1) Definition — Paget disease of bone কী?
Paget disease of bone / Osteitis deformans হলো chronic focal disorder of bone remodelling, যেখানে osteoclast-mediated bone resorption অস্বাভাবিকভাবে বেড়ে যায়, এরপর osteoblast দিয়ে দ্রুত কিন্তু disorganized new bone তৈরি হয়। ফলে bone বড়, দুর্বল, deform, vascular এবং fracture-prone হয়ে যায়। সাধারণত pelvis, femur/tibia, skull, spine বেশি affected হয়।
2) Cause / Etiology & Pathophysiology — কারণগুলো
Exact cause fully known নয়, তবে কয়েকটি factor গুরুত্বপূর্ণ:
- Genetic predisposition
- Family history থাকতে পারে; Endocrine Society guideline অনুযায়ী family history ৫–৪০% পর্যন্ত report হয়েছে, common estimate ১০–২০%।
- SQSTM1/p62 mutation familial ও sporadic Paget disease-এর susceptibility বাড়াতে পারে।
- Abnormal osteoclast activity
- মূল pathology হলো osteoclast overactivity → excessive bone resorption → compensatory osteoblast overactivity → disorganized woven/lamellar “mosaic” bone।
- এই new bone normal bone-এর মতো শক্ত ও organized নয়, তাই deformity/fracture হয়।
- Age-related risk
- সাধারণত ৫০ বছরের পরে বেশি দেখা যায়; elderly population-এ incidental raised ALP বা X-ray finding থেকে ধরা পড়ে।
- Environmental factor
- Environmental trigger suspected, কিন্তু definitive cause প্রমাণিত নয়। MedlinePlus/NIH summary-তে cause uncertain, environmental factor possible বলা হয়েছে।
- Viral hypothesis
- Paramyxovirus/measles-like viral trigger আগে suggest করা হয়েছে, তবে current evidence definitive নয়। Clinical decision সাধারণত genetic + bone turnover abnormality ভিত্তিক।
3) Symptoms — লক্ষণগুলো point আকারে
অনেক patient asymptomatic থাকে; অন্য test করতে গিয়ে ALP high বা X-ray abnormality থেকে ধরা পড়ে। Symptomatic হলে:
- Bone pain
- Deep, dull, constant pain; rest/night pain হতে পারে।
- Pain disease activity বা adjacent osteoarthritis—দুই কারণেই হতে পারে।
- Bone deformity
- Tibia/femur bowing → হাঁটার ভঙ্গি বদলে যায়।
- Skull enlargement → hat size বড় হওয়া, frontal bossing।
- Skull involvement
- Headache, hearing loss, tinnitus।
- Cranial nerve compression হলে visual problem/neurologic symptom হতে পারে।
- Spine involvement
- Back pain, spinal stenosis।
- Nerve root compression → limb pain, tingling, numbness, weakness।
- Pelvis/femur involvement
- Hip pain, altered gait।
- Adjacent hip/knee osteoarthritis develop করতে পারে।
- Warmth over bone
- Highly vascular pagetic bone-এর উপর skin warm লাগতে পারে।
- Fracture
- Minimal trauma-তে pathological fracture হতে পারে।
4) Clinically diagnosis — কীভাবে clinically suspect করবেন?
