ACTOLIND w GEL

Indications

• Type 2 diabetes mellitus
• Polycystic ovary syndrome (off-label use)

Dosage

Children: For children aged 10 years and older, the starting dose is typically 500 mg orally once or twice daily, with gradual increases as needed and tolerated.

Adults: The usual initial dose of metformin is 500 mg orally twice daily or 850 mg once daily, which may be increased gradually based on glycemic control and tolerance.

Mechanism of action

Biguanides, particularly metformin, primarily work by decreasing hepatic glucose production and increasing insulin sensitivity in peripheral tissues. This leads to enhanced uptake and utilization of glucose by the tissues, thereby reducing blood glucose levels. The exact mechanism involves activation of AMP-activated protein kinase (AMPK), which plays a crucial role in energy homeostasis.

Pharmacodynamics

Biguanides lower blood glucose levels without increasing insulin secretion, which helps mitigate the risk of hypoglycemia. They also have beneficial effects on lipid profiles and may reduce the risk of macrovascular complications associated with diabetes. Metformin has been shown to have cardioprotective effects and may aid in weight management in patients with type 2 diabetes.

Pharmacokinetics

Biguanides are absorbed in the gastrointestinal tract, with peak plasma concentrations typically occurring 2 to 3 hours after administration. They are primarily excreted unchanged by the kidneys, and their half-life is approximately 6.2 hours. Renal function significantly affects the pharmacokinetics of biguanides, necessitating dosage adjustments in patients with renal impairment.

Contra-indications

• Severe renal impairment
• Acute or chronic metabolic acidosis
• Diabetic ketoacidosis
• Hypersensitivity to biguanides

Adverse effects

• Gastrointestinal disturbances (nausea, vomiting, diarrhea)
• Lactic acidosis
• Vitamin B12 deficiency
• Hypoglycemia (when used in combination with other antidiabetic medications)

Interactions

• Cationic drugs (e.g., certain antihypertensives) may affect renal clearance
• Alcohol can increase the risk of lactic acidosis
• Diuretics may alter blood glucose levels

Precautions

• Monitor renal function regularly
• Use caution in patients with liver dysfunction
• Discontinue before surgical procedures or radiological studies involving iodinated contrast

Pregnancy

Biguanides should only be used in pregnancy if the potential benefit justifies the potential risk to the fetus. Metformin is the preferred agent in gestational diabetes.

Breast-feeding

Metformin is excreted in breast milk in small amounts. It is generally considered safe during breastfeeding.

Storage

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

Formulations

• Tablets
• Extended-release tablets
• Oral solution

Dosage

Children: Refer to specific clinical guidelines or consult the BNF for Children for appropriate dosing information.

Adults: Refer to specific clinical guidelines or consult the BNF for appropriate dosing information.

Mechanism of action

Didecylamine functions as a surfactant, reducing surface tension and enhancing the solubility of various compounds. It may also exhibit local anesthetic properties by blocking sodium channels, although detailed mechanisms in clinical use are not well documented.

Pharmacodynamics

As a surfactant, didecylamine can alter the physical properties of cell membranes, potentially affecting the absorption and distribution of co-administered drugs. Its local anesthetic effects may result in temporary numbness in localized areas, but the clinical significance of these effects is limited.

Pharmacokinetics

Information on the pharmacokinetics of didecylamine is sparse. However, as a tertiary amine, it is likely to undergo metabolism through N-dealkylation and other pathways in the liver. The specific absorption, distribution, metabolism, and excretion (ADME) parameters remain largely undefined.

Pregnancy

There is limited data on the use of didecylamine in pregnancy. It should be used only if clearly needed and the benefits outweigh any potential risks.

Breast-feeding

Caution is advised when using didecylamine during breastfeeding, as it is unknown whether it is excreted in human milk.

Storage

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

Indications

• Wound care management
• Disinfection of skin and mucous membranes
• Antiseptic for surgical procedures
• Preservative in ophthalmic solutions
• Treatment of minor skin infections

Dosage

Children: Refer to specific product guidelines for appropriate dosing information.

Adults: Refer to specific product guidelines for appropriate dosing information.

Mechanism of action

PHMB exerts its antimicrobial action primarily through disruption of microbial cell membranes. It binds to the negatively charged components of bacterial membranes, leading to cell lysis and death. This mechanism is largely due to its polycationic nature, which allows it to interact with and destabilize the lipid bilayer of bacteria, fungi, and some viruses. Additionally, PHMB may interfere with DNA replication and protein synthesis in microbes, contributing to its overall antimicrobial efficacy.

Pharmacodynamics

The pharmacodynamic profile of PHMB indicates its effectiveness against a wide range of pathogens, including Gram-positive and Gram-negative bacteria, yeasts, and some viruses. Its low minimum inhibitory concentrations (MICs) suggest potent activity. PHMB has a cumulative effect with repeated exposure, and it is known to remain effective in the presence of organic matter, which is significant for its use in clinical and environmental settings.

Pharmacokinetics

PHMB is poorly absorbed systemically when applied topically, which limits its systemic effects and potential toxicity. It is largely retained at the site of application, providing local antimicrobial activity. The elimination half-life of PHMB is not well defined due to its limited absorption; however, it is expected to be excreted primarily through the urine. The pharmacokinetics may vary based on the formulation and route of administration.

Adverse effects

• Skin irritation
• Hypersensitivity reactions
• Allergic dermatitis

Precautions

• Use with caution in patients with a history of sensitivity to similar compounds
• Avoid contact with eyes and mucous membranes

Pregnancy

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

Breast-feeding

There is limited information on the excretion of polyhexamethylene in breast milk. Caution is advised when used during breastfeeding.

Storage

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

Formulations

• Topical solutions
• Gels
• Wipes