RINAVIT COMBINATION PRODUCT SYRUP

Indications

• Papulopustular rosacea
• Inflammatory acne vulgaris

Dosage

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

Adults: For papulopustular rosacea, apply daily for up to 4 months. The treatment course may be repeated; discontinue if no improvement is observed after 3 months. For inflammatory acne vulgaris, apply twice daily, reduced to once daily or alternate days if irritation occurs.

Mechanism of action

Nicotinamide exhibits anti-inflammatory effects by inhibiting the release of pro-inflammatory cytokines and enhancing the barrier function of the skin. It is also involved in the NAD salvage pathway, which is essential for maintaining cellular energy levels and promoting cell repair mechanisms. Additionally, nicotinamide contributes to the synthesis of coenzymes involved in metabolic processes, including the conversion of niacin into NAD+.

Pharmacodynamics

Nicotinamide is known for its ability to improve skin hydration and reduce transepidermal water loss. It has been shown to decrease the appearance of acne lesions and rosacea by modulating inflammatory responses and accelerating cell turnover. Its antioxidant properties also help to protect the skin from oxidative stress and UV damage.

Pharmacokinetics

When applied topically, nicotinamide is absorbed through the skin layers, with minimal systemic absorption. Its peak plasma concentrations are generally low, and the drug has a half-life that varies depending on the route of administration. The metabolism of nicotinamide occurs primarily in the liver, where it is converted into its active forms, including NAD+. The elimination route is via the kidneys, with metabolites excreted in urine.

Contra-indications

• Pregnancy
• Severe acne involving large areas
• Severe skin reactions

Adverse effects

• Sunburn
• Skin reactions (common or very common)
• Cheilitis
• Eyelid oedema
• Flushing
• Dry skin
• Eye irritation
• Photosensitivity reactions
• Transient skin pigmentation changes

Interactions

• Clindamycin
• Topical retinoids
• Abrasive cleaners
• Comedogenic cosmetics

Precautions

• Avoid exposure to UV light, including sunlight and sunlamps
• Wash hands immediately after use
• Avoid contact with eyes and mucous membranes
• Use moisturizers to reduce the risk of skin irritation
• Discontinue treatment if severe irritation occurs

Pregnancy

Avoid use during pregnancy due to potential risks, as limited information is available regarding toxicity.

Breast-feeding

Amount of drug in milk after topical application is probably too small to be harmful; ensure infant does not come in contact with treated areas.

Storage

Store at room temperature away from moisture and light.

Formulations

• Cream
• Gel

Indications

• Vitamin B2 deficiency
• Isoniazid-induced neuropathy (prophylaxis and treatment)
• Metabolic diseases
• Cystathioninuria
• Homocystinuria
• Wilson's disease
• Prevention of penicillamine-induced neuropathy

Mechanism of action

Riboflavin acts as a precursor to flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which are essential coenzymes in various enzymatic reactions. It binds to riboflavin hydrogenase, riboflavin kinase, and riboflavin synthase, facilitating the production of FMN and FAD. These coenzymes are critical for normal tissue respiration and energy metabolism, influencing hydrogen transport in oxidative enzyme systems such as cytochrome C reductase and succinic dehydrogenase. Moreover, riboflavin contributes to the antioxidant activity by aiding in the production of reduced glutathione, a key antioxidant in the body.

Pharmacodynamics

Riboflavin is an easily absorbed, water-soluble micronutrient that supports energy production by assisting in the metabolism of fats, carbohydrates, and proteins. It is vital for red blood cell formation, antibody production, and regulating growth and reproduction. The vitamin plays a significant role in maintaining healthy skin, nails, and hair, as well as supporting thyroid activity. Riboflavin also has therapeutic implications in preventing or treating various eye disorders, including cataracts.

Pharmacokinetics

Riboflavin is rapidly absorbed in the gastrointestinal tract, with its bioavailability influenced by dietary intake. It is primarily excreted through urine, with excess intake leading to bright yellow urine, which is a harmless side effect. The vitamin does not accumulate in the body, necessitating regular dietary intake to maintain adequate levels.

Adverse effects

• Urine discolouration
• Peripheral neuritis

Precautions

• With intravenous use, risk of cardiovascular collapse; resuscitation facilities must be available and monitor closely.

Pregnancy

Crosses the placenta but no adverse effects reported; information at high doses limited.

Breast-feeding

Present in breast milk but no adverse effects reported; information at high doses limited.

Storage

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

Formulations

• 100 mg modified-release tablets
• 50 mg capsules
• 100 mg capsules
• 100 mg tablets
• Oral solution

Indications

• Vitamin deficiency
• Nutritional supplementation
• Prevention of certain diseases
• Supporting metabolic functions

Dosage

Children: Refer to specific guidelines for individual vitamins or consult a healthcare professional for personalized dosing recommendations.

Adults: Refer to specific guidelines for individual vitamins or consult a healthcare professional for personalized dosing recommendations.

Mechanism of action

Vitamins function primarily as coenzymes or precursors for enzyme cofactors in various metabolic pathways. For instance, B vitamins are involved in energy metabolism by assisting in the conversion of carbohydrates, fats, and proteins into energy. Vitamin C acts as an antioxidant, protecting cells from damage, and is also crucial for collagen synthesis. Fat-soluble vitamins like A are involved in vision and immune function, while vitamin D regulates calcium and phosphate metabolism.

