100 MCQs on Forensic Toxicology

1.) The antidote of Endrin is:

A.) Atropin

B.) Paralidoxime


D.) None of the Above

Answer: D.

2.) Which one can caused Blindness?

A.) Ethyl Alcohol

B.) Methyl Alcohol

C.) Glycol

D.) Propanol

Answer: B.

3.) Ammonium sulfate method is used for the extraction of _______ poison from viscera.

A.) Volatile

B.) Mettalic

C.) Insecticides

D.) Non Volatile Organic Poisons

Answer: D.

4.) Poison with Garlic Smell:

A.) Carbolic Acid

B.) Phosphorus

C.) Citric Acid

D.) Mercuric Chloride

Answer: B.

5.) Colour of blood is Cherry red due to:

A.) Hydrogen Sulphide

B.) Methane

C.) Carbon Monoxide

D.) Carbon Tetrachloride

Answer: C.

6.) This is a Spinal Poison:

A.) Strychnine

B.) Yellow Oleander

C.) Cocaine


Answer: A.

7.) Which of the following Insecticides is a cholinesterage inhibitor?



C.) Parathion

D.) Carbamate

Answer: C.

8.) Dry Ash Method is used for the extraction of the following poisons from viscera:

A.) Mettalic Poison

B.) Volatile Poison

C.) Non- Volatile Poison

D.) Vegetable Poison

Answer: A.

9.) Stass Otto Process is used for the extraction of:

A.) Ethnol from blood

B.) Poison from Viscera

C.) Ptylin from Saliva

D.) Uric Acid from Urine

Answer: B.

10.) Sodium and Potassium hydroxides are strongly corrosive due to

A.) Their solvent action on protein material

(B) Their saponifying action on the lipids

(C) Their ability to extract water from the tissues

(D) All of above

Answer: D.

11.) Botulism is a form of:

A.) Volatile Poison

B.) Food Poisoning

C.) Pesticide

D.) Mettalic Poisioning

Answer: B.

12.) Greenish Coloured urine is seen in which of the following poisoning:

A.) Nitric Acid

B.) Carbolic Acid

C.) Sulphuric Acid

D.) Hydrochloric Acid

Answer: B.

13.) Rectified spirit cannot be used for preserving the viscera in case of:

A.) Aconite Poisioning

B.) Organophosphorous Poisoning

C.) Heavy Metal Poisoning

D.) Opiate Poisioning

Answer: B.

14.) The Following is a poisonous mushroom species:

A.) Amanita Phalloides

B.) Morchella Esculenta

C.) Boletus Edulis

D.) Cantharellus cibarius

Answer: A.

15.) Effects of barbiturates onset after:

A.) 12 Hours

B.) 8 Hours

C.) 2 Hours

D.) 6 Hours

Answer: C.

16.) The brick red colour of post mortem lividity is seen in poisoning due to?

A.) Carbon monoxide

B.) Hydrogen sulphide

C.) Phosphorus

D.) Cyanide

Answer : D.

17.) Danbury tremor is seen in?

A.) Mercury poisoning

B.) Iron poisoning

C.) Lead poisoning

D.) Arsenic poisoning

Answer : A.

18.) The combination of alopecia & skin rash, painful peripheral neuropathy and confusion with lethargy are seen in?

A.) Copper poisoning

B.) Nickel poisoning

C.) Selenium poisoning

D.) Thallium poisoning

Answer : D.

19.) Which among the following is a waxy, luminous & translucent poison?

A.) Yellow phosphorous

B.) Cobra venom

C.) Organophosphates

D.) Iodine

Answer : A.

20.) Which is not a feature of aconite poisoning?

A.) Chest pain

B.) Increased blood pressure

C.) Tingling and numbness

D.) Hypersalivation

Answer : B.

21.) A middle aged man presents with paraesthesia of hand and feet. Examination reveals presence of ‘Mees’ lines in the nails and rain drop pigmentation in the hands; The most likely causative toxin for the above mentioned symptoms is :

A.) Lead

B.) Arsenic

C.) Thallium

D.) Mercury

Answer : B.

