PIRICET

Indications

• Constipation
• Bowel cleansing

Dosage

Children: Child 1–11 months: 1 g as required, Child 1–11 years: 2 g as required, Child 12–17 years: 4 g as required.

Adults: 4 g as required, usually administered rectally.

Mechanism of action

When administered rectally, glycerol exerts a hygroscopic and/or local irritant action, drawing water from the tissues into the feces and reflexively stimulating evacuation. It decreases intraocular pressure by creating an osmotic gradient between the blood and intraocular fluid, causing fluid to move from the aqueous and vitreous humors into the bloodstream. Glycerol is classified as a hyperosmotic laxative and may also have lubricating and fecal softening effects.

Pharmacodynamics

Glycerol is commonly classified as an osmotic laxative, acting through its local irritant effects and possibly having lubricating and fecal softening actions. Glycerol suppositories usually produce effects within 15 to 30 minutes, providing quick relief from constipation.

Pharmacokinetics

Glycerol is rapidly absorbed through the gastrointestinal tract. It is metabolized in the liver and other tissues, with a half-life that varies depending on the route of administration. Following rectal administration, glycerol is primarily excreted in urine. The pharmacokinetics may vary based on dosage forms and individual patient factors.

Contra-indications

• Acute abdominal conditions
• Acute inflammatory bowel disease
• Intestinal obstruction
• Severe dehydration

Adverse effects

• Abdominal cramps
• Asthenia
• Gastrointestinal disorders
• Hypermagnesaemia
• Skin reactions
• Urine discolouration

Precautions

• Avoid prolonged contact with skin, especially in incontinent patients or infants wearing nappies due to the risk of irritation and excoriation.
• Excessive use may cause diarrhea and related effects such as hypokalaemia.

Pregnancy

Manufacturers advise avoidance due to limited information available.

Breast-feeding

Manufacturers advise avoidance as there is no information available.

Storage

Store at room temperature, away from direct sunlight.

Formulations

• Glycerol 1g suppositories
• Glycerol 2g suppositories
• Glycerol 4g suppositories
• Glycerol oral suspension

Indications

• Symptomatic relief of allergic rhinoconjunctivitis (hay fever)
• Chronic idiopathic urticaria (hives)

Dosage

Children: For children aged 6 to 12 years, the typical dose is 5 mg once daily for children weighing less than 30 kg, and 10 mg once daily for those weighing 30 kg or more. For children aged 2 to 5 years, 2.5 mg once daily is recommended

Adults: The usual adult dose is 10 mg once daily. In some cases, this can be adjusted based on individual response and tolerability.

Mechanism of action

Cetirizine selectively inhibits the H1 receptor, preventing the action of histamine, which is released during allergic reactions. By blocking these receptors, cetirizine reduces symptoms associated with allergic responses, including itching, sneezing, and runny nose. It also exhibits mild anticholinergic properties, which contribute to its effectiveness in alleviating symptoms.

Pharmacodynamics

Cetirizine has a faster onset of action compared to older antihistamines, providing relief from allergy symptoms within 1 hour of administration. Its effects can last for up to 24 hours, allowing for once-daily dosing. The drug is generally well-tolerated, with sedation being less common than with first-generation antihistamines due to its reduced penetration across the blood-brain barrier.

Pharmacokinetics

Cetirizine is rapidly absorbed after oral administration, with peak plasma concentrations occurring within 1-2 hours. It is approximately 93% bound to plasma proteins. The elimination half-life is about 8 hours in healthy adults, but may be prolonged in individuals with renal impairment. Cetirizine is primarily excreted unchanged in the urine, and dose adjustments may be necessary for patients with significant renal dysfunction.

Contra-indications

• Acute porphyrias
• Severe renal impairment

Adverse effects

• Drowsiness
• Headache
• Anxiety
• Increased appetite
• Asthenia
• Diarrhoea
• Dry mouth
• Dyspnoea
• Fever
• Gastritis
• Gastrointestinal discomfort
• Insomnia
• Nasal complaints
• Nausea
• Oral herpes

Interactions

• Other antihistamines (non-sedating)

Precautions

• Drowsiness may occur and affect performance of skilled tasks, such as cycling or driving
• Alcohol should be avoided

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 in a cool, dry place away from light.

