Tetanus

Clinical Snapshot

Tetanus is a rare, entirely preventable, and non-contagious neurologic emergency caused by Clostridium tetani, an anaerobic, spore-forming, gram-positive bacillus found ubiquitously in soil, dust, and animal or human feces. Its spores are hardy, survive for years outside the body, and germinate into toxin-producing bacteria only when introduced into devitalized, oxygen-poor tissue — a puncture wound, a crush injury, a chronic ulcer, or any wound with dead tissue and poor blood supply.^[1]^[2]

The vegetative bacteria produce tetanospasmin, one of the most potent toxins known. Tetanospasmin binds irreversibly to peripheral motor nerve terminals and travels by retrograde axonal transport into the central nervous system, where it destroys a synaptic vesicle protein required for the release of glycine and GABA — the spinal cord and brainstem's principal inhibitory neurotransmitters.^[2] With inhibitory tone lost, motor neurons fire under unopposed excitatory drive, producing the sustained muscle rigidity and violent spasms that define the disease; in severe cases, disinhibition of autonomic neurons produces a labile, overactive sympathetic nervous system as well.^[2]

Unlike almost every other condition in this platform's infectious disease library, tetanus is never transmitted person to person — there is no human reservoir, no outbreak to trace, and herd immunity plays no role whatsoever in its prevention. Protection is entirely individual: it depends on that specific patient's own vaccination status at the moment of an injury.^[1]

Once tetanus is generalized, it is an ICU-level emergency with a case-fatality rate ranging from under 10% to over 50% depending on incubation period, wound type, and comorbidities — highest in the very old, the very young, and people who inject drugs.^[2]^[1] But the pharmacist's highest-value role in this condition sits at the other end of the timeline entirely: the routine wound visit, the tetanus-prone injury, the patient who "just needs a cut looked at" — where a genuinely simple, structured decision (see Choose Initial Treatment) is what actually prevents a case from ever developing.

Recognize the Condition

Four clinical patterns

Generalized, localized, cephalic, and neonatal tetanus

Generalized tetanus (roughly 80% of cases)

The classic and by far most common presentation. Trismus (lockjaw) — painful spasm of the masseter muscles limiting mouth opening — is typically the first symptom.^[2] As rigidity spreads, sustained contraction of the facial muscles produces risus sardonicus, a fixed, sneering grin with elevated eyebrows, and truncal extensor spasm produces opisthotonus, an arched, backward-curved posture of the neck and spine.^[2]^[1] Spasms are agonizingly painful, can fracture bones and tear muscle from the force of unopposed contraction, and are classically triggered or worsened by light, noise, and touch. As the disease progresses, autonomic instability — labile blood pressure and heart rate, sweating, fever, and dysrhythmia, sometimes swinging between hypertensive "storms" and sudden hypotension or bradycardia — becomes the dominant threat to life, alongside spasm of the respiratory and laryngeal muscles.^[2]

Localized tetanus

Persistent, painful muscle contraction confined to the muscles near the wound itself. Rare, and uncommonly fatal on its own, but can progress to generalized disease and should be taken exactly as seriously.^[2]

Cephalic tetanus

A rare form limited to the head and neck, following a head wound, skull fracture, dental infection, or otitis media. Presents with trismus, neck stiffness, dysphagia, and cranial nerve findings — most often facial nerve palsy — with a real risk of aspiration and laryngeal/respiratory failure. Can progress to generalized tetanus.^[2]

Neonatal tetanus

Follows contamination of the unhealed umbilical stump, typically from non-sterile cord care in an unvaccinated mother. Presents with poor feeding, irritability, facial grimacing, and spastic rigidity triggered by touch; survivors can have lasting neurodevelopmental and motor impairment. Canada has validated the complete elimination of maternal and neonatal tetanus nationally — this form should not be seen in Canadian pharmacy practice, but remains a leading cause of vaccine-preventable death where maternal immunization coverage is incomplete.^[3]

1809 painting by Sir Charles Bell depicting a patient with tetanus in opisthotonus, the body arched backward from sustained extensor spasm

Opisthotonus in a patient with tetanus, painted by Sir Charles Bell in 1809 from his documentation of wounded soldiers after the Battle of Corunna — the same descending rigidity and spasm pattern described above, unchanged in two centuries of clinical description. (Sir Charles Bell, 1809; public domain, Wikimedia Commons)

Incubation period tracks with prognosis

Incubation is typically 3 to 21 days from inoculation to first symptom (average about 10 days), though it can range from a single day to several months depending on the distance of the wound from the central nervous system.^[1] This is a genuinely useful prognostic marker: the shorter the incubation period and the faster symptoms progress once they start, the worse the expected course — a relationship formalized in bedside prognostic scoring systems that also weigh wound type, opioid use disorder, fever, and tachycardia (see Assessment & Diagnosis).^[2]

