Common Med-Surg Medications: What New Nurses Need to Know Before Giving Them

Updated: September 2026

When you’re new to med-surg, a medication pass can feel like a string of questions. What’s this one for? Do I need to check a lab first? Their blood pressure is lower than it was this morning; is it still appropriate to give this? You may recognize a medication from nursing school and still need help figuring out what it means for the patient in front of you. That’s a normal part of learning to be a nurse.

Let’s walk through common med-surg medications, why your patients might be taking them, and what to watch for before and after administration. I’ll share practical tips to help you connect what you learned in pharmacology to what you’re actually doing at the bedside.

You don’t need to memorize every medication before your first shift. You do need to build the habit of knowing why you’re giving it, checking whether it’s appropriate for your patient right now, and knowing when to pause and ask for help. Use this guide as a starting point alongside your facility’s medication resources, orders, and policies.

Common Med-Surg Medications You’ll Encounter

Let’s start with the medication groups you’ll see on a med-surg unit and the nursing considerations that go with them. Your patients’ diagnoses and your unit’s specialty will influence which ones you give most often.

Analgesics: Medications for Pain

You’ll give pain medication frequently on med-surg, especially when caring for patients after surgery. Before you pull a PRN medication, assess the pain, check what the patient has already received, and review the order. What helped earlier? Did it make them unusually sleepy? Has the pain changed?

Here are a few common examples.

Acetaminophen (Tylenol)

Acetaminophen treats mild to moderate pain and reduces fever. You may also see it abbreviated as APAP.

Big safety point: Acetaminophen can be hiding in combination medications, like oxycodone/acetaminophen (Percocet). Count the total from all acetaminophen-containing medications and routes over the past 24 hours, not just the doses labeled “Tylenol.”

The FDA lists an adult maximum of 4,000 mg in 24 hours, but that is not a target or the appropriate limit for every patient. Follow the product instructions and the patient’s ordered limit, and clarify concerns about liver disease or other factors that could require a lower dose. FDA acetaminophen guidance

Nonsteroidal anti-inflammatory drugs (NSAIDs)

Examples include ibuprofen (Advil) and naproxen (Aleve). These medications help with pain and inflammation.

Before administration, assess kidney function, a history of ulcers or gastrointestinal bleeding, and other medications that increase bleeding risk, such as anticoagulants. Just because a medication is available over the counter doesn’t mean it’s appropriate for every hospitalized patient. (FDA NSAID safety information.)

Opioids

Examples of opioids include morphine and oxycodone. The route depends on the medication and formulation: you may encounter IV morphine and oral oxycodone.

With opioids, your assessment needs to go beyond the pain score. Check respiratory rate and quality, level of alertness, blood pressure, and recent medications that can also cause sedation. Opioids can cause life-threatening respiratory depression, and combining them with other sedating medications increases that risk. (Oxycodone prescribing information.)

If your patient is difficult to wake or breathing slowly or shallowly, don’t give another opioid dose. Stay with the patient and activate your facility’s urgent response process.

After giving pain medication, circle back. Reassess pain and function, along with any adverse effects, at an interval appropriate to the medication, route, and facility policy. Is your patient comfortable enough to take deep breaths, reposition, or participate in care? That tells you more than a pain score alone.

Anticoagulants: Medications to Prevent or Treat Blood Clots

Anticoagulants are common med-surg medications you’ll give to help prevent blood clots or treat an existing clot. You’ll often hear them called “blood thinners,” although they don’t actually thin the blood—they interfere with the clotting process.

First, know why your patient is receiving one. A dose to prevent a clot in a hospitalized patient may be very different from a dose used to treat a diagnosed DVT or pulmonary embolism.

Heparin

You may give heparin as a subcutaneous injection for clot prevention or as an IV infusion for treatment. The monitoring differs, too. With an IV infusion, follow your facility’s protocol for lab timing and dose adjustments. Intermittent low-dose subcutaneous heparin generally doesn’t require the same coagulation testing used to adjust an infusion, but you still need to monitor for bleeding and changes in platelet count.

Pay attention to a history of heparin-induced thrombocytopenia (HIT). This serious reaction involves a drop in platelets and can actually increase the risk of dangerous clots. Clarify any history of HIT before administration. (Heparin prescribing information.)

