Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
a light-headed feeling, like you might pass out;
slow heart rate, weak pulse, fainting, slow breathing (breathing may stop);
shortness of breath (even with mild exertion), swelling, rapid weight gain;
severe headache, blurred vision, pounding in your neck or ears; or
liver problems--loss of appetite, stomach pain (upper right side), flu-like symptoms, itching, dark urine, jaundice (yellowing of the skin or eyes).
Severe dizziness or fainting may be more likely in older adults.
Common side effects may include:
dizziness, drowsiness, tiredness;
nausea, vomiting;
sudden warmth, skin redness, sweating;
numbness; or
tingly feeling in your scalp.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Labetalol side effects (more detail)