A bedside clue worth knowing: the spatula test

Touching the posterior pharyngeal wall with a tongue depressor normally provokes a gag reflex that pushes the spatula back out. In a patient with trismus from tetanus, the same stimulus instead provokes an involuntary bite/spasm of the masseter, trapping the spatula against the teeth — a simple, specific bedside finding that helps distinguish tetanus-related trismus from other causes of a stiff jaw.^[2]

Risk Factors

Any wound significantly contaminated with dirt, dust, soil, animal or human feces, or saliva (including animal bites) — even one that looks small or trivial on the surface.^[1]
Puncture wounds, avulsions, and wounds from missiles (gunshot), crush injury, burns, or frostbite.^[1]
Any wound with devitalized (dead) tissue, or a wound/burn for which surgical care is delayed more than 6 hours.^[1]
Chronic wounds — abscesses, cellulitis, and chronic ulcers, particularly in patients with diabetes mellitus or a history of injection drug use.^[1]
Clinical evidence of sepsis in the wound itself.^[1]
Occupational or recreational soil contact — farming, gardening, landscaping, and soil-testing/environmental work are all recognized exposures, and can cause tetanus from injuries that seem minor at the time (see the Saskatchewan case in Special Populations).^[4]
Injection drug use, particularly subcutaneous/intramuscular injection ("skin-popping") — the same anaerobic-wound mechanism implicated in wound botulism.^[1]
Older age: Canadians 75 and older have nearly four times the tetanus incidence of those under 75, driven by a combination of waning vaccine-induced immunity and infrequent adult booster uptake.^[3]
Any gap in documented vaccination history — birth outside Canada, incomplete or lost records, no recollection of prior doses, or a caregiver who declined childhood immunization.^[1]
Humoral immune deficiency (e.g., HIV, agammaglobulinemia, hypogammaglobulinemia) or an immunosuppressive medication, which can blunt the antibody response to tetanus-containing vaccine and change the prophylaxis decision (see Special Populations).^[1]

Red Flags & Refer

Any new trismus, facial or neck muscle spasm, generalized rigidity, or spasms triggered by light, sound, or touch is a medical emergency from the moment it is recognized. Arrange immediate emergency transfer — call 911 rather than having the patient drive themselves — and keep the patient in as quiet, dark, and low-stimulation an environment as possible while awaiting transfer, since external stimuli can trigger or worsen spasms.^[2]^[1]

New difficulty opening the mouth, a fixed grin-like facial expression, or a stiff, arching neck/back posture — especially with an identifiable recent wound, however minor it appeared at the time.^[2]
Any shortness of breath, stridor, or difficulty swallowing/handling secretions accompanying the above — spasm of the laryngeal and respiratory muscles can cause sudden respiratory failure.^[2]
Signs of autonomic instability — sweating, flushing, a racing or irregular heartbeat, or wildly swinging blood pressure — in a patient with the pattern above.^[2]
A wound that meets any tetanus-prone criteria (see Risk Factors) in a patient who cannot confirm at least 3 documented doses of tetanus-containing vaccine, or whose last dose was more than 10 years ago — this patient needs a structured prophylaxis decision today (see Choose Initial Treatment), not a "come back if it gets worse."

The pharmacist's role in active or suspected tetanus is recognition and immediate escalation — never outpatient management, symptomatic treatment, or watchful waiting. Tetanus is a nationally notifiable disease in Canada; the receiving emergency department will coordinate any public health reporting.^[5]

Assessment & Diagnosis

Tetanus is a clinical diagnosis

There is no rapid, reliable laboratory test for tetanus. Diagnosis rests entirely on the history and examination — the pattern of rigidity and spasm described in Recognize the Condition — and treatment should never be delayed while awaiting any test result.^[2]^[1] The Public Health Agency of Canada's national case definition confirms a case on clinical grounds alone: acute-onset hypertonia and/or painful muscular contractions (usually of the jaw and neck) plus generalized muscle spasms, without another apparent medical cause, with or without isolation of C. tetani from a wound and with or without a history of an identifiable injury — wound culture is frequently negative even in genuine disease and is not required to confirm the diagnosis.^[5]

Differential diagnosis

Consider alternative diagnoses when the picture is atypical, particularly in a fully immunized patient:

