A nurse is caring for a client in a provider's office. Click to highlight the findings that indicate an adverse effect of the medication. To deselect a finding, click on the finding again. Nurses' Notes Today: Client returns for follow-up visit after starting labetalol. Client reports feeling more tired since starting the medication and is having trouble sleeping. Client states, "I have also had loose stools several times this week and often get dizzy whenever I stand up." Vital Signs Today: Temperature 37° C (98.6° F) Heart rate 56/min Respiratory rate 14/min Blood pressure 118/76 mm Hg

Feeling more tired since starting the medication: Fatigue is a common adverse effect of beta-blockers like labetalol because they reduce heart rate and cardiac output. This decrease in cardiac output can limit blood flow to muscles and organs, contributing to generalized tiredness. Trouble sleeping: Beta-blockers can interfere with normal sleep patterns by decreasing melatonin secretion and altering sympathetic nervous system activity. Clients may experience difficulty falling asleep or frequent awakenings during the night. Dizziness when standing up (orthostatic hypotension): Labetalol’s alpha- and beta-blocking effects can reduce vascular resistance and blood pressure. When the client stands, the drop in blood pressure can cause lightheadedness or dizziness, especially in the first days of therapy. Heart rate 56/min (bradycardia): Beta-blockers slow the heart rate by decreasing sympathetic stimulation of the SA node. A heart rate below 60/min is considered bradycardia and may lead to fatigue, dizziness, or fainting.