Clinical suspicion করবেন যদি:
- Age >50 + unexplained bone pain/deformity।
- Incidental isolated raised ALP with normal liver enzymes/GGT।
- X-ray-তে typical pagetic change।
- Skull involvement হলে headache/hearing loss।
- Long bone bowing + joint pain।
- Family history of Paget disease।
Typical X-ray signs:
- Cortical thickening
- Coarse trabeculae
- Bone enlargement
- Mixed lytic–sclerotic lesion
- Skull: “cotton wool” appearance
- Vertebra: “picture-frame vertebra”
- Tibia/femur: bowing, lytic “blade of grass/flame-shaped” lesion
Endocrine Society guideline suspected Paget disease-এ suspicious skeletal region-এর plain radiograph recommend করে।
5) Investigations — specific workup
A. First-line investigations
- Serum total ALP + LFT/GGT
- Paget disease active হলে ALP বাড়ে।
- GGT/LFT normal থাকলে raised ALP-এর bone source বেশি suggestive।
- Guideline radiological diagnosis-এর পরে serum total ALP recommend করে।
- Plain X-ray of affected/suspicious bone
- Diagnosis confirm করার সবচেয়ে practical first imaging।
- NIAMS-ও X-ray-কে common diagnostic test হিসেবে উল্লেখ করেছে।
- Radionuclide bone scan / Tc-99m bone scintigraphy
- Disease extent দেখতে।
- Guideline diagnosed Paget disease-এ extent identify করতে bone scan suggest করে।
B. Disease activity ও treatment safety tests
- Bone-specific ALP / PINP
- Liver disease থাকলে total ALP confuse করতে পারে; তখন bone-specific marker useful।
- Serum CTX or urinary NTX
- Bone resorption activity ও response follow-up।
- Serum calcium, phosphate, creatinine/eGFR
- Bisphosphonate দেওয়ার আগে essential।
- Zoledronic acid CrCl <35 mL/min হলে contraindicated।
- 25-OH Vitamin D
- Vitamin D deficiency থাকলে bisphosphonate-এর পরে hypocalcemia risk বাড়ে।
- PTH
- Hyperparathyroidism exclude করতে।
C. Complication-based tests
- MRI spine/brain
- Spinal cord compression, nerve compression, basilar invagination suspected হলে।
- CT scan
- Complex skull/spine/pelvis involvement, surgical planning, suspected sarcomatous change।
- Audiometry
- Skull involvement + hearing loss থাকলে।
- Dental/oral exam
- IV bisphosphonate-এর আগে ONJ risk কমাতে dental assessment useful; MedEx zoledronic acid page-এ oral exam warning আছে।
- Bone biopsy
- Routine নয়; metastatic bone disease, osteosarcoma, atypical aggressive lesion সন্দেহ হলে।
6) Differential diagnosis
- Osteoarthritis
- Osteoporosis with fracture
- Osteomalacia/Vitamin D deficiency
- Bone metastasis
- Multiple myeloma
- Primary hyperparathyroidism
- Fibrous dysplasia
- Chronic osteomyelitis
- Osteosarcoma
- Renal osteodystrophy
7) Complications — সহজভাবে
- Pathological fracture
- Pagetic bone বড় হলেও দুর্বল, তাই minor trauma-তে fracture হতে পারে।
- Bone deformity
- Long bone bowing, skull enlargement, kyphosis।
- Secondary osteoarthritis
- Deformed bone joint-এর উপর abnormal stress দেয় → hip/knee OA হয়।
- Hearing loss
- Skull base involvement হলে auditory nerve/ossicle pathway affected হতে পারে।
- Nerve compression
- Spine/skull involvement → radiculopathy, spinal stenosis, paraplegia rare।
- High-output cardiac failure
- Extensive vascular pagetic bone থাকলে heart বেশি blood pump করতে বাধ্য হয়; severe disease-এ heart failure হতে পারে।
- Hypercalcemia
- Immobilization + high bone turnover থাকলে serum calcium বাড়তে পারে।
- Renal stone
- Excess calcium turnover/immobilization-related hypercalcemia থেকে stone হতে পারে।
- Osteosarcoma / giant cell tumor
- Rare but serious; sudden severe pain, swelling, rapidly enlarging lesion, lytic destruction হলে urgent evaluation।
- Surgical bleeding
- Pagetic bone hypervascular, orthopedic surgery-তে bleeding বেশি হতে পারে।
8) Treatment management — guideline-based
Treatment কাকে দেবেন?
