Pharmacology Essentials — NCLEX-PN

Insulin is a hormone given to lower blood glucose in diabetes, and only regular and rapid-acting insulin may be given IV. Know each type’s peak time, because that is when hypoglycemia is most likely and when the client must have eaten. When mixing, draw up clear (regular) before cloudy (NPH) — “clear before cloudy” — to avoid contaminating the regular vial.

Heparin is an anticoagulant that potentiates antithrombin to prevent new clot formation, used when rapid effect is needed. Monitor aPTT for IV therapy, and keep protamine sulfate available as the antidote; give subcutaneous doses in the abdomen without aspirating or massaging the site. Watch for heparin-induced thrombocytopenia, signaled by a falling platelet count, which requires stopping the drug.

Warfarin is an oral anticoagulant that blocks vitamin K–dependent clotting factors, used for long-term clot prevention. Monitor PT/INR, with a therapeutic INR typically 2–3, and keep vitamin K available as the antidote. Teach the client to keep vitamin-K intake consistent — avoiding sudden swings in leafy greens — since changes shift the INR and the drug interacts with many medications.

Digoxin is a cardiac glycoside that strengthens contraction and slows heart rate in heart failure and atrial fibrillation. Take the apical pulse for a full minute and hold the dose, notifying the provider, if it is below 60; the therapeutic level is a narrow 0.5–2 ng/mL. Watch for toxicity — nausea, visual changes such as yellow or green halos, and arrhythmias — which is worsened by low potassium, so monitor potassium closely.

Acetaminophen is a non-opioid analgesic and antipyretic that relieves pain and fever without the anti-inflammatory or bleeding effects of NSAIDs. The chief danger is hepatotoxicity, so the usual maximum is about 4 g per day — less with liver disease or regular alcohol use — and the overdose antidote is acetylcysteine. Because it is hidden in many combination cold and pain products, teach clients to add up all sources to avoid accidental double-dosing.

Ibuprofen is an NSAID that reduces pain, fever, and inflammation by inhibiting prostaglandins. Give it with food to limit GI upset, and watch for GI bleeding and reduced kidney function, especially in older adults. Avoid it in late pregnancy and in clients with peptic ulcer disease or significant renal impairment.

Morphine is an opioid analgesic for moderate to severe pain that also reduces the work of breathing in some cardiac situations. Its most dangerous effect is respiratory depression, so hold the dose and notify the provider if the respiratory rate is below 12; naloxone is the reversal antidote. Constipation is the most common ongoing side effect, so start a bowel regimen whenever opioids are prescribed.

Naloxone is an opioid antagonist that rapidly reverses respiratory depression and sedation from opioid overdose. Its onset is fast but its duration is short, so monitor for re-sedation because the opioid can outlast the naloxone and require repeat dosing. It is available IV, IM, and subcutaneously, and as an intranasal spray widely distributed for community overdose response.