22.) Deep blue colour of hypostasis is seen in death due to poisoning by

A.) Potassium cyanide

B.) Phosphorus

C.) Aniline dyes

D.) Carbon monoxide

Answer : C.

23.) Which is true about the LD50?

A.) Dose of a substance to which 50% of animals do not show any response.

B.) Dose of a substance which kills 50% of animals exposed.

C.) 50% of the dose of a substance which can kill an animal.

D.) Dose of a substance which can kill 50 animals

Answer: B.

24.) A person was brought by police from the railway platform. He is talking irrelevant. He is having dry mouth with hot skin, dilated pupils, staggering gait and slurred speech. The most probable diagnosis is

A.) Alcohol intoxication

B.) Carbamates poisoning

C.) Organophosphorous poisoning

D.) Dhatura poisoning

Answer: D.

25.) Regarding methanol poisoning

Assertion: Administration of ethanol is one of the treatment modalities

Reason: Ethanol inhibits alcohol dehydrogenase

Please select the most correct option from the following:

A.) Both assertion and reason are true, and the reason is the correct explanation for the assertion

B.)Both assertion and reason are true, and the reason is not the correct explanation for the assertion

C.) Assertion is true, but the reason is false

D.) Assertion is false, but the reason is true

Answer: A.

26.) In methyl alcohol poisoning, there is central nervous system depression, cardiac depression and optic nerve atrophy. These effects are produced due to:

A.) Formaldehyde and formic acid

B.) Acetaldehyde

C.) Pyridine

D.) Acetic acid

Answer: A.

27.) A 39-year-old carpenter has taken two bottles of liquor from the local shop. After about an hour, he develops confusion, vomiting and blurring of vision. He has been brought to the emergency department. He should be given

A.) Naloxone

B.) Diazepam

C.) Flumazelnil

D.) Ethyl alcohol

Answer: D.

28.) Phosphine liberated in the stomach in aluminum phosphide poisoning is toxic to all except

A.) Lungs

B.) Kidneys

C.) Liver

D.) Heart

Answer: B.

29.) Paraquat poisoning causes

A.) Renal failure

B.) Cardiac failure

C.) Respiratory failure

D.) Multiple organ failure

Answer: D.

30.) Ecstasy toxicity causes

A.) Hypereflexia

B.) Trismus

C.) Dilated pupils

D.) All of the above

Answer: D.

31.). A housewife ingests a rodenticide white powder accidentally. She is brought to hospital where the examination shows generalized, flaccid paralysis and an irregular pulse. electrocardiogram shows multiple ventricular ectopics, generalized changes with ST-T. Serum potassium is 2.5 mEq/L. The most likely ingested poison is:

A.) Barium carbonate

B.) Super warfarins

C.) Zinc phosphide

D.) Zinc phosphide

Answer: A.

32.) Following are treatment options for toxic alcohol poisoning except

A.) Fomepizole

B.) Hydroxycobalamin

C.) Thiamine

D.) Folic acid

Answer: B.

33.) Hyperthermia in a patient of poisoning indicate to all, except

A.) Ecstasy

B.) Selective serotonin reuptake inhibitor

C.) Salicylates

D.) Chlorpromazine

Answer: D.

34.) Ophotoxemia refers to

A.) Organophosphorous poisoning

B.) Heavy metal poisoning

C.) Scorpion venom poisoning

D.) Snake venom poisoning

Answer: D.

35.) Elapidaes are

A.) Vasculotoxic

B.) Neurotoxic

C.) Musculotoxic

D.) Nontoxic

Answer: B.

36.) The most useful bedside test to suggest snake bite envenomation is:

A.) Prothrombin time

B.) 20 min whole blood clotting time

C.) International normalized ratio

D.) Platelet count

Answer: B.

37.) Magnan’s symptoms are characteristic of poisoning from:

A.) Alcohol


C.) Cocaine

D.) Ecstasy

Answer: C.

