It is also available under the brand name Aratac (produced by Alphapharm Pty Ltd) in Australia and New Zealand, and further in Australia under the brands Cardinorm and Rithmik as well as a number of generic brands. Also Arycor in South Africa (Produced by Winthrop Pharmaceuticals.). In South America, it is known as Atlansil and is produced by Roemmers. In India, amiodarone is marketed (produced by Cipla Pharmaceutical) under the brand name Tachyra. It is also available in intravenous ampules and vials. The dose of amiodarone administered is tailored to the individual and the dysrhythmia that is being treated. When administered orally, the bioavailability of amiodarone is quite variable. Absorption ranges from 22 to 95%, with better absorption when it is given with food. Administration
Amiodarone IV should be administered via a central venous catheter. It has a pH of 4.08. If administered outside of the standard concentration of 900 mg/500mL it should be administered using a 0.22 micron filter to prevent precipitate from reaching the patient. Amiodarone IV is a known vesicant. For infusions of longer than 1 hour, concentrations of 2 mg/mL should not be exceeded unless a central venous catheter is used. References
Further reading
Siddoway LA (December 2003). "Amiodarone: guidelines for use and monitoring". Am Fam Physician. 68 (11): 2189–2196. PMID 14677664. Archived from the original on 15 May 2008. Retrieved 16 May 2004. External links
"Amiodarone". Drug Information Portal. U.S. National Library of Medicine.
pH
Though it is not common to consider hydronium ions as allosteric regulators, in the case of PBGS, side chain protonation at locations other than the active site has been shown to affect the quaternary structure equilibrium, and thus to affect the rate of its catalyzed reaction as well. Extrinsic allosteric regulators
Small molecule hexamer stabilization
Inspection of the PBGS 6mer* reveals a surface cavity that is not present in the 8mer. Small molecule binding to this phylogenetically variable cavity has been proposed to stabilize 6mer* of the targeted PBGS and consequently inhibit activity. Such allosteric regulators are known as morphlocks because they lock PBGS in a specific morpheein form (6mer*). Lead poisoning
ALAD enzymatic activity is inhibited by lead, beginning at blood lead levels that were once considered to be safe (<10 μg/dL) and continuing to correlate negatively across the range from 5 to 95 μg/dL. Inhibition of ALAD by lead leads to anemia primarily because it both inhibits heme synthesis and shortens the lifespan of circulating red blood cells, but also by stimulating the excessive production of the hormone erythropoietin, leading to inadequate maturation of red cells from their progenitors. A defect in the ALAD structural gene can cause increased sensitivity to lead poisoning and acute hepatic porphyria. Alternatively spliced transcript variants encoding different isoforms have been identified.