Dosing and uses of Tenormin (atenolol)
Adult dosage forms and strengths
tablet
- 25mg
- 50mg
- 100mg
Hypertension
25-50 mg/day PO initially; may be increased to 100 mg/day PO
Angina Pectoris
50 mg/day PO; after 1 week, may be increased to 100 mg/day PO; some patients may require 200 mg/day
Post Myocardial Infarction
Secondary prevention
100 mg PO once daily or divided q12hr for 6-9 days after myocardial infarction (MI)
Alcohol Withdrawal Syndrome (Off-label)
50-100 mg/day PO
Supraventricular Arrhythmias (Off-label)
Prevention
50 mg/day PO, beginning up to 3 days before surgery and continued until 7 days after surgery; may be increased to 100 mg/day
Thyrotoxicosis (Off-label)
25-100 mg PO once daily or divided q12hr
Dosing Modifications
CrCl 15-35 mL/min/1.73 m²: Not to exceed 50 mg/day PO
CrCl <15 mL/min/1.73 m²: Not to exceed 25 mg/day PO
CrCl >35 mL/min/1.73 m²: Dose adjustment not necessary
Pediatric dosage forms and strengths
tablet
- 25mg
- 50mg
- 100mg
Hypertension (Off-label)
0.5-1 mg/kg/day PO; not to exceed 2 mg/kg/day or 100 mg/day
Geriatric dosage forms and strengths
May be necessary to initiate dosing at 25 mg/day PO
Hypertension
25 mg/day PO initially; may be increased to 100 mg/day PO
Angina Pectoris
25 mg/day PO; after 1 week, may be increased to 100 mg/day; some patients may require 200 mg/day
Post Myocardial Infarction
Secondary prevention
100 mg PO once daily or divided q12hr for 6-9 days after MI
Tenormin (atenolol) adverse (side) effects
>10%
Tiredness (13%)
1-10%
Hypotension (10%)
Bradycardia (8%)
Cold extremities (0.5- 7%)
Postural hypotension (2-4%)
Depression (3%)
Nausea (2-3%)
Dreaming (2%)
Drowsiness (2%)
Diarrhea (1-2%)
Fatigue (1-2%)
Leg pain (1-2%)
Lethargy (1-2%)
Lightheadedness (1-2%)
Vertigo (1-2%)
Dyspnea (0.4-2%)
2°/3° atrioventricular (AV) block (1%)
Frequency not defined
Hypotension, severe congestive heart failure (CHF), sick sinus syndrome
Catatonia, disorientation, emotional lability, hallucinations, headache, impaired performance on neuropsychometric tests, psychoses, short-term memory impairment
Purpura, rashes
Nausea
Thrombocytopenia
Elevated serum hepatic enzymes and bilirubin
Impotence, Peyronie disease
Antinuclear antibodies (ANA), lupus syndrome
Visual disturbances, xerophthalmia
Raynaud phenomenon
Warnings
Black box warnings
Ischemic heart disease may be exacerbated after abrupt withdrawaL
Hypersensitivity to catecholamines has been observed during withdrawaL
Exacerbation of angina and, in some cases, MI may occur after abrupt discontinuance
When long-term beta blocker therapy (particularly with ischemic heart disease) is discontinued, dosage should be gradually reduced over 1-2 weeks with careful monitoring
If angina worsens markedly or acute coronary insufficiency develops, beta-blocker administration should be promptly reinitiated, at least temporarily (in addition to other measures appropriate for unstable angina)
Patients should be warned against interruption or discontinuance of beta-blocker therapy without physician advice
Because coronary artery disease (CAD) is common and may be unrecognized, beta-blocker therapy must be discontinued slowly, even in patients treated only for hypertension
Contraindications
2°/3° heart block in patients without pacemaker
Cardiogenic shock
Sinus bradycardia
Sinus node dysfunction
Hypersensitivity
Uncompensated cardiac failure
Pulmonary edema
Cautions
Use with caution in anesthesia or surgery (myocardial depression), bronchospastic disease, cerebrovascular insufficiency, diabetes mellitus, hyperthyroidism or thyrotoxicosis, liver disease, renal impairment, peripheral vascular disease, compromised left ventricular function, advanced age, heart failure
May mask effects of hyperthyroidism
Risk of hypoglycemia and bradycardia in neonates born to mothers who receive the drug at parturition or while breastfeeding, especially in premature infants and those with renal impairment
Use with caution in patients taking calcium-channel blockers or cardiac glycosides or using inhaled anesthetics
Avoid abrupt withdrawal; sudden discontinuance can exacerbate angina and lead to MI
Increased risk of stroke after surgery
In patients receiving clonidine, atenolol should be discontinued several days before withdrawal of clonidine
May cause or exacerbate CNS depression (use with caution in patients with psychiatric illness)
Use in pheochromocytoma (alpha blockade required before use of beta blocker)
Consider preexisting conditions such as sick sinus syndrome before initiating therapy
May potentiate hypoglycemia and may mask its signs and symptoms in patients with diabetes mellitus; use caution
Monitor for worsening of heart failure symptoms in patients with compensated heart failure
Use caution in patients with myasthenia gravis; may precipitate or aggravate symptoms or arterial insufficiency in patients with Raynaut's disease and peripheral vascular disease; use caution and monitor for progression of arterial obstruction
Avoid beta-blockers without alpha1-adrenergic receptor blocking activity in patients with Prinzmetal variant angina; unopposed alpha1-adrenergic receptors mediate coronary vasoconstriction and can worsen anginal symptoms
Exacerbation or induction of psoriasis reported with beta-blocker use; cause and effect not established
Pregnancy and lactation
Pregnancy category: d
Lactation: Drug enters breast milk; neonates born to mothers who are receiving atenolol at parturition or breastfeeding may be at risk for hypoglycemia and bradycardia; use with caution
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Tenormin (atenolol)
Mechanism of action
Blocks response to beta-adrenergic stimulation; cardioselective for beta1 receptors at low doses, with little or no effect on beta2 receptors
Absorption
Bioavailability: 46-60%
Onset: Antihypertensive response, 3 hr
Duration: 12-24 hr (normal renal function)
Peak plasma time: 2-4 hr
Distribution
Protein bound: 6-16%
Vd: 50-75 L/kg
Metabolism
Metabolized to limited extent in liver
Metabolites: No clinically active metabolites
Elimination
Half-life: Children, 4.6 hr; adults, 6-7 hr; neonates, <35 hr; end-stage renal disease, 15-35 hr
Dialyzable: Yes (HD)
Excretion: Feces (50%), urine (40-50%)
Administration
IV Incompatibilities
Y-site: Amphotericin B cholesteryl sulfate
IV Compatibilities
Y-site: Meperidine, meropenem, morphine sulfate
IV Administration
Administer by slow IV infusion at 1 mg/min, either directly undiluted or diluted with D5W or Ns
Storage
Store intact ampoules at room temperature
Protect from light
Admixture in dextrose and NaCl-containing solution is stable for 48 hours