Acute dystonic drug reaction (metoclopramide, first-generation antipsychotics, other dopamine antagonists) — usually resolves with an anticholinergic/antihistamine, and lacks tetanus's progressive rigidity and autonomic instability.
Hypocalcemic tetany — carpopedal spasm and a positive Chvostek's/Trousseau's sign point here rather than to tetanus.
Strychnine poisoning — can closely mimic generalized tetanus, but muscles typically fully relax between spasms, unlike the sustained background rigidity of tetanus.
Temporomandibular joint dysfunction or a dental/peritonsillar abscess — a much more common cause of a "stiff jaw" than tetanus, but should still prompt a tetanus risk assessment of any associated wound.
Meningitis or encephalitis — neck stiffness is shared, but fever, headache, and altered mental status point away from tetanus, which classically spares mentation throughout.^[2]

A simple bedside clue and a prognostic scoring framework

The spatula test described in Recognize the Condition is a useful, specific bedside discriminator for tetanus-related trismus. Once the diagnosis is suspected, prognosis is estimated from readily available bedside factors, with one point assigned for each of: incubation period under 7 days, time from first symptom to first spasm under 48 hours, a high-risk wound source (burns, surgical wounds, septic abortion, umbilical stump, open fracture, or intramuscular injection), opioid use disorder, generalized (rather than localized/cephalic) disease, temperature over 40°C, and heart rate over 120/min (150/min in neonates). Reported mortality rises from under 10% at a score of 0-1 to over 50% at a score of 5-6.^[2]

Treatment Targets

Prevent tetanus before it starts — the single highest-value action, achieved through a structured, correct wound-prophylaxis decision (vaccine, TIG, both, or neither) at every tetanus-prone injury.
In active disease: stop further toxin production at the source through prompt, thorough wound debridement.
Neutralize any circulating, unbound toxin as early as possible with tetanus immune globulin — TIG cannot reverse toxin that has already bound to nerve terminals.
Control muscle rigidity and spasm to prevent exhaustion, fractures, rhabdomyolysis, and respiratory compromise.
Anticipate and manage autonomic instability proactively rather than reactively — it is a leading cause of death in severe disease.
Protect the airway before overt respiratory failure develops, and provide meticulous ICU-level supportive and nutritional care through what can be a weeks-long recovery.
Complete active immunization after recovery — surviving tetanus does not confer immunity against a future episode.

Choose Initial Treatment

Direct treatment rule

Every wound gets two questions before anything else

Clean and, where indicated, debride the wound first — this matters for every wound, not just tetanus-prone ones. Then ask exactly two questions: (1) is this a clean, minor wound or any other (tetanus-prone) wound? and (2) how many documented doses of tetanus-containing vaccine has this patient received, and how long ago was the most recent one? The answers to those two questions — and only those two — determine whether the patient needs a vaccine dose, tetanus immune globulin (TIG), both, or neither. Do not delay this decision while records are requested from another province or country; make the best assessment available today.^[1]

Step 1 — Classify the wound

Clean, minor wound	All other wounds (tetanus-prone)
A fresh, superficial wound with no significant contamination and no devitalized tissue — for example, a clean surgical incision or a superficial cut with no soil/feces/saliva contact. A tick or other insect bite is also treated as a clean, minor wound unless it is unusually deep or visibly contaminated.^[1]	Any wound contaminated with dirt, dust, soil, feces, or saliva (including animal or human bites); puncture wounds; avulsions; wounds from missiles, crush injury, burns, or frostbite; any wound with devitalized tissue; a wound/burn where surgical care is delayed more than 6 hours; and any wound with clinical evidence of sepsis. Chronic wounds — abscesses, cellulitis, chronic ulcers — in a patient with diabetes or a history of injection drug use are classified here as well.^[1]

Clean, minor wound

All other wounds (tetanus-prone)

A fresh, superficial wound with no significant contamination and no devitalized tissue — for example, a clean surgical incision or a superficial cut with no soil/feces/saliva contact. A tick or other insect bite is also treated as a clean, minor wound unless it is unusually deep or visibly contaminated.^[1]

Any wound contaminated with dirt, dust, soil, feces, or saliva (including animal or human bites); puncture wounds; avulsions; wounds from missiles, crush injury, burns, or frostbite; any wound with devitalized tissue; a wound/burn where surgical care is delayed more than 6 hours; and any wound with clinical evidence of sepsis. Chronic wounds — abscesses, cellulitis, chronic ulcers — in a patient with diabetes or a history of injection drug use are classified here as well.^[1]

Step 2 — Match wound type and vaccination history to the indicated prophylaxis

This table reflects current Canadian public health guidance, built on the National Advisory Committee on Immunization's Canadian Immunization Guide, for tetanus post-exposure prophylaxis in wound management.^[1]^[6]

