Strychnine poisoning occurs after accidental or intentional ingestion of strychnine, a bitter-tasting alkaloid most commonly found in rodenticides. Severe neurological impairment manifesting with convulsions and myoclonus and respiratory insufficiency rapidly ensue, and the diagnosis is often made post-mortem, as poisoning is frequently life-threatening.
Presentation
The clinical presentation stems from the deleterious effects of strychnine on the central nervous system (CNS). By reducing the activity of glycine, the main inhibitory neurotransmitter in the CNS, strychnine causes profound motor stimulation as early as 10-30 minutes after ingestion, which is considered to be the main mode of poison introduction into the human body, but rare cases have documented dermal exposure as a mode of poisoning [1] [2] [3]. Muscle spasms and agitation may be encountered early on, followed by characteristic spasms of flexors of the upper limbs and extensors of the lower limbs, opisthotonos and risus sardonicus - spasm of the facial muscles [1]. In addition to enhanced muscle activity, convulsions are a constitutive feature of strychnine poisoning, primarily in the form of generalized attacks [1] [2]. In virtually all cases, convulsions are provoked by sensory stimuli, as hyperacuity of hearing, vision, and tactile sensation are also consequences of poisoning [4]. It must be noted that the patient is awake and conscious at the time of convulsions and during the appearance of muscle spasms [2]. Moreover, hyperthermia, rhabdomyolysis, renal failure due to myoglobinuria, and severe metabolic acidosis can develop in the setting of prolonged spasms [2], but the most important complication is the respiratory failure [3]. Spasms of the muscles of the chest and diaphragm are the main cause of death, and the majority of patients suffer from fatal respiratory distress before even reaching the hospital [2] [3].
Entire Body System
- Severe Pain
When this “off switch” does not work correctly, muscles throughout the body have severe, painful spasms. [web.archive.org]
- Chest Discomfort
One hour after she drank the second bowl of herbal decoction, she suddenly developed tonic contractions of all her limb muscles and carpopedal spasm lasting 5 min, difficulty in breathing, chest discomfort and perioral numbness. [ncbi.nlm.nih.gov]
- Intravenous Administration
Treatment consisted of gastric lavage with water, oral administration of activated charcoal and sorbitol solution, continuous intravenous administration of midazolam and then sodium thiopental, furosemide, sodium bicarbonate and hemodialysis for acute [ncbi.nlm.nih.gov]
Gastrointestinal
- Abdominal Cramps
She then developed trismus and abdominal cramping, after which a family member said the bottle contained a compound called "slang nut." [ncbi.nlm.nih.gov]
- Abdominal Pain
Profound hypokalemia is the most characteristic effect, in addition to abdominal pain, nausea and vomiting, and altered mental status. [emedicine.medscape.com]
Cardiovascular
- Chest Pain
The patient first complained of chest pain, which was originally thought to be caused by a dissecting aneurysm; however, nystagmus, dysesthesia, spastic paraplesia, and hyperreactivity to stimuli shortly developed. [ncbi.nlm.nih.gov]
Jaw & Teeth
- Trismus
BACKGROUND: In 1933 in Leon, Nicaragua, a 22-year-old woman died after an acute convulsive illness in which she experienced trismus, opisthotonos, and hyperpyrexia. [ncbi.nlm.nih.gov]
Classic signs include opisthotonus, facial trismus, and risus sardonicus. Differential diagnosis includes: Tetanus: However, the onset of symptoms is more gradual and the duration much longer than in the case of strychnine poisoning. [umem.org]
- Jaw Pain
CASE REPORT: A 40-year-old Cambodian woman presented to the emergency department with a complaint of jaw pain and spasms. The patient was staying with a relative and drank 2 oz from an unmarked bottle that she thought contained vodka. [ncbi.nlm.nih.gov]
Musculoskeletal
- Muscle Twitch
Strychnine poisoning usually manifests with a prodrome of nausea, agitation, muscle twitching and spasms that develops within minutes of ingestion, but occasionally may not be evident for 1-2 hours. [lifeinthefastlane.com]
The skin perception becomes aggravated, a crawling sensation appears, small muscle twitches, numbness, the slightest sound, light - irritate. Chewing muscles are strongly strained, swallowing is difficult. [en.intoxication-stop.com]