Enoxaparin (Lovenox)

Enoxaparin is a low-molecular-weight heparin you’ll commonly give as a subcutaneous injection. It can be ordered for clot prevention or treatment. Before giving it, review the indication, kidney function, platelet count, and signs of bleeding. Reduced kidney function can affect dosing, so clarify concerns with the pharmacist or prescriber. A history of HIT also requires attention with this medication. (Lovenox prescribing information.)

Warfarin

Warfarin is an oral anticoagulant whose dosing is guided by the INR. Check the latest result and the current dose order rather than assuming your patient will receive the same dose every day. The target INR depends on why the patient takes it. Warfarin also has many medication interactions, so changes to the medication list (including new antibiotics) deserve attention. Your pharmacist is a great resource here. (Warfarin prescribing information.)

Direct oral anticoagulants (DOACs)

You’ll also encounter oral medications such as apixaban (Eliquis). You don’t adjust these with routine INR testing the way you do with warfarin. That doesn’t mean there’s nothing to check! Review the indication, prescribed dose, kidney function, interactions, and bleeding concerns. (Eliquis prescribing information.)

For every anticoagulant, keep bleeding on your radar. Watch for bloody urine, black or bloody stools, persistent bleeding, or an unexplained drop in hemoglobin or blood pressure. Significant bleeding or a sudden change in condition needs urgent assessment and escalation. And if your patient has a procedure coming up, verify the anticoagulation plan before administration. Don’t guess about whether to give or hold the dose; clarify the orders. (That is a reasonable question for the provider!)

Antihypertensives: Medications That Lower Blood Pressure

You’ll give blood pressure medications frequently on med-surg. Before administration, check the patient’s current blood pressure, review the trend, and look at any ordered hold parameters. A blood pressure from several hours ago may not reflect what’s happening now, especially if your patient has since received other medications or had a change in condition.

Here are two classes you’ll commonly encounter.

ACE inhibitors

Examples include lisinopril and enalapril. These medications help blood vessels relax, lowering blood pressure.

With lisinopril, pay attention to blood pressure, kidney function, and potassium. It can increase potassium and affect kidney function, so review relevant lab results and clarify concerns before giving it.

Another serious concern is angioedema, which can cause swelling of the lips, tongue, or throat. A history of angioedema related to an ACE inhibitor is a contraindication. New swelling requires immediate assessment and urgent escalation because it can compromise the airway. (Lisinopril prescribing information.)

Quick story: I once cared for a patient who had been prescribed lisinopril. Before giving it, I asked whether he had taken it before. His wife immediately told me his tongue had swollen during a previous reaction and he had nearly died. That reaction wasn’t in the chart, and a recent neurological injury meant he couldn’t recall it himself.

That’s why I like asking, “Have you taken this before? How did you do with it?” If the patient or family reports a previously undocumented reaction, pause administration, notify the team, and make sure the allergy information is updated.

Beta-blockers

Metoprolol is a common example. Beta-blockers can lower both heart rate and blood pressure, so check both before administration.

Review the ordered parameters and assess how the patient is doing. Are they dizzy or lightheaded? Is their heart rate significantly different from earlier? A concerning assessment deserves clarification, even if the number doesn’t cross an ordered hold parameter. Metoprolol prescribing information

What about IV blood pressure medications?

You may also encounter IV antihypertensives, but an elevated reading doesn’t automatically mean your patient needs an IV medication to bring it down quickly.

Recheck an unexpected reading using proper technique, assess the patient, and communicate concerning findings. The treatment plan depends on the clinical situation. A hypertensive emergency involves new or worsening organ damage and generally requires IV treatment with close monitoring. (American Heart Association guidance.)

Bedside tip: When you call about a blood pressure medication, have the current blood pressure, heart rate, recent trend, symptoms, and medication order ready. “Their blood pressure is lower than earlier, they’re newly dizzy, and this medication is due” gives the provider useful information to act on.

After administration, reassess at an interval appropriate to the medication, route, and facility policy. Follow up on symptoms as well as the numbers.

Antibiotics: Medications to Treat Bacterial Infections

You’ll give antibiotics frequently on med-surg for infections such as pneumonia, urinary tract infections, and skin infections. You may also administer them around surgery to help prevent an infection.

