production. It also contributes to dietary fiber intake, which can aid in digestive health and regulation of blood sugar levels.

Pharmacodynamics

The consumption of maize influences blood glucose and insulin levels due to its carbohydrate content. It has a relatively low glycemic index when consumed in whole form, which can help in managing blood sugar levels. The dietary fiber present in maize can also promote satiety and aid in weight management.

Pharmacokinetics

The digestion of maize begins in the mouth with salivary amylase breaking down starches into simpler sugars. In the stomach and small intestine, enzymes further break down these carbohydrates. The resultant glucose is absorbed into the bloodstream, where it is transported to cells for energy production. The absorption rate can vary based on the form of maize consumed (e.g., whole kernels versus processed forms).

Pregnancy

Maize is generally considered safe for consumption during pregnancy as it is a staple food and provides essential nutrients.

Breast-feeding

Maize is safe to consume while breastfeeding and can provide important nutrients to both the mother and the infant.

Storage

Store in a cool, dry place, away from moisture and pests. Properly sealed containers can help prolong shelf life.

Formulations

• Whole maize grains
• Maize flour (cornmeal)
• Maize starch
• Maize oil

Indications

• Use as a binder in tablet formulations
• Use as a solubilizing agent for poorly soluble drugs
• Topical antiseptic for skin disinfection
• Wound care and management of minor cuts and abrasions

Dosage

Children: Refer to specific product information for paediatric dosing guidelines, as these may vary based on formulation and indication.

Adults: Refer to specific product information for adult dosing guidelines, as these may vary based on formulation and indication.

Mechanism of action

Polyvidone enhances drug solubility and bioavailability by forming complexes with active pharmaceutical ingredients. Its hydrophilic nature allows it to attract water, facilitating the dissolution of drugs. When used as an antiseptic, polyvidone-iodine releases iodine slowly, which exerts a broad-spectrum antimicrobial effect by disrupting microbial cell membranes and denaturing proteins.

Pharmacodynamics

Polyvidone's primary pharmacodynamic action is its ability to solubilize drugs, improving their absorption and therapeutic effectiveness. When used as an antiseptic, polyvidone-iodine exhibits bactericidal, virucidal, and fungicidal properties. The gradual release of iodine from the complex helps maintain a sustained antimicrobial effect, reducing the risk of microbial resistance.

Pharmacokinetics

Polyvidone is poorly absorbed when administered orally, making its systemic effects minimal. Its action is primarily topical, as it acts locally at the site of application. The elimination half-life and metabolic pathways of polyvidone have not been extensively studied, but it is known to be excreted primarily through urine when absorbed. The polymer is stable and does not undergo significant degradation in the body.

Adverse effects

• Allergic reactions
• Skin irritation
• Anaphylaxis (rare)

Precautions

• Use with caution in patients with known allergies to iodine or similar compounds
• Not recommended for use in patients with large wounds or burns without medical supervision

Pregnancy

Polyvidone is generally considered safe for use during pregnancy, but consult a healthcare professional before use.

Breast-feeding

Polyvidone is typically regarded as safe during breastfeeding, but it is advisable to seek medical advice.

Storage

Store in a cool, dry place away from direct sunlight.

Formulations

• Topical solution
• Ointment
• Surgical scrub

Dosage

Children: Refer to specific drug formulations and product labels as purified substances can vary widely in their use and dosing.

Adults: Refer to specific drug formulations and product labels as purified substances can vary widely in their use and dosing.

Mechanism of action

The mechanism of action for purified compounds varies widely depending on the specific substance. Generally, purified drugs exert their effects by interacting with specific biological targets, such as receptors, enzymes, or ion channels, leading to a desired therapeutic effect. This interaction can involve binding to receptors to activate or inhibit signaling pathways, modulating enzymatic activity, or altering physiological processes.

Pharmacodynamics

Pharmacodynamics describes the effects of a drug on the body and the relationship between drug concentration and effect. For purified drugs, this can involve dose-response relationships and the time course of their action. The purified form often enhances potency and reduces variability in response among patients, which can lead to more predictable therapeutic outcomes. The overall effect is determined by the drug's affinity for its target, the efficacy of the drug-receptor interaction, and the downstream signaling pathways activated as a result of this interaction.