Formulations

• Cetirizine hydrochloride 10 mg tablets
• Cetirizine hydrochloride 10 mg oral solution

Indications

• Allergic rhinitis (seasonal and perennial)
• Chronic idiopathic urticaria
• Allergic asthma
• Physical urticaria
• Atopic dermatitis

Dosage

Children: For children aged 6 to 12 years, the usual dose is 5 mg twice daily or 10 mg once daily. For children aged 2 to 5 years, the usual dose is 2.5 mg twice daily or 5 mg once daily

Adults: The usual adult dose is 10 mg once daily, which can be taken with or without food.

Mechanism of action

Cetirizine selectively inhibits peripheral H1 receptors, leading to a reduction in the effects of histamine, a chemical responsible for allergic symptoms. The drug demonstrates negligible anticholinergic and antiserotonergic activity. It has shown to have minimal penetration into the central nervous system, thereby reducing the likelihood of sedation, a common side effect associated with antihistamines.

Pharmacodynamics

Cetirizine exhibits antihistaminic and anti-inflammatory effects that are beneficial in managing allergic conditions. It effectively alleviates symptoms of chronic idiopathic urticaria and both perennial and seasonal allergic rhinitis. Clinical trials have established its efficacy in improving symptoms of allergic respiratory diseases, and it significantly inhibits wheal and flare responses within 20 minutes of administration, with effects lasting for up to 24 hours.

Pharmacokinetics

Cetirizine is well absorbed after oral administration, with peak plasma concentrations typically occurring within 1 hour. It has a long half-life, allowing for once-daily dosing. The drug is primarily eliminated via the kidneys, with a portion being excreted unchanged. Its pharmacokinetic profile demonstrates low potential for significant central nervous system penetration, contributing to its reduced sedation compared to first-generation antihistamines.

Adverse effects

• dry mouth
• drowsiness
• fatigue
• headache
• nausea
• dizziness

Precautions

• Caution in patients with renal impairment
• Caution when driving or operating machinery due to potential drowsiness

Pregnancy

Cetirizine should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus. Consult relevant guidelines.

Breast-feeding

Cetirizine is excreted in breast milk. Caution is advised when administering to nursing mothers.

Storage

Store below 25°C. Protect from light and moisture. Keep out of reach of children.

Formulations

• tablets
• oral solution
• chewable tablets

Mechanism of action

The precise mechanism of action is not well-documented in the provided resources. However, compounds with similar molecular structures often interact with biological pathways through modulation of neurotransmitter systems or receptor activity.

Pharmacodynamics

Pharmacodynamics for compounds like Colour typically involve interactions at the cellular level, influencing physiological responses through receptor binding and modulation of signaling pathways. The specific effects and potency would depend on the context of use and formulation.

Pharmacokinetics

Information on the pharmacokinetics of Colour, including absorption, distribution, metabolism, and excretion, is not provided in the available resources. Generally, pharmacokinetic properties will vary significantly based on formulation and route of administration.

Pregnancy

Safety in pregnancy has not been established. Use only if the benefits outweigh the risks.

Breast-feeding

Caution is advised. There are no adequate studies in breastfeeding women.

Storage

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

Indications

• Enhancement of taste in food and beverages
• Improvement of palatability in nutritional products
• Masking undesirable flavors in medications

Dosage

Children: There is no specific pediatric dosage for flavor agents as they are used as needed to improve the taste of food and beverages.

Adults: There is no specific dosage for flavor agents as they are used as needed to achieve the desired taste and aroma in food and beverages.

Mechanism of action

Flavor compounds interact with taste receptors on the tongue, stimulating the sensory neurons responsible for taste perception. This interaction influences the overall flavor profile of food and beverages, enhancing the eating experience. Some flavors may also have a psychological effect, stimulating appetite or evoking pleasant memories associated with certain tastes.

Pharmacodynamics

While flavor agents are primarily used for sensory enhancement in food, their pharmacodynamic effects are minimal as they are not designed to elicit a pharmacological response. However, certain flavors may influence digestion and metabolism indirectly by enhancing saliva production or affecting gut motility. The enjoyment of flavored products can also lead to increased food intake and satisfaction.

Pharmacokinetics

Flavour compounds are typically ingested and metabolized by the body. Their absorption rates can vary depending on their chemical structure and formulation. Once ingested, they may be rapidly metabolized in the liver and other tissues, with excretion primarily via urine. The specific pharmacokinetic profiles of flavor agents can vary significantly based on their source and chemical properties.

Pregnancy

Flavours are generally considered safe for use during pregnancy, but specific assessments should be made based on the type of flavouring agent.

Breast-feeding

Most flavouring agents are deemed safe during breastfeeding, although it's advisable to consult healthcare professionals regarding specific ingredients.

