DEXADINE

Indications

• Chronic ulcers
• Diabetic foot ulcers
• Pressure ulcers
• Infected wounds
• Non-infected wounds

Dosage

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

Adults: Refer to specific product guidelines. Typically, cadexomer iodine is applied directly to the wound once or twice a week, depending on the wound's condition and exudate level.

Mechanism of action

Cadexomer iodine acts through the slow release of iodine, which is known for its antimicrobial properties. The iodine penetrates bacterial cell walls, leading to cell death. Additionally, cadexomer facilitates the formation of a moist wound environment that promotes healing while absorbing excess fluid and providing a barrier against further infection.

Pharmacodynamics

The pharmacodynamics of cadexomer iodine are characterized by its ability to reduce bacterial load in wounds, promote granulation tissue, and manage moisture levels. Its antimicrobial activity is effective against a wide range of pathogens, including bacteria and fungi. The sustained release of iodine helps maintain effective concentrations at the wound site over time.

Pharmacokinetics

Cadexomer iodine is applied topically, and its absorption through intact skin is minimal. The iodine released has local effects rather than systemic absorption, which minimizes the risk of systemic side effects. The drug is metabolized locally at the site of application, with the iodine being utilized or excreted by the body as needed. The duration of action is influenced by the amount applied and the wound's moisture level.

Adverse effects

• Skin irritation
• Allergic reactions

Precautions

• Use with caution in individuals with a history of hypersensitivity to iodine or similar compounds.
• Monitor for signs of local irritation or allergic reactions.

Pregnancy

There is limited data on the use of cadexomer during pregnancy. Consult a healthcare provider for advice.

Breast-feeding

There is limited data on the use of cadexomer during breastfeeding. Consult a healthcare provider for advice.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Formulations

• Topical ointment
• Gels

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

• Iodine deficiency
• Goiter
• Hypothyroidism
• Thyroiditis
• Fibrocystic breast disease

Dosage

Children: Refer to the BNF for Children for appropriate dosing guidelines based on age and weight.

Adults: Refer to the BNF for appropriate dosing guidelines based on condition and clinical judgment.

Mechanism of action

Molecular iodine inhibits the induction and promotion of carcinogenesis in mammary tissues and has shown beneficial effects in fibrocystic breast disease. It temporarily decreases thyroid hormone production through the acute Wolff-Chaikoff effect, followed by a return to normal hormone synthesis due to down regulation of the sodium-iodide symport. This mechanism can lead to a transient hypothyroid state in some individuals with underlying thyroid conditions.

Pharmacodynamics

Iodine is vital for the synthesis of thyroid hormones thyroxine (T4) and triiodothyronine (T3). It affects the metabolism of amine-derived hormones and plays a role in amino acid metabolism. The acute excess of iodide can lead to decreased circulating levels of T4 and T3 in susceptible individuals, while most people can escape this effect and maintain normal thyroid function.

Pharmacokinetics

Iodine is absorbed primarily in the gastrointestinal tract and is distributed throughout the body, particularly in the thyroid gland, where it is concentrated for hormone synthesis. The kidney plays a significant role in the excretion of excess iodine. The half-life of iodine in the body varies and can be influenced by dietary intake and underlying health conditions.

Adverse effects

• Hypothyroidism
• Hyperthyroidism
• Iodine allergy
• Gastrointestinal disturbances

Interactions

• Thyroid hormones
• Antithyroid drugs
• Lithium
• Diuretics

Precautions

• Use with caution in patients with thyroid dysfunction
• Monitor thyroid function periodically during treatment
• Pregnant or breastfeeding women should consult a healthcare provider before use

Pregnancy

Iodine is essential for fetal thyroid hormone synthesis, but excessive iodine intake should be avoided.

Breast-feeding

Iodine is excreted in breast milk; consult a healthcare provider regarding supplementation.

Storage

Store in a cool, dry place away from light.

Formulations

• Iodine solution
• Iodine tincture
• Potassium iodide tablets

Indications

• Topical drug delivery
• Emulsifying agent in pharmaceutical formulations
• Stabilizing agent in aqueous solutions
• Controlled drug release systems

Dosage

Children: Refer to specific product guidelines for dosing, as it varies based on formulation and intended use.

Adults: Refer to specific product guidelines for dosing, as it varies based on formulation and intended use.

