Introduction: Solanaceous alkaloids, especially hyoscyamine sulphate, are essential topics in B. Pharm pharmacognosy and pharmacology. This group of tropane alkaloids—derived from Atropa, Hyoscyamus and Datura species—exhibits potent anticholinergic (antimuscarinic) activity, key therapeutic uses, characteristic toxicity and distinctive extraction/analytical profiles. B. Pharm students must understand chemical structure, stereochemistry (hyoscyamine vs atropine), mechanism of action, clinical indications, adverse effects, contraindications, pharmacokinetics and laboratory methods (TLC/HPLC/GC-MS). Mastery of hyoscyamine sulphate’s pharmacology and safe handling is crucial for formulation, dispensing and toxicity management. Now let’s test your knowledge with 50 MCQs on this topic.
Q1. Which plant is a primary natural source of hyoscyamine?
- Digitalis purpurea
- Atropa belladonna
- Cinchona officinalis
- Ginkgo biloba
Correct Answer: Atropa belladonna
Q2. Hyoscyamine sulphate belongs to which chemical class of alkaloids?
- Isoquinoline alkaloids
- Tropane alkaloids
- Pyrrolizidine alkaloids
- Indole alkaloids
Correct Answer: Tropane alkaloids
Q3. Hyoscyamine is best described as:
- A racemic mixture of enantiomers
- The levo (L)-isomer of atropine
- An epimer of scopolamine
- A peptide toxin
Correct Answer: The levo (L)-isomer of atropine
Q4. The primary pharmacological action of hyoscyamine sulphate is:
- Beta-adrenergic agonism
- Muscarinic receptor antagonism
- Acetylcholinesterase inhibition
- GABA receptor agonism
Correct Answer: Muscarinic receptor antagonism
Q5. Which muscarinic receptor subtypes does hyoscyamine competitively block?
- Only M2 receptors
- Only M1 and M3 receptors
- All M1–M5 muscarinic receptors
- Only peripheral nicotinic receptors
Correct Answer: All M1–M5 muscarinic receptors
Q6. A common therapeutic use of hyoscyamine sulphate is:
- Treatment of bacterial infections
- Relief of gastrointestinal spasms and irritable bowel syndrome
- Anticoagulation
- Long-term insulin replacement
Correct Answer: Relief of gastrointestinal spasms and irritable bowel syndrome
Q7. Which adverse effect is most characteristic of hyoscyamine’s antimuscarinic activity?
- Excessive salivation
- Diarrhea
- Dry mouth (xerostomia)
- Bradycardia
Correct Answer: Dry mouth (xerostomia)
Q8. In overdose, the preferred antidote for severe central anticholinergic toxicity is:
- Naloxone
- Flumazenil
- Physostigmine
- Atropine
Correct Answer: Physostigmine
Q9. Hyoscyamine sulphate is the sulphate salt primarily to improve:
- Lipid solubility for CNS penetration
- Water solubility and stability for dosage forms
- Volatility for inhalation
- Color for identification
Correct Answer: Water solubility and stability for dosage forms
Q10. Which analytical reagent gives a characteristic color with tropane alkaloids on TLC?
- Dragendorff’s reagent
- Biuret reagent
- Ferric chloride
- Ninhydrin
Correct Answer: Dragendorff’s reagent
Q11. During extraction of hyoscyamine from plant material, initial acidification is used to:
- Convert alkaloids to water-soluble salts
- Precipitate proteins
- Hydrolyze glycosides
- Oxidize alkaloids
Correct Answer: Convert alkaloids to water-soluble salts
Q12. Atropine is chemically best described as:
- The dextrorotatory isomer of hyoscyamine
- A synthetic derivative unrelated to hyoscyamine
- A racemic mixture of hyoscyamine enantiomers
- An esterified form of scopolamine
Correct Answer: A racemic mixture of hyoscyamine enantiomers
Q13. Which measurement technique is most suitable for quantitative determination of hyoscyamine in formulations?
- Thin layer chromatography (qualitative only)
- High-performance liquid chromatography (HPLC)
- Simple microscopy
- pH titration
Correct Answer: High-performance liquid chromatography (HPLC)
Q14. Hyoscyamine’s tertiary amine allows it to:
- Be a permanent positive ion in all pH
- Exist in protonated (ionized) and unprotonated forms depending on pH
- Be a strong acid
- Act as an enzyme
Correct Answer: Exist in protonated (ionized) and unprotonated forms depending on pH
Q15. Which condition is a contraindication to hyoscyamine use?