- Carpopedal Spasm
One hour after she drank the second bowl of herbal decoction, she suddenly developed tonic contractions of all her limb muscles and carpopedal spasm lasting 5 min, difficulty in breathing, chest discomfort and perioral numbness. [ncbi.nlm.nih.gov]
- Muscle Cramp
Its also possible that LSD itself simply causes adverse physical effects, particularly muscle cramping, in persons suceptible to it. [erowid.org]
Face, Head & Neck
- Risus Sardonicus
Muscle spasms and agitation may be encountered early on, followed by characteristic spasms of flexors of the upper limbs and extensors of the lower limbs, opisthotonos and risus sardonicus - spasm of the facial muscles. [symptoma.com]
Classic signs include opisthotonus, facial trismus, and risus sardonicus. Differential diagnosis includes: Tetanus: However, the onset of symptoms is more gradual and the duration much longer than in the case of strychnine poisoning. [umem.org]
Therefore: C onvulsions R eflex increased A wful taste M ind is conscious P upils dilated Awful, bitter taste Clonic-tonic convulsions Opisthotonos: arching back Emprosthotonos: arching forward Pleurothotonus: bending sideward Risus Sardonicus: Evil fixed [medpreponline.com]
This may manifest as painful grimacing (the sardonic smile of risus sardonicus ) or back arching (opisthotonus). [lifeinthefastlane.com]
Consider strychnine toxicity if an individual presents with a generalized seizure-like appearance but without loss of consciousness or extensor posturing with risus sardonicus. [emedicine.medscape.com]
Neurologic
- Seizure
The patient survived despite the development of seizures, lactic acidosis, rhabdomyolysis, and pulmonary infiltrates. Toxicology testing confirmed the presence of strychnine in blood (2.17 mg/L), gastric aspirate, and urine. [ncbi.nlm.nih.gov]
Standard treatment is gastric lavage (stomach pump), which seems to be falling out of favor, and benzodiazepines or phenobarbital to control seizures. [naturespoisons.com]
- Opisthotonus
The clinical features mimic tetanus with sense of suffocation, twitching of muscles, followed by tetanic convulsions and opisthotonus, each lasting half to two minutes. Consciousness is not lost and mind remains clear till death. [medchrome.com]
Classic signs include opisthotonus, facial trismus, and risus sardonicus. Differential diagnosis includes: Tetanus: However, the onset of symptoms is more gradual and the duration much longer than in the case of strychnine poisoning. [umem.org]
This may manifest as painful grimacing (the sardonic smile of risus sardonicus ) or back arching (opisthotonus). [lifeinthefastlane.com]
A phenomenon, called opisthotonus may also occur, in which severe contraction of the paraspinal muscles causes a characteristic arching posture of the neck and back. [calpoison.org]
- Hyperreflexia
The ten main symptoms of strychnine poisoning: Initial symptoms are tightness and twitching of the muscles, agitation and hyperreflexia. Stiffness of the body. Lockjaw. Frothing of the mouth. Cessation of respiration. [chm.bris.ac.uk]
[…] eflex increased A wful taste M ind is conscious P upils dilated Awful, bitter taste Clonic-tonic convulsions Opisthotonos: arching back Emprosthotonos: arching forward Pleurothotonus: bending sideward Risus Sardonicus: Evil fixed grin Dilated pupils Hyperreflexia [medpreponline.com]
Needless to say, a “thumbnail-sized” portion is worrying… Muscle spasms and rigidity generally resolve within 24 hours, although ongoing hyperreflexia and increased tone may persist for up to a week or so. [lifeinthefastlane.com]
Strychnine, an indole found in the seeds, is a powerful central nervous system stimulant that competes with the inhibitory neurotransmitter glycine, producing an excitatory state with hyperreflexia, severe muscle spasm, and convulsions. [thepoisongarden.co.uk]
- Dysesthesia
The patient first complained of chest pain, which was originally thought to be caused by a dissecting aneurysm; however, nystagmus, dysesthesia, spastic paraplesia, and hyperreactivity to stimuli shortly developed. [ncbi.nlm.nih.gov]
- Nystagmus
The patient first complained of chest pain, which was originally thought to be caused by a dissecting aneurysm; however, nystagmus, dysesthesia, spastic paraplesia, and hyperreactivity to stimuli shortly developed. [ncbi.nlm.nih.gov]
Workup
