A 38-year-old woman comes to the office to discuss motion sickness. She is currently feeling well. The patient is planning a vacation cruise and has previously experienced severe nausea and vomiting while sailing. She has 4 children, and her past medical history is notable only for a tubal ligation. The patient does not smoke and drinks only moderate quantities of alcohol. She is not currently taking any medications. Physical examination, including otologic and neurologic examinations, is normal. After the appropriate drug therapy is recommended, this patient should be counseled regarding which of the following side effects?

Question

A 38-year-old woman comes to the office to discuss motion sickness.  She is currently feeling well.  The patient is planning a vacation cruise and has previously experienced severe nausea and vomiting while sailing.  She has 4 children, and her past medical history is notable only for a tubal ligation.  The patient does not smoke and drinks only moderate quantities of alcohol.  She is not currently taking any medications.  Physical examination, including otologic and neurologic examinations, is normal.  After the appropriate drug therapy is recommended, this patient should be counseled regarding which of the following side effects?

Quizplus · Accepted Answer

11ec160b_3c30_b924_9249_134af74affb6_MD0001_00 Perception of motion and orientation is determined by input from the vestibular, visual, and somatosensory systems. These 3 systems are usually congruent, but conflicting input can lead to motion sickness, characterized by nausea, dizziness, and autonomic symptoms (eg, diaphoresis). Integration of these sensory pathways occurs in the vestibular nuclei via muscarinic and histaminic neurotransmission. As such, antimuscarinic agents (eg, scopolamine) and first-generation antihistamines (eg, meclizine, dimenhydrinate) are most effective for management of motion sickness. Anticholinergic side effects are common with these medications and may include blurry vision, dry mouth, urinary retention, and constipation. (Choices A, D, and E) Cough, frequent urination, and nasal congestion are characteristic of stimulation rather than blockade of muscarinic pathways. (Choice B) Diarrhea may be seen with dopamine receptor antagonists (eg, metoclopramide), but these drugs are primarily used for visceral (eg, diabetic gastroparesis), rather than vestibular, nausea. Educational objective: Antimuscarinic agents and antihistamines with antimuscarinic action are most effective for motion sickness prevention. __________ References: Scopolamine (hyoscine) for preventing and treating motion sickness. (http://www.ncbi.nlm.nih.gov/pubmed/21678338)

A 38-Year-Old Woman Comes to the Office to Discuss Motion