A nurse is evaluating a client who received subcutaneous sumatriptan 1 hour ago. Which of the following findings should the nurse identify as an adverse effect of the medication?

A. Visual disturbances: Visual changes can occur as part of a migraine aura, but they are not typically an adverse effect caused by sumatriptan itself. B. Pressure in the chest: Sumatriptan can cause vasoconstriction, leading to chest pressure or tightness. This cardiovascular effect is a known adverse reaction and should be assessed carefully to rule out serious complications. C. Phonophobia: Sensitivity to sound is a symptom of migraines, not a side effect of sumatriptan. It reflects the underlying condition rather than medication-related adverse effects. D. Numbness of the tongue: Tingling or paresthesia can occur in some clients, but numbness of the tongue is less common and not a primary adverse effect of sumatriptan compared with cardiovascular symptoms.