Storage

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

Dosage

Children: Paediatric dosing should be based on the specific drug and condition, as well as established guidelines. Refer to the BNF for Children for accurate dosing information.

Adults: Dosage of medications should always be determined based on specific drug information, patient condition, and clinical guidelines. Refer to appropriate resources for detailed dosing information.

Mechanism of action

The mechanism of action of fresh drugs varies significantly depending on the specific pharmacological agents involved. Generally, fresh medications maintain their chemical integrity and biological activity, ensuring they interact appropriately with biological systems. This often involves binding to specific receptors or enzymes, modulating biochemical pathways, or directly influencing cellular processes.

Pharmacodynamics

Pharmacodynamics describes the effects of fresh drugs on the body, which are contingent on their chemical structure, formulation, and intended use. Fresh medications are expected to produce their desired therapeutic effects without significant toxicity, maintaining a balance between efficacy and safety. The effectiveness of a drug can be influenced by factors such as dosage, route of administration, and the patient's individual response.

Pharmacokinetics

Pharmacokinetics involves the absorption, distribution, metabolism, and excretion of fresh drugs. Fresh medications should be absorbed efficiently when administered, allowing for optimal plasma concentrations. The distribution of the drug throughout the body is influenced by its solubility and protein binding capacity. Metabolism typically occurs in the liver, where the drug may be converted into active or inactive metabolites, followed by excretion primarily through the kidneys.

Dosage

Children: Refer to the BNF for Children for appropriate dosing information in paediatric cases, especially in instances of overdose.

Adults: Refer to the BNF for specific dosing information based on clinical circumstances, particularly in cases of overdose.

Mechanism of action

Ethylene glycol is metabolized by alcohol dehydrogenase to glycoaldehyde, which is subsequently converted to glycolic, glyoxylic, and oxalic acids. These metabolites contribute to anion gap metabolic acidosis and are responsible for tissue injury through the formation of insoluble calcium oxalate crystals.

Pharmacodynamics

The toxicity of ethylene glycol arises from its metabolites, particularly glycolic and oxalic acids. These compounds induce metabolic acidosis, lead to renal failure through calcium oxalate crystal deposition in the kidneys, and can cause neurological impairment. The anion gap increases due to the accumulation of these acids, leading to complications such as cardiovascular instability and potential multi-organ failure.

Pharmacokinetics

Ethylene glycol is rapidly absorbed after oral ingestion. It undergoes first-pass metabolism primarily in the liver, where it is converted into its toxic metabolites. The elimination half-life of ethylene glycol varies but is generally prolonged in cases of renal impairment. Renal excretion of metabolites contributes to the duration of toxicity, necessitating prompt medical intervention in cases of overdose.

Adverse effects

• Metabolic acidosis
• Renal failure
• CNS depression
• Hypocalcemia
• Cardiovascular collapse
• Pulmonary edema

Precautions

• Use with caution in patients with renal impairment
• Monitor for signs of metabolic acidosis
• Evaluate electrolyte levels, particularly calcium

Pregnancy

There is limited data on the safety of ethylene glycol in pregnancy. It should only be used if clearly needed.

Breast-feeding

It is unknown if ethylene glycol is excreted in human milk. Caution is advised.

Storage

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

Formulations

• Liquid

Indications

• Dry eye syndrome
• Ocular irritation
• Inflammation of the eyes

Dosage

Children: Refer to the BNF for Children for appropriate dosing recommendations, as paediatric doses may differ significantly from adult dosages.

Adults: Refer to the specific product guidelines or BNF for appropriate dosing, as doses may vary based on formulation and clinical condition.

Mechanism of action

Natrosol interacts with solid surfaces through hydrogen bonding, which thickens and prolongs the formation time of a water-retaining film. It serves as a drug carrier or microsphere, entrapping other drug molecules and forming a viscous gel-like dispersion that enhances drug diffusion across biological membranes.

Pharmacodynamics

Hydroxyethyl cellulose acts as a demulcent, relieving inflammation, irritation, and dryness of the eyes. It is a key ingredient in ocular formulations, enhancing viscosity and prolonging corneal contact time, which in turn increases intraocular drug levels.

Pharmacokinetics

The pharmacokinetics of hydroxyethyl cellulose involve its solubility and viscosity properties, which facilitate a slow release of active ingredients in formulations. Its absorption and distribution are influenced by the formulation type and the presence of other excipients, though specific pharmacokinetic data for hydroxyethyl cellulose itself is limited due to its local application and use as an inert excipient.

