Low back pain and sciatica

Red Flags

Cauda equina syndrome (saddle anaesthesia, urinary retention or incontinence, faecal incontinence, bilateral leg pain or weakness) — emergency MRI same-day; emergency surgical decompression^[1]
Suspected infection (fever, IV drug use, immunosuppression, recent procedure, severe pain at rest) — investigate spinal abscess/discitis; urgent MRI and ID^[1]
Suspected malignancy (age >50, history of cancer, weight loss, severe progressive pain unrelieved by rest, night pain) — urgent MRI and oncology^[1]
Suspected fracture (trauma, severe osteoporosis, prolonged steroid) — radiograph or MRI; spine immobilisation if unstable^[1]

First-line treatment

Interventions

Reassurance, education, encourage activity^[1]
Most non-specific LBP improves within 6 weeks with normal activity; written information; avoid bed rest; address yellow flags (fear-avoidance, depression, work issues)
Group exercise programme^[1]
Biomechanical (back-specific), aerobic, or mind-body (yoga, tai chi) approaches; tailor to ability and preference; equivalent benefit between modalities; combine with self-management education
Manual therapy (manipulation, mobilisation, soft tissue) — only as part of package^[1]
Component of multimodal package alongside exercise; not a stand-alone treatment; physiotherapy or osteopathy / chiropractic per local pathway
Psychological therapies with cognitive behavioural approach^[1]
Component of multimodal package for chronic LBP and high-risk patients on STarT Back; address fear-avoidance, mood, sleep, function
Avoid ineffective interventions^[1]
Do NOT offer belts, corsets, foot orthotics, rocker sole shoes, traction, acupuncture, ultrasound, PENS, TENS, or interferential therapy for LBP

First-line drug therapy

Drug	Class	Adult	Paediatric	Notes
Ibuprofen or naproxen (NSAID)^[1]	Cyclooxygenase inhibitor	Ibuprofen 400 mg PO TDS-QDS PRN; naproxen 250–500 mg PO BD PRN	Ibuprofen 7–10 mg/kg/dose	First-line analgesic for LBP and sciatica when pain limits function; lowest effective dose, shortest duration; co-prescribe PPI if risk; avoid in CKD, peptic ulcer, severe HF, anticoagulation
Paracetamol (limited evidence in LBP)^[1]	Analgesic	1 g PO QDS PRN, max 4 g/day	15 mg/kg/dose, max 60 mg/kg/day	Limited evidence in non-specific LBP per recent reviews; useful adjunct or alternative when NSAIDs contraindicated
Codeine or weak opioid (selected, short-term)^[1]	Weak opioid	Codeine 30–60 mg PO QDS PRN, max 240 mg/day	—	Reserve for moderate-severe acute pain unrelieved by NSAID/paracetamol; short course only; constipation, dependence; avoid for chronic LBP
Diazepam or short-acting muscle relaxant (severe spasm)^[1]	Benzodiazepine — short-acting	Diazepam 2–10 mg PO BD-TDS for ≤7 days	—	Severe acute muscle spasm; do not use long-term; sedation, dependence; avoid driving
Amitriptyline or duloxetine (chronic LBP with neuropathic component)^[1]	TCA / SNRI	Amitriptyline 10–25 mg PO night, titrate to 75 mg; duloxetine 30–60 mg PO daily	—	Chronic LBP with neuropathic features; not for acute LBP; specialist initiation; review at 8 weeks

Ibuprofen or naproxen (NSAID)^[1]

Cyclooxygenase inhibitor

Adult: Ibuprofen 400 mg PO TDS-QDS PRN; naproxen 250–500 mg PO BD PRN
Paediatric: Ibuprofen 7–10 mg/kg/dose

First-line analgesic for LBP and sciatica when pain limits function; lowest effective dose, shortest duration; co-prescribe PPI if risk; avoid in CKD, peptic ulcer, severe HF, anticoagulation

Paracetamol (limited evidence in LBP)^[1]

Analgesic

Adult: 1 g PO QDS PRN, max 4 g/day
Paediatric: 15 mg/kg/dose, max 60 mg/kg/day

Limited evidence in non-specific LBP per recent reviews; useful adjunct or alternative when NSAIDs contraindicated

Codeine or weak opioid (selected, short-term)^[1]

Weak opioid

Adult: Codeine 30–60 mg PO QDS PRN, max 240 mg/day
Paediatric: —

Reserve for moderate-severe acute pain unrelieved by NSAID/paracetamol; short course only; constipation, dependence; avoid for chronic LBP

Diazepam or short-acting muscle relaxant (severe spasm)^[1]

Benzodiazepine — short-acting

Adult: Diazepam 2–10 mg PO BD-TDS for ≤7 days
Paediatric: —

Severe acute muscle spasm; do not use long-term; sedation, dependence; avoid driving

Amitriptyline or duloxetine (chronic LBP with neuropathic component)^[1]

TCA / SNRI

Adult: Amitriptyline 10–25 mg PO night, titrate to 75 mg; duloxetine 30–60 mg PO daily
Paediatric: —

Chronic LBP with neuropathic features; not for acute LBP; specialist initiation; review at 8 weeks

Safety-net

Most low back pain settles within 6 weeks with continued normal activity — bed rest delays recovery^[1]
Loss of bladder or bowel control, saddle anaesthesia, severe progressive weakness, or fever with back pain — emergency department same-day^[1]
Avoid prolonged opioid use; if needed for >2 weeks, tapering plan and review for chronic pain alternatives^[1]

Referral criteria

Cauda equina syndrome, suspected infection, malignancy, or fractureEmergency department / spinal surgery same-day^[1]
Persistent radicular pain, weakness, or sensory loss ≥6 weeks despite optimal conservative careSpinal surgical assessment or radiology-guided injection^[1]
Suspected axial spondyloarthritis (inflammatory pattern <40 years)Rheumatology with HLA-B27 and SI joint MRI^[1]
High STarT Back risk, chronic disabling pain, or significant psychosocial factorsMultidisciplinary pain rehabilitation programme^[1]

Clinical summary

Risk-stratified assessment, exercise, and multimodal management of low back pain and sciatica in adults ≥16 years.

References

1.NICE Guideline NG59 — Low Back Pain and Sciatica in Over 16s: Assessment and Management (2016, updated 2020); ACP Clinical Practice Guideline 2017; KNGF/Cochrane evidence updates (2020)