A colonoscopy is a diagnostic procedure in which a flexible, lighted tube with a camera mounted on the end is inserted into the large intestine via the anus in order to visualize the intestinal lining of the rectum and colon. It is a useful test to screen for colorectal cancer, as well to evaluate blood in the stool and anemia, inflammatory disease of the colon, intestinal tumors or masses, diverticulosis and other colon abnormalities. Because manipulation of the tube can cause some discomfort, medications are given via a vein, or intravenously, to help with pain and anxiety.
Pain Relievers
Intravenous narcotics are used for relief of procedural discomfort, as well as to help relieve anxiety. Fentanyl, an opioid-type medication, according to Drugs.com, is a commonly used narcotic during a colonoscopy. Propofol is another intravenous narcotic occasionally used, as well as meperidine. Serious side effects with all narcotics, particularly propofol, include diminished breathing, low blood pressure, nausea and vomiting. Propofol can also cause complete loss of consciousness.
Anxiety Medications
Patients are understandably anxious during a colonoscopy, so usually an anti-anxiety drug is used in combination with a narcotic for sedation. Midazolam, or Versed, is one such medication commonly used for sedation during a colonoscopy. RxList states that midazolam is in a class of sedatives called benzodiazepines. It is a short-acting drug and, in addition to relieving anxiety, it has the added effect of acute memory loss, so most patients have little recall of the procedure. Side effects include decreased blood pressure, depressed breathing and retching. Diazepam is another benzodiazepine occasionally used during colonoscopy.
Anti-nausea Drugs
Because the drugs used for pain relief and anxiety during a colonoscopy all have side effects of nausea and vomiting, intravenous anti-nausea drugs are often used to help alleviate nausea and prevent vomiting. Zofran, or ondansetron, is a frequently used drug, which blocks certain serotonin receptors in the central and peripheral nervous systems, and relieves nausea and vomiting, according to RxList. Side effects include sedation, headache and low oxygen in the blood.
Considerations
All medications used during a colonoscopy cause sedation, as well as possible depression of breathing, blood pressure and oxygenation of blood. Patients need to be closely monitored throughout the colonoscopy procedure for these potential complications. Although drug effects are all nearly resolved shortly after the procedure, some residual drowsiness often remains. For this reason, a designated driver must be present at the end of the colonoscopy to provide safe transportation home. It is also recommended that the patient ingest only clear liquids for a period of time after the procedure, until he is fully awake, to prevent choking and aspiration.
