Nursing Field Notes / Pharmacology · NCLEX Drug Review Series

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NCLEX Drugs 4 💗

Nitrates · ARBs "-sartan" · Cardiac Glycosides (digoxin) · Oral Antidiabetics: Sulfonylureas, Biguanides, Glitazones & Gliptins

NG-186 PHARM · CARDIAC + ENDOCRINE Series: NCLEX Drug Review 4 of 8 ADHD-friendly visual edition

Two halves, one page. The cardiac half is about oxygen supply and demand — nitrates open the pipes, ARBs stop angiotensin II at the receptor, and digoxin makes the pump squeeze harder while beating slower. The diabetes half is four oral classes that lower glucose in four completely different places. If you can name the organ each antidiabetic works on, you can predict its side effect.

📄 Simple Nursing original — opens in Drive →

💥 NitratesVasodilate ⇒ ↓ preload & afterload ⇒ ↓ O₂ demand. Never with a PDE-5 "-afil" drug.

🔒 "-sartan" = ARBBlocks angiotensin II at the receptor. Little to no cough — but still ↑K⁺.

🫀 DigoxinApical pulse 1 full minute. Low K⁺ = high toxicity risk. Antidote: digoxin immune Fab.

🍬 Four oral classesOnly the sulfonylurea reliably causes hypoglycemia on its own.

🗺️

LINEUP

STEP 1 · WHAT'S IN THIS SET

Cora's 3-part study map for every drug on this page: CLASS → ACTION → WATCH.

🧭 This installment covers 7 classes

💥Nitrates

🔒ARBs
"-sartan"

🫀Cardiac Glycosides

🍬Sulfonylureas

🥛Biguanides
metformin

💧Glitazones

🔁Gliptins
DPP-4 inhibitors

🧠 Suffix triage: "-sartan" → ARB. "-gliptin" → DPP-4. "-glitazone" → insulin sensitizer. "-ide" endings (glyburide, glipizide, glimepiride) → sulfonylurea. Nitrates and digoxin have no suffix — memorize them by name.

📇 Brand ↔ generic — the pairs NCLEX actually asks

Class	Brand	Generic
Nitrates	Nitro-Bid, Tridil, Transderm-Nitro, Nitrostat	nitroglycerin
	Imdur	isosorbide mononitrate
	Isordil, Sorbitrate	isosorbide dinitrate
ARBs "-sartan"	Atacand	candesartan
	Cozaar	losartan
	Diovan	valsartan
Cardiac glycoside	Lanoxin	digoxin
Sulfonylureas	Amaryl	glimepiride
	DiaBeta, Glynase, Micronase	glyburide
	Glucotrol, Glucotrol XL	glipizide
Biguanide	Glucophage	metformin
Glitazones	Actos	pioglitazone
Glitazones	Avandia	rosiglitazone
Gliptin (DPP-4)	Januvia	sitagliptin

⚠️ Mono- vs di-. Isosorbide mononitrate (Imdur) is the once-daily long-acting maintenance tablet. Isosorbide dinitrate (Isordil) is dosed more often. Neither is the rescue drug — sublingual nitroglycerin is.

🫀 Where the cardiac half acts — one map

🧠 Angina is an arithmetic problem. Supply (coronary flow) must cover demand (rate × wall tension × contractility). Nitrates lower demand and raise supply at the same time.

⚙️

ACTION — HOW EACH ONE WORKS

STEP 2 · MECHANISM

Four mechanisms to hold: a dilated vein, a blocked receptor, a poisoned sodium pump, and four different glucose levers.

💥 Nitrates — peripheral and coronary vasodilators

Action: relax vascular smooth muscle. Venous dilation predominates at lower doses ⇒ ↓ preload; arterial dilation adds ⇒ ↓ afterload. Both drop myocardial oxygen demand. Coronary arteries dilate, improving supply.

🎯 Used to treat and prevent angina, and to lower blood pressure.
🤕 Headache is the classic expected effect — it usually eases with continued therapy.
📉 Check BP before each dose; hypotension and reflex tachycardia are the limiting effects.

🧠 "Nitro = less work for the heart." Less blood coming back, less pressure to push against.

🚨 The absolute nitrate contraindication

Never give a nitrate to a patient who has taken a PDE-5 inhibitor. That is sildenafil (Viagra), tadalafil (Cialis) or vardenafil (Levitra) — the "-afil" drugs.

Both dilate vessels through the same nitric-oxide pathway. Stacked, they can cause profound, refractory hypotension.

⚠️ Always ask before giving nitroglycerin for chest pain — including in the emergency setting and including for female patients, since PDE-5 drugs have other uses such as pulmonary hypertension.

🩹 Transdermal nitrate — the patch-free interval

Continuous nitrate exposure produces tolerance: the drug stops working. The standard fix is a daily nitrate-free window.

