FAROLAX

Indications

• Metabolic acidosis
• Acid-base imbalance
• Urinary alkalinization
• Treatment of certain poisonings
• Cardiac arrest in the context of metabolic acidosis

Dosage

Children: Refer to the BNF for Children for specific pediatric dosages, as they depend on the clinical condition

Adults: Refer to local guidelines and BNF for specific dosing recommendations as they may vary based on clinical condition and severity. General adult dosing for bicarbonate may range from 1 to 2 mEq/kg IV initially, followed by maintenance doses as needed.

Mechanism of action

Bicarbonate acts as a buffer that neutralizes excess acids in the body. It dissociates in solution to produce bicarbonate ions (HCO3-) which can react with hydrogen ions (H+) to form carbonic acid (H2CO3), subsequently leading to the production of carbon dioxide (CO2) and water (H2O). This process helps to raise the pH of the blood and other fluids, counteracting acidosis. Bicarbonate is involved in several metabolic pathways, including the urea cycle and various biosynthetic pathways.

Pharmacodynamics

Bicarbonate's primary pharmacodynamic effect is its ability to buffer hydrogen ions, thus increasing blood pH. This is essential in conditions such as metabolic acidosis, where the body accumulates excess acid. By raising blood pH, bicarbonate can help alleviate symptoms associated with acidemia, such as fatigue, confusion, and shortness of breath. Its effects can also influence the renal and respiratory systems to regulate acid-base homeostasis.

Pharmacokinetics

Bicarbonate is rapidly absorbed from the gastrointestinal tract. It is distributed throughout the body fluids, and its effects can be seen within minutes of administration. The kidneys play a significant role in bicarbonate homeostasis by reabsorbing bicarbonate from urine and excreting hydrogen ions. The elimination half-life can vary, depending on the patient's metabolic state and renal function.

Pregnancy

Use with caution. Consult with a healthcare provider before use.

Breast-feeding

Use with caution. Consult with a healthcare provider before use.

Storage

Store in a cool, dry place away from light.

Indications

• Acidulant in food and beverages
• Preservative in pharmaceutical formulations
• pH adjuster in various chemical preparations

Dosage

Children: Refer to product-specific guidelines for appropriate dosing based on formulation and indication.

Adults: Refer to product-specific guidelines for appropriate dosing based on formulation and indication.

Mechanism of action

Citric acid acts by chelating metal ions, which can enhance the solubility of certain compounds and improve their bioavailability. It also contributes to the acidity of the environment, which can influence enzymatic activity and metabolic pathways, particularly in the degradation of citronellol.

Pharmacodynamics

Citric acid exhibits mild pharmacological effects primarily attributed to its role in metabolic processes. It aids in the regulation of pH levels, which can impact enzymatic reactions and biochemical pathways. The acid's chelating properties may help to reduce the toxicity of certain metal ions in biological systems.

Pharmacokinetics

Citric acid is rapidly absorbed after oral administration and is metabolized in the liver. It undergoes conversion to various metabolites in the citric acid cycle, contributing to energy production. The elimination primarily occurs through urine, with minimal accumulation in the body.

Pregnancy

Citric acid is generally regarded as safe during pregnancy when used in food amounts. However, consult a healthcare provider for advice on medicinal use.

Breast-feeding

Citric acid is considered safe during breastfeeding when consumed in food amounts. For medicinal use, consult a healthcare provider.

Storage

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

Indications

• To enhance the palatability of oral medications
• To improve compliance in pediatric patients
• To mask unpleasant tastes of active pharmaceutical ingredients

Dosage

Children: Refer to specific formulations for guidance, as flavoring agents are typically used in very small quantities and are not dosed independently.

Adults: Refer to specific formulations for guidance, as flavoring agents are typically used in very small quantities and are not dosed independently.

Mechanism of action

Flavor compounds act primarily by stimulating taste receptors on the tongue, which can enhance the overall sensory experience of ingesting a product. Certain flavor compounds may also interact with olfactory receptors, contributing to the perception of flavor through smell. The stimulation of these receptors can lead to increased salivation and improved swallowing.

