Nursing Field Notes / Cardio · Antihypertensive Drug Classes

Beta Blockers 🫀

The "-OLOL" drugs — cardioselective vs nonselective

NG-176 CARDIO ADHD-friendly visual edition

Block beta receptors to slow the heart down and take load off it. Beta-1 lives mostly in the heart; beta-2 lives mostly in the lungs and blood vessels. Cardioselective drugs hit mostly beta-1; nonselective drugs hit both — which is exactly why nonselective agents are dangerous in asthma/COPD.

📄 Simple Nursing original — opens in Drive →

🫀 -OLOL = beta blockerMetoprolol, atenolol, propranolol — slows HR, drops BP, reduces workload.

🫁 Nonselective = lungs at riskPropranolol blocks beta-2 too → bronchospasm risk in asthma/COPD.

🩺 Check HR & BP firstHold and notify per parameters — classic teaching: hold if HR is <60 bpm unless ordered otherwise.

❌ Never stop abruptlyRebound hypertension & tachycardia — taper down instead.

💊

WHAT IT DOES

STEP 1 · THE MECHANISM

One receptor map explains the whole class — where a drug lands decides what it's safe for.

🗺️ Receptor map — beta-1 (heart) vs beta-2 (lungs/vessels)

EXAM TIP Cardioselective beta blockers act mainly on beta-1 receptors in the heart. Nonselective beta blockers hit both beta-1 and beta-2 — including beta-2 receptors in the bronchioles and blood vessels.

🧠 "Cardio-SELECT-ive SELECTS just the heart." Nonselective has no "select" in the name — it hits everything with a beta receptor, heart AND lungs.

🔤 Say the suffix — it tells you the class

-OLOL = beta blocker 🫀
Metoprolol (Lopressor) — cardioselective
Atenolol — cardioselective
Propranolol (Inderal, Inderal LA, Innopran XL) — nonselective
Sotalol (Betapace, Betapace AF) — nonselective, also an antiarrhythmic
Timolol — nonselective; ophthalmic form treats glaucoma

🧠 "A/M come home to the heart" — Atenolol / Metoprolol are the classic cardioselective pair.

⭐ Why we give it — indications

Hypertension
Cardiac arrhythmias — slows conduction
Heart failure (select agents, carefully titrated)
Angina — reduces myocardial O₂ demand
Glaucoma — timolol eye drops reduce intraocular pressure
MI prevention / post-MI

🧠 4 B's from lecture: Bradycardia · BP decrease · Bronchial constriction (nonselective) · Blood sugar masking.

💊 Common generics, trade names & dosing

Generic	Trade	Dose	Route
Propranolol (nonselective)	Inderal, Inderal LA, Innopran XL	80–320 mg/day in 2–4 divided doses	PO, IV, PO-ER
Metoprolol (cardioselective)	Lopressor	25–100 mg/day as a single dose	PO, IV, PO-ER
Sotalol	Betapace, Betapace AF	80 mg twice daily	PO
Timolol	ophthalmic	1 drop of 0.25% in each affected eye, twice daily ~12 hr apart	Ophthalmic

🧠 Metoprolol = give on an empty stomach per label guidance — build that into medication teaching.

⚠️

WATCH FOR

STEP 2 · THE DANGER LIST

Slow heart, low BP, tight airways, and a hidden blood sugar problem — check before you give, not after.

🩺 Hold parameters — check HR & BP before every dose

< 60 bpm or SBP below the ordered cutoff HOLD dose notify provider reassess before next scheduled dose

Always follow the specific prescriber parameters on the order — hold thresholds vary by client and indication. Take HR and BP immediately before giving the dose.

🧠 "No pulse check, no pill." A beta blocker is one of the few meds where skipping the vital-sign check before administration is a med error risk in itself.

🫁 Nonselective + asthma/COPD = danger

Blocking beta-2 receptors in the bronchioles removes bronchodilation and can trigger bronchospasm in a client with a history of asthma or COPD. Never give a nonselective beta blocker (like propranolol) to a client with an asthma history — use a cardioselective agent instead, and even then, use caution.

🧠 "2 for the airway, 1 for the heart." Beta-2 open airways; blocking beta-2 closes them. Cardioselective drugs try to spare that receptor — nonselective ones don't.

