ITEMS IN AFP WITH MESH TERM:
Practical Selection of Antiemetics - Article
ABSTRACT: An understanding of the pathophysiology of nausea and the mechanisms of antiemetics can help family physicians improve the cost-effectiveness and efficacy of therapy. Nausea and vomiting are mediated primarily by visceral stimulation through dopamine and serotonin, by vestibular and central nervous system causes through histamine and acetylcholine, and by chemoreceptor trigger zone stimulation through dopamine and serotonin. Treatment is directed at these pathways. Antihistamines and anticholinergic agents are most effective in patients with nausea resulting from vestibular and central nervous system causes. Dopamine antagonists block dopamine in the intestines and chemoreceptor trigger zone; indications for these agents are similar to those for serotonin antagonists. Serotonin antagonists block serotonin in the intestines and chemoreceptor trigger zone, and are most effective for treating gastrointestinal irritation and postoperative nausea and vomiting. Complementary and alternative therapies, such as ginger, acupressure, and vitamin B6, have variable effectiveness in the treatment of pregnancy-induced nausea.
Flexible Sigmoidoscopy - Article
Evaluation of Chronic Diarrhea - Article
ABSTRACT: Chronic diarrhea, defined as a decrease in stool consistency for more than four weeks, is a common but challenging clinical scenario. It can be divided into three basic categories: watery, fatty (malabsorption), and inflammatory. Watery diarrhea may be subdivided into osmotic, secretory, and functional types. Watery diarrhea includes irritable bowel syndrome, which is the most common cause of functional diarrhea. Another example of watery diarrhea is microscopic colitis, which is a secretory diarrhea affecting older persons. Laxative-induced diarrhea is often osmotic. Malabsorptive diarrhea is characterized by excess gas, steatorrhea, or weight loss; giardiasis is a classic infectious example. Celiac disease (gluten-sensitive enteropathy) is also malabsorptive, and typically results in weight loss and iron deficiency anemia. Inflammatory diarrhea, such as ulcerative colitis or Crohn disease, is characterized by blood and pus in the stool and an elevated fecal calprotectin level. Invasive bacteria and parasites also produce inflammation. Infections caused by Clostridium difficile subsequent to antibiotic use have become increasingly common and virulent. Not all chronic diarrhea is strictly watery, malabsorptive, or inflammatory, because some categories overlap. Still, the most practical diagnostic approach is to attempt to categorize the diarrhea by type before testing and treating. This narrows the list of diagnostic possibilities and reduces unnecessary testing. Empiric therapy is justified when a specific diagnosis is strongly suspected and follow-up is available.