All EMS presentations
ToxicologyClinical presentation

Opioid withdrawal

A streamlined, differential-led presentation for rapid clinical review.

Clinical snapshot

Twenty-second review

  • Opioid withdrawal produces autonomic and gastrointestinal hyperactivity after reduced receptor stimulation; it is distressing but usually less physiologically dangerous than sedative withdrawal.
  • Severe dehydration, pregnancy, chest pain, suicidal risk, co-withdrawal, fever, altered LOC, or inability to maintain safety requires escalation.
  • Keep gastroenteritis or anxiety in the differential; overlapping or concurrent illness remains possible.
  • For opioid withdrawal, trends and combinations of findings are more informative than one isolated vital sign.
Differentials

Compare the clinical patterns

The repeated material is grouped inside each possibility. Open only the condition you need.

Serious3 conditions
Co-ingestionTime-sensitive high-risk possibility

HPI

Clarify last opioid and usual use; symptoms and severity; vomiting or diarrhea.

Signs & symptoms

Altered LOC, fever, seizure, or marked instability suggests another or additional process.

Focused exam

Assess pupils, skin, bowel sounds, temperature, mental status, respiratory pattern, rhythm, and signs of trauma or concealed co-ingestion; Repeat observations because drug effects may evolve.

Brief pathophysiology

Co-ingestion may cause opioid withdrawal through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

Withdrawal commonly causes autonomic hyperactivity. Fever, hypoxemia, hypotension, or marked altered mentation should not be attributed automatically to withdrawal.

Heart rate (bpm)

Often elevated

Tachycardia is common with autonomic activation.

Blood pressure (mmHg)

May rise

Hypertension may occur; hypotension suggests dehydration or another illness.

Temperature (°C)

May rise

Temperature can rise in severe withdrawal; infection must also be considered.

Respiratory rate (breaths/min)

May rise

Tachypnea can reflect agitation or metabolic stress.

Front-load in the triage report

  • Co-ingestion: Altered LOC, fever, seizure, or marked instability suggests another or additional process.
  • Last opioid and usual use?
  • Symptoms and severity?
SepsisTime-sensitive high-risk possibility

HPI

Clarify symptoms and severity; vomiting or diarrhea; pregnancy possibility.

Signs & symptoms

Altered LOC, fever, seizure, or marked instability suggests another or additional process.

Focused exam

Repeat observations because drug effects may evolve; Assess pupils, piloerection, sweating, GI loss, hydration, agitation, pregnancy, treatment history, and other substance use.

Brief pathophysiology

Sepsis may cause opioid withdrawal through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

No single vital sign diagnoses sepsis. New tachypnea, abnormal temperature, tachycardia, or falling pressure—especially with altered mentation or poor perfusion—supports organ dysfunction and urgency.

Respiratory rate (breaths/min)

May rise early

Tachypnea is included in NEWS2 and can precede overt hypotension.

Temperature (°C)

High or low

Absence of fever does not exclude sepsis; hypothermia is concerning.

Heart rate (bpm)

Often rises

Tachycardia is common but may be blunted by age or medication.

Blood pressure (mmHg)

May fall

Relative hypotension and trend matter; profound hypotension can be late.

Front-load in the triage report

  • Sepsis: Altered LOC, fever, seizure, or marked instability suggests another or additional process.
  • Symptoms and severity?
  • Vomiting or diarrhea?
Sedative withdrawalTime-sensitive high-risk possibility

HPI

Clarify vomiting or diarrhea; pregnancy possibility; other substance use.

Signs & symptoms

Altered LOC, fever, seizure, or marked instability suggests another or additional process.

Focused exam

Repeat observations because drug effects may evolve; Assess pupils, piloerection, sweating, GI loss, hydration, agitation, pregnancy, treatment history, and other substance use.

Brief pathophysiology

Sedative withdrawal may cause opioid withdrawal through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

Ventilation is the priority in opioid or sedative toxicity. SpO₂ can look acceptable with supplemental oxygen while dangerous hypoventilation persists.

Respiratory rate (breaths/min)

May fall

Bradypnea, shallow breathing, or apnea indicates ventilatory failure.

Oxygen saturation (SpO₂)

May fall

Desaturation can occur, but SpO₂ does not measure ventilation.

Heart rate (bpm)

Variable

Rate depends on agent, co-ingestants, hypoxia, and baseline.

Blood pressure (mmHg)

May fall

Hypotension can occur in severe toxicity or mixed overdose.

Front-load in the triage report

  • Sedative withdrawal: Altered LOC, fever, seizure, or marked instability suggests another or additional process.
  • Vomiting or diarrhea?
  • Pregnancy possibility?
Common1 condition
Opioid withdrawalCommon presentation pattern

HPI

Clarify last opioid and usual use; symptoms and severity; vomiting or diarrhea.

Signs & symptoms

Mydriasis, yawning, rhinorrhea, aches, diarrhea, and autonomic symptoms may fit.

Focused exam

Assess pupils, skin, bowel sounds, temperature, mental status, respiratory pattern, rhythm, and signs of trauma or concealed co-ingestion; Repeat observations because drug effects may evolve.

