REVIT-C​ ​EFFERVESCENT TABLETS

Indications

• Vitamin C deficiency
• Scurvy
• Adjunct therapy in iron overload conditions

Dosage

Children: Child 1 month–3 years: 125–250 mg daily in 1–2 divided doses; Child 4–11 years: 250–500 mg daily in 1–2 divided doses; Child 12–17 years: 0.5–1 g daily in 1–2 divided doses.

Adults: 500 mg daily, taken in 1-2 divided doses, depending on the clinical condition and dietary needs.

Mechanism of action

Ascorbic acid functions primarily as a reducing agent, facilitating enzymatic reactions in the body, including the hydroxylation of proline and lysine in collagen synthesis. It also plays a role in the absorption of iron from the gastrointestinal tract and enhances the immune response.

Pharmacodynamics

Ascorbic acid is crucial for the maintenance of connective tissue and is involved in the metabolism of several amino acids. Its antioxidant properties help to mitigate oxidative stress and may play a role in reducing the risk of chronic diseases.

Pharmacokinetics

Ascorbic acid is absorbed in the intestines and is widely distributed throughout the body. The renal clearance of ascorbic acid is dose-dependent, with higher doses leading to increased excretion. The half-life varies but is generally around 15 to 30 minutes in healthy individuals, with tissue saturation levels influencing its retention.

Contra-indications

• Hypercalcaemia
• Hyperoxaluria
• Patients with cardiac dysfunction

Adverse effects

• Abdominal pain
• Headache
• Nausea
• Vomiting
• Diarrhoea
• Constipation
• Weight loss
• Polyuria
• Sweating
• Thirst
• Vertigo

Interactions

• Increases risk of cardiovascular adverse effects with iron chelators
• Increases risk of cardiovascular adverse effects with deferiprone
• Increases risk of cardiovascular adverse effects with desferrioxamine

Precautions

• Use with caution in patients with iron overload
• Monitor for symptoms of overdose

Pregnancy

High doses teratogenic in animals but therapeutic doses unlikely to be harmful.

Storage

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

Formulations

• Ascorbic acid 50 mg tablets
• Ascorbic acid 100 mg tablets
• Ascorbic acid 200 mg tablets
• Ascorbic acid 250 mg tablets
• Ascorbic acid 500 mg capsules

Indications

• Antioxidant support
• Immune system support
• Anti-inflammatory effects
• Culinary uses

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations based on age and condition.

Adults: Refer to specific product guidelines or clinical recommendations, as dosages may vary based on the form of citrus used (e.g., juice, supplements).

Mechanism of action

Citrus fruits contain a variety of bioactive compounds, including ascorbic acid (vitamin C), flavonoids, and limonoids. These compounds exert their effects through antioxidant activity, modulating cellular signaling pathways, and enhancing immune function. The flavonoids in citrus may inhibit oxidative stress and inflammation, contributing to their health-promoting effects.

Pharmacodynamics

The pharmacodynamic properties of citrus components are largely attributed to their antioxidant capacity and ability to scavenge free radicals. The bioactive compounds interact with various cellular pathways, potentially reducing the risk of chronic diseases such as cardiovascular disease and certain cancers. The vitamin C content also plays a crucial role in collagen synthesis and immune support.

Pharmacokinetics

Citrus bioactive compounds are absorbed in the gastrointestinal tract, with vitamin C being readily absorbed. The metabolism of flavonoids occurs primarily in the liver through phase I and II metabolic processes, resulting in various metabolites that can exert biological effects. The elimination half-lives of these compounds vary, and they are primarily excreted via the urine.

Pregnancy

Citrus fruits are generally considered safe during pregnancy. However, excessive consumption may lead to gastrointestinal discomfort, and pregnant individuals should consult with healthcare providers regarding their diet.

Breast-feeding

Citrus fruits are safe during breastfeeding, but it is advisable to consume them in moderation as they may cause gastrointestinal discomfort in some infants.

Storage

Citrus fruits should be stored in a cool, dry place. They can also be refrigerated to extend freshness, but should be kept in a breathable bag to avoid moisture accumulation.

Formulations

• fresh fruit
• juice
• essential oil

Indications

• Antioxidant support
• Anti-inflammatory effects
• Cardiovascular health
• Potential cancer prevention
• Enhanced immune function

Dosage

Children: There is no established

Adults: Dosage varies based on the specific flavonoid and its formulation. General guidance suggests consuming flavonoid-rich foods, with no standard therapeutic doses established.

Mechanism of action

Flavonoids exert their biological effects primarily through their ability to modulate cell signaling pathways and gene expression. They can act as antioxidants, scavenging free radicals, and chelating metal ions. Flavonoids also influence various enzymes involved in metabolic processes, including those responsible for drug metabolism. They may inhibit cyclooxygenase and lipoxygenase, thus reducing inflammation, and they can also modulate nitric oxide synthesis, contributing to vasodilation and improved cardiovascular health.

Pharmacodynamics

Flavonoids interact with various cellular receptors and signaling pathways, which can lead to anti-inflammatory, anti-cancer, and cardioprotective effects. Their antioxidant activity helps to prevent oxidative stress, which is implicated in numerous chronic diseases. Some flavonoids have been shown to influence the activity of certain transcription factors, such as NF-kB and Nrf2, enhancing the cellular defense mechanisms against oxidative damage.

Pharmacokinetics

Flavonoids are generally well-absorbed in the gastrointestinal tract, although their bioavailability can vary significantly based on their chemical structure and the presence of other dietary components. After absorption, they are extensively metabolized in the liver and may be conjugated to form glucuronides or sulfates. The elimination half-life of flavonoids can also vary, but many are excreted in urine as metabolites. Their distribution throughout the body can be influenced by factors such as lipophilicity and protein binding.

Adverse effects

• Gastrointestinal disturbances
• Headaches
• Allergic skin reactions
• Potential liver toxicity at high doses

Interactions

• May interact with anticoagulants, increasing bleeding risk
• Can affect the metabolism of certain medications due to enzyme inhibition

Precautions

• Use with caution in patients with liver disease
• Monitor for allergic reactions in sensitive individuals
• Consult healthcare professionals before use in pregnancy or breastfeeding

Pregnancy

Flavonoids should be used during pregnancy only if clearly needed, due to the limited data on their safety.

Breast-feeding

Caution is recommended as flavonoids may pass into breast milk.

Storage

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

Formulations

• Capsules
• Tablets
• Liquid extracts
• Powdered forms