Pharmacodynamics

The use of flavoring agents in pharmaceuticals can influence compliance, particularly in children and individuals who may have difficulty swallowing pills. By enhancing the taste of a medication, these agents can reduce gag reflex and aversion, potentially improving therapeutic outcomes. However, the pharmacodynamic effects are largely dependent on the individual's taste preferences and sensitivities.

Pharmacokinetics

The pharmacokinetics of flavoring agents vary widely depending on the specific compounds used. Generally, these compounds are rapidly absorbed through the gastrointestinal tract upon ingestion, with their effects occurring within minutes. Some flavoring agents may undergo metabolism in the liver, while others may be excreted unchanged. The specific absorption, distribution, metabolism, and excretion (ADME) profiles depend on the chemical structure of each flavor compound.

Pregnancy

Generally considered safe, but specific flavoring agents may need to be evaluated individually.

Breast-feeding

Generally considered safe, but specific flavoring agents may need to be evaluated individually.

Storage

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

Indications

• Vision correction
• Phototherapy for skin conditions (e.g., psoriasis, eczema)
• Treatment of seasonal affective disorder (SAD)
• Circadian rhythm disorders
• Wound healing

Dosage

Children: Light therapy for paediatric patients should be approached with caution and always under professional guidance. Specific dosages will depend on the individual treatment protocol and condition being addressed.

Adults: Dosage of light therapy varies based on the condition being treated and should be tailored to individual needs, typically ranging from 15 minutes to 2 hours of exposure per day depending on the specific treatment protocol.

Mechanism of action

Light affects biological systems primarily through phototransduction, which involves the conversion of light into electrical signals within photoreceptor cells in the retina. This process initiates a cascade of biochemical reactions that ultimately lead to visual perception. In addition, specific wavelengths of light can interact with various biological molecules, triggering cellular responses such as the production of vitamin D through skin exposure to UVB radiation.

Pharmacodynamics

The pharmacodynamic effects of light are highly dependent on its wavelength and intensity. Short-wavelength blue light (around 480 nm) is known to influence circadian rhythms by affecting melatonin secretion. In therapeutic settings, light can modulate biological responses, such as promoting wound healing, reducing inflammation, and alleviating symptoms of seasonal affective disorder (SAD) through bright light therapy.

Pharmacokinetics

Light does not undergo traditional pharmacokinetic processes such as absorption, distribution, metabolism, or excretion. Instead, its effects are immediate and localized, depending on the intensity and duration of exposure. The penetration depth of light varies with wavelength; for example, UV light can penetrate the skin and affect deeper tissues, while visible light primarily affects the surface layers.

Pregnancy

There is limited data on the effects of light exposure during pregnancy. However, excessive exposure to bright light can be harmful to both the mother and the developing fetus.

Breast-feeding

Light exposure is generally considered safe while breastfeeding, but excessive exposure should be avoided to prevent potential harm to the infant.

Storage

Light should be properly controlled and managed in environments where it is used, ensuring that exposure levels are safe and effective.

Dosage

Children: Refer to BNF for Children for specific recommendations regarding the consumption of orange juice in children.

Adults: There is no standard dosage for orange juice as it is typically consumed as a beverage. Moderation is advised, especially for individuals on certain medications.

Mechanism of action

The exact mechanism of action of orange juice is not fully understood, but it is known to contain compounds that can influence the metabolism of certain drugs. For instance, it may affect the activity of cytochrome P450 enzymes, particularly CYP3A4, which can alter the pharmacokinetics of medications.

Pharmacodynamics

Orange juice is known to enhance the bioavailability of certain nutrients and may influence the pharmacological effects of some drugs. Its high vitamin C content contributes to various physiological functions, including antioxidant activity, which may indirectly support overall health.

Pharmacokinetics

The pharmacokinetics of orange juice itself are not extensively studied, but it is generally absorbed well through the gastrointestinal tract. The compounds in orange juice can affect the absorption and metabolism of medications, leading to varied clinical effects depending on the drug in question.

Interactions

• orange juice + celiprolol: Unknown (decreases exposure)

Formulations

• juice
• whole fruit

Mechanism of action

Oxides do not have a single mechanism of action as they are a broad category of compounds. However, in general, metal oxides can exhibit catalytic properties, while non-metal oxides may participate in biochemical reactions by forming acids or bases upon dissolution in water.