Pharmacodynamics

Vitamins exert their effects by participating in biochemical reactions and influencing metabolic pathways. For example, vitamin A is vital for vision and immune response, while vitamin D is important for maintaining bone health through its role in calcium absorption. The effects of vitamins can vary significantly depending on their solubility, with water-soluble vitamins typically being excreted more readily than fat-soluble ones, which can accumulate in the body.

Pharmacokinetics

The absorption of vitamins varies; water-soluble vitamins are generally absorbed in the small intestine and excreted in urine, while fat-soluble vitamins require dietary fats for absorption and are stored in the liver and fatty tissues. The bioavailability of vitamins can be affected by dietary composition, age, and health status. Elimination half-lives also differ; for instance, vitamin C has a shorter half-life compared to vitamin A, which can persist in the body for longer periods.

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Constipation
• Headache
• Fatigue
• Allergic reactions

Interactions

• Fat-soluble vitamins (A, D, E, K) can accumulate and cause toxicity when taken in excess, especially with other supplements
• Certain medications (e.g., anticoagulants) may interact with vitamin K
• Vitamin C can enhance the absorption of iron supplements

Precautions

• Use caution in patients with kidney disease when taking vitamin D
• Monitor for signs of toxicity with high-dose vitamin supplementation
• Consider dietary sources of vitamins before recommending supplements

Pregnancy

Vitamins are generally considered safe during pregnancy when taken at recommended dosages. However, excessive intake, particularly of fat-soluble vitamins, should be avoided.

Breast-feeding

Most vitamins are safe during breastfeeding at recommended doses, but excessive amounts can affect breast milk composition.

Storage

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

Formulations

• Tablets
• Capsules
• Soft gels
• Powders
• Liquid solutions
• Chewable tablets

Mechanism of action

Binds to riboflavin hydrogenase, riboflavin kinase, and riboflavin synthase. Riboflavin is the precursor of flavin mononucleotide (FMN, riboflavin monophosphate) and flavin adenine dinucleotide (FAD). The antioxidant activity of riboflavin is principally derived from its role as a precursor of FAD and the role of this cofactor in the production of the antioxidant reduced glutathione. Reduced glutathione is the cofactor of the selenium-containing glutathione peroxidases among other things. The glutathione peroxidases are major antioxidant enzymes. Reduced glutathione is generated by the FAD-containing enzyme glutathione reductase. Riboflavin is converted to 2 coenzymes, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which are necessary for normal tissue respiration. Riboflavin is also required for activation of pyridoxine, conversion of tryptophan to niacin, and may be involved in maintaining erythrocyte integrity. Riboflavin functions as the coenzyme for flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), which primarily influence hydrogen transport in oxidative enzyme systems (eg, cytochrome C reductase, succinic dehydrogenase, xanthine oxidase). Two active forms of riboflavin exist ... coenzyme flavin mononucleotide (FMN) and coenzyme flavin adenine dinucleotide (FAD). They are formed by reaction of riboflavin with 1 and 2 molecules of ATP as follow: riboflavin + ATP = riboflavin-P (FMN) + ADP; FMN + ATP = riboflavin-ADP (FAD) + PP. Riboflavin is a water-soluble, yellow, fluorescent compound. The primary form of the vitamin is as an integral component of the coenzymes flavin mononucleotide (FMN) and flavin-adenine dinucleotide (FAD). It is in these bound coenzyme forms that riboflavin functions as a catalyst for redox reactions in numerous metabolic pathways and in energy production. ... The redox reactions in which flavocoenzymes participate include flavoprotein-catalyzed dehydrogenations that are both pyridine nucleotide (niacin) dependent and independent, reactions with sulfur-containing compounds, hydroxylations, oxidative decarboxylations (involving thiamin as its pyrophosphate), dioxygenations, and reduction of oxygen to hydrogen peroxide. There are obligatory roles of flavocoenzymes in the formation of some vitamins and their coenzymes. For example, the biosynthesis of two niacin-containing coenzymes from tryptophan occurs via FAD-dependent kynurenine hydroxylase, an FMN-dependent oxidase catalyzes the conversion of the 5'-phosphates of vitamin B6 to coenzymic pyridoxal 5'-phosphate, and an FAD-dependent dehydrogenase reduces 5,10-methylene-tetrahydrofolate to the 5'-methyl product that interfaces with the B12-dependent formation of methionine from homocysteine and thus with sulfur amino acid metabolism. For more Mechanism of Action (Complete) data for Riboflavin (7 total), please visit the HSDB record page.

Pharmacodynamics

Riboflavin or vitamin B2 is an easily absorbed, water-soluble micronutrient with a key role in maintaining human health. Like the other B vitamins, it supports energy production by aiding in the metabolising of fats, carbohydrates, and proteins. Vitamin B2 is also required for red blood cell formation and respiration, antibody production, and for regulating human growth and reproduction. It is essential for healthy skin, nails, hair growth and general good health, including regulating thyroid activity. Riboflavin also helps in the prevention or treatment of many types of eye disorders, including some cases of cataracts.