38.) Which of these groups is usually designated as one of the most sensitive sub-populations for exposures to toxic substances?

A.) Adult women

B.) Infants

C.) Adult men

D.) Adolescents

Answer: B.

39.) Which of the following terms is used to describe the dose of a drug required to kill 50% of a group of animals?

A.) LD50

B.) LD1

C.) ED50

D.) ED99

Answer: C.

40.) What term is applied to a drug which is effective against a relatively rare medical problem?

A.) Patent Drug

B.) Orphan Drug

C.) Rare disease medicine

D.) Drug

Answer: Orphan Drug

41.)    A toxic substance produced by biological system is referred as a:

A.) Toxicant

B.) Toxin

C.) Xenobiotic

D.) Poison

Answer: B

42.) Allergic contact dermatitis is

A.) a non-immune response caused by a direct action of an agent on the skin

B.) an immediate type I hypersensitivity reaction

C.) a delayed type IV hypersensitivity reaction

D.) characterized by the intensity of reaction being proportional to the elicitation dose

Answer: C.

43.) The reference dose (RfD) is generally determined by applying which of the following default procedures?

A.) an uncertainty factor of 100 is applied to the NOAEL in chronic animal studies

B.) a risk factor of 1000 is applied to the NOAEL in chronic animal studies

C.) a risk factor of 10,000 is applied to the NOAEL in subchronic animal studies

D.) an uncertainty factor between 10,000 and 1 million is applied to the NOEL from chronic animal studies

Answer: A.

44. Which of the following concerning the use of the “benchmark dose” in risk assessment is NOT correct?

A.) can use the full range of doses and responses studied

B.) allows use of data obtained from experiments where a clear “no observed adverse effect level” (NOAEL) has been attained

C.) may be defined as the lower confidence limit on the 10% effective dose

D.) is primarily used for analyses of carcinogenicity data and has limited utility for analyses of developmental and reproduction studies that generate quantal data

Answer: D.

45.) Administration by oral gavage of a test compound that is highly metabolized by the liver versus subcutaneous injection will most likely result in

A.) less parent compound present in the systemic circulation

B.) lower levels of metabolites in the systemic circulation

C.) more systemic toxicity

D.) less systemic toxicity

Answer: A.

46.) The phrase that best defines “toxicodynamics” is the:

A.) linkage between exposure and dose

B.) linkage between dose and response

C.) dynamic nature of toxic effects among various species

D.) dose range between desired biological effects and adverse health effects

Answer: B.

47.) Which of the following was banned under the Delaney clause of the Food Additive Amendment of 1958?

A.) butylated hydroxytoluene

B.) sulfamethazine

C.) cyclamate

D.) phytoestrogens

48.) Which of the following is NOT an initiating event in carcinogenesis?

A.) DNA adduct formation

B.) DNA strand breakage

C.) mutation of proto-oncogenes

D.) mitogenesis

Answer: D.

49.) Which of the following toxicity can occur due to single exposure?

A.) Acute toxicity

B.) Sub-acute toxicity

C.) Sub-chronic toxicity

 D.) Chronic toxicity

Answer: A.

50.) Which of the following assumptions is NOT correct regarding risk assessment for male reproductive effects in the absence of mechanistic data?

A.) an agent that produces an adverse reproductive effect in experimental animals is assumed to pose a potential reproductive hazard to humans

B.) in general, a non-threshold is assumed for the dose-response curve for male reproductive toxicity

C.) effects of xenobiotics on male reproduction are assumed to be similar across species unless demonstrated otherwise

D.) the most sensitive species should be used to estimate human risk

Answer: B.

51.) Which of the following toxins comes from the castor oil plant?

A.) Atropine. 

B.) Ricin. 

C.) Digitalin. 

D.) Strychnine.

Answer: B.

52.) A drug that induces alterations in perception and mood (without either arousing or inhibiting brain activity) is known as:

A.) A Depressant

B.) Cutting Agent

C.) Stimulant

D.) Hallucinogen

Answer: D.

