1Continue pembrolizumab and restrict sodium because the findings represent transient fluid retention.
2Administer an antidiarrheal and schedule routine follow-up because endocrine effects resolve without treatment.
3Increase pembrolizumab frequency to reverse tumor-related cortisol suppression and improve blood pressure.
4Hold pembrolizumab, obtain urgent endocrine evaluation, and begin prescribed corticosteroid replacement and hemodynamic support.✓ Correct answer
Explanation
Pembrolizumab can cause primary or secondary adrenal insufficiency and immune-mediated hypophysitis. Hypotension, hyponatremia, nausea, fatigue, and very low cortisol require urgent assessment and hormone replacement; hemodynamic instability can represent adrenal crisis. Pembrolizumab is withheld according to severity and can be resumed after clinical improvement when the treatment team determines it is safe. Continuing or intensifying therapy without treating the endocrinopathy is unsafe.
Clinical reasoning Checkpoint inhibition can remove immune tolerance to endocrine tissue. Cortisol deficiency reduces vascular tone and free-water clearance, producing hypotension and hyponatremia.
Decision rule Suspected immune-mediated adrenal insufficiency requires treatment interruption, urgent cortisol and pituitary evaluation, corticosteroid replacement, and stabilization.
Scenario A client receiving pembrolizumab has new profound fatigue, nausea, hypotension, hyponatremia, and a very low morning cortisol concentration.
Immune-mediated adrenal insufficiency — Primary or secondary cortisol deficiency caused by immune checkpoint inhibitor therapy.
Hypophysitis — Inflammation of the pituitary gland that can reduce ACTH and other pituitary hormones.