Genryzon Pretreatment Screening

---
name: genryzon-pretreatment-screening
description: Pretreatment screening checklist before starting Genryzon (somatrogon, weekly long-acting growth hormone) in a child with confirmed paediatric growth hormone deficiency. Ensures thyroid, adrenal, glucose, ocular, tumour, and Prader-Willi status are checked before the first dose to prevent adrenal crisis, wasted therapy, unmasked hypothyroidism, unrecognised hyperglycaemia, missed intracranial hypertension, or sudden death in PWS. Use when a clinician asks what to check before starting somatrogon, workup before Genryzon, baseline tests for weekly GH, screening for adrenal insufficiency before GH, or is about to prescribe Genryzon in a paediatric GHD case. Grounded in the Pfizer India Product Monograph (Genryzon LPD, 2022 — PfLEET 2022-0081166).
---

# Genryzon Pretreatment Screening

Complete this checklist **BEFORE** the first Genryzon dose in a child with confirmed paediatric GHD. Missing any of these leads to preventable harm.

---

## Step 1 — Reconfirm the diagnosis of GHD

Genryzon is indicated **only** for growth disturbance due to insufficient GH secretion. Before starting, verify:

- **Two provocative GH stimulation tests** consistent with GHD (or one test + supportive auxology + low IGF-1/IGFBP-3 SDS + MRI evidence, per local guideline)
- **Auxology consistent with GHD:** height SDS <−2, or height SDS <−1.5 with poor growth velocity, or drop in height percentile
- **MRI pituitary** to identify structural cause (idiopathic vs organic; excludes intracranial tumour — see Step 5)
- **Bone age** — for growth-potential assessment and later discontinuation planning

**Do NOT start** in constitutional delay of growth and puberty (CDGP), familial short stature, or other non-GHD causes of short stature — Genryzon is not indicated and does not improve final height in these conditions.

---

## Step 2 — Thyroid function

**Order:** TSH + free T4.

**Why:** hypothyroidism blunts the response to growth hormone. Somatrogon can also unmask previously undiagnosed central hypothyroidism (GH increases T4→T3 conversion).

**Action:**
- **Pre-existing hypothyroidism → treat first.** Do not start Genryzon until euthyroid on levothyroxine
- **Normal at baseline** → recheck TFTs at each 6–12 month review
- **Consider central hypothyroidism** in any child with a hypothalamic/pituitary pathology on MRI — treat empirically per specialist judgement even if TSH looks "normal"

---

## Step 3 — Adrenal function

**Why:** GH may unmask **central (secondary) hypoadrenalism**. Starting somatrogon in an unrecognised ACTH-deficient child risks adrenal crisis under stress. Additionally, GH decreases cortisone→cortisol conversion, so children already on glucocorticoid replacement may need dose escalation once GH is started.

**Order:**
- **Morning cortisol** (8 AM) — the entry-level test
- If borderline or clinical suspicion → **ACTH stimulation test** or ITT per local protocol
- If organic pituitary lesion / multiple pituitary hormone deficiency → **assume central hypoadrenalism** and start hydrocortisone replacement empirically

**Action:**
- **Any evidence of central hypoadrenalism → start hydrocortisone replacement BEFORE Genryzon**, and warn family about stress dosing / sick-day rules
- **Already on glucocorticoid replacement → plan to review dose at 4–8 weeks** after starting Genryzon; often needs dose ↑
- **Normal adrenal axis at baseline** → still monitor for symptoms of adrenal insufficiency (fatigue, hypotension, hypoglycaemia) at each visit

---

## Step 4 — Glucose tolerance

**Why:** GH reduces insulin sensitivity and can precipitate hyperglycaemia. Higher-risk children (family history of T2DM, obesity, high-risk ethnicity, previous glucocorticoid exposure, syndromic obesity) must be flagged.

**Order:**
- **Fasting plasma glucose + HbA1c** as baseline
- **OGTT** if any risk factor or borderline FPG/HbA1c

**Action:**
- **Normal at baseline** → repeat FPG/HbA1c annually (more often if risk factors)
- **Impaired fasting glucose / IGT / overt diabetes** → involve paediatric diabetologist; if starting Genryzon anyway, plan **more frequent glucose monitoring** and be prepared to **adjust insulin/OAD doses upwards** once GH is on board

---

## Step 5 — Tumour clearance

**Why:** somatrogon is **contraindicated in active malignancy**. Children with prior CNS pathology require specific clearance.

