Before administering digoxin to an adult, the LPN/VN should:

Measure the apical pulse for 1 full minute. Digoxin slows the heart, so the apical pulse is counted for one full minute before each dose; the drug is held and the prescriber notified if the adult rate falls below 60 bpm. Blood pressure, edema, and respiratory rate are not the specific safety check for digoxin.

A patient is receiving warfarin. Which laboratory value guides dosing?

PT/INR. Warfarin is monitored by the PT/INR, with a usual target of 2.0-3.0, and its antidote is vitamin K. The aPTT instead tracks heparin therapy, which is reversed with protamine sulfate.

Which insulin has the longest duration with essentially no peak?

Glargine (Lantus). Glargine is a long-acting basal insulin lasting 24 or more hours with a flat, peakless profile. Lispro is rapid-acting, regular insulin is short-acting, and NPH is intermediate-acting with a defined 4-12 hour peak.

Common Drug Classifications — Free NCLEX-PN Guide 2026

Key Takeaways

Take the apical pulse for 1 full minute before digoxin; hold if adult HR < 60
Warfarin is monitored by PT/INR (2.0-3.0); heparin by aPTT (1.5-2.5× control)
Rinse the mouth after inhaled corticosteroids to prevent oral candidiasis
Assess respiratory rate before opioids; hold if RR < 12 and keep naloxone available
Hold metformin before iodinated contrast to prevent lactic acidosis

Think in Classes, Not Individual Drugs

The NCLEX-PN rarely asks you to recall a single fact about one drug; it asks what you assess or hold before giving a class and which lab or antidote pairs with it. Learning the class suffix and its safety rule covers dozens of drugs at once.

Cardiovascular Medications

Class (suffix)	Examples	Action	Key Nursing Check
ACE inhibitors (-pril)	lisinopril, enalapril	Block angiotensin II	Dry cough, hyperkalemia, first-dose hypotension; hold for angioedema
ARBs (-sartan)	losartan, valsartan	Block angiotensin receptors	Like ACE-I but little cough
Beta blockers (-olol)	metoprolol, atenolol	Lower HR and contractility	Hold if HR < 60 or SBP low; mask hypoglycemia
Calcium channel blockers (-dipine)	amlodipine, diltiazem	Vasodilate	Edema, constipation, monitor BP
Diuretics	furosemide (loop), HCTZ	Increase urine output	Loop wastes K+; monitor electrolytes, I&O, daily weight

Digoxin (cardiac glycoside). Positive inotrope, negative chronotrope. Therapeutic level 0.5-2.0 ng/mL. Take the apical pulse for 1 full minute; hold and notify if adult HR < 60 (infant < 90-100). Early toxicity = anorexia, nausea, visual halos, bradycardia; hypokalemia worsens toxicity, so loop diuretics raise the risk.

Anticoagulant	Monitor	Antidote
Heparin	aPTT (1.5-2.5× control)	Protamine sulfate
Enoxaparin	usually none; anti-Xa if needed	Protamine (partial)
Warfarin	PT/INR 2.0-3.0	Vitamin K; FFP for urgent reversal

Respiratory and Gastrointestinal Medications

Class	Examples	Use	Nursing Point
SABA	albuterol	Acute bronchospasm (rescue)	Rapid onset; may cause tachycardia/tremor
LABA	salmeterol	Maintenance	Never for an acute attack; pair with an ICS in asthma
Inhaled corticosteroid	fluticasone, budesonide	Reduce airway inflammation	Rinse mouth to prevent thrush; not a rescue drug
PPI (-prazole)	omeprazole, pantoprazole	Reduce acid	Give 30-60 min before the first meal
Antacids	calcium carbonate	Neutralize acid	Separate from other drugs by 1-2 hr
Antiemetic	ondansetron	Nausea	Monitor QT prolongation

Endocrine: Insulins

Type	Onset	Peak	Duration	Example
Rapid	10-30 min	30 min-3 hr	3-5 hr	lispro, aspart
Short (regular)	30-60 min	2-4 hr	5-8 hr	Humulin R
Intermediate (NPH)	1-2 hr	4-12 hr	12-18 hr	Humulin N
Long	1-2 hr	none/flat	24+ hr	glargine, detemir

When mixing, draw up clear (regular) before cloudy (NPH) to avoid contaminating the regular vial.
Never mix long-acting glargine/detemir with any other insulin.
Watch for hypoglycemia at the insulin's peak; only regular insulin is given IV.
Oral agents: hold metformin before iodinated contrast (lactic-acidosis risk) and resume after renal function is confirmed; sulfonylureas (glipizide) cause hypoglycemia.

Pain and Central Nervous System Medications

Opioids. Assess respiratory rate before giving and hold if RR < 12; also assess sedation and pain. Constipation is an expected effect requiring a bowel regimen. Keep naloxone (Narcan) available for reversal.

Opioid	Equianalgesic	Note
Morphine	10 mg IV / 30 mg PO	Reference standard
Hydromorphone	1.5 mg IV / 7.5 mg PO	~5× more potent than morphine
Fentanyl	100 mcg IV	Very potent, rapid onset

Non-opioids and their ceilings:

Drug	Maximum	Concern
Acetaminophen	4 g/day adults; 3 g/day elderly/liver disease	Hepatotoxic in overdose; antidote acetylcysteine
Ibuprofen (NSAID)	3.2 g/day	GI bleed, renal injury, fluid retention
Ketorolac (NSAID)	5 days maximum	Strong analgesia, high GI/renal risk

Note the FDA caps acetaminophen at 325 mg per dosage unit in prescription opioid combinations to limit liver injury.

CNS classes:

Class	Examples	Watch For	Antidote/Reversal
Benzodiazepines	lorazepam, diazepam	Respiratory depression, falls	flumazenil
Antiepileptics	phenytoin (level 10-20 mcg/mL), valproic acid, levetiracetam	Drug levels, CBC, gum hyperplasia (phenytoin)	—
SSRIs	sertraline, fluoxetine	2-4 weeks to full effect; serotonin syndrome	—

Classic trap: stopping an SSRI because it "isn't working" after a few days — therapeutic effect takes weeks, and abrupt discontinuation causes withdrawal.

How to Reason Through Classification Items

When a question names an unfamiliar drug, recognize the suffix or class and apply the class rule rather than searching your memory for that exact drug. A name ending in -olol is a beta blocker, so you check the heart rate and remember it can blunt hypoglycemia warning signs; -pril signals an ACE inhibitor, so you watch for a dry cough and hyperkalemia; -statin is a lipid-lowering agent that interacts with grapefruit juice.

Pair each high-alert class with its monitoring value and antidote: heparin with aPTT and protamine, warfarin with INR and vitamin K, opioids with respiratory rate and naloxone, digoxin with the apical pulse and its 0.5-2.0 ng/mL range. When the stem asks what to do before giving a drug, the answer is the assessment that detects the drug's most dangerous effect — pulse for digoxin and beta blockers, respiratory rate for opioids, blood glucose for insulin and sulfonylureas.

This class-based pattern recognition is faster and far more reliable than rote drug-by-drug recall, and it is precisely how experienced nurses keep hundreds of medications safe in daily practice.

NCLEX-PN

7.4 Common Drug Classifications