Endo Hypopituitarism Assess Replace

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name: endo-hypopituitarism-assess-replace
description: Recommends assessing for hypopituitarism and replacing hormone deficits in patients with acromegaly at diagnosis and during follow‑up. Triggered by confirmed elevated IGF‑1, post‑surgical or post‑radiation evaluation, or emergence of symptoms such as fatigue, cold intolerance, or loss of libido.
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# Assess for hypopituitarism and replace hormone deficits

## STEP 1 — Gather Information
Collect clinical symptoms of pituitary deficiency (fatigue, weight change, cold/heat intolerance, hypotension, hypoglycemia, loss of libido, menstrual disturbances, erectile dysfunction) and baseline laboratory tests: morning cortisol or ACTH stimulation test, TSH with free T4, LH/FSH with estradiol (women) or testosterone (men), prolactin, and review prior IGF‑1 and GH levels. Document any history of pituitary surgery, radiation, or tumor size.  
**Action:** Proceed to step 2 to evaluate for hypopituitarism based on symptoms and labs.

## STEP 2 — Rule In / Rule Out
If any suggestive symptom **or** any abnormal baseline pituitary hormone (low cortisol, low TSH with low/normal free T4, low LH/FSH/sex steroids, or inappropriately low prolactin) is present → rule in possible hypopituitarism.  
If no symptoms and all baseline pituitary hormones are normal → rule out clinically significant hypopituitarism at this time.  
**Action:** If ruled in, proceed to step 3 to classify deficient axes; if ruled out, continue routine acromegaly monitoring and reassess if symptoms develop.

## STEP 3 — Classify or Stratify
Classify deficiency by axis: central adrenal (low cortisol with inadequate ACTH response), central hypothyroidism (low/normal TSH with low free T4), central gonadal (low LH/FSH with low sex steroids), and note GH axis (IGF‑1 low despite GH excess is atypical; GH replacement generally contraindicated in active acromegaly). Stratify severity as mild (asymptomatic, lab‑only), moderate (symptomatic but stable), or severe (symptomatic with hemodynamic instability or myxedema).  
**Action:** Document deficient axes and their severity, then proceed to step 4 for replacement decisions.

## STEP 4 — Decide
Initiate physiologic hormone replacement for each deficient axis: glucocorticoid (hydrocortisone) for adrenal insufficiency, levothyroxine for central hypothyroidism, sex steroid (testosterone/estrogen±progestin) for gonadal deficiency; monitor for overtreatment and adjust doses to maintain target levels (e.g., morning cortisol 5‑25 µg/dL, TSH within reference, sex steroids in age‑appropriate range). Avoid GH replacement unless pituitary surgery/radiation has cured acromegaly and IGF‑1 remains low after oncologic control.  
**Action:** Start replacement, schedule follow‑up clinical assessment and labs in 6‑8 weeks, then every 6‑12 months or sooner if symptoms change.

## Clinical Guardrails / Mimics / Pitfalls
Do not initiate glucocorticoids without confirming adrenal insufficiency due to risk of adrenal suppression; avoid over‑replacement of thyroid hormone which can exacerbate cardiomyopathy or atrial fibrillation or bone loss; recognize that central hypothyroidism may present with normal or low TSH, so free T4 must be checked; prolactin elevation from stalk effect often does not require dopamine agonist unless symptomatic; GH replacement is contraindicated in active acromegaly as it may stimulate tumor growth; stress‑dose glucocorticoids are needed during illness or surgery for adrenal‑insufficient patients.

## Concrete Clinical Example
A 48‑year‑old woman with acromegaly undergoes transsphenoidal surgery; postoperative IGF‑1 normalizes. Six months later she reports fatigue, weight gain, and amenorrhea. Labs show morning cortisol 4 µg/dL (low), ACTH 5 pg/mL (low/normal), TSH 0.8 µIU/mL (low‑normal) with free T4 0.6 ng/dL (low), LH 1.2 IU/L, FSH 2.0 IU/L, estradiol <15 pg/mL. Diagnosis: central adrenal insufficiency, central hypothyroidism, and gonadal deficiency. She is started on hydrocortisone 15 mg AM/5 mg PM, levothyroxine 75 µg daily, and transdermal estradiol 50 µg twice weekly with cyclic progesterone. Symptoms improve at 8‑week follow‑up; labs are now within target ranges. She continues routine acromegaly surveillance with annual pituitary hormone review.

**Source:** Acromegaly: An Endocrine Society Clinical Practice Guideline, Endocrine Society, 2014, DOI:10.1210/jc.2014-2700