53.) Which of the following is commonly known as ecstasy?

A.) Amphetamine

B.) 3,4-methylenedioxymethamphetamine (MDMA).

C.) Methamphetamine

D.)3,4-methylenedioxyamphetamine (MDA).

Answer: B.

54.) The active components of cannabis responsible for its hallucinogenic properties are the tetrahydrocannabinols (THCs). Which of the following forms of cannabis has the highest concentration of THCs?

A.) Hashish

B.) Cannabis Oil

C.) Cannabis

D.) Marijuana

Answer: A.

55.) The current legal limit for the maximum concentration of alcohol that is allowed in the breath of drivers is:

A.) 35 μg/100ml.

B.) 35 mg/100ml. 

C.) 80 mg/100ml. 

D.) 80 μg/100ml.

Answer: A.

56.) If an individual previously exposed to a particular substance exhibits an enhanced immune response when he encounters it for a second time, this condition is known as:

A.) Accumulation

B.) Idiosyncrasy

C.) Tolerance

D.) Sensitivity

Answer: D.

57.) A drug or other chemical compound whose manufacture, distribution, possession, and use is regulated by the legal system:

A.) Controlled Substance

B.) Medicine

C.) Branded Medicine

D.) All of the above

Answer: A.

58.) Bluish discolouration of neck of tooth due to

A.) Arsenic

B.) Bismuth

C.) Copper

D.) Nicotine

Answer: D.

59.) Surgical interference may be needed especially in children after poisoning by:

A. ) Hydrocyanic acid

B.) Caustic potash

C.) Hydrochloric acid

D.) Carbolic acid

Answer: B.

60.) One of the following solvents is not metabolized in the body to cyanide:

A.) Isopropanol

B.) Nitroprusside

C.) Acetonitrile

D.) Acrylonitrile

Answer: A.

61.) In poisoning with hydrocyanic acid, nitrates are given in order to:

A.) Reduce cyanide

B.) Induce vasodilatation

C.) Produce methaemoglobin

D.) Oxidise cyanide

Answer: C.

62.) After skin contamination, the patient passed into coma with miosis and finally acute nephritis, the poison is:

A.) Oxalic acid

B.) Nitric acid

C.) Hydrocyanic acid

D.) Carbolic acid

Answer: D.

63.) The dose of Na thiosulphate for treatment of cyanide poisoning in children is:

A.). 112.5 mg/kg IV over 10-20 min.

B.). 412.5 mg/kg IV over 10-20 min

C.) 412.5 mg/kg IV over 2 min

D.) 412.5 mg/kg IV over 5 min

Answer: B.

64.) An old traffic policeman in a busy street of Cairo is liable to suffer from:

A.)  Spastic gait

B.) Tremors

C.) Masked face

D.) Wrist and ankle drop

Answer: D.

65.) Blue line in the gingival margin in case of lead poisoning is due to deposition of:

A.) Lead chromate

B.) Lead sulphide

C.) Lead subacetate

D.) Lead iodide

Answer: B.

66.) N-acetylcysteine (Mucomyst) has which of the following properties when given for acute acetaminophen poisoning?

A) Prior use of activated charcoal is acceptable if indicated for the situation.

B) The dose is determined by estimating the dose of acetaminophen ingested and administering an equal milligram dose.

C) Optimal outcome is achieved when it is administered within 24-48 hours after ingestion.

D) It acts as a cofactor in generating sufficient ATP to maintain cell wall integrity.

Answer: A.

67.) The specific antidote in case of iron poisoning is:


B). Deferoxamine


D.) Penicillamine

Answer: B.

68.) Acute toxicity of organophosphates causes:

A.) Urine retention

B.) Oliguria

C.) Urine incontinence

D.) Anuria

Answer: C.

69.) Prolonged prothrombin time occurs in cases of poisoning with:

A.) Parathion

B.) Warfarin

C.) Paraquat

D.) Zinc sulphide

Answer: B.

