Which of the following is a common adverse effect of oxytocin?

Oxytocin is a hormone commonly used in clinical settings, especially for its role in inducing labor and controlling postpartum hemorrhage. One of the frequently observed adverse effects associated with oxytocin administration is vomiting. This effect can be attributed to the hormone's actions not only on the uterus but also on the central nervous system, potentially affecting areas that control nausea and vomiting.

While the other listed options are possible adverse effects of various medications, they are not typically associated with oxytocin. For example, arrhythmias can occur due to other drugs affecting cardiac function but aren't a recognized common effect of oxytocin. Seizures are also more closely linked to different medications or conditions and are not standard risks with oxytocin. Lastly, constipation is generally not a direct concern with oxytocin use; indeed, oxytocin can sometimes stimulate bowel activity due to its effects on smooth muscles. Therefore, recognizing vomiting as a common adverse effect of oxytocin highlights the importance of monitoring patients for this reaction during and after administration.