Pharmacodynamics

The pharmacodynamics of oxides depend on the specific type of oxide and its interaction with biological systems. For instance, metal oxides may have antimicrobial properties, while certain non-metal oxides can influence metabolic pathways through their acid-base chemistry. The effects vary widely, necessitating specific studies for each oxide's role in therapeutic contexts.

Pharmacokinetics

The pharmacokinetics of oxides are also variable. Many metal oxides are poorly soluble and thus have limited absorption when ingested. Non-metal oxides, such as carbon dioxide, can be readily absorbed and utilized in metabolic processes. The distribution, metabolism, and excretion of oxides depend on their chemical form and the biological system in which they are involved.

Pregnancy

Not applicable as oxide is not a drug but a class of chemical compounds.

Breast-feeding

Not applicable as oxide is not a drug but a class of chemical compounds.

Storage

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

Indications

• Bowel preparation prior to colonoscopy
• Preparation for other gastrointestinal diagnostic procedures

Dosage

Children: For children, the dosage must be determined according to age and weight. Refer to the BNF for Children for specific dosing guidelines.

Adults: For adults, the typical dosage for bowel preparation is 20 mg of sodium picosulfate (or as directed on the product label), usually taken in the evening before the procedure, often combined with magnesium citrate.

Mechanism of action

Sodium picosulfate is a contact laxative that inhibits the absorption of water and electrolytes while increasing their secretion into the intestinal lumen. It is converted by colonic bacterial enzyme sulfatase into an active metabolite, bis-(p-hydroxy-phenyl)-pyridyl-2-methane (BHPM), which acts directly on the colonic mucosa to stimulate colonic peristalsis.

Pharmacodynamics

Sodium picosulfate is classified as a stimulant laxative and has been shown to effectively produce a purgative effect in conjunction with magnesium citrate. In clinical studies, a significant majority of patients undergoing colonoscopy reported that sodium picosulfate-containing preparations provided effective bowel cleansing.

Pharmacokinetics

Sodium picosulfate is converted in the colon by bacterial enzymes into its active form, which exerts its effects locally in the colonic mucosa. The onset of action typically occurs within 6 to 12 hours after administration, depending on individual factors such as gastrointestinal motility.

Contra-indications

• Hypersensitivity to picosulfate or any of its components
• Severe dehydration
• Intestinal obstruction
• Appendicitis
• Acute abdominal pain of unknown origin
• Severe inflammatory bowel disease

Adverse effects

• Abdominal cramps
• Diarrhea
• Nausea
• Vomiting
• Electrolyte imbalance
• Dehydration

Interactions

• May interact with other laxatives, increasing the risk of dehydration and electrolyte imbalance
• Potentially alters the absorption of other medications taken simultaneously

Precautions

• Use with caution in patients with renal impairment
• Monitor electrolytes in prolonged use
• Not recommended for use in children under 12 years unless advised by a healthcare professional

Pregnancy

There is limited data on the use of sodium picosulfate during pregnancy. It should only be used if clearly needed and prescribed by a healthcare provider.

Breast-feeding

Sodium picosulfate is excreted in breast milk, but at therapeutic doses, it is not expected to adversely affect the nursing infant. Caution is advised.

Storage

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

Formulations

• Oral solution
• Tablets

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

Mechanism of action

Picosulfuric acid, as sodium picosulfate, is a contact laxative. Sodium picosulfate inhibits the absorption of water and electrolytes, and increases their secretion into the intestinal lumen. It is hydrolyzed by colonic bacterial enzyme, sulfatase, to form an active metabolite bis-(p-hydroxy-phenyl)-pyridyl-2-methane (BHPM), which acts directly on the colonic mucosa to stimulate colonic peristalsis.

Pharmacodynamics

Sodium picosulfate is a stimulant laxative that in conjunction with magnesium citrate, produces a purgative effect on stools. In a multicentre, observational study comprising of patients undergoing colonoscopy, more than 93.0% of the patients receiving sodium picosulfate-containing preparations reported the colon cleansing effect to be effective.

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.