What is the typical IV dose for morphine when used for chest pain in the ED?

• A. 1–2 mg IV
• B. 4–6 mg IV
• C. 2–4 mg IV; may repeat
• D. 5–8 mg IV

Answer: (C)

The key idea is that IV morphine for chest pain is given in small, titratable doses to relieve pain while allowing rapid reassessment. The typical starting dose is 2–4 mg IV, and you administer it, then reassess the patient’s pain and vitals. If pain remains, you can give additional small doses (often 2 mg) every few minutes until relief is achieved, without pushing a large single dose all at once. This approach minimizes the risk of oversedation, respiratory depression, or hypotension while you obtain adequate analgesia. Higher single doses, such as 4–6 mg or 5–8 mg, are less desirable as starting choices because they raise the likelihood of adverse effects and reduce your ability to titrate to effect. A 1–2 mg initial dose is often insufficient for significant chest pain in many patients, underscoring why the 2–4 mg range with repeat dosing best fits typical practice.