Treat করবেন যদি:
- Paget-related bone pain থাকে
- Active disease: high ALP/bone turnover marker
- Skull/spine/weight-bearing bone involvement
- Osteolytic lesion বা deformity progression
- Fracture risk / planned orthopedic surgery
- Neurologic compression
- Hypercalcemia due to immobilization
- High-output cardiac failure suspected
Endocrine Society most active Paget disease with future complication risk-এ bisphosphonate recommend করে এবং contraindication না থাকলে single 5 mg IV zoledronic acid treatment of choice বলে।
9) Bangladesh prescription-context drug list
MedEx Bangladesh-এ Paget disease indication-এর under-এ listed generics হলো: Alendronic acid, Risedronate sodium, Risedronate sodium + Calcium carbonate, Salmon calcitonin, Zoledronic acid।
A. First-line disease-modifying drug
1) Generic name: Zoledronic acid / Zoledronate
- Therapeutic category: Bisphosphonate preparation
- Pharmacological class: Nitrogen-containing bisphosphonate; osteoclast-mediated bone resorption inhibitor
- Purpose / কেন used হয়: Paget disease-এর high bone turnover suppress করে, bone pain কমায়, ALP normalize করে, long remission দেয়।
- Dose & duration: 5 mg IV infusion once, infusion time ≥15 minutes। Retreatment usually needed হয় না within several years unless biochemical/clinical relapse। Endocrine Society table: zoledronate 5 mg single infusion over 15 min; retreatment seldom required within 5 years।
- Before infusion: serum creatinine/eGFR, calcium, phosphate, 25-OH vitamin D check; adequate hydration।
- Calcium/Vit D: Paget patient-এ zoledronic acid-এর পরে especially first 2 weeks elemental calcium 1500 mg/day + vitamin D 800 IU/day advised।
- Common side effects: fever, myalgia, headache, arthralgia, limb pain, flu-like illness, nausea/vomiting/diarrhea, eye inflammation।
- Serious risk: hypocalcemia, renal toxicity, osteonecrosis of jaw, atypical femur fracture, severe musculoskeletal pain।
- Contraindication: hypocalcemia, CrCl <35 mL/min or acute renal impairment, hypersensitivity।
- Interaction: aminoglycosides/loop diuretics → hypocalcemia risk; nephrotoxic drugs → renal toxicity; renal-excreted drugs monitor।
- Bangladesh available brand name with strength:
- Aclasta — 5 mg/100 mL IV infusion
- Bonizol — 5 mg/100 mL IV infusion
- Zandra — 5 mg/100 mL IV infusion
- Zoldix — 5 mg/100 mL IV infusion
- Zoledron — 5 mg/100 mL IV infusion
- Zolenic — 5 mg/100 mL IV infusion
- Zoltero — 5 mg/100 mL IV infusion
MedEx lists these 5 mg/100 mL brands in Bangladesh.
Bangladesh doctors commonly use: symptomatic/active Paget disease-এ IV zoledronic acid সবচেয়ে practical first-line, কারণ one-time infusion এবং long remission।
B. Oral bisphosphonate alternatives
2) Generic name: Alendronic acid / Alendronate
- Therapeutic category: Bisphosphonate preparation
- Pharmacological class: Osteoclast inhibitor; bone hydroxyapatite binding antiresorptive
- Purpose / কেন used হয়: Zoledronic acid unavailable/contraindicated/intolerant হলে oral alternative হিসেবে bone turnover কমাতে।
- Paget dose: 40 mg orally once daily for 6 months। MedEx alendronic acid page-এ Paget dose 40 mg once daily for 6 months উল্লেখ আছে।
- Administration: সকালে empty stomach, full glass water, 30 মিনিট upright; food/calcium/antacid পরে।
- Side effects: dyspepsia, esophagitis/esophageal ulcer, dysphagia, abdominal pain, constipation/diarrhea, musculoskeletal pain, headache, rare ONJ/atypical femur fracture।
- Contraindication: esophageal stricture/achalasia, inability to sit/stand 30 min, hypocalcemia, hypersensitivity, CrCl <35 mL/min not recommended।
- Interaction: calcium/antacid/iron/magnesium reduce absorption; NSAID/aspirin increases upper GI adverse effects।
- Bangladesh available brand name with strength:
- Alendon — 10 mg tablet
- Alendon — 70 mg tablet
MedEx lists Alendon 10 mg and 70 mg by Beximco.