Pharmacokinetics

Pharmacokinetics involves the absorption, distribution, metabolism, and excretion (ADME) of a drug. For purified substances, absorption can be more efficient due to the absence of impurities that may affect solubility or stability. Distribution may also be enhanced, leading to higher bioavailability. Metabolism can be influenced by the structure of the purified compound, as it may be metabolized more readily by liver enzymes. Excretion typically occurs through the kidneys or liver, depending on the molecular characteristics of the purified drug.

Pregnancy

Consult with a healthcare professional, as the safety of purified forms of medications during pregnancy may vary depending on the specific substance.

Breast-feeding

Consult with a healthcare professional, as the safety of purified forms of medications during breastfeeding may vary depending on the specific substance.

Storage

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

Indications

• Silicosis
• Chronic obstructive pulmonary disease (COPD)
• Lung cancer associated with silica exposure

Dosage

Adults: Silica is not administered as a drug, but rather

Mechanism of action

Silica, particularly crystalline forms like quartz and cristobalite, can induce cytotoxicity and morphological transformation in cells. The cytotoxic effects are attributed to the presence of silanol groups and trace iron on the silica surface, which can generate reactive oxygen species. These interactions lead to cellular damage and transformation, suggesting multiple molecular mechanisms underlying silica's biological effects. The activity is sensitive to the silica's surface structure and composition, indicating that the biological response is a phenomenon originating from the silica's surface characteristics.

Pharmacodynamics

Silica's pharmacodynamic effects are largely related to its cytotoxic and transforming properties, particularly in lung tissue. The inhalation of crystalline silica can lead to the activation of inflammatory pathways, oxidative stress, and apoptosis in alveolar macrophages and epithelial cells. This can result in chronic inflammation, fibrosis, and ultimately, diseases such as silicosis and lung cancer. The degree of these effects varies based on the type of silica, its crystalline structure, and the presence of surface modifications.

Pharmacokinetics

The pharmacokinetics of silica is complex as it is not absorbed systemically when inhaled or ingested. Instead, inhaled silica particles can deposit in the alveolar region of the lungs, where they may persist for long periods. The body responds to silica exposure through inflammatory processes, and macrophages attempt to phagocytize silica particles. However, the persistence of these particles can lead to chronic lung conditions. Clearance mechanisms are inefficient, leading to prolonged retention in lung tissue.

Adverse effects

• Cytotoxicity
• Morphological transformation of cells
• Respiratory issues
• Silicosis
• Lung cancer

Precautions

• Use caution in occupational settings with silica dust exposure
• Regular monitoring of lung function in exposed individuals

Pregnancy

There is insufficient data on the effects of silica on pregnancy. It is advised to minimize exposure.

Breast-feeding

Limited data available; caution is advised due to potential respiratory effects.

Storage

Store in a cool, dry place, away from moisture and incompatible materials.

Formulations

• Crystalline silica
• Amorphous silica (diatomaceous earth)
• Silica gel

Indications

• Nutritional supplementation
• Energy source in enteral nutrition
• Excipient in pharmaceutical formulations

Dosage

Children: Refer to specific guidelines or product inserts for dosing information, as it can vary based on the context of use.

Adults: Refer to specific guidelines or product inserts for dosing information, as it can vary based on the context of use.

Mechanism of action

Starch is broken down into glucose units by enzymes such as amylase during digestion. The glucose is then absorbed in the intestines and utilized for energy production in the body's cells. This pathway involves hydrolysis of the glycosidic bonds, converting starch into simpler sugars.

Pharmacodynamics

Starch primarily serves as an energy source. Its digestion and absorption lead to an increase in blood glucose levels, which provides energy for metabolic processes. In this context, it plays a crucial role in maintaining energy homeostasis in the body.

Pharmacokinetics

Starch is not absorbed in its polymeric form; it must first be enzymatically hydrolyzed into simpler sugars such as maltose and glucose. The digestion and absorption of starch occur predominantly in the small intestine, with glucose being readily absorbed into the bloodstream. The rate of absorption can vary depending on the type of starch and its physical form.

Adverse effects

• Allergic reactions
• Gastrointestinal discomfort
• Diarrhea
• Constipation

Precautions

• Use with caution in individuals with known allergies to starch or starch derivatives
• Monitor for gastrointestinal symptoms in patients with a history of digestive disorders

Pregnancy

Starch is generally considered safe for use during pregnancy. However, it should be consumed in moderation as part of a balanced diet.

Breast-feeding

Starch is deemed safe for nursing mothers when used in moderation as part of a balanced diet.

Storage

Store in a cool, dry place away from moisture and direct sunlight.

