How Poison Actually Works: Writing Toxins Realistically

Your character drinks poisoned wine. They immediately clutch their throat, gasp dramatically, and fall dead within seconds. Except that's not how ingested poison works. Poison taken by mouth needs time to be absorbed through digestive system before it can take effect - minimum 15-30 minutes, often longer.

Or your character is poisoned but saved by "the antidote" - a generic cure that works on any poison. Except antidotes are highly specific. There's no universal antidote. Treatment for arsenic won't help with cyanide. Treatment for snake venom won't help with plant toxins.

Poison in fiction is often portrayed with Hollywood convenience rather than toxicological reality. Understanding how poison actually works - absorption time, symptom progression, treatment options - makes your poisoning scenes believable and your mysteries harder to solve through impossible means.

How Poison Actually Kills

Poison is any substance that damages or kills through chemical reaction in body. Mechanism varies by poison type.

Poison Categories

**Neurotoxins**: Attack nervous system. Cause paralysis, seizures, or respiratory failure. Examples: many snake venoms, botulinum toxin, organophosphates.

**Cytotoxins**: Kill cells directly. Cause tissue death and organ damage. Examples: some mushroom toxins, radiation poisoning.

**Cardiotoxins**: Affect heart function. Cause arrhythmia or cardiac arrest. Examples: digitalis, aconite.

**Hemotoxins**: Destroy blood cells or prevent clotting. Cause internal bleeding. Examples: some snake venoms, warfarin.

**Metabolic poisons**: Interfere with cellular processes. Block oxygen use or disrupt metabolism. Examples: cyanide, carbon monoxide.

Dose Makes the Poison

Dosage is critical. Small amount might cause illness. Large amount kills. Tiny amount might be undetectable.

**Lethal dose varies**: By victim's size, health, age. Child needs less poison than adult. Sick person more vulnerable than healthy.

**Cumulative poisons**: Some accumulate in body over time. Small non-lethal doses become lethal when built up. Arsenic, lead, mercury work this way.

Delivery Methods and Timing

How poison enters body determines how fast it works.

Ingested (Swallowed)

**Slowest method**: Must travel through stomach and intestines, be absorbed into bloodstream, then reach target organs.

**Timing**: Minimum 15-30 minutes before symptoms. Often 30-60 minutes. Can be hours for slow-acting poisons.

**Food delays absorption**: Poison in full stomach takes longer to absorb than poison on empty stomach.

**Vomiting window**: If victim vomits quickly (within 15-20 minutes), might expel poison before absorption. Once absorbed, vomiting doesn't help.

**Taste issue**: Many poisons taste bad (bitter, metallic). Must be disguised in strongly flavored food/drink or victim notices.

Injected (Venom, Dart, Syringe)

**Faster**: Enters bloodstream directly or from muscle.

**Timing**: Minutes to symptoms. 5-30 minutes typically, depending on injection site and poison type.

**Location matters**: Injection near major blood vessel (neck, groin) acts faster than extremity. Heart and brain affected first once poison reaches bloodstream.

**Still not instant**: Even injected poison needs time to circulate and accumulate at target organs.

Inhaled (Gas, Smoke, Powder)

**Fastest method**: Absorbed through lungs directly into bloodstream. Large surface area, rich blood supply.

**Timing**: Seconds to minutes for symptoms.

**Examples**: Carbon monoxide, hydrogen cyanide gas, chlorine gas, poisonous smoke.

**Escape possibility**: If removed from poison gas quickly enough, may survive. Prolonged exposure increasingly lethal.

Contact (Skin Absorption)

**Slowest and least reliable**: Skin is barrier. Only certain poisons can penetrate it.

**Timing**: Hours to days typically. Rarely lethal unless prolonged contact with potent toxin.

**Examples**: Some plant toxins (poison ivy causes reaction not death), certain insecticides, ricin (through mucous membranes).

**Mucous membranes faster**: Eyes, nose, mouth have thinner barriers. Contact poisoning more effective here but still slower than other methods.

