Pruritus Caused by Drug

This study compares the incidence of pruritus (itching) requiring treatment between two doses of intrathecal morphine (0.1 mg vs 0.2 mg) when used for spinal anesthesia during cesarean section. The study aims to determine if the lower dose (0.1 mg) can reduce pruritus incidence while maintaining adequate pain relief.

Opioids are often added with a local anesthetic to enhance the duration and quality of spinal anesthesia for cesarean delivery patients. However, spinal opioids are associated with a wide variety of side effects such as nausea, vomiting, (N/V) and pruritus (itching). The occurrence of pruritus can vary between 30% and 100% making pruritus the most common side-effect of intrathecal opioids and this rate is even higher in pregnant patients. Pruritus may require treatment which can be ineffective or sometimes reverse the analgesic effect of the opioids. Ondansetron is a safe and very commonly used Serotonin receptor antagonist treatment for local anesthetic opioid-induced pruritus used in pregnancy. The effect of different administration times of ondansetron in reducing pruritus or N/V in cesarean section (CS) cases has not been extensively studied and thus, this prospective study can help guide future clinical management of side effects caused by spinal intrathecal morphine administration.