Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Sectral (Acebutolol). If you are concerned about side effects, discuss the risks and benefits of Sectral (Acebutolol) with your doctor.

The following side effects have been reported by at least 1% of people taking Sectral (Acebutolol). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• dizziness
• drowsiness (slight)
• dry eyes
• nausea
• skin rash
• unusual tiredness or weakness

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• breathing difficulty or wheezing
• dizziness upon rising (orthostatic hypotension)
• increased sensitivity to allergens
• signs of heart problems (e.g., fast, irregular heartbeat or pulse, chest pain, sudden weight gain, difficulty breathing, leg swelling)
• signs of liver problems (e.g., nausea, vomiting, Diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• signs of pneumonia (e.g., Fever, chills, shortness of breath, cough)
• symptoms of Lupus (e.g., joint, muscle or chest pain, shortness of breath, difficulty breathing)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Sectral (Acebutolol).

Sectral®

100 mg
Each white-to-off-white, shield-shaped, film-coated tablet, scored on one side with "SECTRAL" above the score line and "100" below it, with "rPr" in a heart on the other side, contains 100 mg of Sectral (Acebutolol). Nonmedicinal ingredients: cellulose, colloidal silicon dioxide, croscarmellose sodium, D&C Yellow No. 10 Aluminum Lake, dicalcium phosphate, magnesium stearate, Opadry II White Y-22-7719, polyethylene glycol, povidone, and talc. Sectral (Acebutolol) does not contain gluten, lactose, or tartrazine.

200 mg
Each blue, shield-shaped, film-coated tablet, scored on one side with "SECTRAL" above the score line and "200" below it, with "rPr" in a heart on the other side, contains 200 mg of Sectral (Acebutolol). Nonmedicinal ingredients: cellulose, colloidal silicon dioxide, croscarmellose sodium, dicalcium phosphate, FD&C Blue No. 1 Aluminum Lake, magnesium stearate, Opadry II White Y-22-7719, polyethylene glycol, povidone, and talc. Sectral (Acebutolol) does not contain gluten, lactose, or tartrazine.

Do not take Sectral (Acebutolol) if you:

• are allergic to Sectral (Acebutolol) or any ingredients of the medication
• are in cardiogenic shock
• are scheduled for anesthesia with an agent that causes myocardial Depression (e.g., ether)
• have a severely slow heart rate
• have Congestive Heart Failure
• have an irregular heart rhythm called sick sinus syndromehave pheochromocytoma
• have right ventricular failure due to pulmonary hypertension (excessive blood pressure in the lungs)
• have serious heart block (second- and third-degree AV block)
• have severe circulation disorders of the extremities (i.e., legs, hands)

There may be an interaction between Sectral (Acebutolol) and any of the following:

