HCA2 and HCA3 inhibit cyclic adenosine monophosphate (cAMP) production and thus suppress the release of free fatty acids (FFAs) from body fat, reducing their availability to the liver to synthesize the blood-circulating lipids in question. A decrease in free fatty acids also suppresses liver expression of apolipoprotein C3 and PPARg coactivator-1b, thus increasing VLDL-C turnover and reducing its production. Niacin also directly inhibits the action of diacylglycerol O-acyltransferase 2 (DGAT2) a key enzyme for triglyceride synthesis.The mechanism behind niacin increasing HDL-C is not totally understood, but seems to occur in various ways. Niacin increases apolipoprotein A1 levels by inhibiting the breakdown of this protein, which is a component of HDL-C. It also inhibits HDL-C hepatic uptake by suppressing production of the cholesterol ester transfer protein (CETP) gene. It stimulates the ABCA1 transporter in monocytes and macrophages and upregulates peroxisome proliferator-activated receptor gamma, resulting in reverse cholesterol transport. Combined with statins
Extended release niacin was combined with the lovastatin trade-named Advicor, and with simvastatin, trade-named Simcor as prescription drug combinations. Advicor was approved by the U.S. Food and Drug Administration (FDA) in 2001. Simcor was approved in 2008. Subsequently, large outcome trials using these niacin and statin therapies were unable to demonstrate incremental benefit of niacin beyond statin therapy alone. The FDA withdrew approval of both drugs in 2016.
Perianal cellulitis, also known as perianitis or perianal streptococcal dermatitis, is a bacterial infection affecting the lower layers of the skin (cellulitis) around the anus. It presents as bright redness in the skin and can be accompanied by pain, difficulty defecating, itching, and bleeding. This disease is considered a complicated skin and soft tissue infection (cSSTI) because of the involvement of the deeper soft tissues.Perianal cellulitis is most commonly caused by group A beta-hemolytic streptococcus bacteria (Streptococcus pyogenes), which resides normally ("in small numbers") in the human throat and on the human skin. Other less common causes may include infection with group B beta-hemolytic streptococci (Streptococcus agalactiae), a bacteria found in the human vagina of some, or Staphylococcus aureus, a common component of the bacterial community in the human nose and/or skin.Perianal cellulitis occurs mainly in male children between six months and 10 years of age, however, there are documented cases of perianal cellulitis in adults as well. Oral antibiotics are the first line treatment for perianal cellulitis and may be used in combination with topical antibiotics. Since the infection occurs within the deeper layers of skin, using a topical treatment by itself may not be effective. In about 20% of cases, recurrence of perianal streptococcal dermatitis infection occurs within 3.5 months. Routine hygiene practices should also be encouraged in children and adults in order to reduce the risk of recurrent infection. Signs and symptoms
Perianal cellulitis manifests as multiple symptoms that are inconsistent with a systemic disease.