Beatty NC, Arendt KW, Niesen AD, Wittwer ED, Jacob AK Analgesia after Cesarean delivery: a retrospective comparison of intrathecal hydromorphone and morphine. J Clin Anesth. 2013 Aug;25(5):379-383. doi: 10.1016/j.jclinane.2013.01.014. Epub 2013 Aug 17.
Macario A, Royal MA A literature review of randomized clinical trials of intravenous acetaminophen (paracetamol) for acute postoperative pain. Pain Pract. 2011 May-Jun;11(3):290-6. doi: 10.1111/j.1533-2500.2010.00426.x. Epub 2010 Nov 28. Review.
Singh SI, Rehou S, Marmai KL, Jones PM The efficacy of 2 doses of epidural morphine for postcesarean delivery analgesia: a randomized noninferiority trial. Anesth Analg. 2013 Sep;117(3):677-85. doi: 10.1213/ANE.0b013e31829cfd21. Epub 2013 Aug 6.
Wong JY, Carvalho B, Riley ET Intrathecal morphine 100 and 200 µg for post-cesarean delivery analgesia: a trade-off between analgesic efficacy and side effects. Int J Obstet Anesth. 2013 Jan;22(1):36-41. doi: 10.1016/j.ijoa.2012.09.006. Epub 2012 Nov 15.
Intravenous Versus Oral Acetaminophen for Postoperative Pain Control After Cesarean Delivery
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.