• acetylcholinergic agonists (e.g., acetylcholine, methacholine, Pilocarpine)
• Aldesleukin
• Aliskiren
• alpha agonists (e.g., brimonidine, Clonidine, methyldopa)
• alpha/beta agonists (e.g., Epinephrine, norepinephrine)
• alpha blockers (e.g., Alfuzosin, Doxazosin, Tamsulosin)
• Alzheimer's medications (e.g., Donepezil, Galantamine, Rivastigmine)
• Amiodarone
• amphetamines (e.g., Dextroamphetamine, Lisdexamfetamine)
• angiotensin-converting enzyme inhibitors (ACEIs; Captopril, Enalapril, Ramipril)
• angiotensin receptor blockers (ARBs; e.g., candasartan, Irbesartan, Losartan)
• anti-psychotics (e.g., Chlorpromazine, Clozapine, Haloperidol, Olanzapine, Quetiapine, Risperidone)
• barbiturates (e.g., butalbital, pentobarbital, Phenobarbital)
• other beta-adrenergic blockers (e.g., Atenolol, Propranolol, Sotalol)
• beta2-agonists (e.g., salbutamol, formoterol, terbutaline)
• brimonidine
• Bromocriptine
• Cabergoline
• calcium channel blockers (e.g., Amlodipine, Diltiazem, Nifedipine, Verapamil)
• Ceritinib
• chloroquine
• diabetes medications (e.g., glipizide, Glyburide, insulin, Metformin, Rosiglitazone)
• diazoxide
• Digoxin
• Dipyridamole
• Disopyramide
• diuretics (water pills; e.g., Furosemide, Hydrochlorothiazide, triamterene)
• Dronedarone
• Duloxetine
• Entacapone
• ephedrine
• ergot alkaloids (e.g., Dihydroergotamine, ergonovine, ergotamine, methylergonovine)
• Fentanyl
• Fingolimod
• grass pollen allergen extract
• hydroxychloroquine
• levodopa
• lidocaine
• Methylphenidate
• monoamine oxidase inhibitors (M.O.S. e.g., Moclobemide, Phenelzine, Rasagiline, Selegiline, Tranylcypromine)
• nitrates (e.g., isosorbide dinitrate,  isosorbide mononitrate, nitroglycerine)
• nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., Ibuprofen, Ketorolac, Naproxen)
• Octreotide
• Pentoxifylline
• phenylephrine
• phosphodiesterase 5 inhibitors (e.g., Sildenafil, Tadalafil, Vardenafil)
• Primaquine
• Pseudoephedrine
• quinine
• reserpine
• rifabutin
• rifampin
• Rituximab
• theophyllines (e.g., Aminophylline, Oxtriphylline, Theophylline)
• Tizanidine
• tolcapone
• Yohimbine

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Sectral (Acebutolol). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Sectral (Acebutolol).

Allergic Reactions: Sectral (Acebutolol), like other beta-blockers, increase sensitivity to allergens. It may also make treating severe allergic reactions more difficult.

Asthma and other breathing problems: Sectral (Acebutolol) and other beta-blockers may cause symptoms of asthma to worsen. Low doses of Sectral (Acebutolol) may be used with caution by people with asthma who do not respond to or who cannot tolerate other treatment.

Heart failure: Sectral (Acebutolol) may make the symptoms of congestive heart failure worse, by slowing down the heart rate and heartbeat strength. If you have congestive heart failure, discuss with your doctor how Sectral (Acebutolol) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Sectral (Acebutolol), and whether any special monitoring is needed.

Kidney function: Kidney Disease or reduced kidney function may cause Sectral (Acebutolol) to build up in the body, causing side effects. If you have reduced kidney function or kidney disease, discuss with your doctor how Sectral (Acebutolol) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Sectral (Acebutolol), and whether any special monitoring is needed.

Low blood sugar: The signs of low blood sugar may not be as noticeable to people taking Sectral (Acebutolol). People with Diabetes who take insulin or other medications that work by reducing the blood sugar should be cautious and monitor blood sugar carefully while taking Sectral (Acebutolol).

Stopping the medication abruptly: Sectral (Acebutolol) should not be stopped suddenly by people who take it to treat angina. There have been reports of severe worsening of angina and of Heart Attack or abnormal heart rhythms occurring for people with angina pectoris who have done this.

Surgery: If you are scheduled for surgery, inform all doctors involved in your care that you are taking Sectral (Acebutolol).

Systemic lupus erythematosus: Sectral (Acebutolol) can worsen or activate the symptoms of lupus. If you experience swollen and painful joints, fever, fatigue, or rash on the nose and cheeks while taking Sectral (Acebutolol), contact your doctor.

Thyroid disorders: Sectral (Acebutolol) may mask the signs of Hyperthyroidism (overactive thyroid). If the medication is stopped suddenly, the symptoms of hyperthyroidism may become much worse.

Pregnancy: There has been no experience with the use of Sectral (Acebutolol) by pregnant women. Sectral (Acebutolol) should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Sectral (Acebutolol), contact your doctor immediately.

Breast-feeding: Sectral (Acebutolol) passes into breast milk. If you are a breast-feeding mother and are taking Sectral (Acebutolol), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Sectral (Acebutolol) have not been established for children.

Seniors: Seniors may be more likely to experience side effects of Sectral (Acebutolol), because of reduced kidney or liver function. Your doctor may prescribe a lower dose of Sectral (Acebutolol).