The last six days

Drug of the Day history

Six days of cards in one scroll — rationale, dosing, monitoring and the pearl. Today's card is IV Acetaminophen.

Saturday, October 24

Electrolyte / antiarrhythmic

🧪Magnesium Sulfate

High alert

The torsades answer, the eclampsia answer, and a reflex check every hour.

Why it works

Stabilizes the myocardial membrane and shortens the QT interval, terminating torsades. In pre-eclampsia it raises the seizure threshold through CNS depression and calcium antagonism.

Quick dosing reference

›Torsades with a pulse: 1–2 g IV over 15 min
›Torsades in arrest: 1–2 g IV push
›Eclampsia: 4–6 g load over 20–30 min, then 1–2 g/hr

IV minutes

What you monitor

•Deep tendon reflexes hourly on infusion
•RR, LOC, and urine output
•Magnesium level and ECG

Watch out

Loss of patellar reflex is the first sign of toxicity. Calcium gluconate is the antidote — know where it is.

Baddie pearl

Reflexes gone, then respirations, then the heart. Check reflexes before you touch the pump.

Friday, October 23

Direct arterial vasodilator

💊Hydralazine

Reliable pressure drop with a reflex tachycardia chaser.

Why it works

Relaxes arteriolar smooth muscle directly, lowering SVR. Because it does not touch the heart, the baroreceptor reflex answers with tachycardia and increased cardiac output — a problem in coronary disease.

Quick dosing reference

›10–20 mg IV q4–6 hrs PRN
›Onset is slower than labetalol — do not restack early
›Obstetric hypertension: 5–10 mg IV q20–40 min

IV 5–20 min · peak 15–30 min · duration 2–6 hrs

What you monitor

•BP q10–15 min after the dose
•HR for reflex tachycardia
•Headache, flushing, and orthostatics

Watch out

The slow onset invites dose stacking. Wait the full 20 minutes before you decide it failed.

Baddie pearl

Avoid in active angina — the reflex tachycardia raises myocardial oxygen demand.

Thursday, October 22

Short-acting insulin

🩸Regular Insulin

Brand: Humulin R

High alert

The only insulin that goes IV — and every dose is an independent double-check.

Why it works

Drives glucose and potassium intracellularly. That potassium shift is exactly why it is part of hyperkalemia treatment, always paired with dextrose unless glucose is already high.

Quick dosing reference

›Hyperkalemia: 10 units IV with 25 g dextrose (D50 1 amp)
›DKA infusion: 0.1 units/kg/hr, titrated per protocol
›Correction scale: per facility protocol, never improvised

IV 10–15 min · peak 30 min · duration 1–2 hrs (IV)

What you monitor

•Glucose q1 hr on infusion, and 30–60 min after hyperkalemia dosing
•Potassium and ECG
•Hypoglycemia symptoms in the sedated patient

Watch out

Hypoglycemia can present as agitation or somnolence in a post-op patient and gets mistaken for emergence delirium.

Baddie pearl

Insulin for hyperkalemia moves potassium — it does not remove it. Something else has to eliminate it.

Wednesday, October 21

Alpha-1 agonist vasopressor

🔺Phenylephrine

Brand: Neo-Synephrine

High alert

Raises pressure and drops heart rate — the tachycardic hypotensive's friend.

Why it works

Pure alpha-1 vasoconstriction raises SVR with no beta activity, so there is no increase in myocardial oxygen demand. The reflex bradycardia from the baroreceptor response is expected, not an error.

Quick dosing reference

›Bolus: 50–200 mcg IV q10–15 min
›Infusion: 0.5–3 mcg/kg/min titrated to MAP
›Standard PACU bolus syringe: 100 mcg/mL

Immediate · duration 5–20 min

What you monitor

•BP q2–5 min during titration
•HR — reflex bradycardia
•IV site for extravasation and blanching

Watch out

It squeezes an empty tank. If the patient is dry or bleeding, volume and source control come first.

Baddie pearl

Hypotensive and tachycardic: phenylephrine. Hypotensive and bradycardic: ephedrine.

Tuesday, October 20

NSAID

🌡️Ketorolac

Brand: Toradol

Opioid-sparing gold — until you check the kidneys and the surgeon's preference.

Why it works

Non-selective COX inhibition drops prostaglandin-mediated inflammatory pain, which is why it works so well for orthopedic and dental post-op pain. Same prostaglandin blockade reduces renal perfusion and platelet aggregation.

Quick dosing reference

›Under 65 yrs: 30 mg IV q6 hrs (max 120 mg/day)
›65+ yrs, under 50 kg, or renal impairment: 15 mg IV q6 hrs (max 60 mg/day)
›Max 5 days total by any route

IV 30 min · peak 1–2 hrs · duration 6 hrs

What you monitor

•Creatinine and urine output
•Surgical site bleeding and drain output
•GI symptoms and hemoglobin

Watch out

Confirm the surgeon approves — many spinal fusion, flap, and bariatric services prohibit it entirely.

Baddie pearl

Scheduled ketorolac plus acetaminophen cuts opioid need dramatically. Ask for it.

Monday, October 19

Corticosteroid

🧊Dexamethasone

Brand: Decadron

The quiet PONV multiplier — and airway swelling insurance.

Why it works

Anti-inflammatory and central antiemetic effect that takes 1–2 hours to peak, so it is given at induction, not in recovery. Also reduces airway edema after difficult intubation or head and neck surgery.

Quick dosing reference

›PONV prophylaxis: 4–8 mg IV at induction
›Airway edema: 4–10 mg IV q6 hrs
›Give over 1–2 min

1–2 hrs · duration up to 72 hrs

What you monitor

•Glucose, especially in diabetics
•Perineal burning if pushed fast in an awake patient
•Wound healing and infection signs on repeat dosing

Watch out

Rapid IV push in an awake patient causes intense perineal itching or burning. Dilute and go slow.

Baddie pearl

Pairs with ondansetron — two different receptors beat one bigger dose.

Educational reference only. Doses shown are typical adult ranges and are not a substitute for your facility protocol, pharmacy, prescriber orders, or clinical judgment. Always verify before administration.

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