🔄 Rotate patch sites; remove the old patch before applying a new one.
⏱️ Common regimen: wear the patch about 12–14 hours, then leave it off for a 10–12 hour patch-free interval — usually overnight.
🧤 Wear gloves and avoid touching ointment or patch adhesive; wipe the old site.

🧠 "Patch off at night, receptors reset by morning."

🔒 ARBs vs ACE inhibitors — same pathway, two different cut points

🧠 "ACE cuts the supply line; the SARTAN locks the door." Same destination, different tactic — which is exactly why the cough disappears on an ARB but the potassium problem does not.

🫀 Digoxin — inside the heart muscle cell

🧠 "Dig makes it STRONGER and SLOWER." Positive inotrope, negative chronotrope, negative dromotrope — three words, one drug.

🎯 Narrow therapeutic index — the digoxin window

⚠️ A digoxin level in the "therapeutic" band does not rule out toxicity if the potassium is low. Treat the patient and the potassium, not just the number.

🍬 The diabetes half — four classes, four addresses

🧠 "Squeeze, Silence, Sensitize, Signal." Sulfonylureas squeeze insulin out · metformin silences the liver · glitazones sensitize muscle and fat · gliptins boost the gut's signal.

🔬 Inside the beta cell — why a sulfonylurea causes hypoglycemia and a gliptin usually doesn't

🧠 Forced vs amplified. A sulfonylurea pushes insulin out no matter what the glucose is doing. A gliptin only turns up a signal the meal already started.

💉 IV nitroglycerin — the details that get tested

🎛️ Always on an infusion pump, titrated to blood pressure and pain, with continuous monitoring.
🧪 Nitroglycerin adsorbs onto standard PVC tubing, so the manufacturer's supplied or specially designated tubing is used — check the product and facility protocol.
📉 Take a blood pressure before starting and with every titration; hypotension is the dose-limiting effect.

🧠 Tridil is the IV one. Nitrostat is the sublingual tablet, Nitro-Bid the ointment, Transderm-Nitro the patch.

⏱️ Long-acting nitrate vs rescue nitrate

Rescue: sublingual nitroglycerin — fast on, short-lived, taken at the moment of chest pain.

Maintenance: isosorbide mononitrate (Imdur) or dinitrate (Isordil) — taken on a schedule to prevent angina, never to treat an attack in progress.

⚠️ A patient who reaches for Imdur during chest pain has been taught wrong. Rescue therapy is the sublingual tablet or spray.

🔒 Why ACE + ARB together is generally avoided

Both suppress the same pathway. Combining them adds little benefit and stacks the same risks — hyperkalemia, hypotension and renal injury.

🧠 One brake on the RAAS at a time. If you see both on the same MAR, it is worth a clarification call.

✅ Where digoxin actually earns its place

🫀 Heart failure — improves contractility and cardiac output, and can reduce symptoms.
💓 Atrial fibrillation / flutter — slows the ventricular rate by slowing AV conduction.
🧪 Because it is renally cleared and has a narrow window, it needs level checks, potassium checks and pulse checks in a way most cardiac drugs do not.

🧠 Digoxin does not fix the underlying disease — it changes how the heart behaves while the disease is treated.

🚨

WATCH — SAFETY & ADVERSE EFFECTS

STEP 3 · ASSESS

Digoxin toxicity and hypoglycemia are the two emergencies hiding on this page.

🚨 Digoxin toxicity — the classic picture

🧠 "A-B-C-D of dig toxicity": Anorexia first · Bradycardia · Confusion & Colour vision (yellow-green) · Dysrhythmias.

🩺 Before every digoxin dose

💓 Apical pulse for one full minute. Hold and notify if it is below 60/min in an adult (or outside whatever parameters are written).
🧪 Check the most recent K⁺, magnesium and renal function.
🍽️ Ask about appetite, nausea and vision changes — these come before the rhythm changes.

⚠️ Pediatric hold parameters are different and higher — always use the age-appropriate order.

🚨 Metformin and lactic acidosis

Rare, but serious. Suspect it with malaise, myalgia, unusual somnolence, abdominal distress, hyperventilation and unexplained hypotension in a patient on metformin.

🧪 Risk rises with renal impairment, dehydration, hypoxia, sepsis, heart failure and heavy alcohol use.
💉 Iodinated contrast studies: metformin is commonly withheld around the procedure and restarted only after renal function is rechecked. Follow the facility protocol — the exact timing varies.

🧠 "Metformin hates dye and dehydration."

💧 Glitazones and fluid retention

Pioglitazone and rosiglitazone reduce insulin resistance, but they cause renal sodium and fluid retention — which means edema, weight gain, and the risk of precipitating or worsening heart failure.

