When a client first takes a nitrate, which symptom often occurs?

• A. Nausea and vomiting
• B. Stomach cramps
• C. Headaches
• D. Irregular pulse rate

Answer: (C)

Nitrates cause vasodilation by releasing nitric oxide, which relaxes smooth muscle in blood vessels. When the cerebral arteries dilate, it can trigger a throbbing headache because of increased blood flow and pressure in the meninges. This headache after the first dose is a common and expected reaction as the body adapts to the new level of vascular relaxation. Other side effects like flushing or dizziness can accompany this widespread vasodilation, and while nausea or changes in pulse may occur in some individuals, the headache is the symptom most often reported initially.