Stop the infusion and notify the provider immediately for IV-site blanching, coolness, or pain (extravasation).
Before you read
Test yourself first: 5 questions
Question 1 of 5
A client with Parkinson disease is prescribed carbidopa-levodopa. The nurse teaches the client that the carbidopa component primarily serves what purpose?
Answer: B. Carbidopa is a peripheral decarboxylase inhibitor. It prevents the breakdown of levodopa in the peripheral tissues, allowing more levodopa to cross the blood-brain barrier and reducing peripheral side effects such as nausea. It does not directly stimulate dopamine receptors, replace acetylcholine, or block dopamine.
Question 2 of 5
A client receiving IV dopamine at a moderate dose for hypotension should be monitored for which therapeutic effect?
Answer: B. At moderate (beta-adrenergic) doses, dopamine increases myocardial contractility and heart rate, raising cardiac output and blood pressure. The nurse expects an increase in blood pressure as the therapeutic effect. Dopamine does not decrease heart rate, and it is used to raise (not lower) blood pressure and support perfusion; it is also a vesicant requiring careful IV site monitoring.
Question 3 of 5
A client taking an antipsychotic develops extrapyramidal symptoms of pill-rolling tremor, masklike face, shuffling gait, and bradykinesia. Which adverse effect should the nurse document?
Answer: B. Drug-induced parkinsonism (pseudoparkinsonism) presents with the classic parkinsonian triad: resting (pill-rolling) tremor, rigidity, masklike facies, and bradykinesia with a shuffling gait. It results from dopamine blockade and is often managed with anticholinergics or dose adjustment.
Question 4 of 5
A dopamine infusion is ordered at 5 mcg/kg/min for a 70 kg patient. The bag contains 400 mg in 250 mL. What pump rate in mL/hr is correct? (Round to the nearest whole number.)
Answer: B. Dose per minute = 5 x 70 = 350 mcg/min, which is 21,000 mcg/hr or 21 mg/hr. Concentration = 400 mg / 250 mL = 1.6 mg/mL. Rate = 21 / 1.6 = 13.1, which rounds to 13 mL/hr. The other values come from unit-conversion errors.
Question 5 of 5
A client with moderate-to-severe Alzheimer disease is started on memantine. The nurse understands this drug works by which mechanism?
Answer: A. Memantine is an N-methyl-D-aspartate (NMDA) receptor antagonist that modulates glutamate activity, which is thought to protect neurons from excitotoxicity. It is not a cholinesterase inhibitor, a dopamine agonist, or a benzodiazepine.
Keep the streak going with more questions like these, each with a full rationale.
What is dopamine?
Its effects are dose-dependent: low doses can increase renal perfusion, moderate doses increase cardiac contractility, and high doses cause vasoconstriction to raise blood pressure. It is a high-alert medication given by infusion pump, often through a central line.
Key points to remember
- Effects are dose-dependent: higher infusion rates produce alpha-mediated vasoconstriction and increased blood pressure.
- Always administered as a titrated IV infusion via pump, ideally through a central venous catheter.
- Increases heart rate, contractility, and myocardial oxygen demand, which can provoke dysrhythmias and angina.
- Extravasation causes severe tissue necrosis; phentolamine is the antidote injected into the affected site.
- Correct hypovolemia with fluids before or alongside dopamine for shock.
- Incompatible with sodium bicarbonate and other alkaline solutions, which inactivate the drug.
Nursing priorities
- Monitor blood pressure, heart rate, ECG, and urine output continuously and titrate to ordered targets.
- Inspect the IV site frequently for blanching, coolness, or pain indicating infiltration; stop the infusion immediately if extravasation occurs.
- Use a central line when possible and an infusion pump for all rates.
- Taper the infusion gradually rather than abruptly stopping to avoid rebound hypotension.
- Keep phentolamine available for extravasation management.
Red flags: report now
- Stop the infusion and notify the provider immediately for IV-site blanching, coolness, or pain (extravasation).
- Report new dysrhythmias, tachycardia, chest pain, or sudden severe hypertension.
- Never give through tubing flushed with sodium bicarbonate or mix with alkaline solutions.
- Decreasing urine output despite adequate pressure should be reported.
References
Clinical references for this topic