Start with a simple question: What infection are we treating or preventing? Knowing the reason helps you connect the medication to your patient’s assessment, lab results, and treatment plan.

Examples you may encounter include:

• Penicillins: Amoxicillin and piperacillin/tazobactam (Zosyn).
• Cephalosporins: Cefazolin (Ancef), ceftriaxone (Rocephin), and cephalexin (Keflex).
• Other antibiotics: Vancomycin and metronidazole (Flagyl).

These medications aren’t interchangeable. The choice depends on factors such as the suspected bacteria, infection site, culture results, allergies, and patient’s condition.

Before giving an antibiotic

Review the allergy history and what actually happened when the patient took the medication. “It made me nauseated” and “My throat swelled up” are very different histories. Document the reported reaction and clarify concerns with the pharmacist or prescriber rather than making assumptions.

If cultures are ordered, coordinate collection before the first antibiotic dose when possible. If collection is delayed, communicate promptly so the team can avoid delaying urgent treatment, particularly when sepsis is suspected. Nurses play an important role in both accurate allergy histories and timely culture collection. (ANA/CDC guidance.)

For IV antibiotics, verify the dilution, infusion rate, line compatibility, and IV site. Don’t assume two antibiotics run over the same amount of time just because their bags look similar. Check your medication resource or ask the pharmacist.

Are IV antibiotics stronger than oral antibiotics?

Not necessarily. IV administration delivers medication directly into the bloodstream, but the appropriate route depends on the drug, infection, and patient’s ability to absorb oral medication. For an appropriate patient, switching to an effective oral antibiotic is part of good treatment. It doesn’t automatically mean they’re receiving something “weaker.” (IDSA guidance.)

What to monitor afterward

Watch for new rashes, hives, swelling, breathing changes, and other signs of a reaction. If a reaction develops during an infusion, stop the infusion and assess the patient; breathing difficulty, throat swelling, or sudden instability requires an immediate emergency response.

Also report new, significant diarrhea. Antibiotic-associated diarrhea can sometimes signal C. difficile infection and deserves assessment. (Ceftriaxone prescribing information.)

Bedside tip: At the beginning of your shift, check antibiotic due times, IV access, and any ordered drug levels. If a dose is delayed or an infusion is interrupted, communicate and document what happened so the next treatment decision is based on accurate information.

Insulin: Medications to Manage Blood Glucose

Insulin is one of the common med-surg medications that requires careful coordination. You’re connecting the glucose result, the medication order, and what’s happening with your patient’s nutrition. Before administration, verify the insulin name, concentration, dose in units, route, and timing. Review the current glucose result and recent insulin doses, and complete any independent double-check required by your facility.

Know what each dose is doing

Your patient may have several insulin orders, each with a different purpose:

• Basal insulin: Provides background coverage. Insulin glargine (Lantus) is one example.
• Prandial, or mealtime, insulin: Covers the carbohydrates a patient eats. Rapid-acting insulin such as lispro (Humalog) may be ordered for this.
• Correction insulin: Addresses an elevated glucose level using the prescribed scale or calculation.

Mealtime and correction doses may use the same insulin, but they serve different purposes. Read each order carefully so you don’t omit or duplicate a dose. (American Diabetes Association hospital guidance.)

Coordinate mealtime insulin with the actual meal

A tray being delivered doesn’t necessarily mean your patient is about to eat. They may be nauseated, need help getting set up, or be leaving for a procedure. Verify that the patient can eat and coordinate administration with the specific insulin order. For example, Humalog’s prescribing information directs administration within 15 minutes before a meal or immediately afterward. Other formulations may have different instructions. (Humalog prescribing information.)

What if the patient is NPO?

Don’t assume “not eating” means “hold all insulin.” Clarify the plan for basal, mealtime, and correction doses.

Patients with type 1 diabetes still need basal insulin when NPO. The dose may need adjustment by the treating team, but omitting basal coverage can put them at risk for diabetic ketoacidosis. Follow the ordered plan and promptly clarify missing or conflicting instructions. (American Diabetes Association hospital guidance.)

