A home care nurse administers oral morphine to the patient with cancer pain.
When will the nurse expect the medication to reach peak activity?

Choice A rationale

Myasthenia gravis is an autoimmune neuromuscular disorder characterized by weakness and fatigue of the skeletal muscles. Improvement of ptosis after administration of edrophonium (Tensilon), a short-acting acetylcholinesterase inhibitor, is a diagnostic indicator of myasthenia gravis.

Choice B rationale

Cerebral palsy is a group of permanent movement disorders that appear in early childhood. It is primarily caused by abnormal development or damage to the brain and does not exhibit rapid improvement with edrophonium.

Choice C rationale

Multiple sclerosis is a chronic illness involving the central nervous system, where the immune system attacks the protective sheath (myelin) that covers nerve fibers. It does not respond to edrophonium as myasthenia gravis does.

Choice D rationale

Muscle spasm refers to an involuntary contraction of a muscle that can be sudden and painful. This condition is not typically diagnosed or treated with edrophonium, which is specific for myasthenia gravis. .

Choice A rationale

Unstable angina is characterized by sudden, severe chest pain that occurs at rest or with minimal exertion and is not relieved by nitroglycerin. It represents an imminent risk of myocardial infarction.

Choice B rationale

Ischemic heart disease can cause various types of angina, including stable, unstable, and Prinzmetal’s angina. The term “ischemic” refers to a lack of blood flow to the heart muscle, but this choice is too broad.

Choice C rationale

Stable angina occurs when there is an imbalance between myocardial oxygen supply and demand, typically during physical exertion or emotional stress. It is characterized by predictable chest pain that is relieved by rest or nitroglycerin.

Choice D rationale

Prinzmetal’s angina, also known as variant angina, is caused by a spasm in the coronary arteries, which leads to a temporary reduction in blood flow. It can occur at rest and is not necessarily related to the imbalance of myocardial supply and demand.