Formulations

• Powder
• Granules
• Tablets
• Suspensions

Indications

• Used as an excipient in drug formulations
• Pleurodesis for the management of recurrent pleural effusions

Dosage

Children: Refer to specific guidelines for paediatric use, as dosing may differ based on age and clinical condition.

Adults: Refer to specific guidelines for the appropriate dosage in pleurodesis and other applications, as it may vary based on clinical context.

Mechanism of action

Talc exhibits very good absorptive properties, allowing it to absorb moisture and other substances effectively. This characteristic is particularly useful in pharmaceutical formulations, where it may enhance the stability and texture of the drug product.

Pharmacodynamics

Talc's primary pharmacodynamic effect is its ability to act as an inert filler and bulking agent in pharmaceutical preparations. It does not have any intrinsic pharmacological activity but serves to improve the physical properties of formulations, such as flowability and compressibility.

Pharmacokinetics

Talc is not absorbed systemically when used as an excipient or in medical procedures. Its effects are local, and it remains in the site of application, where it functions primarily as a mechanical agent. The pharmacokinetics of talc in the context of its use in pleurodesis involves its ability to promote adhesion of the pleural surfaces, thereby preventing fluid accumulation.

Pregnancy

Talc is classified as a substance with minimal systemic absorption, but safety during pregnancy has not been well established. Consult relevant guidelines.

Breast-feeding

Talc is not expected to be absorbed in significant amounts; however, caution is advised and consult guidelines.

Storage

Store in a cool, dry place, away from direct sunlight.

Mechanism of action

Histamine release is a key mediator in allergic rhinitis and urticaria. As a result, loratadine exerts it's effect by targeting H1 histamine receptors. Loratadine binds to H1 histamine receptors found on the surface of epithelial cells, endothelial cells, eosinophils, neutrophils, airway cells, and vascular smooth muscle cells among others. H1 histamine receptors fall under the wider umbrella of G-protein coupled receptors, and exist in a state of equilibrium between the active and inactive forms. Histamine binding to the H1-receptor facilitates cross linking between transmembrane domains III and V, stabilizing the active form of the receptor. On the other hand, antihistamines bind to a different site on the H1 receptor favouring the inactive form. Hence, loratadine can more accurately be classified as an "inverse agonist" as opposed to a "histamine antagonist", and can prevent or reduce the severity of histamine mediated symptoms. All of the available H1 receptor antagonists are reversible, competitive inhibitors of the interaction of histamine with H1 receptors. /H1 Receptor Antagonists/ H1 antagonists inhibit most responses of smooth muscle to histamine. /H1 Antagonists Receptors/ Within the vascular tree, the H1 antagonists inhibit both the vasoconstrictor effects of histamine and, to a degree, the more rapid vasodilator effects that are mediated by H1 receptors on endothelial cells. /H1 Receptor Antagonists/ H1 antagonists strongly block the action of histamine that results in increased capillary permeability and formation of edema and wheal. /H1 Receptor Antagonists/ For more Mechanism of Action (Complete) data for LORATADINE (6 total), please visit the HSDB record page.

Pharmacodynamics

Like other 2nd generation antihistamines, loratadine is selective for peripheral H1 receptors. Loratadine does not penetrate effectively into the central nervous system and has poor affinity for CNS H1-receptors. These qualities result in a lack of CNS depressant effects such as drowsiness, sedation, and impaired psychomotor function.

Mechanism of action

Ethylene glycol toxicity results from its metabolism to glycolic acid and other toxic metabolites. The accumulation of glycolate and the elimination kinetics of ethylene glycol and its metabolites are not well understood, so studies with male Sprague-Dawley rats and mixed breed dogs have been carried out. Ethylene glycol was administered by gavage to rats and dogs which were placed in metabolic cages for urine and blood sample collection at timed intervals. The peak plasma level of ethylene glycol occurred at 2 hr after dosing and that of glycolate between 4-6 hr. The rate of ethylene glycol elimination was somewhat faster in rats with a half-life of 1.7 hr compared to 3.4 hr in dogs. The maximum plasma level of glycolate was greater in rats although the pattern of accumulation was similar to that in dogs. Glycolate disappeared from the plasma at the same time as ethylene glycol, suggesting a slower rate of elimination of the metabolite than that of ethylene glycol. Renal excretion of ethylene glycol was an important route for its elimination accounting for 20-30% of the dose. Renal excretion of glycolate represented about 5% of the dose. Ethylene glycol induced an immediate, but short lived diuresis compared to that in control rats. Minimal clinical effects (mild acidosis with no sedation) were noted at these doses of ethylene glycol (1-2 g/kg) in both rats and dogs. The results indicate that the toxicokinetics of ethylene glycol and glycolate were similar in both species. The effect of 0.35 to 0.8 mmol/kg glycolic acid and 1.0 to 4.4 mmol/kg sodium glycolate on cyclopropane-epinephrine induced cardiac arrhythmias was examined using dogs. Doses of 0.35 to 0.5 mmol/kg glycolic acid increased the duration of arrhythmias in the 13 dogs tested, whereas doses >0.5 mmol/kg decreased or totally eliminated the arrhythmias in each of 11 dogs. Depression was observed for many of the dogs at higher doses. Sodium glycolate was much less effective in decreasing the arrhythmias, with 3 mmol/kg being required and its action being transient.