Important Bangladesh note: Paget dose is 40 mg/day, কিন্তু MedEx-listed brand strength 10 mg/70 mg; তাই exact regimen specialist judgement ছাড়া prescribe করা ঠিক নয়।
3) Generic name: Risedronate sodium
- Therapeutic category: Bisphosphonate preparation
- Pharmacological class: Osteoclast-mediated bone resorption inhibitor
- Purpose / কেন used হয়: Oral alternative; Paget disease activity কমাতে।
- Guideline Paget dose: 30 mg orally once daily for 2 months। Endocrine Society table: risedronate 30 mg/day for 2 months।
- Administration: সকালে empty stomach, water দিয়ে, 30 মিনিট upright; food/calcium/antacid আলাদা।
- Side effects: chest pain, dysphagia/odynophagia, heartburn, GI upset, diarrhea/constipation, headache, severe bone/joint/muscle pain, jaw pain/swelling।
- Contraindication: hypocalcemia, CrCl <30 mL/min, pregnancy/lactation, hypersensitivity।
- Interaction: calcium/magnesium/aluminum antacid/supplement absorption কমায়; aspirin/NSAID GI irritation বাড়ায়।
- Bangladesh available brand name with strength:
- Risedon — 150 mg
- Risonet — 35 mg, 150 mg
- Salost — 5 mg, 150 mg
- Salost DR — 35 mg delayed-release
- Sedron — 5 mg, 35 mg
MedEx lists these risedronate brands/strengths.
Important Bangladesh note: Guideline Paget dose 30 mg/day; MedEx-listed strengths 5/35/150 mg বেশি osteoporosis-oriented. তাই active Paget disease-এ exact dose availability না থাকলে IV zoledronic acid preferred।
4) Generic name: Risedronate sodium + Calcium carbonate
- Therapeutic category: Bisphosphonate preparation
- Pharmacological class: Bisphosphonate + calcium supplement co-package
- Purpose / কেন used হয়: Risedronate with calcium support; MedEx Paget indication list-এ আছে, তবে active Paget-এর guideline regimen-এর substitute নয়।
- Dose form: 1 tablet risedronate 35 mg once weekly + 6 tablets calcium carbonate 500 mg remaining days।
- Side effects: risedronate-related GI irritation, dysphagia, heartburn, jaw pain; calcium-related constipation/GI upset।
- Interaction: calcium/antacid risedronate absorption কমায়; separate timing প্রয়োজন।
- Bangladesh available brand name with strength:
- Risedon Plus — 35 mg + 500 mg tablet, Square Pharmaceuticals PLC।
C. Second-line / special situation
5) Generic name: Salmon calcitonin
- Therapeutic category: Hormone in bone formation by inhibiting bone resorption
- Pharmacological class: Calcitonin hormone analogue; osteoclast inhibition
- Purpose / কেন used হয়: Bisphosphonate contraindicated/intolerant হলে active Paget disease-এ second-line; hypercalcemia থাকলেও useful হতে পারে। MedEx says active Paget disease when alternative treatments not suitable।
- Dose: 100 IU SC/IM daily; MedEx range: 50 IU 3 times weekly to 100 IU/day।
- Duration: Usually 3–6 months or response-guided; ALP follow-up।
- Side effects: nausea/GI disturbance, dizziness, flushing, tingling, unpleasant taste, rash, abdominal pain, urinary frequency, tremor, injection-site inflammation।
- Contraindication: hypersensitivity, hypocalcemia।
- Interaction: digitalis/cardiac glycosides, calcium-channel blockers may need dose adjustment; may decrease lithium concentration।
- Bangladesh available brand name with strength:
- Calcitonin — 100 IU/mL injection, City Overseas Ltd।
D. Supportive drugs doctors often add
6) Generic name: Calcium carbonate + Vitamin D3
- Therapeutic category: Specific mineral & vitamin combined preparation
- Pharmacological class: Calcium supplement + cholecalciferol
- Purpose / কেন used হয়: Zoledronic acid/bisphosphonate-এর পরে hypocalcemia prevent; bone health support; vitamin D deficiency correction।
- Dose: Paget patient receiving zoledronic acid: elemental calcium 1500 mg/day divided + vitamin D 800 IU/day, especially first 2 weeks।
- Common Bangladesh dosing forms: Calcium 500 mg + D3 200 IU, or Calcium 500/600 mg + D3 400 IU; MedEx usual dosing 1 tab twice daily depending strength।
- Side effects: constipation, nausea, vomiting, stomach cramps, dry mouth, increased thirst/urination if excess।
- Contraindication: hypercalcemia, renal calculi/nephrolithiasis, hyperthyroidism, Zollinger–Ellison syndrome।
- Interaction: tetracycline/doxycycline/minocycline absorption কমায়; digoxin toxicity risk; other calcium/vit D/calcitriol excess hypercalcemia risk।
- Bangladesh available brand examples with strength:
- A-Cal D — 500 mg + 200 IU
- A-Cal DX — 500 mg + 400 IU
- Acical-D — 500 mg + 200 IU
- Acical-DX — 600 mg + 400 IU
- Calbo-D — 500 mg + 200 IU
- Calcin-D — 500 mg + 200 IU
- Calcin-DX — 600 mg + 400 IU
- Calvimax D — 500 mg + 200 IU
- Ipical-D — 500 mg + 200 IU
- Ipical DX — 600 mg + 400 IU
MedEx lists many brands; examples above are from the listed Bangladesh brands.
