Atars - General Information
Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of carotenoids found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products.
Pharmacology of Atars
Atars is effective for the treatment of Atars deficiency. Atars refers to a group of fat-soluble substances that are structurally related to and possess the biological activity of the parent substance of the group called all-trans retinol or retinol. Atars plays vital roles in vision, epithelial differentiation, growth, reproduction, pattern formation during embryogenesis, bone development, hematopoiesis and brain development. It is also important for the maintenance of the proper functioning of the immune system.
Atars for patients
Drug Interactions: Women on oral contraceptives have shown a significant increase in plasma vitamin A levels.
The intravenous administration. Hypervitaminosis A. Sensitivity to any of the ingredients in this preparation. Use in Pregnancy: Safety of amounts exceeding 6,000 Units of vitamin A daily during pregnancy has not been established at this time. The use of vitamin A in excess of the recommended dietary allowance may cause fetal harm when administered to a pregnant woman. Animal reproduction studies have shown fetal abnormalities associated with overdosage in several species. Malformations of the central nervous system, the eye, the palate, and the urogenital tract are recorded. Vitamin A in excess of the recommended dietary allowance is contraindicated in women who are or may become pregnant. If vitamin A is used during pregnancy, or if the patient becomes pregnant while taking vitamin A, the patient should be apprised of the potential hazard to the fetus.
Additional information about Atars
Atars Indication: For the treatment of vitamin A deficiency.
Mechanism Of Action: Vision:Atars (all-trans retinol) is converted in the retina to the 11-cis-isomer of retinaldehyde or 11-cis-retinal. 11-cis-retinal functions in the retina in the transduction of light into the neural signals necessary for vision. 11-cis-retinal, while attached to opsin in rhodopsin is isomerized to all-trans-retinal by light. This is the event that triggers the nerve impulse to the brain which allows for the perception of light. All-trans-retinal is then released from opsin and reduced to all-trans-retinol. All-trans-retinol is isomerized to 11-cis-retinol in the dark, and then oxidized to 11-cis-retinal. 11-cis-retinal recombines with opsin to re-form rhodopsin. Night blindness or defective vision at low illumination results from a failure to re-synthesize 11-cis retinal rapidly.
Epithelial differentiation: The role of Atars in epithelial differentiation, as well as in other physiological processes, involves the binding of Atars to two families of nuclear retinoid receptors (retinoic acid receptors, RARs; and retinoid-X receptors, RXRs). These receptors function as ligand-activated transcription factors that modulate gene transcription. When there is not enough Atars to bind these receptors, natural cell differentiation and growth are interrupted.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Vitamin A
Synonyms: all-trans-retinol; All-trans-Retinyl alcohol; all-trans-Vitamin A; All-trans-Vitamin A alcohol; all-trans-Vitamin A1; beta-Retinol; Retin-11,12-t2-ol (9CI); Retinol; trans-Retinol; trans-Vitamin A alcohol; Vitamin A (Feed); Vitamin A alcohol; Vitamin A Palmitate; Vitamin A Solubilized; Vitamin A1; Vitamin A1 alcohol; Vitamin A cryst; [11,12-3H]-Retinol
Drug Category: Anti-acne Agents; Essential Vitamin; Vitamins (Vitamin A)
Drug Type: Small Molecule; Nutraceutical; Approved
Other Brand Names containing Vitamin A: A-Mulsal; A-Sol; A-Vi-Pel; A-Vitan; Acon; Afaxin; Agiolan; Agoncal; Alcovit A; Alphalin; Alphasterol; Anatola; Anatola A; Anti-Infective vitamin; Antixerophthalmic vitamin; Aoral; Apexol; Apostavit; Aquasol A; Aquasol A Parenteral; Aquasynth; Atars; Atav; Avibon; Avita; Avitol; Axerol; Axerophthol; Bentavit A; Biosterol; Chocola A; Cylasphere; Del-VI-A; Disatabs Tabs; Dofsol; Dohyfral A; Epiteliol; Hi-A-Vita; Homagenets Aoral; Homagenets aorl; Lard Factor; M.V.C. 9+3; M.V.I. Pediatric; M.V.I.-12; Mvc Plus; Myvpack; Nio-A-Let; Oleovitamin A; Ophthalamin; Plivit A; Prepalin; Retrovitamin A; Ro-a-vit; Sehkraft A; Solu-A; Super A; Testavol; Testavol S; Thalasphere; Vaflol; Vafol; Veroftal; Vi-Alpha; Vi-Dom-A; Vi-a; Vio-A; Vitavel A; Vitpex; Vogan; Vogan-Neu; Vogan-nu; Zineb; Zineb 80; Zinosan N; alin; asterol; tROL;
Absorption: Readily absorbed from the normal gastrointestinal tract
Toxicity (Overdose): Acute toxicity (single ingestion of 7 500 RE or 25 000 IU per kg or more): Signs and symptoms may be delayed for 8 to 24 hours and include: increased intracranial pressure, headache, irritability, drowsiness, dizziness, lethargy, vomiting, diarrhea, bulging of fontanels in infants, diplopia, papilledema. Peeling of skin around mouth may be observed from 1 to several days after ingestion and may spread to the rest of the body.
Chronic, excessive ingestion (1 200 RE or 4 000 IU/kg daily for 6 to 15 months) may produce symptoms of pseudotumor cerebri, anorexia, weakness, arthralgias, bone pain, bone demineralization, dry skin, cracked lips, brittle nails, hair loss, splenomegaly, hepatomegaly, hypoplastic anemia, leukopenia, optic neuropathy, and blindness. Increased plasma concentrations of vitamin A occur but do not necessarily correlate with toxicity.
Protein Binding: <5% of circulating vitamin A is bound to lipoproteins in blood in normal condition, but may be up to 65% when hepatic stores are saturated because of excessive intake. When released from liver, vitamin A is bound to retinol-binding protein (RBP). Most vitamin A circulates in the form of retinol bound to RBP.
Biotransformation: Hepatic. Retinol is conjugated with glucuronic acid; the B-glucuronide undergoes enterohepatic circulation and oxidation to retinol and retinoic acid. Retinoic acid undergoes decarboxylation and conjugation with glucuronic acid.
Half Life: 1.9 hours
Dosage Forms of Atars: Tablet Oral
Solution / drops Oral
Chemical IUPAC Name: 3,7-dimethyl-9-(2,6,6-trimethyl-1-cyclohexenyl)nona-2,4,6,8-tetraen-1-ol
Chemical Formula: C20H30O
Vitamin A on Wikipedia: http://en.wikipedia.org/wiki/Vitamin_A
Organisms Affected: Humans and other mammals