Atenolol: Uses, Indications, Dosages, Precautions, Contraindications, Side Effects & Interactions

Atenolol

(a-ten-oh-lol)
Classification 
Pharmacotherapeutic: Beta1-adrenergic blocker
Clinical: Antihypertensive, antianginal, antiarrhythmic

Apo-Atenol (CAN)

Novo-Atenol (CAN)

Tenormin

CATEGORY AND SCHEDULE

Pregnancy Risk Category: D

Do not confuse:

atenolol/albuterol/Altenol

Tenormin/thiamine/Imuran

General Information

Atenolol is a cardioselective beta blocker. It prevents the heart from beating too fast and is mainly used to treat irregular heart rhythms (arrhythmias) and chest pain (angina). It can also be given after a heart attack to protect the heart from further damage. Atenolol is also used to treat high blood pressure, but it is not usually used to start treatment. Non-cardioselective beta-blockers are less likely to cause breathing difficulties, however, they are usually not given to patients with asthma. It can also slow down the body's response to hypoglycemia, low blood sugar if you have diabetes and take insulin

Atenolol can cause severe reactions such as: Overdose can cause profound bradycardia, hypotension. Abrupt withdrawal can cause diaphoresis, palpitations, headaches, tremors. Can precipitate HF, myocardial infarction, or MI in patients with heart disease; thyroid storm in patients with thyrotoxicosis; Peripheral ischaemia in patients with existing peripheral vascular disease. Hypoglycemia can occur in previously controlled diabetes. Thrombocytopenia (unusual bruising, bleeding) occurs rarely. Antidote: glucagon

Action

Competitively blocks b-adrenergic receptor stimulation within vascular smooth muscle; produces negative chronotropic activity (decreases the discharge rate of the SA node, increases recovery time), slows the conduction of the atrioventricular (AV) node, decreases heart rate, negative inotropic activity, decreases myocardial O2 consumption; also decreases the renin-aldosterone-angiotensin system at high doses, inhibits b2 receptors in the bronchial system at higher doses

Therapeutic Effect

Slows sinus node heart rate, decreasing cardiac output and blood pressure, BP. Decreases myocardial oxygen demand

Availability (Rx)

Tablets: 25 mg, 50 mg, 100 mg

Uses

Mild to moderate hypertension; prophylaxis of angina pectoris; suspected or known MI (IV use), MI prophylaxis

Unlabeled uses: Migraine prophylaxis, supraventricular tachycardia prophylaxis (PSVT), unstable angina, alcohol withdrawal, lithium-induced tremor

Precautions

Major surgery, breastfeeding, diabetes mellitus, renal disease, thyroid disease,

CHF, COPD, asthma, well-compensated heart failure, dialysis, myasthenia gravis, Raynaud’s disease, pulmonary edema

Black Box Warning: Abrupt discontinuation

Make sure to tell your doctor if:

• You have heart problems

• You have a long-term kidney problem

• You have diabetes

• You have a lung disorder such as asthma

or bronchitis

• You have psoriasis

• You are taking other medicines

Indications and Dosages

‣ To Treat Hypertension

PO

• Adults: Initially, 25-50 mg once a day. May increase dose up to 100 mg once a day

• Elderly: Usual initial dose, 25 mg a day

• Children: Initially, 0.5-1 mg/kg/dose given once a day. Range: 0.5-1.5 mg/kg/day. Maximum: 2 mg/kg/day or 100 mg/day

‣ To Treat Angina pectoris

PO

• Adults: Initially, 50 mg once a day. May increase dose up to 200 mg

once a day

• Elderly: Usual initial dose, 25 mg a day. Range same as for adults

‣ To Treat acute MI

PO

• Adults: 100 mg once daily or 50 mg twice daily for 6–9 days post-MI

‣ Dosage in Renal Impairment

• Dosage interval is modified based on creatinine clearance

‣ Dosage in Hepatic Impairment

• No dose adjustment

Pharmacokinetics

Incompletely absorbed from the GI tract. Protein binding: 6%-16%. Minimal liver metabolism. Primarily excreted unchanged in urine. Removed by hemodialysis. Half-life: 6-7 h (increased in impaired renal function)

Implementation

PO route

• Given before meals, at bedtime; tablet may be crushed or swallowed whole; give with food to prevent GI upset; reduced dosage in renal dysfunction; take at same time each day

• Store protected from light, moisture; place in cool environment

Contraindications

Cardiogenic shock, overt heart failure, second- or third-degree heart

block, severe bradycardia

Cautions: Elderly, renal impairment, peripheral vascular disease,

diabetes, thyroid disease, bronchospastic disease, compensated HF, myasthenia

gravis, psychiatric disease, history of anaphylaxis to allergens, concurrent use

with digoxin, verapamil, or diltiaZEM

Interactions

Individual drugs

• Digoxin, diltiazem, hydrALAZINE, methyldopa, prazosin, reserpine, verapamil: increased hypotension, bradycardia

