9.4 High-Alert Medications and Analgesic Safety

The current TCO names analgesic as a drug-agent class. It also names antineoplastic and immunologic agents — classes with less day-to-day primary-care prescribing but high harm when the FNP misses a toxicity. Insulin and anticoagulants are high-alert in every safety framework (ISMP and hospital lists). This section is Implementation safety: how you prescribe pain medicine, what you never stack, and when you pick up the phone to oncology instead of "adjusting" a cycle.

Opioids: principles, not a homemade MME statute

CDC's clinical practice guideline for prescribing opioids (2022 update) is the document to think with. Teach the principles; do not invent a single unpublished milligram-morphine-equivalent number and call it "the CDC cutoff." The 2016 version was widely misread as a hard ceiling. The 2022 language walks that back toward individualized care.

• Nonopioid therapy first for many kinds of chronic noncancer pain: acetaminophen, topical NSAIDs, oral NSAIDs when the gut, kidney, and heart allow, duloxetine or a TCA for some neuropathic and musculoskeletal pain, topical lidocaine, physical therapy, behavioral strategies. Cancer pain, sickle cell, palliative, and acute postoperative pathways are not the same as chronic low-back pain in clinic.
• If an opioid is used, immediate-release before extended-release / long-acting. Do not start a fentanyl patch or ER oxycodone in an opioid-naïve primary-care patient with a sprain.
• Use the lowest effective dose for the shortest duration that treats the pain, then reassess. Acute prescriptions are often a few days, not a month.
• Naloxone belongs in the plan when overdose risk is present: prior overdose, substance-use disorder, benzodiazepine or gabapentinoid co-use, higher opioid doses, household members at risk. Co-prescribe and teach. This is not an accusation; it is a fire extinguisher.
• MME awareness means you can compare regimens and recognize that risk rises as dose rises. It does not mean you fail the item if you cannot recite one unpublished magic number. If a stem asks what to do at a high dose, the answer is reassess benefit and harm, offer naloxone, avoid stacking sedatives, and seek a safer plan — not "double the ER tablet."
• Do not stack opioids with benzodiazepines when you can avoid it. Check the prescription-drug monitoring program. Offer a taper when harm exceeds benefit; tapers are slower than students think.

Vignette. A 46-year-old with chronic mechanical back pain, no red flags, already on ibuprofen at the gut's limit: the next move is not ER morphine. It is a nonopioid stack you have not tried (acetaminophen scheduled if the liver allows, topical NSAID, PT, address sleep and mood), then a short IR opioid only if function still collapses, with a stop date and naloxone if you write the opioid.

Acetaminophen: 4 grams is the adult ceiling, and the bottle lies

For a healthy adult, 4 g/day from all sources is the usual labeled maximum. Many clinicians and some product labels use a lower daily cap (often 3 g) in older adults, chronic alcohol use, active liver disease, and malnutrition. Do not invent a new unpublished number for every comorbidity; do teach "lower than 4 g when the liver is not ordinary."

Hidden acetaminophen is the Implementation trap. Hydrocodone/acetaminophen, oxycodone/acetaminophen, butalbital combinations, many "sinus" and "PM" OTCs, and cough syrups all count. A patient taking two extra-strength OTC tablets four times a day plus a combination opioid has already overshot. Write the total daily acetaminophen on the plan. Acute overdose is a transfer-and-N-acetylcysteine problem, not a "drink milk and recheck AST next month" problem.

NSAIDs: gut, kidney, heart, and the ductus

NSAIDs (ibuprofen, naproxen, high-dose aspirin, ketorolac, many COX-2–selective agents still have some cardiovascular signal) cause dyspepsia and gastrointestinal bleeding, acute kidney injury (especially with ACE inhibitor/ARB + diuretic — the "triple whammy"), sodium retention, heart-failure decompensation, and excess cardiovascular events. Use the lowest dose for the shortest time. Prefer topical NSAIDs for localized osteoarthritis when you can. Avoid NSAIDs in late pregnancy: they can close the fetal ductus arteriosus prematurely. FDA also warns against NSAID use from about 20 weeks because of fetal kidney effects and oligohydramnios. Treat "I am 34 weeks and my back hurts" as acetaminophen and physical measures, not naproxen.

