263 ) A 69 year old man with history of metastatic prostate cancer is admitted with nausea, vomiting and constipation of three days duration. He denies any abdominal pain. He was seen in the oncology clinic for severe bone pain and was started on sustained release Oxycodone as well as short acting oxycodone one week ago. His pain is well-controlled but he is distressed by his newly developed symptoms. On examination, his temperature is 98F, Heart rate is 130/min, Respiratory rate 20/min and Blood pressure 120/80 mm Hg. Chest is clear to auscultation and abdominal examination is benign. Obstructive series is negative for bowel obstruction. A CT scan of the adbomen does not reveal any small bowel obstruction. The patient is given promethazine and metoclopromide for vomiting. Which of the following opiod-induced adverse effects are expected to be persistent despite continued use of opiod analgesics ?
A) Nausea
B) Drowsiness
C) Constipation
D) Respiratory depression
E) Itching
Filed under: USMLE Test Prep | Tagged: ARCHER GASTROENTEROLOGY, Archer oncology, archer palliative care, STEP 3 ONCOLOGY, USMLE STEP 3 GASTROENEROLOGY, USMLE STEP 3 ONCOLOGY, usmle step 3 palliative care |
Archer USMLE Step 3 Blog 
C Constipation
c
C) Constipation
C
C;)Opioid-induced constipation (OIC) is the most common and debilitating side effect of opioids.6 The concentration of opioid receptors in the GI tract is highly dense.4-6 Activation of these receptors, particularly mu receptors, inhibits gastric emptying, reduces mucosal secretions, and increases fluid reabsorption.6,7 These factors cause stools to become hard and dry, and constipation ultimately develops.6,7 The constipating effects of opioids are considered to be dose related and are more common with long-term use. – See more at: http://www.uspharmacist.com/content/d/feature/c/38031/#sthash.CPjUQq4x.dpuf