Atenolol

Beta-blocker; antihypertensive; used to lower high blood pressure.

High blood pressure, Angina, and Heart attack

Tell your doctor or pharmacist if you are taking or if you are planning to take any over-the-counter or prescription medications with atenolol. Doses of one or both drugs may need to be changed or a different drug may need to be prescribed. The following drugs and drug classes may interact with atenolol:

• Drugs that increase the effects:
• alcohol
• antiarrhythmics (eg, quinidine)
• astemizole (Hismanal)
• calcium channel blockers
• chlorpromazine (eg, Thorazine)
• cimetidine (eg, Tagamet)
• contraceptives, oral (eg, Ortho-Novum)
• hydralazine (Apresoline)
• phenothiazines
• terfenadine (Seldane)
• tricyclic antidepressants
• Drugs that may decrease the effects:
• dobutamine (eg, Dobutrex)
• dopamine (eg, Inotropin)
• epinephrine IV (eg, Adrenalin)
• isoproterenol (eg, Isuprel)
• nicotine
• norepinephrine (Levophed)
• nonsteroidal anti-inflammatory drugs (eg, ibuprofen)
• penicillins (eg, ampicillin)
• phenobarbital (eg, Barbita)
• rifampin (eg, Rifadin)
• salicylates (eg, aspirin)
• thyroid hormones (eg, levothyroxine sodium)
• Atenolol increases the effects of the following drugs:
• digoxin (eg, Lanoxin)
• lidocaine (eg, Xylocaine)
• reserpine
• Miscellaneous:
• antipyrine
• calcium channel blockers (eg, verapamil)
• chlorpromazine (eg, Thorazine)
• clonidine (eg, Catapres)
• disopyramide (eg, Norpace)
• guanethidine (eg, Ismelin)
• haloperidol (eg, Haldol)
• hydralazine (eg, Apresoline)
• nondepolarizing neuromuscular blockers (eg, metocurine iodide)
• terbutaline (eg, Brethine)
• theophylline (eg, Theo-Dur)

Every drug can cause side effects, but most people have no, or minor, side effects. Tell your doctor or pharmacist if any of the following occurs:

Digestive Tract: Nausea; vomiting; stomachache; gas; diarrhea; constipation; bloating; heartburn; appetite changes; indigestion; colon problems; enlarged liver.

Nervous System: Depression; anxiety; nervousness; hallucinations; short-term memory loss; behavior changes; disorientation; confusion; fainting; weakness; dizziness; vertigo (feeling of whirling motion); lightheadedness; tiredness; sleeplessness; sleep disturbances; nightmares; decreased concentration; sedation; headache; chills; increased or decreased sensitivity to stimulation; fatigue; twitching/tremor; drowsiness; abnormal, vivid dreams; altered consciousness; dizziness when rising quickly from a sitting or lying position; catatonia; stroke; unstable emotions; mood changes; slurred speech; restlessness; gout.

Circulatory System: Changes in heart rate; chest pain; cold extremities; numbness of hands; palpitations (pounding in the chest); changes in blood pressure; heart failure; abnormal ECG; swelling; heart arrest; irregular heartbeat; swelling of arms and legs; decreased exercise tolerance; pacemaker activation; decreased blood platelets.

Respiratory System: Shortness of breath or difficulty breathing; cough; nasal congestion; wheezing; upper respiratory infection; sinus infection; fluid in the lungs; bronchitis; asthma; bronchospasm; sore throat and throat spasms; dry mouth.

Skin: Rash; hives; swelling; flushing or paleness; abnormal sensations; increased pigmentation; itching and irritation; hair loss; sweating; dry skin; psoriasis; acne.

Muscular System: Aching, painful joints and muscles; back pain; arthritis; limb pain; extremity pain; leg pain; muscle weakness; muscle cramps; limping.

Urinary and Reproductive Tract: Painful urination; inability to urinate; frequent urination; urination difficulties; urinary tract infection; excessive urination at night; kidney inflammation; bladder inflammation; sexual problems; Peyronie's disease (fibrous hardening of the penis); decreased sex drive; impotence.