Watch for hypoglycemia

New sweating, shakiness, confusion, or unusual drowsiness should prompt a glucose check and assessment. Some patients have few warning symptoms, so scheduled monitoring still matters. If hypoglycemia occurs, follow your facility’s treatment and recheck protocol promptly. A patient who cannot safely swallow needs an alternative to oral treatment; severe symptoms require urgent help.

Bedside tip: If you’ve already given mealtime insulin and your patient suddenly can’t eat, address it right away. Check their glucose, notify the appropriate team members, and follow your facility’s protocol rather than waiting for symptoms.

Diuretics: Medications to Help Remove Excess Fluid

Diuretics help the kidneys remove sodium and water through urine. You’ll encounter them when caring for patients with conditions such as heart failure and fluid overload. Before administration, review the patient’s blood pressure, kidney function, electrolytes, and fluid status. Look at recent urine output, intake and output trends, and daily weights when ordered. Connect those findings to your assessment: Are they short of breath? Do they have edema? Are they dizzy when they stand?

Furosemide (Lasix)

Furosemide is a loop diuretic. Along with increased urine output, it can cause fluid depletion and electrolyte losses, including low potassium and magnesium. Review the relevant lab results and any replacement orders. If something is concerning, clarify the plan rather than assuming a potassium supplement on the medication list means the patient’s potassium is currently normal. (Furosemide prescribing information.)

Spironolactone (Aldactone)

Spironolactone is a potassium-sparing diuretic. It can raise potassium, especially in patients with impaired kidney function or those taking potassium supplements or other medications that increase potassium, such as lisinopril.

That’s why “check the potassium” means more than looking for a low result. Know which direction the medication can push it, and review the patient’s other medications, too. (Spironolactone prescribing information.)

What to monitor afterward

Follow urine output, blood pressure, symptoms, and ordered labs. For a patient being treated for fluid overload, assess whether breathing and edema are improving. Report an unexpectedly poor urine response, new dizziness, hypotension, or concerning lab changes.

Bedside tip: Before giving a diuretic, make a bathroom plan with your patient. Put the urinal and call light within reach, help arrange a bedside commode if appropriate, and explain when to call for assistance. If you’re measuring output, let them know why you need them to save their urine. A little preparation makes things easier for both of you.

Electrolyte Replacements: Potassium and Magnesium

You’ll frequently encounter orders to replace electrolytes on med-surg. Potassium chloride and magnesium sulfate are two examples worth getting familiar with.

Before administration, check the latest lab result, kidney function, urine output, and replacement already given. Make sure you’re acting on the right result; a lab drawn before an earlier replacement dose may not reflect the patient’s current level.

Potassium chloride

Potassium may be ordered orally or by IV infusion. The route and dose depend on the patient’s potassium level, symptoms, ability to take oral medication, and treatment plan.

Potassium must never be given by IV push. IV potassium requires an appropriate infusion solution and controlled administration using an infusion pump. Verify the concentration, ordered rate, type of IV access, and monitoring requirements against your facility’s policy. Concentrated potassium chloride must be diluted before administration. (Potassium chloride prescribing information.)

Assess the IV site during the infusion. If your patient reports burning or pain, check the site promptly rather than assuming it’s something they just have to tolerate. Potassium leaking outside the vein can cause tissue injury. IV potassium safety information

Magnesium sulfate

IV magnesium sulfate may be ordered to replace a low magnesium level. Check the ordered dose, dilution, and infusion rate, along with the patient’s kidney function. Magnesium is cleared by the kidneys, so impaired kidney function increases the risk of accumulation and toxicity. Follow the ordered monitoring plan and promptly report concerning changes such as new weakness, hypotension, or slowed breathing. (Magnesium sulfate prescribing information.)

Know the follow-up plan

Your job isn’t finished when you give the replacement. Check whether repeat labs are ordered and when they should be collected. If your unit uses an electrolyte replacement protocol, confirm that your patient meets its criteria before using it.

Bedside tip: During handoff, be specific about what was replaced, how much the patient actually received, and what’s still pending. “Potassium replacement is ordered” tells the next nurse much less than “The first bag finished, the second is infusing, and the repeat lab is due afterward.”