70.) The second stage of acute acetaminophen toxicity is characterized by:

A.) Abnormalities of liver function tests

B.) Bleeding tendencies due to coagulation defect

C.) Nausea and malaise

D.) Right upper quadrant pain and tenderness

Answer: A.

71.) Which of the following is specific antidote for acute acetaminophen toxicity:


B.) Mucomyst



Answer: B.

72.) Benzodiazepines act on the CNS through the following mechanism:

A.) Increasing catecholamines

B.) Increasing serotonin

C.) Increasing the activity of GABA

D.) Decreasing the activity of GABA

Answer: C.

73.) In case of foodborne botulism, the toxin is:

A.) Formed in the duodenum

B.) Formed in the colon

C.) Formed in the intestine

D.) Formed in the canned food before consumption

Answer: D.

74.) MAcEwen’s sign is a manifestation of massive intake of:

A.) Atropine

B.) Opium

C.) Methanol

D). Ethanol

Answer: D.

75.) One of the following manifestations is an indication of severe ethanol intoxication:

A.) Euphoria and sense of well-being

B.) Marked muscular incoordination

C.) Increased confidence

D.) Aggressive behaviour

Answer: B.

76.) In case of acute CO poisoning, coma and death with lively red colour occur at a carboxy haemoglobin level of:

A.) 10-20%

B.) 20-30%

C.) 30-40%

D.) 50- 60 %

Answer: D.

77.) Pathological jealousy is diagnostic of:

A.) Cocaine intoxication

B.) Cannabis intoxication

C.) Alcoholic intoxication

D.) Tobacco intoxication

Answer: C.

78.) With regard to the alcohols which is false?

A.) Methanol causes snow storm vision in severe intoxication

B.) Ingestion of both methanol and ethylene glycol causes a metabolic acidosis with an increased anion gap and an increased osmolar gap

C.) Neither methanol or ethylene glycol are absorbed through the skin

D.) You might expect to find oxalate crystals in the urine of a pt who had an ethylene glycol OD

Answer: C.)

79.) Which of the following plants is not poisonous?

A.) Oleander

B.) Castor bean

C.) Wandering jew

D.) Water hemlock

Answer: C.

80.) The most common target organ of toxicity is the:

A.) heart

B.) lung

C.) CNS (brain and spinal cord)

D.) skin

Answer: C.

81.). the organs least involved in systemic toxicity are:

A.) brain and peripheral nerves

B.) muscle and bone

C.) liver and kidney

D.) hematopoietc system and lungs

Answer: B.

82.) If two organophosphate insecticides are absorbed into an organism, the result will be:

A.) additive effect

B.) synergestic effect

C.) potentiation

D.) substraction effect

Answer: A.

83.) If propyl alcohol and carbon tetrachloride are chronically absorbed into an organism, the effect on the liver would be

A.) additive effect

B.) synergesic

C.) potentiation

D.) substraction effect

Answer: C.

84.) The treatment of strychnine induced convulsions by diazepam is an example of —-

A.) chemical antagonism

B.) dispositional antagonism

C.) receptor antagonism

D.) functional antagonism

Answer: D.

85.) The most rapid exposure to a chemical would occur through which of the following routes:

A.) oral

B.) subcutaneous

C.) inhalation

D.) intramuscular

Answer: C.

86.) A chemical that is toxic to the brain but which is detoxified in the liver would be expected to be:

A.) more toxic orally than intramuscularly

B.) more toxic rectally than intravenously

C.) more toxic via inhalation than orally

D.) more toxic on the skin than intravenously

Answer: C.

87.) The LD50  is calculated from :

A.) a quantal dose-response curve

B.) a hormesis dose –response curve

C.) a graded dose-response curve

D.) a log-log dose-response curve

Answer: A.

88.) A U-shaped graded toxicity dose-response curve is seen in humans with:

A.) pesticides

B.) sedatives

C.) opiates

D.) vitamins

Answer: D.

89.) The TD1 / ED99 is called-

A.) margin of safety

B.) therapeutic index

C.) potency ratio

D.) efficacy ratio

Answer: A.