Pregnancy

Data regarding the safety of hydroxyethyl cellulose during pregnancy is limited. It is recommended to consult a healthcare provider before use.

Breast-feeding

Hydroxyethyl cellulose is generally considered safe during breastfeeding, but it is advisable to seek medical advice prior to use.

Storage

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

Formulations

• Hydroxyethyl cellulose ophthalmic solution
• Hydroxyethyl cellulose gel

Indications

• Digestive aid
• Anti-inflammatory treatment
• Support for wound healing
• Sinusitis relief
• Potential adjunct in cardiovascular health

Dosage

Children: Pediatric dosing for bromelain is not well established. It is important to consult with a healthcare professional for appropriate dosing in children.

Adults: The typical dosage of bromelain supplements varies, but is often in the range of 200 to 400 mg taken 2 to 3 times daily. It is advisable to refer to specific product labels and consult healthcare professionals for personalized dosing recommendations.

Mechanism of action

Bromelain, the primary active compound in pineapple, exerts its effects by breaking down proteins into amino acids and peptides. This proteolytic activity is thought to facilitate digestion and reduce inflammation. Additionally, bromelain may enhance the absorption of certain antibiotics and other medications by improving gastrointestinal tract conditions.

Pharmacodynamics

Bromelain has shown anti-inflammatory, analgesic, and antithrombotic effects. It may modulate immune responses, reduce swelling, and promote healing. The pharmacodynamic properties of pineapple are largely attributed to bromelain, which acts on various pathways, including the modulation of cytokine production and inhibition of pro-inflammatory mediators.

Pharmacokinetics

Bromelain is rapidly absorbed in the gastrointestinal tract following oral administration. The bioavailability of bromelain can be affected by food intake, with some studies suggesting that it is best absorbed on an empty stomach. The elimination half-life is not well-defined, but its effects can persist due to its interactions with various biological pathways.

Adverse effects

• Allergic reactions in sensitive individuals
• Diarrhea
• Nausea
• Abdominal pain
• Heartburn

Interactions

• May interact with anticoagulants due to bromelain content
• Potential interaction with certain antibiotics
• Can affect the metabolism of some drugs due to effects on cytochrome P450 enzymes

Precautions

• Use with caution in individuals with known allergies to pineapple or bromelain
• Should be used cautiously in individuals with gastrointestinal disorders
• Consider potential interactions with anticoagulant medications

Pregnancy

Generally considered safe in food amounts, but high doses or supplements should be avoided due to potential uterine contractions.

Breast-feeding

Likely safe in food amounts; however, high doses or supplements should be avoided as effects are not well studied.

Storage

Store in a cool, dry place away from direct sunlight. Fresh pineapple should be refrigerated and consumed promptly.

Formulations

• Fresh pineapple
• Canned pineapple
• Pineapple juice
• Bromelain supplements

Indications

• Plant growth regulation
• Agricultural applications as a growth inhibitor

Dosage

Children: Not applicable.

Adults: Refer to the relevant agricultural guidelines for specific applications.

Mechanism of action

In an in vitro study, propylene acts as a plant growth inhibitor by inhibiting the oxidation of indole-3-acetic acid by peroxidase in the presence of superoxide anion radicals. This inhibition is linked to the activation of an iron complex (compound III) shuttle, which enhances the reaction rate between superoxide and peroxidase, ultimately affecting plant growth processes. Propylene is a less effective inhibitor compared to ethylene.

Pharmacodynamics

The pharmacodynamic effects of propylene are primarily observed in its role as a growth inhibitor in plants. By modulating the oxidation of phytohormones like indole-3-acetic acid, propylene can influence various growth responses in plants, potentially affecting processes such as cell elongation and division.

Pharmacokinetics

Information on the pharmacokinetics of propylene in humans is not well-documented, as its primary uses are industrial and agricultural. Its metabolism may be influenced by environmental factors, and its effects are primarily studied in the context of plant biology rather than human pharmacology.

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

• Management of diabetes
• Weight management
• Sugar substitutes in food and beverages

Dosage

Children: Refer to the BNF for Children for specific dosage information. Caution is advised when using artificial sweeteners in children.

Adults: Refer to the BNF for specific dosage information. Generally, saccharin is used in very small quantities due to its high sweetness intensity.

Mechanism of action

Saccharin activates specific T2R bitter taste receptors, contributing to the perception of sweetness and the bitter aftertaste associated with saccharin and acesulfame-K. Additionally, it has been shown to stimulate transient receptor potential vanilloid-1 (TRPV1) receptors, which are present in taste receptor cells and nerve terminals throughout the oral cavity. The activation of TRPV1 may play a role in the aftertaste or metallic taste sensation often reported with saccharin consumption.