Common Historical Poisons

Arsenic

**Classic murder poison**: Readily available historically (rat poison, pigments, medicines). Tasteless when dissolved.

**Symptoms**: Nausea, vomiting, abdominal pain, diarrhea (often bloody), dehydration. Mimics cholera or food poisoning.

**Timing**: Acute poisoning shows symptoms in 30 minutes to 2 hours. Death in hours to days without treatment.

**Chronic poisoning**: Small doses over time accumulate. Causes general illness, hair loss, skin lesions. Takes weeks to months. Hard to detect as murder.

**Treatment**: Supportive care (fluids, electrolytes). Chelation therapy if available (modern treatment). Historical survival was possible but difficult.

Cyanide

**Fast-acting**: Blocks cells from using oxygen. Body suffocates at cellular level.

**Symptoms**: Rapid breathing, confusion, seizures, loss of consciousness, cardiac arrest. Bitter almond smell (some people can't detect this).

**Timing**: Symptoms within minutes. Death within minutes to hours depending on dose.

**Sources**: Natural (bitter almonds, apple seeds, cassava) and synthetic. Historically less common than modern era.

**Treatment**: Antidote exists (hydroxocobalamin, sodium thiosulfate) but must be given quickly. Without treatment, often fatal.

Hemlock

**Famous plant poison**: Socrates' execution method.

**Symptoms**: Gradual paralysis starting in legs and moving upward. Conscious throughout. Eventually respiratory paralysis causes death by suffocation.

**Timing**: Symptoms start 30 minutes to 2 hours after ingestion. Death in 2-6 hours.

**Treatment**: No specific antidote. Supportive care (artificial respiration) can keep victim alive until poison metabolizes. Otherwise fatal.

Aconite (Wolfsbane, Monkshood)

**Extremely toxic plant**: Called "queen of poisons."

**Symptoms**: Numbness and tingling in mouth and extremities, nausea, vomiting, weakness, confusion, heart arrhythmias, cardiac arrest.

**Timing**: Symptoms within 10-30 minutes. Death within 2-6 hours.

**Treatment**: No specific antidote. Supportive care for heart and breathing. Often fatal despite treatment.

Belladonna (Deadly Nightshade)

**Anticholinergic poison**: Blocks nervous system signals.

**Symptoms**: Dilated pupils, blurred vision, dry mouth, flushed skin, fever, hallucinations, delirium, seizures, coma.

**Timing**: Symptoms within 30-60 minutes. Death (if untreated) in hours to days.

**Distinctive**: Widely dilated pupils are diagnostic. Phrase "mad as a hatter, blind as a bat, red as a beet, hot as hell, dry as a bone."

**Treatment**: Antidote exists (physostigmine) but risky. Supportive care often sufficient if patient survives acute phase.

Symptoms and Progression

Poisoning isn't instant collapse. There's progression.

Early Stage (First Symptoms)

**Common early signs**: Nausea, dizziness, confusion, weakness, numbness, tingling, abdominal pain.

**Victim might not recognize**: Early symptoms can seem like illness, food poisoning, drunkenness. Victim may not realize they're poisoned until serious symptoms develop.

**Still functional**: Victim can still move, talk, think (though increasingly impaired). Not immediately incapacitated.

Mid-Stage (Serious Symptoms)

**Specific poison effects emerge**: Paralysis, seizures, hallucinations, severe pain, difficulty breathing, heart irregularities.

**Victim knows something's very wrong**: Can no longer dismiss as minor illness. Clear medical emergency.

**Function severely impaired**: May collapse, unable to walk, confusion worsening, speech difficult.

Late Stage (Organ Failure)

**Critical systems failing**: Respiratory failure, cardiac arrest, multi-organ failure, coma.

**Loss of consciousness**: Victim no longer aware or able to respond.

**Death or survival**: Depends on treatment, dose, and victim's constitution.

Writing the Progression

Show stages rather than instant collapse:

"She felt dizzy suddenly, nauseated. Too much wine, maybe. She reached for her water glass. Her hand was shaking. Why was her hand shaking? The room tilted. She tried to stand, stumbled. Her legs wouldn't hold her. Something was very wrong."

This is more realistic than: "She drank the wine and immediately fell dead."