Aspirin: secondary, not casual primary prevention

Secondary prevention after atherosclerotic cardiovascular disease (prior MI, stent, ischemic stroke or TIA in the indicated pathway) is still a reason many adults take low-dose aspirin unless bleeding risk forbids it.

Primary prevention is no longer a default vitamin. Current USPSTF language: initiating low-dose aspirin for primary prevention in adults 60 years and older is a Grade D — do not start. Ages 40–59 with a 10-year CVD risk of 10% or more is Grade C — individualize. Bleeding risk, diabetes, and shared decision-making belong in that conversation (Chapter 8). Do not add aspirin to a 72-year-old wellness visit "for the heart" when there is no atherosclerotic event and no other indication (such as some stent protocols already managed by cardiology).

Insulin and anticoagulants are high-alert even when they are indicated

Insulin errors are wrong vial, wrong pen, meal-time mismatch, and stacked correction doses. Write the type, the number of units, and the meal relationship in plain language. Beers criticizes sliding-scale insulin as the sole regimen in older adults. Hypoglycemia kills faster than a slightly high A1c in a frail patient. Hold or reduce when the patient is not eating; do not "just keep the 20 units" through a gastroenteritis.

Anticoagulants (warfarin, DOACs, heparins) join antiplatelets and NSAIDs as a bleed stack. Know the indication, the kidney for DOAC dose, the INR plan for warfarin (Section 9.2), and when to hold for a procedure — usually with the clinician who owns the indication. Do not start a DOAC on top of full-dose warfarin "to be safer." Do not treat a DOAC bleed with vitamin K as if it were warfarin; reversal is agent-specific and often an emergency-department move.

Antineoplastic class: the FNP does not adjust chemo

Antineoplastic agents are on the current TCO with less primary-care ownership than analgesics or antihypertensives. Your job:

• Recognize toxicity: fever in neutropenia is an emergency, not "viral syndrome and call oncology Monday." Mucositis, uncontrolled vomiting, new dyspnea on bleomycin- or checkpoint-inhibitor lists, chest pain on fluoropyrimidines, and unexplained bruising all leave primary care the same day.
• Support antiemetics already on the oncology plan (ondansetron, olanzapine, dexamethasone, NK1 antagonists as prescribed). You may treat constipation from ondansetron. You do not add a QT-stacking antiemetic on top of three others without looking.
• Infection risk: counsel killed-vaccine timing with oncology; live vaccines are usually deferred; a sick contact plan matters more than a new herb.
• Do not adjust chemotherapy doses, skip days, or substitute a tablet because the patient "felt tired." Call the treating oncologist or send the patient in.

Immunologic drugs in primary care: steroids and DMARDs

Vaccines are Chapter 6.4. Here the immunologic class means systemic corticosteroids and disease-modifying antirheumatic drugs you comanage.

Systemic glucocorticoids cause hyperglycemia, hypertension, mood change, gastritis, osteoporosis, avascular necrosis, infection, and HPA-axis suppression after more than a short course. Write a taper when duration is not a few days. Do not start a second burst every month for "sinus" without a diagnosis. Bone protection and Pneumocystis prophylaxis belong to prolonged high-dose plans — typically specialist-directed; do not invent a primary-care threshold you cannot source.

DMARDs (methotrexate, hydroxychloroquine, sulfasalazine, biologics) need a monitoring concept, not a copied hospital protocol you cannot defend. Methotrexate: regular CBC, liver enzymes, and creatinine, daily folate, no trimethoprim (Section 9.2), no pregnancy, limit alcohol. Hydroxychloroquine: baseline and periodic ophthalmology for retinopathy. Biologics: screen tuberculosis and hepatitis B before start; hold and call rheumatology for fever or a serious infection. You refill when labs are current and the specialist plan is intact. You do not add a live vaccine or start TMP-SMX for "easy UTI" on methotrexate.

Exam trap. An analgesic item that looks like "which pain pill" is often a safety item: hidden acetaminophen, NSAID in late pregnancy, ER opioid in a naïve patient, aspirin for a healthy 70-year-old, or tramadol on an SSRI. Name the harm. Then name the safer next drug.