Pharmacodynamics

Due to its high sweetness intensity, saccharin can effectively mimic the taste of sugar without contributing to caloric intake. It alters taste perception by engaging receptors responsible for taste sensation, particularly affecting the sweet and bitter taste pathways. Its effect on TRPV1 receptors suggests a complex interaction that may enhance the sensory experience of sweetness while also causing potential off-tastes.

Pharmacokinetics

Saccharin is not metabolized by the body and is excreted unchanged in the urine. Its absorption occurs in the gastrointestinal tract, but due to its non-nutritive nature, it does not undergo significant metabolic processes. The pharmacokinetic profile indicates that saccharin has a rapid onset of action with a prolonged sweet taste effect, although individual responses may vary.

Adverse effects

• Allergic reactions
• Headaches
• Nausea
• Gastrointestinal disturbances

Precautions

• Use with caution in individuals with a history of hypersensitivity to saccharin or its derivatives
• Avoid excessive consumption to prevent possible adverse effects

Pregnancy

Saccharin is generally not recommended during pregnancy due to potential risks, although human studies have shown no clear evidence of harm.

Breast-feeding

Saccharin is excreted in breast milk; caution is advised when used by nursing mothers.

Storage

Store in a cool, dry place away from light.

Formulations

• Tablets
• Powder

Indications

• Preservation of food products
• Preservation of pharmaceutical formulations
• Antimicrobial agent in cosmetic products

Dosage

Children: Refer to specific product guidelines for dosage as it varies by formulation and intended use.

Adults: Refer to specific product guidelines for dosage as it varies by formulation and intended use.

Mechanism of action

Sorbate acts primarily by inhibiting the growth of fungi and some bacteria. It interferes with the microbial cell membrane, disrupting its integrity and function, which leads to cell death. The presence of sorbate alters the pH and osmotic balance within the microbial cell, inhibiting key metabolic processes necessary for reproduction and survival.

Pharmacodynamics

Sorbate exhibits its antimicrobial effects at relatively low concentrations. It is most effective in acidic environments, typically at a pH of 4.5 or lower. The compound is more effective against yeasts and molds compared to bacteria. Its mode of action is primarily through the inhibition of fatty acid synthesis and alteration of membrane permeability in target microorganisms.

Pharmacokinetics

Sorbate is generally regarded as having low toxicity and is rapidly metabolized in the human body. It is absorbed in the gastrointestinal tract when ingested and is then distributed throughout the body. The compound undergoes conversion to various metabolites and is primarily excreted via the urine. Its half-life and specific metabolic pathways can vary depending on the form of administration and individual patient factors.

Pregnancy

There is limited data on the safety of sorbate in pregnancy. Use only if clearly needed and potential benefits justify the risks.

Breast-feeding

There is insufficient information regarding the excretion of sorbate in human milk. Caution is advised when administering to nursing mothers.

Storage

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

Indications

• Constipation
• Diagnostic aid in colonoscopy preparation
• Management of hyperosmolality in various conditions

Dosage

Children: For children, the dosage should be determined based on age and condition, and it is advised to refer to the BNF for Children for specific dosing guidelines.

Adults: The typical dose for adults is 30 to 150 mL of sorbitol solution (70%) taken orally, as needed, usually before bedtime.

Mechanism of action

Sorbitol exerts its laxative effect by drawing water into the large intestine, thereby stimulating bowel movements. It acts as a hygroscopic agent, pulling water from tissues into the feces, which reflexively stimulates evacuation. In metabolic pathways, sorbitol is produced from glucose via aldose reductase and is converted to fructose by sorbitol dehydrogenase, with implications in diabetic complications such as retinopathy.

Pharmacodynamics

Sorbitol's laxative effect results from its osmotic properties, which increase the water content of the stool and soften it, facilitating easier passage. Additionally, sorbitol can induce apoptosis in certain cancer cell lines, indicating potential therapeutic implications beyond its laxative use. The modulation of intracellular signaling pathways through the regulation of proteins such as Bax and Bcl-2 suggests a complex role in cellular health and disease.

Pharmacokinetics

Sorbitol is poorly absorbed in the gastrointestinal tract, which contributes to its efficacy as a laxative. It is metabolized in the liver, primarily through the polyol pathway. The absorption and distribution of sorbitol are affected by its osmotic properties, leading to increased intestinal water retention. Its elimination is primarily via renal excretion, with minimal systemic absorption, thus reducing the risk of systemic side effects.