**Verify:**
- **Any prior intracranial tumour must be inactive** — imaging within the recommended surveillance interval
- **Antitumour therapy (surgery, radiation, chemotherapy) must be completed** before starting GH
- **Childhood cancer survivors** — flag for elevated risk of **second neoplasm** on GH (especially meningioma after cranial radiation); document baseline surveillance plan
- **No active malignancy anywhere** — check most recent oncology/imaging summary

**Action:**
- **Any suggestion of tumour activity → do not start.** Loop oncology in for clearance
- **Cleared for GH** → document the clearance in the notes with date and imaging reference

---

## Step 6 — Baseline fundoscopy

**Why:** benign intracranial hypertension (IH) with papilloedema, headache, vision changes, nausea/vomiting is a recognised somatrogon adverse event. A baseline fundus exam provides a comparator if IH is later suspected.

**Order:** fundoscopy — by ophthalmology if available, or by trained clinician

**Action:**
- **Baseline documented** → refer to comparator if any later ocular / neurological symptoms
- **Baseline abnormal** (papilloedema, unexplained disc changes) → do NOT start Genryzon; investigate the underlying cause

---

## Step 7 — Rule out Prader-Willi syndrome (or confirm it's PWS + GHD)

**Why:** somatrogon has not been studied in PWS. Sudden death has been reported in PWS children on GH who have **severe obesity, upper airway obstruction, sleep apnoea, or unidentified respiratory infection**. Genryzon is **not indicated** for PWS-related growth failure unless the child also has confirmed GHD.

**Action:**
- **Suspected PWS features** (neonatal hypotonia, hyperphagia, hypogonadism, characteristic facies, obesity) → **do not start** until PWS is excluded by methylation testing / SNRPN analysis
- **Confirmed PWS without confirmed GHD** → Genryzon not indicated. Refer to PWS specialist
- **Confirmed PWS WITH confirmed GHD** → treatment may proceed but with:
  - Formal **sleep study** to exclude/quantify sleep apnoea before starting
  - **ENT review** if any upper airway concern
  - **Weight-management plan** and family counselling about respiratory risk
  - **Never start** during an intercurrent respiratory infection

---

## Step 8 — Baseline auxology and family readiness

**Document at baseline:**
- Standing height, weight, BMI, height SDS, weight SDS, mid-parental height SDS
- Growth velocity from prior visits (cm/year)
- Bone age (X-ray of left hand)
- Tanner stage
- Pubertal onset timing (age at breast bud / testicular volume 4 mL)

**Confirm family is ready:**
- Understand the diagnosis and expected duration of therapy
- Can commit to a weekly injection routine (any day of week, any time of day, but same day each week)
- Trained in pen technique, injection sites (abdomen / thighs / buttocks / upper arms), rotation, and disposal
- **Caregiver assigned** for injections into upper arms or buttocks (child cannot self-inject those sites)
- Knows what to do if a dose is missed (see the missed-dose rule) and what red-flag symptoms to escalate

---

## Guardrails

- **Do not compress this checklist to "just check TFTs".** Adrenal, glucose, ocular, tumour, and PWS steps each block a specific harm
- **Central hypoadrenalism can be occult** — a normal random cortisol does not exclude it. If any hypothalamic / pituitary structural lesion is present, err on the side of starting hydrocortisone replacement before GH and confirming with formal testing later
- **A single normal FPG does not exclude glucose intolerance** — repeat at follow-up, and use HbA1c / OGTT in high-risk children
- **Baseline fundoscopy** avoids the diagnostic dilemma of "was that papilloedema present before we started?" if IH is later suspected
- **Do NOT start during any acute intercurrent illness** — acute critical illness (post open-heart / abdominal surgery, multiple trauma, acute respiratory failure) is an absolute contraindication
- **Never start Genryzon in a child with active malignancy** — pause GH pending oncology clearance
- **In female adolescents post-menarche**, consider whether OCP / other oral estrogen therapy is likely to be started — this influences later IGF-1 titration (see `genryzon-igf1-titration`)
- **Document everything** — batch number of the first pen, all baseline values, all clearance letters. Growth hormone therapy is often audited

---

## Source

Pfizer Products India Pvt. Ltd. **GENRYZON® (Somatrogon) Solution for Injection in Pre-filled Pen — Prescribing Information (India).** LPD version 2022-0081166 (PfLEET 2022-0081166). Sections 4.3 "Contraindications" and 4.4 "Special Warnings and Precautions for Use".