Antidotes and Treatment

Specific Antidotes Are Rare

**No universal antidote**: Each poison requires specific treatment if antidote exists at all.

**Common antidotes**:

- Cyanide: hydroxocobalamin, sodium thiosulfate

- Opioids: naloxone (Narcan)

- Acetaminophen: N-acetylcysteine

- Heavy metals: chelation therapy

- Snake venom: antivenin (specific to snake species)

**Most poisons have no antidote**: Treatment is supportive care.

Supportive Care

Without specific antidote, treatment keeps victim alive while body metabolizes poison:

**Breathing support**: Artificial respiration, oxygen, ventilator.

**Circulation support**: IV fluids, medications to stabilize blood pressure and heart rhythm.

**Organ support**: Dialysis for kidney failure, treating symptoms as they arise.

**Decontamination**: Activated charcoal (binds poison in stomach), gastric lavage (stomach pumping - mostly outdated), washing skin.

**Time**: Keep victim alive long enough for poison to break down naturally.

Medieval/Historical Treatment

**Very limited**: No modern antidotes, no ventilators or dialysis, no IV fluids.

**Induced vomiting**: Using emetics (substances that cause vomiting). Only helps if done quickly, before absorption.

**Theriac**: Historical "universal antidote" that didn't actually work. Mixture of many ingredients including viper flesh. Placebo at best.

**Survival was luck**: Strong constitution, sub-lethal dose, or body metabolizing poison fast enough.

Fantasy Antidotes

If writing fantasy with magical antidotes:

**Consider limitations**: Is there universal antidote (very powerful magic) or specific cures for specific poisons? How rare/expensive? Can it cure any poison or only if given in time?

**Create tension**: Even with magic cure, might not reach victim in time. Or cure is extremely rare. Or requires identifying poison first.

Detection and Mystery

Poison Detection (Historical)

**Very difficult**: No toxicology labs. Relied on symptoms, circumstantial evidence, taste/smell.

**Metallic poisons easier**: Arsenic, antimony, mercury leave traces. Could be detected chemically (by 1800s) or observed in body/organs during autopsy.

**Plant poisons harder**: Organic compounds break down. Less obvious at autopsy unless distinctive symptoms present.

**Perfect murder weapon**: Historical poisoning was hard to prove, making it attractive to murderers.

Modern Detection

**Toxicology screens**: Blood and tissue analysis can identify most poisons. Takes time (not instant results like TV shows).

**Requires suspicion**: Have to test for specific things. Can't test for "poison" generally - need idea what to look for.

**Some poisons still difficult**: Rare toxins or those that break down quickly might be missed.

Creating Mystery

**Delayed symptoms**: Victim poisoned hours before symptoms. Hard to identify when poisoning occurred.

**Mimics natural death**: Poison causing heart attack or stroke. Looks like natural causes unless someone suspects foul play.

**Uncommon poison**: Investigators don't think to test for rare or exotic toxin.

**Multiple suspects**: Many people had opportunity during relevant time window.

Common Mistakes

**Instant death from drinking**: Needs time to absorb. Minimum 15-30 minutes, usually longer.

**Dramatic throat clutching**: Symptom of choking, not poisoning. Poisoning causes varied symptoms depending on type.

**Generic "antidote"**: No universal cure. Treatment is specific to poison.

**Vomiting cures it**: Only helps if done immediately, before absorption. Once absorbed, too late.

**Poisoner unaffected**: If poisoning shared food/drink, poisoner must avoid consuming it or have taken preventive measure.

**No residue**: Liquid poisons leave residue in glass/bottle. Solid poisons leave powder or particles. Investigators can test these.

Making It Work

Research the specific poison you're using if it's real. Match symptoms to poison type. Respect absorption timing - no instant death from swallowed poison. Show symptom progression from early warning signs to serious deterioration.

Be specific about treatment - no magical cure-all antidotes. Most treatment is keeping victim alive while poison metabolizes. Historical settings have very limited treatment options, making poison more deadly.

For mysteries, use poison's timing and detection difficulty to create challenges. For fantasy, establish clear rules about magical antidotes and maintain consistency.

Realistic poison is scarier than Hollywood poison because it's believable. Symptoms that progress inexorably, limited treatment options, race against time for antidote - these create genuine tension based on toxicological reality.