Mechanism of action

Poloxamer acts primarily by reducing the surface tension at the interface between different phases, such as oil and water. This property allows it to stabilize emulsions and improve the solubility of poorly soluble drugs. Additionally, poloxamer can form micelles in solution, encapsulating hydrophobic drugs and facilitating their delivery in the body.

Pharmacodynamics

Poloxamer exhibits surfactant properties that can enhance drug absorption and bioavailability by altering the permeability of biological membranes. Its action as a solubilizing agent can improve the pharmacological effects of drugs by ensuring they remain in a bioavailable form longer. The polymeric nature of poloxamer can also lead to sustained release of encapsulated drugs, prolonging their therapeutic effect.

Pharmacokinetics

Poloxamer is poorly absorbed when administered orally and is primarily excreted unchanged in the feces. Its absorption through the skin is minimal, making it more suitable for topical applications. The pharmacokinetics can vary based on the formulation and route of administration, with its action typically being localized rather than systemic.

Adverse effects

• Skin irritation
• Allergic reactions
• Gastrointestinal disturbances
• Headache

Precautions

• Use with caution in patients with known allergies to surfactants
• Assess for skin sensitivity before use
• Monitor for adverse reactions during therapy

Pregnancy

Safety during pregnancy has not been established. Use only if clearly needed and potential benefits justify the risks.

Breast-feeding

It is not known whether poloxamer is excreted in human milk. Caution is advised when administering to nursing mothers.

Storage

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

Formulations

• Poloxamer 188 (used as a surfactant in various formulations)
• Poloxamer 407 (used in pharmaceutical formulations and drug delivery systems)

Indications

• Constipation
• Bowel preparation prior to surgical procedures or diagnostic tests

Dosage

Children: Refer to specific guidelines or BNF for Children for dosing information.

Adults: Refer to specific guidelines or BNF for detailed dosing information.

Mechanism of action

Polyethylene glycol works by osmotically retaining water in the intestinal lumen, which increases the water content of the stool. This enhances the passage of stool through the intestines and promotes bowel movements. The high molecular weight of polyethylene glycol prevents its absorption in the gastrointestinal tract, ensuring that it remains in the lumen to exert its effects.

Pharmacodynamics

The pharmacodynamic profile of polyethylene glycol involves its ability to increase stool water content, thereby reducing stool consistency and facilitating easier passage. It does not stimulate intestinal motility directly but rather relies on the osmotic effect to promote bowel evacuation. The onset of action typically occurs within 24 to 96 hours after ingestion.

Pharmacokinetics

Polyethylene glycol is not absorbed systemically, and its pharmacokinetics are characterized by its presence solely in the gastrointestinal tract. It is excreted unchanged in the stool. The volume of polyethylene glycol administered can influence the effectiveness and timing of its action, but its absorption is negligible, making systemic side effects rare.

Adverse effects

• Abdominal cramping
• Diarrhea
• Nausea
• Vomiting
• Bloating
• Flatulence

Precautions

• Use with caution in patients with gastrointestinal disorders or bowel obstruction.
• Ensure adequate hydration during use to prevent dehydration.

Pregnancy

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

Breast-feeding

Polyethylene glycol is excreted in breast milk in very small amounts and is generally regarded as safe during breastfeeding.

Storage

Store at room temperature, away from moisture and heat.

Formulations

• Powder for oral solution
• Liquid formulation

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

Molecular iodine is known to inhibit the induction and promotion of N-methyl-n-nitrosourea-induced mammary carcinogenesis, to regress 7,12-dimethylbenz(a)anthracene-induced breast tumors in rats.It has also been shown to have beneficial effects in fibrocystic human breast disease. An acute iodide excess (above the preexisting dietary intake) transiently decreases the production of thyroid hormones in the thyroid gland; this is referred to as the acute Wolff-Chaikoff effect. In normal people, this is followed by a return to normal levels of hormone synthesis, referred to as escape from the acute Wolff-Chaikoff effect, without a significant change in circulating hormone levels. Escape is thought to be the result of down regulation of the sodium-iodide symport (NIS), the iodide transporter in the thyroid gland, resulting in a decrease in the intrathyroidal iodine and the resumption of normal hormone synthesis. An acute or chronic excess of iodide can also decrease circulating T4 and T3 levels and induce a hypothyroid state in some people who have underlying thyroid disorders. These effects are the result of a failure to escape from the acute Wolff-Chaikoff effect. Most people who experience iodine-induced hypothyroidism recover when the excess iodine intake is discontinued.