Antiemetics: Medications for Nausea and Vomiting

Nausea can make it difficult for patients to eat, take oral medications, or participate in care. Antiemetics help relieve it, but take a moment to assess what’s happening before reaching for the PRN. When did the nausea start? Has the patient vomited? Are they also having abdominal pain or distention? What have they already received, and did it help?

Ondansetron (Zofran)

Ondansetron is a common example you may give orally or by IV, depending on the order and formulation. Check the last dose, ordered frequency, and route. For IV administration, verify the administration rate in your medication resource.

One safety consideration is QT prolongation, which can increase the risk of a dangerous heart rhythm. Review known QT concerns, relevant electrolytes, and other medications that prolong the QT interval. Low potassium or magnesium deserves particular attention, especially in a patient who has been vomiting.

Clarify concerns before administration. Ondansetron should be avoided in patients with congenital long QT syndrome, and ECG monitoring is recommended for certain patients at increased risk. (Ondansetron prescribing information.)

Reassess the nausea and the patient

After administration, check whether symptoms improved and whether the patient can tolerate permitted fluids, food, or medications.

Persistent vomiting, worsening abdominal pain, or new distention needs further assessment and communication with the provider. Symptom relief doesn’t establish that the underlying problem has resolved. Ondansetron can mask signs of progressive ileus or gastric distention in some patients after abdominal surgery. Ondansetron safety information

Bedside tip: If your patient is too nauseated to take their morning medications, address that early. Give the ordered antiemetic when appropriate, reassess, and coordinate the remaining medications. If they vomit after taking a medication, don’t automatically repeat the dose; check with the pharmacist or prescriber.

Bowel Medications: Managing Constipation

Bowel medications may not feel like the most urgent part of your med pass, but they deserve an assessment, too. Start by asking when your patient last had a bowel movement, what’s normal for them, and whether they’re having discomfort or difficulty passing stool.

Common examples include:

• Polyethylene glycol (MiraLAX): An osmotic laxative that helps retain water in the stool, making it easier to pass. It’s a powder mixed with liquid for oral administration. (MedlinePlus: Polyethylene glycol.)
• Senna (Senokot): A stimulant laxative that increases bowel activity. It may cause abdominal cramping. (MedlinePlus: Senna.)
• Docusate (Colace): A stool softener that helps make stool easier to pass. It works differently from a stimulant laxative, so don’t assume the two are interchangeable. (MedlinePlus: Stool softeners.)

Before administration, check what’s actually happening

Review recent bowel movements, stool consistency, abdominal symptoms, and what bowel medications the patient has already received. If they’re having loose stools, review the ordered hold parameters and clarify the plan as needed.

New or worsening abdominal pain, significant distention, or vomiting needs further assessment before giving a routine laxative. Don’t assume every patient who hasn’t had a bowel movement simply needs another dose. Symptoms suggesting bowel obstruction require prompt communication with the provider.

If your patient declines, find out why

They may have had several loose stools overnight, be worried about an accident, or not understand why the medication was ordered. That conversation can uncover information you won’t find by simply documenting “refused.” Explain the purpose, respect their decision, and document the refusal and stated reason. Communicate ongoing refusals or unresolved constipation so the team can reassess the plan.

Bedside tip: Make it easier for your patient to tell you what happened. “Have you had a bowel movement today? Was it hard, formed, or loose?” is more useful than “Your bowels doing okay?” Document the response and follow up on whether the ordered regimen is helping.

Putting Your Medication Knowledge Into Practice

You don’t need to memorize every detail about common med-surg medications before your first shift. Start with why your patient is receiving each medication, the key things to check before giving it, and the response you’re looking for. Keep looking things up and asking questions; that’s part of building your nursing judgment.

Medications also give you clues about the bigger picture. As you review your patient’s orders, practice connecting them to the diagnosis, assessment findings, and lab results. Those connections help the plan of care make more sense.

More Resources for Med-Surg Nurses 📚

To further support your journey as a med-surg nurse, check out these helpful blog posts ⬇️

• Med-Surg Nursing: Top Tips for New Nurses
• Responsibilities of Day Shift Med-Surg Nurses vs. Night Shift Med-Surg Nurses
• Med-Surg Report Sheet: The Perfect Med Surg Brain Sheet
• Med-Surg Patients and Procedures: What to Expect and How to Prepare