🍬 Masks hypoglycemia in diabetics

Normally, low blood sugar triggers a sympathetic response — tachycardia, tremor, sweating. Beta blockers blunt tachycardia and tremor, hiding two of the earliest warning signs. Diaphoresis (sweating) may be the only clue left.

🧠 "Beta blocks the alarm bell, not the fire." The hypoglycemia is still happening — the client just can't feel the usual warning signs. Teach diabetics to check blood glucose rather than rely on symptoms.

❌ Never stop abruptly — rebound crisis

💊 Beta blocker taken daily — receptors adapt, upregulate

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🛑 Abrupt discontinuation — receptors suddenly unopposed

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🚨 Rebound hypertension, tachycardia, angina, MI risk

Always taper the dose down over days to weeks under provider guidance — never stop cold turkey, even if the client "feels fine."

🧠 "Wean, don't wham." Same rebound-crisis warning applies to clonidine — both drugs quiet the sympathetic system, and stopping suddenly lets it come roaring back.

⚠️ Other adverse effects to report

Cold hands/feet, dizziness, lightheadedness
Confusion, depression, unusual fatigue
Rash, fever, sore throat, unusual bleeding/bruising
Slow pulse or difficulty breathing/wheezing

🧠 Teach the client to notify their provider for any of these — several overlap with the hold-parameter red flags.

🗣️

TEACH

STEP 3 · WHAT THE CLIENT NEEDS TO HEAR

Check your own pulse, never quit cold turkey, and know your diabetes symptoms may hide.

✅ Teaching checklist

🩺 Check pulse before each dose — hold and call if below parameters

❌ Never stop abruptly — taper only under provider guidance

🍬 Diabetics: check glucose, don't rely on tremor/tachycardia

🫁 Asthma/COPD history? Flag it before starting a nonselective agent

🧎 Rise slowly — orthostatic hypotension can occur

🧠 "PULSE-TAPER-SUGAR-BREATHE." Four words, four teaching points, in the order they matter most.

💊 Drug interactions to flag

Antidepressants — bradycardia, increased beta-blocker effect
NSAIDs — decreased beta-blocker effect
Diuretics — increased hypotension
Clonidine — paradoxical hypertensive effects if combined/stopped incorrectly
Cimetidine, lidocaine — increased beta-blocker toxicity

🧠 Clonidine + beta blocker is a special case — if both are being stopped, the beta blocker is typically tapered off first to avoid unopposed alpha stimulation and a hypertensive spike.

🆚 Cardioselective vs Nonselective — tell them apart

Feature	Cardioselective	Nonselective
Receptors blocked	Mainly β1 (heart)	β1 AND β2 (heart + lungs/vessels)
Examples	Metoprolol, atenolol	Propranolol, sotalol, timolol
Asthma/COPD	Preferred, still use caution	Avoid — bronchoconstriction risk
Diabetic hypoglycemia masking	Less pronounced	More pronounced
Abrupt stop	Never — rebound risk	Never — rebound risk

🧠 "Select the heart, spare the lungs — until you go nonselective." The suffix -olol tells you the family; the selectivity tells you who's safe to give it to.

⚡

QUICK RECALL

SAY IT OUT LOUD

🫀 -OLOLblocks beta receptors — cardioselective (β1) vs nonselective (β1 + β2)

🫁 Nonselective + asthma= bronchospasm risk — avoid

🩺 Check HR/BP firsthold below parameters, commonly HR <60

❌ Never stop abruptlyrebound HTN & tachycardia — taper only

🎯 Cover & check — 4 rapid-fire questions

Q1: Why is a nonselective beta blocker risky in a client with asthma?

It blocks beta-2 receptors in the bronchioles too, removing bronchodilation and risking bronchospasm. Cardioselective agents mainly spare beta-2.

Q2: What should the nurse do before giving a scheduled beta blocker?

Check apical HR and BP; hold the dose and notify the provider if they're below the ordered parameters (commonly HR under 60 bpm).

Q3: Why should a beta blocker never be stopped abruptly?

The body has adapted to constant beta blockade; sudden withdrawal leaves receptors unopposed, causing rebound hypertension, tachycardia, and increased angina/MI risk. Taper instead.

Q4: A diabetic client on a beta blocker has low blood sugar. What symptom might NOT appear?

Tachycardia and tremor may be masked. Diaphoresis (sweating) may be the only remaining sign, so the client should check blood glucose rather than rely on symptoms.