History of tetanus-containing vaccine	Clean, minor wound — Vaccine	Clean, minor wound — TIG	All other wounds — Vaccine	All other wounds — TIG
Unknown history, or fewer than 3 documented doses	Yes	No	Yes	Yes
3 or more doses, less than 5 years since the last dose	No	No	No^*	No^*
3 or more doses, 5 to under 10 years since the last dose	No	No	Yes	No^*
3 or more doses, 10 or more years since the last dose	Yes	No	Yes	No^*

^*Exception: a patient with humoral immune deficiency (e.g., HIV, agammaglobulinemia, hypogammaglobulinemia) or on an immunosuppressive medication may not mount an adequate response to vaccine alone. For any wound other than clean/minor, give both TIG and an age-appropriate vaccine dose regardless of how much time has passed since the last dose — consult the Medical Officer of Health as needed.^[1]

When both vaccine and TIG are indicated, give them at the same visit but at different anatomical sites with separate needles/syringes — never mix them or give both in the same limb. Do not give tetanus-containing vaccine into the gluteal region.^[1]

Which vaccine, by age

Age	Age-appropriate tetanus-containing vaccine
2 months up to and including 6 years	A pediatric DTaP-containing combination vaccine per the routine childhood schedule, or a Tdap-IPV-containing product if that schedule has already been completed
7 to 17 years	Tdap or Tdap-IPV
18 years and older	Tdap or Tdap-IPV. Td (no pertussis component) is a reasonable alternative if Tdap was already given recently or the pertussis component is not desired.

^[1]

Primary series and routine boosters — the other half of prevention

Complete protection is a primary series of at least 3 appropriately spaced doses, after which more than 99% of vaccinees develop protective antibody levels, followed by a booster every 10 years — or earlier, per the table above, if a tetanus-prone wound occurs in between.^[6]^[1] Every wound encounter is also an opportunity to check whether a patient is even due for their routine decennial booster, independent of the wound itself.

Tetanus immune globulin — dosing, and why prophylaxis and treatment doses differ

TIG is a human-plasma-derived product providing immediate passive protection until the patient's own vaccine-driven immunity develops.^[1] For wound prophylaxis, the standard dose is 250 units given by deep intramuscular injection in patients 7 years and older (4 units/kg in younger children).^[7] This is a much smaller dose than what is used to treat established clinical tetanus (see Special Populations and the Drug Tables), where historical regimens ranged as high as 3,000-6,000 units, though more recent evidence suggests 500 units achieves comparable effect.^[2]^[8] Give TIG as soon as possible after a tetanus-prone wound is identified; in a completely unimmunized patient it can still be considered up to 21 days after injury, together with vaccine.^[1]

Non-Pharmacologic Treatment

Clean and, where indicated, debride every wound thoroughly — this is the foundation of both prophylaxis and active-disease management, since it removes the anaerobic environment the organism needs to keep producing toxin.^[1]^[2]
In active tetanus, nurse the patient in a quiet, dimly lit, low-stimulation room — spasms are triggered and worsened by light, noise, and touch, so minimizing unnecessary handling and stimulation is a genuine part of therapy, not just comfort care.^[2]
Admit every case of active/suspected tetanus to an ICU-capable setting with continuous cardiorespiratory and autonomic monitoring, and a proactive, low threshold for securing the airway before overt respiratory failure develops.^[2]
Prefer tracheostomy over prolonged endotracheal intubation when ventilatory support extends beyond about 10 days — an endotracheal tube itself can stimulate spasms.^[2]
Provide high-calorie nutritional support (enteral or parenteral as needed) — the metabolic demands of sustained muscle contraction are substantial, and the illness and recovery are protracted.^[2]
Standard precautions are sufficient throughout — tetanus is not transmitted person to person, so no isolation is required.^[1]
Arrange physical and rehabilitation therapy proactively as spasms ease, since recovery from severe disease is measured in weeks to months.^[2]