⚖️ Daily weights; report a rapid gain.
🫁 Report new or worsening dyspnea, orthopnea or ankle swelling.
🧪 Liver enzymes are monitored with this class.

⚠️ Not appropriate for patients with symptomatic heart failure. This is the "-glitazone" question NCLEX loves.

🍬 Hypoglycemia — recognize and treat

The sulfonylureas are the class on this page that most reliably causes it. Metformin, glitazones and gliptins rarely cause it alone, but can when combined with insulin or a sulfonylurea.

😰 Shaky, sweaty, tachycardic, hungry, irritable, confused; late — seizure, unresponsiveness.
🍬 Conscious and able to swallow: give a fast-acting carbohydrate, recheck in about 15 minutes, repeat if still low, then follow with a longer-acting snack or meal.
💉 Unresponsive: nothing by mouth — glucagon or IV dextrose per protocol.

🧠 Older adults on glyburide are the classic prolonged-hypoglycemia patient — long duration plus reduced renal clearance.

⚠️ Gliptin red flag — pancreatitis

Cases of acute pancreatitis have been reported with DPP-4 inhibitors. Teach patients to report severe, persistent abdominal pain that may radiate to the back, with or without vomiting — and to stop the drug and seek care.

🧠 "Januvia + knife-in-the-back pain = stop and call."

📊 Hypoglycemia risk, side by side

Class	Hypoglycemia alone?	Signature adverse effect	Key monitoring
Sulfonylureas glimepiride, glyburide, glipizide	Yes — highest here	Hypoglycemia, weight gain	Glucose; take with the first meal of the day
Biguanide metformin	Not usually	GI upset (most common); lactic acidosis (rare)	Renal function; hold around iodinated contrast per policy
Glitazones pioglitazone, rosiglitazone	Not usually	Edema, weight gain, heart-failure risk	Daily weight, edema, dyspnea, liver enzymes
Gliptins sitagliptin	Not usually	Reports of pancreatitis; joint pain	Abdominal pain, renal function

⚠️ Metformin is generally the first-line oral agent for newly diagnosed type 2 diabetes when there is no contraindication — the source sheet flags this and it is a frequent test point.

📋

TEACH — WHAT THE PATIENT MUST HEAR

STEP 4 · EDUCATE

Sublingual nitroglycerin technique and hypoglycemia self-rescue are the two things that save lives at home.

✅ Sublingual nitroglycerin — the technique to teach

🪑 Sit or lie down first. The drug drops blood pressure; standing invites a fall.
👅 Place one tablet under the tongue and let it dissolve — do not chew or swallow it.
📞 If chest pain is unimproved or worsening about 5 minutes after the first dose, call emergency services, then continue as directed — commonly up to a total of three doses, five minutes apart.
🫙 Store in the original dark container, tightly closed, away from heat, light and moisture. Do not decant into a pill organizer.
📅 Note the expiry and replacement schedule; potency is lost over time.
🍷 Alcohol adds to the hypotension. Rising slowly and avoiding hot showers helps.

⚠️ Follow the prescriber's written instruction for how many doses and when to call — protocols vary, and the "call after the first dose" advice is now standard in many settings.

🤕 Expect the nitrate headache

Throbbing headache and flushing are common and reflect vasodilation. Patients often stop the drug because of it — so teach it in advance.

💊 It usually lessens with continued use.
🗣️ Tell patients to report it rather than skip doses, so the prescriber can adjust.
🌀 Dizziness on standing is expected; sit up slowly.

🔒 ARB teaching — almost ACE, with one difference

🧪 Potassium still rises — avoid potassium-based salt substitutes.
🤰 Contraindicated in pregnancy, like ACE inhibitors.
🗣️ Report swelling of the face, lips or tongue — angiedema is far less common, but not impossible.
🫖 The cough is what is missing: an ARB is the usual switch when an ACE inhibitor causes one.

📋 Digoxin teaching card

💓 Teach the patient (or caregiver) to take their own radial pulse for a full minute before each dose and to hold and call if it is below the number the prescriber set.
🍽️ Report loss of appetite, nausea, vomiting or diarrhea — these usually come first.
👁️ Report blurred or yellow-green vision, halos around lights.
🍌 Ask before starting or stopping a diuretic, potassium supplement or antacid.
⏰ Take it at the same time each day; do not double up on a missed dose without instruction.
📋 Carry an up-to-date medication list — many drugs change digoxin levels.

🧠 "Count, look, eat." Count the pulse, look at the lights, notice the appetite — three home checks that catch toxicity early.

✅ Oral antidiabetic teaching essentials

🍽️ Metformin with food reduces the GI upset; extended-release tablets are swallowed whole.
🌅 Sulfonylureas with the first meal of the day — and never skip that meal after taking one.
🍬 Everyone on a sulfonylurea carries a fast-acting carbohydrate.
🍷 Alcohol lowers glucose and can cause a flushing reaction with some sulfonylureas.
🤒 Sick-day rules: illness, vomiting or poor intake change everything — patients need a written plan.