Adverse effects

• Diarrhea
• Abdominal cramps
• Nausea
• Vomiting
• Electrolyte imbalances

Precautions

• Use with caution in patients with renal impairment
• May exacerbate gastrointestinal conditions

Pregnancy

Sorbitol is generally considered safe during pregnancy, but should be used under medical supervision.

Breast-feeding

Sorbitol is excreted in breast milk in small amounts; consult a healthcare provider before use.

Storage

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

Formulations

• Oral solution
• Syrup

Indications

• Food coloring agent
• Beverage coloring agent
• Cosmetic coloring agent

Dosage

Children: Refer to specific food product guidelines, as tartrazine is used as a coloring agent rather than a medication with a defined dosage.

Adults: Refer to specific food product guidelines, as tartrazine is used as a coloring agent rather than a medication with a defined dosage.

Mechanism of action

Tartrazine acts primarily as a colorant, providing a yellow hue to products. It is believed to exert its effects by interacting with proteins and other molecules in the food matrix to produce a stable color. The exact biochemical pathways of its action in the human body are not well-defined, but its primary role is as a dye rather than a pharmacologically active substance.

Pharmacodynamics

As a food dye, tartrazine does not have pharmacological properties in the traditional sense since it is not intended to exert therapeutic effects. However, it can cause hypersensitivity reactions in some individuals, particularly those with asthma or aspirin intolerance. The effects of tartrazine can vary based on individual sensitivities, with some people experiencing allergic reactions.

Pharmacokinetics

Tartrazine is absorbed from the gastrointestinal tract after ingestion. It is metabolized in the liver, and its metabolites are excreted primarily via the urine. The half-life of tartrazine in humans is not well-studied, but its rapid absorption and excretion suggest a short duration of action. Individuals with impaired renal function may experience altered pharmacokinetics.

Contra-indications

• Hypersensitivity to tartrazine or any of its components
• History of asthma or other allergic conditions in patients who are sensitive to tartrazine

Adverse effects

• Allergic reactions including urticaria and asthma exacerbation
• Headache
• Nausea
• Hyperactivity in children

Interactions

• May interact with other allergens, potentially exacerbating allergic reactions
• Use with caution in patients taking other medications that can cause allergic reactions

Precautions

• Caution in patients with a history of allergic reactions
• Monitor for signs of hypersensitivity, especially in asthmatic patients
• Not recommended for children with known sensitivities

Pregnancy

There are no adequate and well-controlled studies in pregnant women. Use only if clearly needed.

Breast-feeding

Caution is advised as it is unknown if tartrazine is excreted in human milk.

Storage

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

Formulations

• Powder for food coloring
• Liquid formulations for food and beverage products

Mechanism of action

When administered rectally, glycerin exerts a hygroscopic and/or local irritant action, drawing water from the tissues into the feces and reflexively stimulating evacuation. Glycerin decreases intraocular pressure by creating an osmotic gradient between the blood and intraocular fluid, causing fluid to move out of the aqueous and vitreous humors into the bloodstream. Glycerin (glycerol) and sorbitol are hyperosmotic laxatives. When administered rectally, glycerin and sorbitol exert a hygroscopic and/or local irritant action, drawing water from the tissues into the feces and reflexly stimulating evacuation. The extent to which the simple physical distention of the rectum and the hygroscopic and/or local irritant actions are responsible for the laxative effects of some of these drugs is not known. Only extremely high oral doses of sorbitol (25 g daily) or glycerin exert laxative action. /Glycerin/ decreases intraocular pressure by creating an osmotic gradient between the blood and intraocular fluid, causing fluid to move out of the aqueous and vitreous humors into the bloodstream. The physicochemical effects of a series of alkanols, alkanediols and glycerol on erythrocyte shape and hemolysis at 4 and 20 degrees C were examined. We calculated the dielectric constant of the incubation medium, Ds, and the dielectric constant of the erythrocyte membrane Dm in the presence of organic solutes. The ratio Ds/Dm = -38.48 at 20 degrees C defines the normal biconcave shape in a medium without hemolytic agents. A decrease in Ds/Dm favors externalization or internalization with consequent hemolysis. Alkanols and alkanediols convert biconcave erythrocytes into echinocytes, which is accompanied by an increase in the projected surface area. Glycerol converts biconcave erythrocytes into stomatocytes, which was accompanied by a marginal decrease in the projected surface area. Progressive externalization in alkanols and alkanediols or internalization in glycerol resulted in a decrease in the projected surface area and the formation of smooth spheres. The degree of shape change induced was related to the degree of hemolysis and the ratio Ds/Dm. A decrease in temperature reduced both the degree of shape change and hemolysis. .../Thus/ physicochemical toxicity may be a result of a temperature dependent hydrophobic interaction between the organic solutes and the membrane and is best interpreted by the ability of the solutes to change Ds and Dm.