7) Generic name: Paracetamol / Acetaminophen
- Therapeutic category: Non-opioid analgesic
- Pharmacological class: Analgesic–antipyretic
- Purpose / কেন used হয়: Bone pain/joint pain control; zoledronic acid infusion-এর acute-phase fever/myalgia কমাতে। MedEx zoledronic acid page also notes acetaminophen after infusion may reduce acute-phase reaction।
- Adult dose: 500–1000 mg every 6–8 hours PRN; usual max 3–4 g/day, liver disease/alcohol use/low body weight হলে lower max।
- Side effects: usually safe; overdose → severe hepatotoxicity।
- Interaction: alcohol, warfarin chronic high dose, other paracetamol-containing combination।
- Bangladesh available brand examples:
- Napa — 500 mg
- Ace — 500 mg
- Fast — 500 mg
- Xcel — 500 mg
- Napa One/Fast One — 1000 mg
MedEx lists common 500 mg brands including Ace, Fast, Napa.
8) Generic name: Aceclofenac / Etoricoxib — short-course pain control
- Therapeutic category: NSAID / COX-2 selective NSAID
- Pharmacological class: Anti-inflammatory analgesic
- Purpose / কেন used হয়: Paget-related adjacent osteoarthritis বা inflammatory musculoskeletal pain-এ short-term pain relief; disease-modifying নয়।
- Aceclofenac dose: 100 mg orally twice daily after food, short course।
- Etoricoxib dose: 60–90 mg once daily short course, patient risk অনুযায়ী।
- Side effects: gastritis/ulcer/bleeding, renal dysfunction, fluid retention, BP rise; etoricoxib-এ CV risk caution।
- Interaction: anticoagulant/antiplatelet, steroid, ACEi/ARB/diuretic, CKD, peptic ulcer disease।
- Bangladesh available brand examples:
- Aceclofenac: Avenac 100 mg, Biofenac 100 mg, Reservix 100 mg, Vaxtin 100 mg, Aceclofenac 100 mg। MedEx lists many 100 mg brands.
- Etoricoxib: Etorix 60/90/120 mg, Recox 60/90 mg, Etoshine 60/90 mg, X Dol 60/90/120 mg।
10) Practical prescription pattern in Bangladesh
Common doctor-used list:
- Zoledronic acid 5 mg/100 mL IV infusion — single dose
- First-line for symptomatic/active Paget disease.
- Used because one dose gives long biochemical remission and good pain response.
- Calcium carbonate + Vitamin D3
- Given around bisphosphonate therapy to prevent hypocalcemia and correct deficiency.
- Paracetamol 500–1000 mg PRN
- Pain/fever/myalgia control; especially after zoledronic infusion.
- NSAID short course
- If adjacent osteoarthritis/joint pain prominent and renal/GI/CV risk acceptable.
- Alendronate / Risedronate
- Oral alternative when IV zoledronic acid unsuitable; but Bangladesh strength availability may not match classic Paget regimen.
- Salmon calcitonin injection
- Rarely used now; mainly if bisphosphonate contraindicated or not tolerated.