An immediate laboratory workup comprising serum lactate levels, arterial blood gasses (ABG), pH measurement, and renal function tests must be performed in patients who are admitted to the hospital with profound spasms and generalized convulsions, to initiate adequate therapeutic measures and to save the patient's life. The diagnosis of strychnine poisoning may be difficult to make, however, as poisoning by this substance is very rare, but details from patient history such as recent exposure to rodenticides or use of intravenous drugs (strychnine was shown to be added as an adulterant drug to cocaine, heroin, and amphetamines) may be helpful [2]. Interview with friends or family should be conducted to assess the mental state of the patient, like attempted suicide using strychnine is also an important mode of intoxication [1]. In patients with an undisclosed cause of symptoms, especially in the setting of a sudden death, a routine toxicology report and a meticulous post-mortem examination are necessary [5]. Identifying strychnine as the underlying cause of symptoms can be made by its quantitative evaluation in body fluids (blood and urine) and tissues. Gas chromatography (GC) is recommended, both anti-mortem and post-mortem [1] [3]. It is the main diagnostic tool, and two methods have been mentioned in literature - GC-flame ionization detection (GC-FID) and GC nitrogen-phosphorus detection (GC-NPD) [3]. Mass spectrometry is another laboratory procedure that could be performed for detection of strychnine [1] [3].
X-Ray
- Pulmonary Infiltrate
The patient survived despite the development of seizures, lactic acidosis, rhabdomyolysis, and pulmonary infiltrates. Toxicology testing confirmed the presence of strychnine in blood (2.17 mg/L), gastric aspirate, and urine. [ncbi.nlm.nih.gov]
Treatment
Successful treatment requires aggressive airway control and treatment of seizures with benzodiazepines or barbiturates. Neuromuscular blockade may be required. [ncbi.nlm.nih.gov]
Prognosis
If the patient survives past 24 hours, the prognosis is good and a full recovery is probable. [path.upmc.edu]
Etiology
(See Etiology, Presentation, and Workup .) Since the mid-20th century, anticoagulant substances have been the mainstays of rodenticide products. [emedicine.medscape.com]
Epidemiology
The pathophysiology and epidemiology of strychnine poisoning is reviewed and discussed in context. [ncbi.nlm.nih.gov]
[…] major books: (1) Toxicology of Organophosphate and Carbamate Compounds, (2) Veterinary Toxicology: Basic and Clinical Principles, (3) Handbook of Toxicology of Chemical Warfare Agents, (4) Anticholinesterase Pesticides: Metabolism, Neurotoxicity, and Epidemiology [books.google.de]
(See Epidemiology.) [1] Red squill The botanical preparation of red squill, containing a cardiac glycoside as an active ingredient, was used as a rodenticide for many years. [emedicine.medscape.com]
Pathophysiology
The pathophysiology and epidemiology of strychnine poisoning is reviewed and discussed in context. [ncbi.nlm.nih.gov]
Prevention
The Centers for Disease Control and Prevention (CDC) protects people’s health and safety by preventing and controlling diseases and injuries; enhances health decisions by providing credible information on critical health issues; and promotes healthy living [web.archive.org]
What makes tetanus different is that it prevents the release of glycine at the nerve terminal. [calpoison.org]
[email protected] The Centers for Disease Control and Prevention (CDC) protects people’s health and safety by preventing and controlling diseases and injuries; enhances health decisions by providing credible information on critical health issues; and [emergency.cdc.gov]
References
- Rosano TG, Hubbard JD, Meola JM, Swift TA. Fatal strychnine poisoning: application of gas chromatography and tandem mass spectrometry. J Anal Toxicol. 2000;24(7):642-647.
- Wood DM, Webster E, Martinez D, Dargan PI, Jones AL. Case report: Survival after deliberate strychnine self-poisoning, with toxicokinetic data. Crit Care. 2002;6(5):456-459.
- Greene R, Meatherall R. Dermal exposure to strychnine. J Anal Toxicol. 2001;25(5):344-347.
- Porter RS, Kaplan JL. Merck Manual of Diagnosis and Therapy. 19th Edition. Merck Sharp & Dohme Corp. Whitehouse Station, N.J; 2011.
- Kodikara S. Strychnine in amoxicillin capsules: a means of homicide. J Forensic Leg Med. 2012;19(1):40-41.