Pharmacodynamics

Glycerin is commonly classified as an osmotic laxative but may act additionally or alternatively through its local irritant effects; it may also have lubricating and fecal softening actions. Glycerin suppositories usually work within 15 to 30 minutes.

Mechanism of action

Cetirizine, a metabolite of _hydroxyzine_, is an antihistamine drug. Its main effects are achieved through selective inhibition of peripheral H1 receptors. The antihistamine activity of cetirizine has been shown in a variety of animal and human models. _In vivo_ and _ex vivo_ animal models have shown insignificant anticholinergic and antiserotonergic effects. In clinical studies, however, dry mouth was found to be more frequent with cetirizine than with a placebo. In vitro receptor binding studies have demonstrated no detectable affinity of cetirizine for histamine receptors other than the H1 receptors. Studies with radiolabeled cetirizine administration in the rat have demonstrated insignificant penetration into the brain. _Ex vivo_ studies in the mouse have shown that systemically administered cetirizine does not occupy cerebral H1 receptors significantly. Cetirizine, a human metabolite of hydroxyzine, is an antihistamine; its principal effects are mediated via selective inhibition of peripheral H1 receptors. The antihistaminic activity of cetirizine has been clearly documented in a variety of animal and human models. In vivo and ex vivo animal models have shown negligible anticholinergic and antiserotonergic activity. In clinical studies, however, dry mouth was more common with cetirizine than with placebo. In vitro receptor binding studies have shown no measurable affinity for other than H1 receptors. Autoradiographic studies with radiolabeled cetirizine in the rat have shown negligible penetration into the brain. Ex vivo experiments in the mouse have shown that systemically administered cetirizine does not significantly occupy cerebral H1 receptors.

Pharmacodynamics

**General effects and respiratory effects** Cetirizine, the active metabolite of the piperazine H₁-receptor antagonist hydroxyzine, minimizes or eliminates the symptoms of chronic idiopathic urticaria, perennial allergic rhinitis, seasonal allergic rhinitis, allergic asthma, physical urticaria, and atopic dermatitis. The clinical efficacy of cetirizine for allergic respiratory diseases has been well established in numerous trials. **Effects on urticaria/anti-inflammatory effects** It has anti-inflammatory properties that may play a role in asthma management. There is evidence that cetirizine improves symptoms of urticaria. Marked clinical inhibition of a wheal and flare response occurs in infants, children as well as adults within 20 minutes of one oral dose and lasts for 24 h. Concomitant use of cetirizine reduces the duration and dose of topical anti-inflammatory formulas used for the treatment of atopic dermatitis.

Mechanism of action

Ethylene glycol is metabolized by alcohol dehydrogenase to glycoaldehyde, which is then metabolized to glycolic, glyoxylic, and oxalic acids. These acids, along with excess lactic acid are responsible for the anion gap metabolic acidosis. Oxalic acid readily precipitates with calcium to form insoluble calcium oxalate crystals. Tissue injury is caused by widespread deposition of oxalate crystals and the toxic effects of glycolic and glyoxylic acids.

Mechanism of action

Interacts with the solid surface through hydrogen bonding to thicken and prolong the formation time of a water-retaining film. Hydroxyethyl cellulose acts as a drug carrier or microsphere to entrap other drug molecules and form a viscous gel-like dispersion, enabling drug diffusion across biological membranes.

Pharmacodynamics

Hydroxyethyl cellulose acts as a demulcent by relieving inflammation or irritation and dryness of eyes. It acts as one of the key ingredient and viscosity-enhancing agent to prolong corneal contact time and increase intraocular drug levels.

Mechanism of action

In an in vitro study of the mechanism of action of ethylene as a plant growth inhibitor, the effects of ethylene and some of its analogs, including propylene, on the oxidation of indole-3-acetic acid were examined. Ethylene and its analogs inhibited the oxidation of indole-3-acetic acid by peroxidase under conditions where the iron complex (compound III, an oxy-ferrous complex of peroxidase) shuttle was activated. Inhibition occurred only in the presence of the superoxide anion radical 02(-). Spectral and kinetic data indicated that ethylene and its analogs enhanced the rate of reaction of 02(-) with peroxidase; ie, the iron complex (compound III) shuttle, resulting in the formation of compound III. Propylene was a less effective inhibitor than ethylene.