11) Monitoring follow-up
- Baseline: ALP, LFT/GGT, calcium, phosphate, creatinine/eGFR, 25-OH vitamin D।
- Treat vitamin D deficiency and hypocalcemia before bisphosphonate।
- After zoledronic acid: check calcium if symptomatic or high-risk।
- Serum ALP at 3–6 months; then 6–12 monthly if active/high-risk।
- Bone scan/X-ray not routinely repeated unless symptoms persist, ALP rises, or lytic lesion monitoring needed।
- New severe focal pain/swelling → urgent X-ray/MRI to exclude fracture/sarcoma।
12) Prevention — কীভাবে complication prevent করবেন?
Primary prevention নিশ্চিতভাবে নেই, কারণ exact cause unknown। তবে complication prevention করা যায়:
- Family history থাকলে age >50 থেকে serum ALP + targeted X-ray consider।
- Unexplained isolated raised ALP হলে liver source exclude করে bone evaluation।
- Adequate vitamin D/calcium intake, especially before/after bisphosphonate।
- Fall prevention: walking aid, home safety, vision correction।
- High-impact exercise avoid if weight-bearing pagetic bone involved; physiotherapy-guided low-impact exercise।
- Hearing symptom থাকলে early audiometry।
- Dental assessment before IV bisphosphonate; invasive dental procedure আগে plan।
- Persistent new severe bone pain, swelling, deformity progression হলে urgent evaluation।
- Surgery planned on pagetic bone হলে pre-operative bisphosphonate specialist plan; bleeding risk কমাতে পারে।
Overview / Summary
Paget disease of bone হলো focal high-turnover bone remodelling disorder, যেখানে bone বড় কিন্তু structurally weak হয়। Diagnosis সাধারণত X-ray + raised ALP + bone scan for extent দিয়ে হয়। Symptomatic/active disease-এর first-line treatment হলো bisphosphonate, বিশেষ করে Zoledronic acid 5 mg IV single infusion। Bangladesh MedEx অনুযায়ী disease-specific available generics হলো alendronic acid, risedronate, risedronate+calcium, salmon calcitonin, zoledronic acid।
Actionable Plan / Steps
- Suspect করলে: ALP + LFT/GGT + X-ray affected bone।
- Confirm হলে: bone scan দিয়ে extent map করুন।
- Before treatment: Ca, phosphate, creatinine/eGFR, 25-OH vitamin D, dental review।
- Symptomatic/active/high-risk হলে: Zoledronic acid 5 mg IV once if CrCl ≥35 and calcium normal।
- Calcium 1500 mg elemental/day + Vit D 800 IU/day at least first 2 weeks after infusion।
- Follow-up ALP at 3–6 months, then 6–12 monthly।
- Red flags: sudden severe pain, swelling, fracture, neurologic deficit, hearing loss → urgent imaging/specialist referral।
Reference List — Textbook + Guideline + DOI
- Harrison’s Principles of Internal Medicine, 21st ed. Chapter: Disorders of Bone and Mineral Metabolism / Paget Disease of Bone.
- Davidson’s Principles and Practice of Medicine, 24th ed. Chapter: Metabolic Bone Disease.
- Robbins & Cotran Pathologic Basis of Disease, 10th ed. Chapter: Bones, Joints, and Soft Tissue Tumors—Paget disease / osteitis deformans.
- Singer FR, Bone HG, Hosking DJ, et al. Paget’s Disease of Bone: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2014;99(12):4408–4422. DOI: 10.1210/jc.2014-2910.
- Ralston SH, Corral-Gudino L, Cooper C, et al. Diagnosis and Management of Paget’s Disease of Bone in Adults: A Clinical Guideline. Journal of Bone and Mineral Research. 2019;34(4):579–604. DOI: 10.1002/jbmr.3657.
- Ralston SH, Langston AL, Reid IR. Pathogenesis and management of Paget’s disease of bone. The Lancet. 2008;372:155–163. DOI: 10.1016/S0140-6736(08)61035-1.
Md.Rafiqul Islam Lipu,Date:-13-06-2026 Saturday Time:-02-57-33 Pm