Quiz 60: Pharmacotherapy of Bowel Disorders and Other Gastrointestinal Conditions
Ulcerative colitis is an inflammatory bowel disease (IBD), in which ulcers and inflammation occur in the colon and rectum. The inflammation increases the rate of bowel clearance. Sulfasalazine is a drug of choice for IBD. Sulfasalazine is a prodrug, which is metabolized into 5-amino salicylic acid (5-ASA) and sulfapyridine (SP) by the colon bacteria. This is poorly absorbed from the small intestine, most of the drug reaches colon where it is reduced by the colon bacteria. The 5-ASA is responsible for the anti-inflammatory effects of sulfasalazine, whereas the sulfapyridine is responsible for its side effects.
Decreased magnesium can result in seizures. Magnesium sulfate is used in the treatment is seizures due to hypomagnesemia in children, pregnant women and adults.
The dicyclomine (Bentyl) act by inhibiting the muscarinic type of acetylcholine receptors (mACh). So, it decrease the peristaltic movement mediated through the muscarinic receptors, and thus relieve diarrhoea. Dicyclomine is used in the treatment of irritable bowel syndrome. Loperamide (Imodium) is chemically similar to morphine (opioid alkaloid), which causes decreased gastric motility and constipation. But, this drug do not cross blood brain barrier (BBB) as morphine, so do not produce any CNS (central nervous system) effects. Thus, both dicyclomine and loperamide can relieve the symptoms of irritable bowel syndrome.