Mechanism of action

...it has been shown that the activation of particular T2R bitter taste receptors is partially involved with the bitter aftertaste sensation of saccharin and acesulfame-K. ... /This study/ addressed the question of whether /they/ could stimulate transient receptor potential vanilloid-1 (TRPV1) receptors, as these receptors are activated by a large range of structurally different chemicals. Moreover, TRPV1 receptors and/or their variants are found in taste receptor cells and in nerve terminals throughout the oral cavity. Hence, TRPV1 activation could be involved in the ... aftertaste or even contribute to the poorly understood metallic taste sensation. Using Ca(2+) imaging on TRPV1 receptors heterologously expressed in the human embryonic kidney (HEK) 293 cells and on dissociated primary sensory neurons,... /it was found/ that in both systems, .../sweeteners/ activate TRPV1 receptors, and, moreover, they sensitize these channels to acid and heat. ... /it was/also found that TRPV1 receptors were activated by CuSO(4), ZnSO(4), and FeSO(4), three salts known to produce a metallic taste sensation. In summary, .../the/ results identify a novel group of compounds that activate TRPV1 and, consequently, provide a molecular mechanism that may account for off tastes of sweeteners and metallic tasting salts.

Mechanism of action

Sorbitol exerts its laxative effect by drawing water into the large intestine, thereby stimulating bowel movements. ... Sorbitol exerts hygroscopic and/or local irritant action, drawing water from tissues into feces and reflexly stimulating evacuation. The polyol pathway consists of two enzymes aldose reductase (AR) and sorbitol dehydrogenase (SDH); the former is the first enzyme in the polyol pathway, that catalyzes the reduction of glucose to sorbitol, the latter is the second one, that converts sorbitol to fructose using by NAD(+) as a cofactor. ... SDH activity, the second step in the polyol pathway, might make a greater contribution to the etiology of diabetic retinopathy than does the first step involving AR. /This paper proposes/ a novel hypothesis that polymorphisms of SDH gene may be correlated with SDH gene expression levels in diabetic retinas, thus being a valuable genetic marker for diabetic retinopathy. It has been reported that sorbitol induces apoptosis in several cancer cell lines. ... In /this/ study, the intracellular signaling pathways of sorbitol-induced apoptosis in human K562 cells were investigated using both morphological analysis and DNA fragmentation technique. In this study, we demonstrated that sorbitol-induced apoptosis in human K562 cells is a concentration- and time-dependent manner. This sorbitol-induced apoptosis in human K562 cells was also accompanied by the up-regulation of Bax, and down-regulation of p-Bcl-2, but no effect on the levels of Bcl-X(L). Moreover, the sorbitol treatment resulted in a significant reduction of mitochondria membrane potential, increase in the release of mitochondrial cytochrome c (cyt c), and activation of caspase 3. Furthermore, treatment with caspase 3 inhibitor (z-DEVD-fmk) was capable of preventing the sorbitol-induced caspase 3 activity and cell death. These results clearly demonstrate that the induction of apoptosis by sorbitol involves multiple cellular/molecular pathways and strongly suggest that pro- and anti-apoptotic Bcl-2 family proteins, mitochondrial membrane potential, mitochondrial cyt c, and caspase 3, they all participate in sorbitol-induced apoptotic process in human K562 cells. Chronic diabetic complications, in particular, nephropathy, peripheral and autonomic neuropathy, "diabetic foot," retinopathy, and cardiovascular disease, remain the major cause of morbidity and mortality in patients with diabetes mellitus. Growing evidence indicates that both increased activity of the sorbitol pathway of glucose metabolism and enhanced oxidative stress are the leading factors in the pathogenesis of diabetic complications. The relation between the two mechanisms remains the area of controversy. One group has reported that increased sorbitol pathway activity has a protective rather than detrimental role in complication-prone tissues because the pathway detoxifies toxic lipid peroxidation products. Others put forward a so-called "unifying hypothesis" suggesting that activation of several major pathways implicated in diabetic complications (eg, sorbitol pathway) occurs due to increased production of superoxide anion radicals in mitochondria and resulting poly(ADP-ribose) polymerase activation. This review (a) presents findings supporting a key role for the sorbitol pathway in oxidative stress and oxidative stress-initiated downstream mechanisms of diabetic complications, and (b) summarizes experimental evidence against a detoxifying role of the sorbitol pathway, as well as the "unifying concept."