What happens if I miss a dose?

Take the missed dose as soon as you remember. If your next dose is less than 8 hours away, skip the the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention if you think you have used too much of this medicine.

Symptoms of an labetalol overdose may include uneven heartbeats, shortness of breath, bluish-colored fingernails, dizziness, weakness, fainting, or seizure (convulsions).

What should I avoid while taking labetalol?

Labetalol can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert. Avoid drinking alcohol, which could increase drowsiness and dizziness while you are taking labetalol.

What are the possible side effects of labetalol?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Call your doctor at once if you have any of these serious side effects:

• slow or uneven heartbeats;

• feeling light-headed, fainting;

• feeling short of breath, even with mild exertion;

• swelling of your ankles or feet;

• nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);

• depression; or

• cold feeling in your hands and feet.

Other less serious side effects are more likely to occur, such as:

• decreased sex drive, impotence, or difficulty having an orgasm;

• sleep problems (insomnia);

• tired feeling; or

• anxiety, nervousness.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

What other drugs will affect labetalol?

Before taking labetalol, tell your doctor if you are using:

• allergy treatments (or if you are undergoing allergy skin-testing);

• clonidine (Catapres);

• guanabenz (Wytensin);

• an MAO inhibitor such as isocarboxazid (Marplan), tranylcypromine (Parnate), phenelzine (Nardil), or selegiline (Eldepryl, Emsam);

• a diabetes medication such as insulin, glyburide (Diabeta, Micronase, Glynase), glipizide (Glucotrol), chlorpropamide (Diabinese), or metformin (Glucophage);

• a heart medication such as nifedipine (Procardia, Adalat), reserpine (Serpasil), verapamil (Calan, Verelan, Isoptin), diltiazem (Cartia, Cardizem);

• medicine for asthma or other breathing disorders, such as albuterol (Ventolin, Proventil), bitolterol (Tornalate), metaproterenol (Alupent), pirbuterol (Maxair), terbutaline (Brethaire, Brethine, Bricanyl), and theophylline (Theo-Dur, Theolair); or

• cold medicines, stimulant medicines, or diet pills.

If you are using any of these drugs, you may not be able to take labetalol, or you may need dosage adjustments or special tests during treatment.

There may be other drugs not listed that can affect labetalol. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Where can I get more information?

• Your pharmacist has additional information about labetalol written for health professionals that you may read.