Drug Name Atarax

Antidotes for cyanide poisoning (A). Cyanide ions (CN-) enter the organism in the form of hydrocyanic acid (HCN); the latter can be inhaled, released from cyanide salts in the acidic stomach juice, or enzymatically liberated from bitter almonds in the gastrointestinal tract. The lethal dose of HCN can be as low as 50 mg.
The degree of binding is governed by the concentration of the reactants and the affinity of a drug for a given protein. Albumin concentration in plasma amounts to 4.6 g/100 mL or O.6 mM, and thus provides a very high binding capacity (two sites per molecule). As a rule, drugs exhibit much lower affinity for plasma proteins than for their specific binding sites (receptors).

 

Bound to its transport protein, transcobalamin, vitamin B12 is destined for storage in the liver or uptake into tissues. A frequent cause of vitamin B12 deficiency is atrophic gastritis leading to a lack of intrinsic factor. Besides megaloblastic anemia, damage to mucosal linings and degeneration of myelin sheaths with neurological sequelae will occur (pernicious anemia).
This singlelayered epithelium is made up of enterocytes and mucus-producing goblet cells. On their luminal side, these cells are joined together by zonulae occludentes (indicated by black dots in the inset, bottom left).