90.) All of the following are reasons for selective toxicity except

a) transport differences between cell

b) biochemical differences between cell

c) cytology of male neurons versus female neurons

d) cytology of plant cells versus animal cells

Answer: C.

91.) Following are a side effect of Digoxin toxicity, except:

A.) Bradycardia

B.) Yellow vision changes

C.) Scooping of the T segment on ECG

D.) Hypokalemia

Answer: D.

92.) Which of the following chelating agents is recommended for acute Lead poisoning with signs of encephalopathy? 

A.) Succimer

B.) Penicillamine

C.) Dimercaprol

D.) Dimercaprol + Calcium EDTA

Answer: D.

93.) which one of the following symptoms is not of Ciguatera poisoning?

A.) Myalgias

B.) Flushing

C.) Metallic taste

D.) Reversal of temperature sensation

Answer: B.

94.) Which of the following statements characterize a difference between poisonings in children and adults?

A) More children die from poisonings than adults.

B) Many adults do not seek assistance for a poisoning until symptoms appear.

C) Most poisonings in children involve plants; whereas most adults are poisoned with chemicals in the workplace.

D) Children are not likely to ingest substances that adults find distasteful.

Answer: B.

95.) Which of the following is true regarding the Poison Prevention Packaging Act of 1970?

A) It has had little effect on preventing poisonings in children.

B) Poison prevention efforts like safety packaging should only be directed toward parents of young children.

C) It requires that packaging be child-proof so that no preschool-aged children can open the container.

D) Oral prescription drugs, with certain exceptions, are required to be dispensed in child resistant containers.

Answer; D.

96.) Which of the following first aid measures is appropriate for the situation?

A) A child has swallowed an unknown household cleaner and 2-4 ounces of water was given orally.

B) An adult spilled some liquid insecticide on his arm 30 minutes ago and he rolls up his shirt that was in contact with the chemical.

C) Two cleaners are mixed in a toilet bowl and the custodian covers his mouth and nose with a napkin to protect against the irritating fumes.

D) A teenager is sprayed in the face with chemicals in a high school chemistry laboratory and the teacher searches for the antidote to apply to his face and eyes.

Answer: A.

97.) Which of the following is true regarding the gastric decontamination of a drug taken as an overdose two hours prior to seeking assistance?

A) Ipecac syrup should be administered at the scene regardless of the circumstances.

B) At a health care facility, the patient should receive gastric lavage which has demonstrated to have superior recovery of tablet material.

C) At the health care facility, the use of activated charcoal should be considered if contraindications are not present.

D) A cathartic such as magnesium citrate is all that should be administered.

Answer: C.

98.) Which of the following is true regarding therapy with multiple doses of activated charcoal for a poisoning?

A) For drugs for which it is effective, the elimination half-life of the drug can be decreased by multiple doses of activated charcoal.

B) It should be used for most drug overdoses.

C) Substances with a short duration in the body are more likely to respond to this therapy.

D) It should be avoided in patients with hyperactive bowel sounds.

Answer: A.

99.) Which of the following describes a typical toxic effect from an acute overdose of acetaminophen?

A) Serum bilirubin and the INR begin to rise sharply within the first 6 hours of ingestion.

B) Patients are typically symptomatic within 6 hours of ingestion.

C) By 7 to 8 days after ingestion, patients with serious liver injury begin to exhibit hepatic encephalopathy and other signs and symptoms of liver failure.

D) More children develop liver injury from acute acetaminophen over-dosage than adults.

Answer: C.

100.) A patient who has acutely ingested acetaminophen eight hours ago has a serum acetaminophen concentration of 220 mcg/mL. No other drugs are suspected. Which of the following would be appropriate?

A) Repeat the serum concentration and wait two hours for the results.

B) Assess the serum concentration as being associated with low to no risk of toxicity.

C) Administer ipecac syrup followed by activated charcoal.

D) Begin therapy with N-acetylycysteine (Mucomyst).

Answer: D.