Pharmacologic Treatment Options

Drug / intervention	Role	Dose / use	Important adverse effects	Teaching points
Tdap vaccine Preferred	Active immunization — routine decennial booster and first-choice wound-prophylaxis vaccine (adds pertussis coverage)	Single 0.5 mL IM dose, per the wound-prophylaxis decision table or the routine 10-year booster schedule	Injection-site pain/swelling, mild fever; rarely an Arthus-type hypersensitivity reaction with frequent re-dosing	Give at a different site than TIG if both are indicated, using a separate syringe; never into the gluteal region
Td vaccine Alternative	Active immunization when the pertussis component is not desired or was already given recently	Single 0.5 mL IM dose	Injection-site pain/swelling, mild fever	Reasonable substitute for Tdap in the same wound-prophylaxis decision table
Tetanus immunoglobulin (TIG) Preferred	Passive immunization — immediate protection while active immunity develops	Prophylaxis: 250 units IM (4 units/kg under age 7). Treatment of active tetanus: historically up to 3,000-6,000 units IM; 500 units IM appears comparably effective per more recent evidence	Injection-site soreness; hypersensitivity is rare since this is a human-plasma product	Always give at a different site than the vaccine dose, with a separate syringe — never combine them
Metronidazole Preferred	First-line antibiotic for active tetanus	500 mg IV every 6-8 hours, per local protocol and severity	GI upset, metallic taste, disulfiram-like reaction with alcohol, peripheral neuropathy with prolonged use	Preferred specifically because it lacks penicillin's GABA-antagonist activity — a genuinely important, non-obvious point in a disease already defined by lost GABA-mediated inhibition
Penicillin G Avoid	Historically used for active tetanus; now avoided	Not recommended as first-line therapy for tetanus	Hypersensitivity reactions, PLUS a theoretical GABA-A receptor antagonist effect that can worsen the very rigidity/spasm the toxin already causes	The single most important antibiotic-selection point in this chapter: choose metronidazole instead, even though penicillin remains appropriate for many other infections
Diazepam Preferred	First-line benzodiazepine for spasm control	10-40 mg IV every 1-8 hours, titrated to prevent spasms lasting more than 5-10 seconds	Sedation, respiratory depression at high cumulative doses, propylene glycol-related lactic acidosis with prolonged high-dose infusion	Requires meticulous, individualized titration in an ICU setting; midazolam is often preferred for prolonged infusion to avoid the lactic-acidosis risk
Magnesium sulfate (injection) Adjunct	Adjunct for spasm and autonomic instability control	5 g IV bolus, then 2-3 g/hour continuous infusion, titrated to serum magnesium 4-8 mEq/L	Areflexia and respiratory depression at excessive levels; hypotension	Monitor the patellar (knee-jerk) reflex at the bedside — its loss is an early, actionable sign of impending magnesium toxicity
Baclofen Special situation	Adjunct for refractory rigidity, ICU setting only	Intrathecal infusion in refractory cases, per specialist protocol; not a first-line agent	Sedation, hypotension, respiratory depression; abrupt discontinuation (especially intrathecal) can be life-threatening	Reserved for rigidity refractory to benzodiazepines and magnesium — specialist-directed, not initiated outside ICU care

Special Populations

Older adults

Canadians 75 and older have nearly quadruple (3.87 times) the tetanus incidence of those under 75, representing the age group at highest documented risk nationally — driven by waning vaccine-induced immunity decades after a childhood series, combined with low uptake of the routine 10-year adult booster.^[3] Every wound encounter, and ideally every periodic medication review, in an older adult is a genuine opportunity to check booster status rather than assuming a long-ago childhood series is still protective.

People who inject drugs

Maintain a high index of suspicion for tetanus risk in any wound related to injection drug use, particularly subcutaneous/intramuscular injection — the same anaerobic-wound mechanism responsible for wound botulism in this population.^[1] These patients are also disproportionately likely to have an incomplete or unknown vaccination history, and this encounter is a genuine opportunity for harm-reduction engagement alongside the tetanus assessment itself.

Occupational and recreational soil exposure

A 2023 Canadian case report illustrates how easily this risk is missed: a 33-year-old Saskatchewan soil-testing technologist with occupational dirt exposure across three prairie provinces developed generalized tetanus 10 days after small, self-treated hand abrasions from a physical altercation — abrasions minor enough that he never sought medical attention for them at the time. His vaccination history included at least 5 childhood doses but none in adulthood, with his last dose roughly 20 years earlier. He required 17 days of hospitalization, including ICU admission and intubation for hypercapnic respiratory failure, and was left with post-discharge muscle spasticity and a herniated disc requiring surgery, though he ultimately returned to work with minimal motor sequelae two years later.^[4] The case is a genuinely useful teaching example on two fronts: a small, "not worth a doctor's visit" wound can still be tetanus-prone when soil-contaminated, and a full childhood series does not remain protective indefinitely without adult boosters.

Pregnancy

Pregnancy is not a contraindication to either tetanus-containing vaccine or TIG — do not withhold indicated wound prophylaxis because a patient is pregnant. (Routine antenatal Tdap dosing for pertussis protection of the newborn is a separate, scheduled recommendation outside the scope of this wound-management chapter.)

Neonates, and Canada's maternal/neonatal tetanus elimination

Canada has formally validated the elimination of both maternal and neonatal tetanus, with zero confirmed cases identified across a national epidemiologic review spanning 1995-2019.^[3] This form of tetanus should not be encountered in Canadian pharmacy practice, but it remains a significant cause of vaccine-preventable neonatal death in regions with incomplete maternal immunization coverage, and is a useful global-health context point.