• EPHEDrine, pseudoephedrine: increased hypertension

• DOPamine, insulin, theophylline: decreased effect of each of these drugs

Drug classifications

• Amphetamines: increased hypertension

• Anticholinergics, antihypertensives: cardiac glycosides, increased hypotension, bradycardia

• Antidiabetic agents (oral) MAOIs: decreased effect of each of these drugs

• Sympathomimetics (cough, cold preparations): mutual inhibition

Drug/laboratory tests

• May increase serum ANA titer, serum BUN, creatinine, potassium, uric acid, lipoprotein, triglycerides

Drugs/food

• None known

Herbal

• Hawthorn: increased atenolol effect

• Ephedra (ma huang): decreased atenolol effect ginseng, yohimbe may worsen hypertension

• Garlic: may increase antihypertensive effect

Side effects

• CNS: Depression, disorientation, dizziness, drowsiness, emotional lability, fatigue, fever, lethargy, light-headedness, short-term memory loss, vertigo

• CV: Arrhythmias, including bradycardia and heart block; cardiogenic shock; cold arms and legs; heart failure; mesenteric artery thrombosis; mitral insufficiency;

myocardial reinfarction; orthostatic hypotension; Raynaud’s phenomenon

• EENT: Dry eyes, laryngospasm, pharyngitis

• GI: Diarrhea, ischemic colitis, nausea

• GU: Renal failure

• HEME: Agranulocytosis

• MS: Leg pain

• RESP: Bronchospasm, dyspnea, pulmonary emboli, respiratory distress, wheezing

• SKIN: Erythematous rash

• Other: Allergic reaction

 

Nursing considerations

Baseline assessment

• Assess B/P, apical pulse immediately before drug is administered (if pulse is

60/min or less, or systolic B/P is less than 90 mm Hg, withhold medication,

contact physician). Antianginal: Record onset, quality (sharp, dull, squeezing),

radiation, location, intensity, duration of anginal pain, precipitating factors

(exertion, emotional stress)

• Assess baseline renal/hepatic function tests

Intervention/evaluation

• Monitor B/P for hypotension, pulse for bradycardia, respiration for difficulty in

breathing, EKG. Monitor daily pattern of bowel activity, stool consistency

• Assess for evidence of HF: dyspnea (particularly on exertion or lying down),

nocturnal cough, peripheral edema, distended neck veins

• Monitor I&O (increased weight, decreased urinary output may indicate HF)

• Assess extremities for pulse quality, changes in temperature (may indicate worsening peripheral vascular disease)

• Assist with ambulation if dizziness occurs

Equipment must be available for anaphylaxis

• Monitor hypertension, B/P during beginning treatment, periodically thereafter; pulse q4hr; note rate, rhythm, quality: apical/radial pulse before administration; notify prescriber of any significant changes (pulse ,50 bpm); ECG

• Hypotension: may be caused in hemodialysis

• Hypoglycemia: may be masked in diabetes mellitus

• Check for baselines in renal, liver function tests before therapy begins

• Assess for edema in feet, legs daily; monitor I&O, daily weight; check for jugular vein distention, crackles bilaterally, dyspnea (CHF)

Evaluation

Positive therapeutic result

• Decreased B/P in hypertension (after 1-2 wk)

• Absence of dysrhythmias

• Absence of MI

• Decreased angina/pain

• Increased activity tolerance

Patient/family teaching

• Instruct patient Do not abruptly discontinue medication

• Teach patient how to take pulse and B/P at home; advise when to notify prescriber

• Instruct patient to comply with weight control, dietary adjustments, modified exercise program

• Advise patient to carry/wear emergency ID for products, allergies, conditions being treated; tell patient product controls symptoms but does not

cure

• Teach patient to take product as prescribed, not to double doses, skip doses; take any missed doses as remembered if at least 6 hr until next

dose

• Advise patient that to reduce hypotensive effect, go from lying to standing slowly

• Advise patient that product may mask symptoms of hypoglycemia in diabetic patients

•While patient is being weaned from atenolol, tell him to perform minimal physical

activity to prevent chest pain

• Caution patient to avoid hazardous activities if dizziness, drowsiness is present

• Teach patient to report symptoms of CHF: difficult breathing, especially on exertion or when lying down, night cough, swelling of extremities or bradycardia, dizziness, confusion, depression, fever, unusual bruising/bleeding

• Explain to patient that atenolol may alter serum glucose level and mask hypoglycemia

• Inform to patient that the patient that he may experience fatigue and reduced tolerance to exercise and that he should notify his prescriber if this interferes with his normal lifestyle

• Advise patient to use contraception while taking this product, avoid breastfeeding

• Advise patient to restrict salt, alcohol intake

• Advise patient that therapeutic antihypertensive effect noted in 1–2 wks

Treatment of Overdose:

Lavage, IV atropine for bradycardia, IV theophylline for bronchospasm, digoxin, O2, diuretic for cardiac failure, hemodialysis, IV glucose for hyperglycemia, IV diazepam (or phenytoin) for seizures