Exploring Differences Between Common Beta Blockers

March 15, 2021

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BETA BLOCKERS- The differences…
Cardioselectivity for Beta-1: All Beta blockers lose their cardio-selectivity at higher doses.  Avoid beta blockers in patients with asthma, COPD, and peripheral vascular disease and diabetes unless there are compelling indications, such as ischemic heart disease and prevention of second myocardial infarction (MI).

  • Beta-1 selective drugs include: Acebutalol (Sectral®), Atenolol (Tenormin®), Bisoprolol (Zebeta®), Metoprolol (Lopressor® or Toprol-XL®)

ISA (intrinsic sympathomimetic activity) in theory may have advantages in beta blockers in patients with borderline CHF, sinus bradycardia or peripheral vascular disease.  These agents do not appear to be as protective against cardiovascular events as other beta blockers.  They may increase the risk of MI, thus should not be used.

  • Penbutalol (Levatol®) and Pindolol (Visken®) and Acebutalol (Sectral®)  have ISA, causing less resting bradycardia and lipid changes

 
Lipophilic Beta-Blockers:  All Beta Blockers cross the Blood Brain Barrier, but the extent to which they enter the brain depends on the lipophilicity.

  • Propranolol (Inderal®) (least cardio selective BB) and Metoprolol (Lopressor®/Toprol-XL®) are relatively lipophilic. More lipophilic BB cause more CNS side effects such as depression.

Hydrophilic Beta Blockers:

  • Atenolol (Tenormin®) and Nadolol (Corgard®) are more water soluble (weakly lipophilic).  Less likely to cause sedation.

 
Non-Vasodilating beta blockers

  • Propranolol (Inderal®), Metoprolol (Lopressor®, Toprol-XL®), Atenolol (Tenormin®), are associated with insulin resistance, and decreased insulin secretion.

 
Vasodilating beta-blockers:

  • Carvedilol (Coreg®), Nebivolol (Bystolic®), Labetalol (Normodyne®) do not cause hyperglycemia. Are the best choice for a diabetic patient.

 
Mechanism: Beta blockers
Beta-blockers slow heart rate and reduce myocardial contractility. In hypertensive patients, they reduce total peripheral resistance.
Proposed mechanisms include:

  • -stimulation of renin secretion is blocked
  • -cardiac contractility is decreased, thus decreasing cardiac output
  • -central sympathetic output is decreased
  • -decrease in heart rate decreases cardiac output
  • -Beta blocker action may combine all the above mechanisms

 
Indications for beta blockers:

  • Patients with rapid resting heart rate (a-fib, paroxysmal supraventricular tachycardia)
  • Heart failure, post-MI
  • High coronary disease risk
  • Angina
  • Hypertension
  • Prevention of migraine (propranolol).  Documentation of efficacy is less clear for metoprolol, atenolol, and nadolol.

 
Warnings/precautions

  • Caution with diabetics: Diabetes (watch for “masking” of hypoglycemic symptoms)
  • Caution in patients with Raynauds or peripheral vascular disease
  • Caution in COPD/ asthma or bronchospastic disease
  • Caution in depressed patients—avoid lipid soluble BB (propranolol & metoprolol)
  • Caution in hyperlipidemia; increases LDL and decreases HDL

 
Patient Education

  • Report dizziness or hypotension
  • Sedation with lipid soluble beta blockers (propranolol & metoprolol)
  • Avoid rapid withdrawal: taper dose over 14 days.
  • Sexual dysfunctions (impotence & decreased libido)

 
NOTES: Beta Blockers:

  • All beta blockers lower blood pressure to a similar extent, and can be dosed once or twice daily.
  • Cardioselectivity is dose dependent
  • May increase triglycerides
  • Carvedilol (Coreg®), Metoprolol (Toprol-XL®), and Bisoprolol (Zebeta®) are the only beta-blockers with mortality evidence for use in heart failure.  (However, the COMET study showed that carvedilol is the most effective)

 
BETA BLOCKERS— MOST COMMON Non-Selective Beta Blockers
(beta-1 and beta-2 activity – are more likely to cause peripheral vasoconstriction, bronchoconstriction, delayed recovery from hypoglycemia in Type-1 diabetes, and impair exercise performance.  Not a good choice for patients with asthma/COPD)

DrugLipophilicityHalf LifeIndicationDoseComments
Nadolol
(Corgard®)
LOWLONGAngina, HTN, A-fib10-240mg/day
Propranolol
(Inderal®)
HIGHShort, but LA formula availableAngina, HTN, tremor, Migraine PxTabs: 10-40mg QID
LA-CAPs: 80-160/day max=320mg
High risk of fatigue.  Low concentrations in breast milk

 
BETA BLOCKERS- MOST COMMON beta-1 selective
(remember beta selectivity is lost at higher doses)

DrugLipophilicityHalf LifeIndicationDose RangeComments
Atenolol (Tenormin®)LOWLONGA-fib for rate control.
HTN: no improvement in mortality
25-100mgRenal elimination
Metoprolol tartrate
Immediate release (Lopressor®)
ModerateMediumAngina, hypertension, post MI25-400mg
Metoprolol
Succinate extended release (Toprol-XL®)
ModerateLONG
(once a day)
Heart failure, HTN, angina, a-fib12.5-400mgSuccinate is long acting
Nebivolol
(Bystolic®)
LOWLONGHTN,5-40mgNot indicated for HF in USA

 
BETA-BLOCKERS MOST COMMON alpha-1 antagonist activity
(these cause peripheral vasodilation)

DrugLipophilicityHalf LifeIndicationDose RangeComments
Carvedilol
(Coreg®)
Moderate1st-pass metabolism.
Moderate
Heart Failure, Hypertension,
LVD after MI
3.125mg BID to 25mg BID maximum of 50 mg BIDNOT cardioselective
Labetalol (Trandate®) (Normodyne®)LOWModerateHypertension100mg-400mg BIDNOT cardioselective. Preferred BB in PREGNANCY. Low concentration in breast milk.
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Eighteen beta blockers are listed in Up-To-Date’s website. I find it beneficial to sort them out into the most common ones on the community pharmacist’s shelves.
I remember early on in my career when propranolol (Inderal®) changed from the round orange, blue, green tablets to hexagonal tablets because the manufacturer’s patent expired in July 1985. Now, nebivolol (Bystolic®) is the only branded beta-blocker left on our shelves, and a prior authorization is usually the case if a clinician needs to prescribe it. Over time, beta blockers have proven to be cheap and effective.
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