Humoral immune deficiency and immunosuppression

Patients with a humoral immune deficiency (HIV, agammaglobulinemia, hypogammaglobulinemia) or on an immunosuppressive medication may not respond adequately to tetanus-containing vaccine alone. For any wound other than clean/minor, give both TIG and an age-appropriate vaccine dose in these patients, regardless of how much time has passed since their last documented dose — consult the Medical Officer of Health if there is any uncertainty.^[1]

Diabetic foot ulcers and other chronic wounds

Chronic wounds — diabetic foot ulcers, venous or pressure ulcers, and chronic cellulitis — are classified as tetanus-prone in the wound-prophylaxis table above, precisely because they don't look like a fresh traumatic injury and are easy to overlook as a tetanus risk during routine chronic-wound care.^[1] Build a tetanus-status check into any structured wound-care follow-up for these patients.

Renal and hepatic impairment

No dose adjustment is required for tetanus-containing vaccine or TIG in renal or hepatic impairment. Among the active-treatment drugs, adjust benzodiazepine dosing/monitoring for hepatic impairment (diazepam has active metabolites that can accumulate), and reduce the magnesium sulfate infusion rate and increase monitoring frequency in renal impairment, since reduced clearance raises the risk of magnesium toxicity — watch the patellar reflex especially closely in this group.

Monitoring & Follow-Up

After giving wound prophylaxis, document exactly what was given (vaccine, TIG, or both), the anatomical site of each, and the lot number, and update the patient's own immunization record — this documentation is what allows the next tetanus-prone wound to be assessed accurately instead of defaulting to "unknown history."^[1]
Refer any patient who received prophylaxis because of an unknown or incomplete history to Public Health to complete the full primary series — a single wound-triggered dose is not a substitute for a proper 3-dose series.^[1]
For active/suspected tetanus, once stabilized and escalated to emergency/ICU care, monitor respiratory status, spasm frequency/severity, and autonomic parameters (heart rate, blood pressure) continuously — recovery is protracted, typically weeks, and can take months for full resolution.^[2]
Complete a full primary tetanus vaccination series at recovery from clinical tetanus, regardless of how many doses the patient had before the illness. Surviving a natural tetanus infection does not confer future immunity — unlike most infections in this platform's library, the tiny amount of toxin involved in even a severe clinical case is far too small to trigger a durable protective antibody response. This is a genuinely high-yield, easy-to-miss point: a patient who has already "had tetanus" still needs the same full series as someone who has never had a dose.^[2]^[8]
Tetanus is a nationally notifiable disease in Canada — confirm that public health reporting has occurred for any confirmed case, typically coordinated by the treating hospital.^[5]

Treatment Failure / Next Step

Spasms continuing or worsening despite adequate benzodiazepine titration: escalate the ICU care plan — add or increase magnesium sulfate infusion, and involve critical care for propofol or neuromuscular blockade with mechanical ventilation if rigidity is truly refractory.^[2]
Autonomic instability (labile blood pressure/heart rate) refractory to magnesium and sedation: involve critical care/cardiology for further management; avoid non-selective beta-blockers, which have been associated with sudden cardiac death in this setting, and use a short-acting agent like esmolol only with strict titration and monitoring if a beta-blocker is felt necessary.^[2]
Ongoing or recurrent toxemia despite TIG and antibiotics: reassess the wound for incompletely debrided or undrained tissue and consider repeat surgical exploration — the wound remains the toxin source until it is truly controlled.^[1]^[2]
Uncertainty persists about a patient's vaccination history after reasonable effort to obtain records: treat as unimmunized/inadequately immunized per the decision table, and refer to Public Health both to pursue the records and to complete the primary series going forward — do not leave the prophylaxis decision unresolved while records are pending.^[1]
TIG is not immediately available at the point of care: do not delay wound care or the vaccine dose while arranging TIG access — follow local/zone processes to obtain it as soon as possible, and give it as soon as it arrives (it retains meaningful benefit for up to about 21 days post-injury in a completely unimmunized patient).^[1]

Common Errors to Avoid

Treating a small, "not worth a doctor's visit" wound as automatically low-risk — a soil-contaminated abrasion can cause tetanus exactly as the Saskatchewan case in Special Populations illustrates.^[4]
Assuming a completed childhood vaccination series remains protective indefinitely — protection wanes, and the decennial booster genuinely matters, especially in older adults.^[3]
Giving TIG and the vaccine dose in the same syringe or at the same injection site — always use separate syringes and different anatomical sites.^[1]
Withholding indicated vaccine or TIG because a patient is pregnant — pregnancy is not a contraindication to either.
Reaching for penicillin as the antibiotic of choice for active tetanus out of habit — its GABA-antagonist activity can worsen the disease's own core mechanism; use metronidazole instead.^[2]
Assuming that surviving a tetanus infection confers future immunity — it does not, and the full primary series must still be completed at recovery.^[2]^[8]
Delaying prophylaxis while waiting for immunization records to arrive from another province, territory, or country — make the best assessment available at the visit instead.^[1]
Overlooking tetanus risk in chronic wounds (diabetic foot ulcers, chronic ulcers) because they don't present as a fresh traumatic injury.^[1]
Missing tetanus in the differential for new trismus/jaw stiffness because it "looks dental" — a genuine wound history should always be asked about.
Assuming a tick or insect bite always needs TIG regardless of vaccination history — it is treated as a clean, minor wound unless unusually deep or visibly soil-contaminated.^[1]

