ppgl-pain-management-medication-selection

name	ppgl-pain-management-medication-selection
description	Selects analgesic medications for PPGL pain management while avoiding agents that may provoke hypertensive crisis. Triggers include metastatic PPGL patient requiring pain management, assessing safe analgesic options in PPGL, and managing pain while preventing hypertensive crisis.

Pain Management Medication Selection for PPGL Avoiding Hypertensive Crisis Risk

STEP 1 — Gather Information

Collect patient data: metastatic PPGL status, pain location (bone, spinal, soft tissue), pain severity, current medications, history of hypertensive crisis, catecholamine levels, GI symptoms (constipation, nausea/vomiting, ileus), renal/hepatic function, and comorbidities.
Action: Proceed to assess need for antiemetic or analgesic therapy.

STEP 2 — Rule In / Rule Out

Determine if the patient requires antiemetic therapy for nausea/vomiting.

• If yes → Rule in need for safe antiemetic selection.
• If no → Skip antiemetic selection and proceed to analgesic choice.
  Action: Based on presence of nausea/vomiting, move to antiemetic evaluation or direct analgesic selection.

STEP 3 — Classify or Stratify

Classify pain type (nociceptive vs neuropathic) and GI symptom severity (constipation, ileus).

• For neuropathic pain → consider adjuvant agents (e.g., gabapentin, amitriptyline) with caution for hypertensive risk.
• For constipation/ileus → avoid selective α‑blockers (doxazosin) and metoclopramide/domperidone; prefer prochlorperazine, chlorpromazine, or metyrosine.
• For opioid‑induced nausea → avoid metoclopramide/domperidone; use prochlorperazine or chlorpromazine.
  Action: Select medication class based on pain type and GI profile.

STEP 4 — Decide

Choose specific agent:

• For nausea/vomiting → prochlorperazine 5–10 mg IV/PO q6h PRN or chlorpromazine 10–25 mg IV/PO q6h PRN, monitoring for hypotension.
• For severe constipation → metyrosine 0.5–2 g/day divided doses, titrate to effect, monitor catecholamines.
• For baseline pain → opioid (e.g., oxycodone 5–10 mg PO q4–6h PRN) with laxative regimen; avoid NSAIDs if renal impairment.
• If hypertensive crisis occurs → IV phentolamine 5 mg bolus, then infusion 0.1–0.5 mg/kg/h, monitor BP and GI symptoms.
  Action: Prescribe selected medication with monitoring plan.

Clinical Guardrails / Mimics / Pitfalls

Avoid metoclopramide and domperidone due to hypertensive crisis risk; avoid selective α‑blockers (doxazosin, prazosin) for GI symptoms as they are ineffective; use phenoxybenzamine only if available (not in Japan), otherwise rely on injectable phentolamine with strict BP monitoring; opioids may worsen constipation — co‑prescribe laxatives; corticosteroids can trigger crisis — avoid unless essential; monitor for hypotension and GI symptoms during phentolamine use.

Concrete Clinical Example

A 62‑year‑old with metastatic PPGL to lumbar spine reports worsening back pain and nausea. Nausea present → rule in antiemetic need. Pain classified as nociceptive with mild constipation → avoid metoclopramide/domperidone, choose prochlorperazine 10 mg PO q8h PRN for nausea and oxycodone 5 mg PO q4h PRN for pain with senna laxative. No hypertensive crisis observed; pain and nausea controlled after 48 h.

Source: Japan Endocrine Society Clinical Practice Guideline for the Diagnosis and Management of Pheochromocytoma and Paraganglioma 2025, Japan Endocrine Society, 2025, doi:10.1507/endocrj.EJ25-0165