Mechanism of action

...Some quartz and cristobalite dusts (crystalline) as well as the diatomaceous earths (amorphous), but not the pyrogenic amorphous silica, were cytotoxic and induced morphological transformation of SHE cells in a concentration-dependent manner. The ranking in cytotoxicity was different from that in transforming potency, suggesting two separate molecular mechanisms for the two effects. The cytotoxic and transforming potencies were different from one dust to another, even among the same structural silicas. The type of crystalline structure (quartz vs cristobalite) and the crystalline vs biogenic amorphous form did not correlate with cytotoxic or transforming potency of silica dusts. Comparison of cellular effects induced by original and surface modified samples revealed that several surface functionalities modulate cytotoxic and transforming potencies. The cytotoxic effects appeared to be related to the distribution and abundance of silanol groups and to the presence of trace amounts of iron on the silica surface. Silica particles with fractured surfaces and/or iron-active sites, able to generate reactive oxygen species, induced SHE cell transformation. The results show that the activity of silica at the cellular level is sensitive to the composition and structure of surface functionalities and confirm that the biological response to silica is a surface originated phenomenon. In vivo exposure of rat lungs to crystalline silica either by intratracheal instillation or by inhalation results in an increase in mRNA levels for inducible nitric oxide synthase (iNOS) in bronchoalveolar lavage cells (BALC), elevated nitric oxide (.NO) production by BALC, and an increase in .NO-dependent chemiluminescence (CL) from alveolar macrophages (AM). Induction of iNOS message occurs in both AM and polymorphonuclear leukocytes (PMN) harvested from silica-exposed lungs but is not significantly elevated in lavaged lung tissue. This review presents characteristics of simple and complicated coal workers' pneumoconiosis (CWP) as well as pathologic indices of acute and chronic silicosis by summarizing results of in vitro, animal, and human investigations. These results support four basic mechanisms in the etiology of CWP and silicosis: a) direct cytotoxicity of coal dust or silica, resulting in lung cell damage, release of lipases and proteases, and eventual lung scarring; b) activation of oxidant production by pulmonary phagocytes, which overwhelms the antioxidant defenses and leads to lipid peroxidation, protein nitrosation, cell injury, and lung scarring; c) activation of mediator release from alveolar macrophages and epithelial cells, which leads to recruitment of polymorphonuclear leukocytes and macrophages, resulting in the production of proinflammatory cytokines and reactive species and in further lung injury and scarring; d) secretion of growth factors from alveolar macrophages and epithelial cells, stimulating fibroblast proliferation and eventual scarring. Results of in vitro and animal studies provide a basis for proposing these mechanisms for the initiation and progression of pneumoconiosis. Data obtained from exposed workers lend support to these mechanisms. /The authors/ reported previously that freshly fractured silica (FFSi) induces activator protein-1 (AP-1) activation through extracellular signal-regulated protein kinases (ERKs) and p38 kinase pathways. In the present study, the biologic activities of FFSi and aged silica (ASi) were compared by measuring their effects on the AP-1 activation and phosphorylation of ERKs and p38 kinase. The roles of reactive oxygen species (ROS) in this silica-induced AP-1 activation were also investigated. FFSi-induced AP-1 activation was four times higher than that of ASi in JB6 cells. FFSi also caused greater phosphorylation of ERKs and p38 kinase than ASi. FFSi generated more ROS than ASi when incubated with the cells as measured by electron spin resonance (ESR). Studies using ROS-sensitive dyes and

Mechanism of action

It has very good absorptive properties.