E-Sel Care 20% WSP

Indications

• Selenium deficiency
• Antioxidant therapy
• Support in thyroid function
• Potential adjunctive treatment in cancer therapy

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations.

Adults: Refer to the BNF for specific dosing recommendations.

Mechanism of action

Selenite acts as a source of selenium, which is incorporated into selenoproteins. These proteins play essential roles in antioxidant defense, thyroid hormone metabolism, and immune function. The selenium from selenite is metabolized to selenophosphate, which is a precursor for the synthesis of selenoamino acids and subsequently selenoproteins.

Pharmacodynamics

Selenite exhibits antioxidant properties by enhancing the activity of antioxidant enzymes, such as glutathione peroxidase. This helps to reduce oxidative stress in the body. The effects of selenite can vary depending on the dose and duration of exposure, with low doses being beneficial and high doses potentially leading to toxicity.

Pharmacokinetics

Selenite is absorbed in the gastrointestinal tract and is distributed throughout the body, with a preference for high accumulation in the liver, kidney, and muscle tissues. The elimination half-life of selenium varies but is generally a few days. Selenium is primarily excreted through urine, and its metabolism involves conversion to various seleno compounds.

Formulations

• Sodium selenite

Indications

• Prevention of vitamin E deficiency
• Antioxidant therapy
• Support in conditions related to oxidative stress

Dosage

Children: Refer to BNF for Children for specific dosage guidelines.

Adults: Refer to BNF for specific dosage guidelines.

Mechanism of action

Tocopherol acts as a radical scavenger, primarily functioning as an antioxidant for lipid bilayers. It donates hydrogen atoms to free radicals, trapping them and preventing cellular damage. Its effectiveness is influenced by its location within the membrane and its interaction with cytosolic reductants like ascorbate. Tocopherol can trap multiple radicals, including alkyl and peroxy radicals.

Pharmacodynamics

The antioxidant properties of tocopherol lead to significant pharmacodynamic effects, including the inhibition of cell death through modulation of protein kinase C (PKC). Tocopherol also exhibits anti-inflammatory effects, which can be attributed to its influence on cytokines, prostaglandins, prostanoids, and thromboxanes. These interactions may contribute to its protective effects in various pathological conditions.

Pharmacokinetics

Tocopherol is absorbed in the intestines and its bioavailability can be influenced by dietary fat intake. It is transported in the plasma primarily bound to lipoproteins. Tocopherol is stored in adipose tissue and the liver, and its elimination occurs through bile and urine. The half-life of tocopherol can vary depending on the individual's nutritional status and other factors.

Pregnancy

Tocopherol is generally considered safe during pregnancy, but it is advisable to consult a healthcare provider before use.

Breast-feeding

Tocopherol is excreted in breast milk, and while it is considered safe, a healthcare provider should be consulted for specific recommendations.

Storage

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

Mechanism of action

Tocopherol acts as a radical scavenger. It mainly acts as an antioxidant for lipid bilayers. Tocopherol's functions depend on the H-atom donating ability, location, and movement within the membrane, as well as the efficiency in the radical recycling by some cytosolic reductants such as ascorbate. Tocopherol actions are related to the trap of radicals, and it has been shown that even in the absence of substituents in the ortho-positions, tocopherol can trap more than two radicals. The type of radicals available for tocopherol are alkyl and peroxy.

Pharmacodynamics

The antioxidant effects of tocopherol can be translated into different changes at the pharmacodynamic level. In vitro studies have shown that this antioxidant activity can produce modification in protein kinase C (PKC) which will later be translated into an inhibition of cell death. Some other derivate effects are the anti-inflammatory properties of tocopherol which can be related to the modulation of cytokines or prostaglandins, prostanoids and thromboxanes.