Clinical Decision Algorithm

Algorithm A — Recognizing and escalating active tetanus

New trismus, facial/neck rigidity, or muscle spasm — especially if triggered by light, sound, or touch

Treat as tetanus on clinical grounds alone — there is no rapid confirmatory test, and wound culture is frequently negative even in true disease^[2]^[5]

Call 911 / arrange immediate emergency transfer. Move the patient to a quiet, dark, low-stimulation environment while awaiting transfer^[2]

In the emergency department: debride the wound, give TIG (treatment dose) and metronidazole (avoid penicillin), control spasm with benzodiazepines/magnesium, and manage the airway proactively — admit to an ICU-capable setting^[2]^[1]

Algorithm B — Wound tetanus-prophylaxis decision pathway

Any new wound presenting for care

Clean and, where indicated, debride the wound first — regardless of tetanus risk

Classify the wound: clean/minor, or any other (tetanus-prone) wound — contaminated with dirt/feces/soil/saliva, puncture, avulsion, crush/missile/burn/frostbite injury, devitalized tissue, delayed surgical care over 6 hours, or a chronic wound in diabetes/injection drug use^[1]

Assess vaccination history: number of documented tetanus-containing doses and time since the most recent one — do not delay while records are requested from elsewhere^[1]

Clean, minor wound

3+ doses, under 10 years since last dose: no vaccine, no TIG

Unknown history, fewer than 3 doses, OR 10+ years since last dose: give vaccine now; TIG not needed^[1]

Any other (tetanus-prone) wound

3+ doses, under 5 years since last dose: no vaccine, no TIG (unless humoral immune deficiency — see Special Populations)

3+ doses, 5 years or more since last dose: give vaccine now; TIG not needed

Unknown history or fewer than 3 doses: give BOTH vaccine and TIG now, at different sites with separate syringes; refer to Public Health to complete the primary series^[1]

Document exactly what was given and where, and update the patient's own immunization record for next time^[1]

Drug Tables

How to use this table: vaccine and TIG doses reflect the wound-prophylaxis decision table in Choose Initial Treatment; ICU drug doses require patient-specific confirmation (renal/hepatic function, weight, concurrent sedation) and are shown for context, not community initiation. Select any drug name to open its complete Pharmasist Drug Database page.

Tetanus Toxoid-Containing Vaccines — Active Immunization

See Choose Initial Treatment for the full wound-prophylaxis decision table and age-appropriate vaccine selection.

Drug	Dosage	Adverse effects	Drug interactions	Comments
Tdap — Diphtheria, Tetanus, and Acellular Pertussis Vaccine (Boostrix)	Ages 7 and older: Single 0.5 mL IM dose	Injection-site pain/swelling, mild fever; rarely an Arthus-type reaction with frequent re-dosing	None significant	First-choice vaccine for both the routine 10-year adult booster and wound prophylaxis — adds pertussis coverage.
Tdap — Tetanus Toxoid, Reduced Diphtheria Toxoid and Acellular Pertussis Vaccine (Adacel)	Ages 7 and older: Single 0.5 mL IM dose	Injection-site pain/swelling, mild fever; rarely an Arthus-type reaction with frequent re-dosing	None significant	A second approved Tdap product — interchangeable with Boostrix for booster/prophylaxis purposes.
Tdap-IPV (Adacel-Polio)	Ages 7 and older: Single 0.5 mL IM dose	As above, plus standard inactivated poliovirus vaccine component reactions	None significant	Adds inactivated poliovirus coverage — used where a polio booster is also indicated (e.g., some catch-up schedules).
Td — Tetanus and Diphtheria Toxoids Adsorbed	Adults: Single 0.5 mL IM dose	Injection-site pain/swelling, mild fever	None significant	Alternative when the pertussis component is not desired or was already given recently.

Tetanus Immunoglobulin (TIG) — Passive Immunization

Prophylaxis and treatment doses differ substantially — see the dose column. Always give at a different anatomical site than the vaccine dose, using a separate syringe.