📊 Pick-the-drug table

If the question mentions…	Think	Because
Chest pain + a "-afil" drug taken today	Hold the nitrate	Severe additive hypotension
Patch worn continuously, drug "stopped working"	Nitrate tolerance	Needs a daily nitrate-free interval
Persistent dry cough on an antihypertensive	Switch to an ARB	Bradykinin is not affected by "-sartan"
Loss of appetite + halos around lights	Digoxin toxicity	GI first, then visual
Digoxin + furosemide, patient weak and nauseated	Check potassium	Hypokalemia potentiates digoxin
Scheduled for a CT with contrast, on Glucophage	Metformin held per policy	Renal risk and lactic acidosis
New weight gain and ankle edema on an oral diabetes drug	Glitazone	Fluid retention, heart-failure risk
Severe abdominal pain radiating to the back on Januvia	Suspect pancreatitis	Reported DPP-4 adverse effect
Skipped breakfast after taking the morning pill, now shaky	Sulfonylurea hypoglycemia	Insulin was released anyway

🤒 Sick-day rules for oral antidiabetics

🧪 Check glucose more often — illness usually pushes it up, even when eating less.
💧 Keep fluids going; dehydration is what turns metformin from safe into risky.
📞 Call for persistent vomiting, inability to keep fluids down, or glucose readings outside the range the prescriber set.
❌ Do not simply stop the medication without instruction — but do report that you are ill.

🧠 "Sick days need a written plan, not a guess."

🧾 The two "always ask" questions on this page

💊 Before nitroglycerin: "Have you taken anything for erectile dysfunction or pulmonary hypertension in the last few days?"
🩻 Before contrast imaging: "Are you taking metformin, and what did the ordering team say about holding it?"

⚠️ Both questions are asked before the drug or the scan, not after. They are the highest-yield safety checks in this installment.

⚡

QUICK RECALL

SAY IT OUT LOUD

💥 NitratesSit down · SL · call for help · never with "-afil" · patch-free interval

🔒 "-sartan"Receptor block · no cough · still ↑K⁺ · not in pregnancy

🫀 DigoxinApical pulse 1 min · anorexia first · halos · low K⁺ = toxic

🍬 OralsSulfonylurea = hypoglycemia · metformin = GI & contrast · glitazone = edema · gliptin = pancreatitis

🎯 Cover & check — 8 rapid-fire questions

Q1: A man with chest pain says he took tadalafil last night. What do you do about the nitroglycerin order?

Do not give it. Nitrates and PDE-5 inhibitors together can cause profound, hard-to-treat hypotension. Notify the prescriber and report the timing of the dose.

Q2: Why is a transdermal nitrate patch removed for part of every day?

To prevent tolerance. A common regimen is wearing it about 12 to 14 hours, then a 10 to 12 hour patch-free interval, usually overnight.

Q3: What is the mechanistic difference between an ACE inhibitor and an ARB?

An ACE inhibitor blocks the enzyme that makes angiotensin II — and also blocks bradykinin breakdown, causing the cough. An ARB blocks angiotensin II at its receptor, leaving bradykinin alone, so there is little to no cough.

Q4: Name digoxin's three "tropic" effects.

Positive inotropic (stronger contraction, better cardiac output), negative chronotropic (slower rate), negative dromotropic (slower AV conduction).

Q5: A patient on digoxin and furosemide reports nausea and seeing yellow-green halos. What is the priority lab?

Serum potassium, along with the digoxin level. The diuretic can cause hypokalemia, which makes digoxin toxic even at a level inside the usual range.

Q6: Which oral antidiabetic on this page is usually first-line for a newly diagnosed type 2 patient?

Metformin, when there is no contraindication such as significant renal impairment.

Q7: Which class causes fluid retention and can worsen heart failure?

The glitazones — pioglitazone and rosiglitazone. Monitor daily weight, edema and dyspnea.

Q8: Why does a sulfonylurea cause hypoglycemia when a gliptin usually doesn't?

A sulfonylurea forces the beta cell to release insulin regardless of the glucose level. A gliptin raises incretin levels, which amplify insulin release mainly when glucose is already high.

🧠 The mnemonics to walk in with

"Nitro + afil = no fill" — never combine nitrates with PDE-5 inhibitors.
"ACE cuts the supply line; the SARTAN locks the door."
"Dig makes it stronger and slower" — and A-B-C-D for its toxicity.
"Squeeze, Silence, Sensitize, Signal" — sulfonylurea, metformin, glitazone, gliptin.

🧠 Close the page and rebuild the seven classes from the four mnemonics alone before you move on to installment 5.