Senses: Blurred vision; dry, burning or irritated eyes; eye inflammation; visual disturbances; ringing in the ears; ear ache; taste changes; eye pain; double vision; lazy or drooping eyelid; abnormal tearing.

Other: Fever; Raynaud's disease (blood deficiency in fingers, toes, ears, and nose); weight changes; facial swelling; changes in blood sugar levels; infection; abnormal or increased liver tests; low white blood cells; abnormal bleeding or bruising.

Do not use in the following situations:

• allergy to atenolol
• heart disorders

Use with caution in the following situations:

• low magnesium levels
• anesthesia or major surgery
• bronchospastic diseases
• decreased heart rate
• diabetes
• heart failure
• kidney disease
• liver disease
• low blood pressure
• low blood sugar
• low potassium concentrations in blood
• muscle weakness
• overactive thyroid
• vascular diseases
• Wolff-Parkinson-White syndrome

Discontinuing therapy: If discontinued suddenly, atenolol may mask the signs of hyperthyroidism (overactive thyroid). If thyroid patients stop taking this medication too suddenly, symptoms of hyperthyroidism (eg, a rapid pulse) may occur. Sudden discontinuation has also caused worsening of angina (chest pain), heart attacks, irregular heartbeats, and death. Other serious withdrawal symptoms include: Sweating, palpitations (pounding in the chest), headache, and discomfort. Withdraw atenolol slowly over one to two weeks.

Diabetes: Atenolol can mask signs of hypoglycemia (low blood sugar) and alter blood sugar levels. Your doctor may need to alter your dose of diabetic medications while taking atenolol. Atenolol does not promote low blood sugar levels like the other drugs in this category.

Glaucoma: Atenolol may cause a reduction in intraocular pressure. It may interfere with the glaucoma screening test. Withdrawal may lead to a return of increased intraocular pressure.

Allergic reaction: Patients with a history of allergic reaction to various allergens may not respond to the usual doses of epinephrine used to treat the allergic reaction.

Pregnancy: Adequate studies have not been done in pregnant women. Use only if clearly needed and if potential benefits outweigh the possible hazards to the fetus. Problems occurring during delivery include: Slowed breathing and lowered pulse rate, blood sugar, and birth weights in infants whose mothers have been on chronic therapy.

Studies have shown a potential adverse effect on the fetus. Use only if clearly need and if potential benefits outweigh the possible risks.

Breastfeeding: Atenolol appears in breast milk. Discontinue nursing when taking.

Children: Safety and effectiveness have not been established.

Elderly: Higher doses may increase the occurrence of slowed heart rate.

• If a dose is missed, take it as soon as possible. If several hours have passed or if it is nearing time for the next dose, do not double the dose to "catch up" (unless your doctor tells you to). If more than one dose is missed or it is necessary to establish a new dosage schedule, tell your doctor or pharmacist. Use as prescribed.
• Diabetes - May mask signs of low blood sugar or alter blood glucose levels.
• Brand interchange - Do not change from one brand of this drug to another without talking with your pharmacist or doctor. Products manufactured by different companies may not be equally effective.
• Tell your pharmacist or doctor before using other prescription or nonprescription products including nasal decongestants, diet aids, and nonprescription cold preparations.
• Do not discontinue medication suddenly, unless your doctor tells you to. Sudden stopping may worsen angina (chest pain) or cause serious side effects.
• May cause drowsiness, dizziness, lightheadedness, or blurred vision. Use caution while driving or performing other tasks requiring alertness, coordination, and/or physical dexterity.
• Notify your doctor if these symptoms occur: Difficulty breathing, especially on exertion or when lying down; night cough; swelling of the extremities; slow pulse rate; dizziness; lightheadedness; confusion or depression; rash; fever; sore throat; unusual bleeding or bruising; fatigue with exertion; cough; or unusually fast heartbeat.
• Tell your doctor or dentist of your atenolol use before any type of surgery.
• Store at room temperature; avoid excessive heat. Protect from light, moisture, freezing.

Atenolol slows the heart rate, slows conduction of nerve impulses in the heart or other organs, reduces output of the heart at rest and during exercise, and lowers blood pressure.