Brief pathophysiology

Opioid withdrawal may explain the presenting symptoms through a common clinical mechanism, while serial assessment checks for complications or an alternate cause.

Vital-sign pattern

What the trend may show

Possible pattern

Withdrawal commonly causes autonomic hyperactivity. Fever, hypoxemia, hypotension, or marked altered mentation should not be attributed automatically to withdrawal.

Heart rate (bpm)

Often elevated

Tachycardia is common with autonomic activation.

Blood pressure (mmHg)

May rise

Hypertension may occur; hypotension suggests dehydration or another illness.

Temperature (°C)

May rise

Temperature can rise in severe withdrawal; infection must also be considered.

Respiratory rate (breaths/min)

May rise

Tachypnea can reflect agitation or metabolic stress.

Front-load in the triage report

  • Mydriasis, yawning, rhinorrhea, aches, diarrhea, and autonomic symptoms may fit.
  • Last opioid and usual use?
  • Symptoms and severity?
Mimics2 conditions
GastroenteritisImportant alternative presentation

HPI

Clarify last opioid and usual use; symptoms and severity; vomiting or diarrhea.

Signs & symptoms

GI and autonomic symptoms may overlap.

Focused exam

Assess pupils, skin, bowel sounds, temperature, mental status, respiratory pattern, rhythm, and signs of trauma or concealed co-ingestion; Repeat observations because drug effects may evolve.

Brief pathophysiology

Gastroenteritis can resemble opioid withdrawal through overlapping symptoms or referred physiology despite a different primary mechanism.

Vital-sign pattern

What the trend may show

Possible pattern

Volume loss may first appear as tachycardia or postural symptoms; hypotension is a later sign. Fever or blood loss changes the likely cause and risk.

Heart rate (bpm)

May rise

Tachycardia may reflect volume depletion, fever, or distress.

Blood pressure (mmHg)

May fall

Relative or orthostatic change can precede resting hypotension.

Pulse pressure (mmHg)

May narrow

Reduced stroke volume can narrow pulse pressure as depletion worsens.

Temperature (°C)

Variable

Fever supports infection; hypothermia may occur in severe illness.

Front-load in the triage report

  • GI and autonomic symptoms may overlap.
  • Last opioid and usual use?
  • Symptoms and severity?
AnxietyImportant alternative presentation

HPI

Clarify symptoms and severity; vomiting or diarrhea; pregnancy possibility.

Signs & symptoms

GI and autonomic symptoms may overlap.

Focused exam

Repeat observations because drug effects may evolve; Assess pupils, piloerection, sweating, GI loss, hydration, agitation, pregnancy, treatment history, and other substance use.

Brief pathophysiology

Anxiety can resemble opioid withdrawal through overlapping symptoms or referred physiology despite a different primary mechanism.

Vital-sign pattern

What the trend may show

Possible pattern

Withdrawal commonly causes autonomic hyperactivity. Fever, hypoxemia, hypotension, or marked altered mentation should not be attributed automatically to withdrawal.

Heart rate (bpm)

Often elevated

Tachycardia is common with autonomic activation.

Blood pressure (mmHg)

May rise

Hypertension may occur; hypotension suggests dehydration or another illness.

Temperature (°C)

May rise

Temperature can rise in severe withdrawal; infection must also be considered.

Respiratory rate (breaths/min)

May rise

Tachypnea can reflect agitation or metabolic stress.

Front-load in the triage report

  • GI and autonomic symptoms may overlap.
  • Symptoms and severity?
  • Vomiting or diarrhea?
Red flags

Findings that should escalate concern

  • Severe dehydration, pregnancy, chest pain, suicidal risk, co-withdrawal, fever, altered LOC, or inability to maintain safety requires escalation.
  • Co-ingestion, sepsis, or sedative withdrawal: Altered LOC, fever, seizure, or marked instability suggests another or additional process.
Related medications

Medication recognition

HydromorphoneOxycodoneMethadoneNaloxone
Related EMS presentations

Continue the clinical pathway

General MedicalNausea / vomitingToxicologyOverdose / drug poisoningToxicologyAlcohol intoxicationMental HealthAcute anxiety / panic symptomsMental HealthBehavioural crisis / agitation
References

Clinical and academic sources

Curated clinical guidance and peer-reviewed evidence supporting this presentation. Current BCEHS guidance, medical direction, and local policy remain authoritative for practice.

BCEHS Handbook — specific CPGs

  1. J12: OpioidsBC Emergency Health Services Handbook

    Official BCEHS clinical practice guidance for opioids.

Supporting clinical and academic evidence

  1. CEDIS Presenting Complaint List updateCanadian Association of Emergency Physicians

    Presenting-complaint terminology and categorization context. It does not establish a prehospital “top 100” ranking.

  2. Guidelines for establishing a poison centreWorld Health Organization

    Clinical toxicology context for time-critical poisoning, supportive care, consultation, and poison-centre expertise.

  3. Management of opioid use disorder: 2024 update to the national clinical practice guidelineCMAJ · 2024

    Canadian evidence-based withdrawal assessment, buprenorphine context, harm reduction, and linkage to care.