What are the possible diagnosis and next steps for a 50-year-old male patient with a 1-month history of cough, back pain, and elbow joint discomfort, who has hypertension managed with Amlodipine (amlodipine), a history of cholecystectomy, and presents with morning and nighttime joint discomfort, limited weight-bearing capacity on the right arm, and lower back pain upon certain movements?

Differential Diagnosis and Management Approach

Primary Recommendation

This patient's chronic cough on amlodipine requires immediate discontinuation of the medication and switching to an alternative antihypertensive, as amlodipine-associated cough is a recognized cause of chronic cough that can only be effectively treated by stopping the drug. 1 The musculoskeletal symptoms (lateral epicondylitis and mechanical low back pain) represent separate but concurrent conditions that require conservative management after excluding red flag pathology.

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Immediate Action: Address the Cough

Amlodipine-Induced Cough

• Discontinue amlodipine immediately regardless of the temporal relationship between cough onset and medication initiation 1
• Cough resolution typically occurs within 1-4 weeks of cessation, though may take up to 3 months in some patients 1
• Switch to an angiotensin receptor blocker (ARB) for hypertension management, as the incidence of cough with ARBs is similar to control drugs 1
• While amlodipine can theoretically be used to suppress ACE inhibitor-induced cough 1, calcium channel blockers themselves can cause chronic cough 1

Rule Out Pertussis

• Consider testing for Bordetella pertussis, particularly given the 1-month duration of cough with concurrent back pain 2
• A 48-year-old patient with severe cough and back pain may have cough-induced musculoskeletal injury, including rib fractures 2
• Order chest X-ray to exclude pneumothorax, rib fracture, or other pulmonary pathology if cough is severe 2

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Musculoskeletal Assessment: Red Flag Screening

Back Pain Evaluation

Screen for emergent conditions before attributing symptoms to mechanical causes: 3

• Malignancy risk factors: Age >50 years (patient is 50), unexplained weight loss, history of cancer 3, 4
• Infection indicators: Fever, recent bacterial infection, immunosuppression 3
• Fracture risk: Age >70 years (not applicable), significant trauma, prolonged corticosteroid use 3
• Cauda equina syndrome: Urinary retention, saddle anesthesia, fecal incontinence, bilateral motor deficits 3, 5

Physical Examination Findings Analysis

• Lower back pain with all ranges of motion returning to baseline suggests mechanical low back pain rather than radiculopathy 3
• Pain with internal rotation of right leg may indicate sacroiliac joint involvement 6
• No radicular symptoms (no leg weakness, numbness, or positive straight-leg raise documented) 3
• Right lateral epicondyle tenderness consistent with lateral epicondylitis (tennis elbow) 6

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Diagnostic Workup

Imaging Decision

Do NOT order routine imaging for this patient's back pain 3

• No red flags present (no neurologic deficits, no constitutional symptoms, no history of cancer) 3, 4
• Mechanical low back pain without radiculopathy does not require imaging 3
• Imaging only indicated if symptoms persist beyond 1 month without improvement or if red flags develop 3, 4

Laboratory Studies

• Chest X-ray: To evaluate for cough-related complications (rib fracture, pneumothorax) and exclude pulmonary pathology 2
• Bordetella pertussis serology: If clinical suspicion for whooping cough given duration and severity 2
• No routine labs needed for mechanical back pain without red flags 3

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Treatment Plan

1. Medication Management

• Discontinue amlodipine immediately 1
• Start ARB (e.g., losartan 50mg daily or valsartan 80mg daily) for hypertension control 1
• Acetaminophen 650-1000mg every 6 hours as needed for back pain and elbow pain as first-line analgesic 3, 4
• NSAIDs (ibuprofen 400-600mg three times daily) if acetaminophen insufficient, with caution given hypertension 3, 4

2. Conservative Management for Musculoskeletal Pain

Lateral Epicondylitis (Right Elbow):

• Activity modification: Avoid repetitive gripping and lifting >5kg 6
• Ice application 15-20 minutes three times daily 6
• Counterforce bracing (tennis elbow strap) 6
• Physical therapy referral for eccentric strengthening exercises 6

Mechanical Low Back Pain:

• Avoid prolonged bed rest - maintain activity as tolerated 4
• Physical therapy referral for core strengthening and flexibility exercises 3
• Reassess psychosocial factors: depression, anxiety, job dissatisfaction that predict chronicity 3
• Consider STarT Back tool to risk-stratify for chronic disability 3

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Follow-Up Timeline

Week 2-4

• Reassess cough resolution after amlodipine discontinuation 1
• If cough persists beyond 4 weeks, consider other causes: upper airway cough syndrome, asthma, gastroesophageal reflux disease 7, 8
• Monitor blood pressure control on new ARB therapy 1

Week 4-6

• Reevaluate musculoskeletal symptoms 3
• If back pain persists without improvement after 1 month, consider imaging (lumbar spine X-rays initially) 3
• If elbow pain not improving, consider corticosteroid injection or orthopedic referral 6

Earlier Reassessment Warranted If:

• Severe pain or functional deficits develop 3
• New neurologic symptoms appear (leg weakness, numbness, bowel/bladder dysfunction) 3, 4
• Constitutional symptoms develop (fever, weight loss) 3, 4
• Cough worsens or respiratory distress occurs 2

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Key Clinical Pitfalls to Avoid

• Do not continue amlodipine - medication discontinuation is the only uniformly effective treatment for calcium channel blocker-induced cough 1
• Do not attribute all symptoms to arthritis without ruling out serious pathology, particularly in patients with chronic cough and back pain 4, 2
• Do not order unnecessary imaging for mechanical back pain without red flags - this increases costs without improving outcomes 3
• Do not miss pertussis in adults with prolonged cough, as it can cause significant musculoskeletal complications including rib fractures 2
• Do not prescribe prolonged bed rest for back pain - this leads to deconditioning and increased disability 4