Drug	Dosage	Adverse effects	Drug interactions	Comments
Tetanus Immunoglobulin (Human) — HyperTET	Wound prophylaxis, age 7+: 250 units IM Wound prophylaxis, under age 7: 4 units/kg IM Treatment of active tetanus: Historically up to 3,000-6,000 units IM; 500 units IM appears comparably effective per more recent evidence	Injection-site soreness; hypersensitivity is rare since this is a human-plasma product, unlike equine antitoxins used for other toxin-mediated diseases	May blunt the immune response if given at the same site/syringe as the vaccine dose — always separate	Provides immediate passive protection while active vaccine-driven immunity develops.

Antimicrobial Therapy for Active Tetanus

Antibiotics treat the local wound infection/organism burden — they do not neutralize circulating toxin, which is TIG's role.

Drug	Dosage	Adverse effects	Drug interactions	Comments
Metronidazole	Adults: 500 mg IV every 6-8 hours, per local protocol and severity	GI upset, metallic taste, peripheral neuropathy with prolonged use	Disulfiram-like reaction with alcohol	First-line — lacks penicillin's GABA-antagonist activity, a genuinely important distinction in a disease already defined by lost GABA-mediated inhibition.
Penicillin G	Avoid: Not recommended as first-line therapy for active tetanus	Hypersensitivity reactions, PLUS a theoretical GABA-A receptor antagonist effect that can worsen tetanus-related rigidity/spasm	None significant at standard doses	No longer recommended for tetanus specifically, despite remaining first-line for many other infections — choose metronidazole instead.

Spasm and Autonomic Control (ICU Setting)

Meticulous, individualized titration in an ICU setting is standard — these are not community-pharmacy-initiated therapies, but pharmacists should understand the regimen a hospitalized patient is on.

Drug	Dosage	Adverse effects	Drug interactions	Comments
Diazepam	Adults: 10-40 mg IV every 1-8 hours, titrated to prevent spasms lasting more than 5-10 seconds	Sedation, respiratory depression at high cumulative doses, propylene glycol-related lactic acidosis with prolonged high-dose use	Additive CNS/respiratory depression with opioids and other sedatives	First-line for spasm control; midazolam is often preferred for prolonged continuous infusion to avoid the lactic-acidosis risk.
Midazolam	Adults: 5-15 mg/hour IV continuous infusion	Sedation, respiratory depression	Additive CNS/respiratory depression with opioids and other sedatives	Preferred over diazepam for prolonged continuous infusion — shorter half-life, no propylene glycol/lactic-acidosis concern.
Magnesium Sulfate, Injection	Adults: 5 g IV bolus, then 2-3 g/hour continuous infusion, titrated to serum magnesium 4-8 mEq/L	Areflexia and respiratory depression at excessive serum levels; hypotension	Additive neuromuscular blockade with other CNS/neuromuscular depressants	Adjunct for spasm and autonomic instability control — monitor the patellar reflex at the bedside as an early clinical marker of impending toxicity.
Baclofen	Refractory cases only: Intrathecal infusion per specialist protocol; not first-line	Sedation, hypotension, respiratory depression; abrupt discontinuation (especially intrathecal) can be life-threatening	Additive CNS depression with other sedatives	Reserved for rigidity refractory to benzodiazepines and magnesium — typically given intrathecally, specialist-directed.

References

Tetanus Prevention, Prophylaxis and Wound/Injury Management Standard #08.400 — Primary Care Alberta, Provincial Immunization Program (Public Health, CDC & Screening). Standard #08.400, Published June 15, 2026
Tetanus — StatPearls Publishing (Bae C, Bourget D). StatPearls [Internet], Treasure Island (FL), 2026
Epidemiology of tetanus in Canada, 1995-2019 — Canadian Journal of Public Health (Salem N, Huang G, Squires SG, Salvadori MI, Li YA). Can J Public Health 2023;114(3):432-440
Tetanus in a vaccinated soil expert - a case report — BMC Infectious Diseases (Medu O, Ogunyemi N, Hennink M, et al.). BMC Infect Dis 2023;23:760
National case definition: Tetanus — Public Health Agency of Canada. Government of Canada, Case Definitions for Communicable Diseases
Tetanus toxoid: Canadian Immunization Guide — National Advisory Committee on Immunization / Public Health Agency of Canada. Government of Canada, Canadian Immunization Guide
Tetanus Immune Globulin (Human) HyperTET, 250 Units — Prescribing Information — Grifols Therapeutics LLC. DailyMed, U.S. National Library of Medicine
Tetanus — MSD Manual Professional Edition. MSD Manual Professional Edition

Professional reference only. Apply clinical judgment and verify patient-specific decisions against current authoritative guidance and product information.