- Hypotension
- Acute angle-closure glaucoma
- Peptic ulcer disease
- Hypothyroidism
Correct Answer: Acute angle-closure glaucoma
Q16. The main route of elimination for hyoscyamine and metabolites is:
- Renal excretion
- Exhaled air
- Biliary excretion only
- Fecal elimination exclusively
Correct Answer: Renal excretion
Q17. Which pharmacokinetic property allows hyoscyamine to have central nervous system effects?
- High molecular weight preventing crossing of BBB
- Ability to cross the blood–brain barrier
- Exclusive binding to plasma proteins
- Rapid renal clearance preventing CNS activity
Correct Answer: Ability to cross the blood–brain barrier
Q18. A typical anticholinergic sign seen in hyoscyamine poisoning is:
- Constricted pupils
- Excessive lacrimation
- Flushed, hot, dry skin with dilated pupils
- Profuse sweating
Correct Answer: Flushed, hot, dry skin with dilated pupils
Q19. Which metabolic organ primarily metabolizes hyoscyamine?
- Liver
- Kidney cortex
- Pulmonary alveoli
- Pancreas
Correct Answer: Liver
Q20. In the context of pharmacy, hyoscyamine sulphate tablets are commonly indicated for:
- Antibiotic therapy
- Antispasmodic management of colic and IBS
- Hypoglycemia treatment
- Anticoagulation
Correct Answer: Antispasmodic management of colic and IBS
Q21. Which laboratory technique can provide structural identification of hyoscyamine by mass fragments?
- Infrared spectroscopy only
- Gas chromatography–mass spectrometry (GC-MS)
- Light microscopy
- Sound frequency analysis
Correct Answer: Gas chromatography–mass spectrometry (GC-MS)
Q22. The tropane ring system in hyoscyamine contains how many carbon atoms in the bicyclic skeleton?
- 5 carbons
- 7 carbons
- 8 carbons
- 9 carbons
Correct Answer: 8 carbons
Q23. Which test in pharmacopoeias commonly assesses identity of hyoscyamine salts?
- Melting point alone
- UV-visible spectroscopy and HPLC assay
- Saccharin assay
- Acid-base titration only
Correct Answer: UV-visible spectroscopy and HPLC assay
Q24. Compared to atropine, hyoscyamine is:
- More cardiotoxic and not used clinically
- The active levo-isomer with generally greater muscarinic potency
- An inactive metabolite of atropine
- A glycoside form of atropine
Correct Answer: The active levo-isomer with generally greater muscarinic potency
Q25. Which of the following is a clinical use of hyoscyamine beyond GI indications?
- Treatment of bacterial meningitis
- Palliative control of excessive respiratory secretions
- Long-term depression therapy
- Antifungal agent
Correct Answer: Palliative control of excessive respiratory secretions
Q26. In pharmacology, hyoscyamine’s blockade of muscarinic receptors at the eye causes:
- Miosis and accommodation spasm
- Mydriasis and cycloplegia
- Increased lacrimation
- Improved near vision
Correct Answer: Mydriasis and cycloplegia
Q27. Which symptom differentiates anticholinergic poisoning from sympathomimetic poisoning?
- Hyperreflexia
- Diaphoresis (sweating) present in anticholinergic
- Dry skin in anticholinergic, sweaty skin in sympathomimetic
- Bradycardia in sympathomimetic
Correct Answer: Dry skin in anticholinergic, sweaty skin in sympathomimetic
Q28. The first step in isolation of hyoscyamine from dried plant material typically is:
- Direct solvent extraction with hexane
- Extraction with acidified aqueous medium
- Strong base hydrolysis
- Cold steam distillation
Correct Answer: Extraction with acidified aqueous medium
Q29. Which metabolite interaction is relevant for hyoscyamine when co-administered with other anticholinergic drugs?
- Synergistic increase in anticholinergic effects
- Complete metabolic inactivation
- Conversion to atropine enhancing cholinesterase
- Protection from renal excretion
Correct Answer: Synergistic increase in anticholinergic effects
Q30. Which pharmaceutical consideration is important for hyoscyamine sulphate tablets?
- They must be stored frozen
- Protect from light and moisture to maintain potency
- They are light-resistant and need no special storage
- They require gaseous nitrogen packaging only
Correct Answer: Protect from light and moisture to maintain potency
Q31. Which laboratory color test detects basic nitrogenous alkaloids like hyoscyamine on TLC?
- Milli-Q reagent
- Dragendorff’s reagent producing orange spots
- Benedict’s reagent producing blue spots
- Biuret reagent
Correct Answer: Dragendorff’s reagent producing orange spots
Q32. In pediatric poisoning with hyoscyamine, which sign is especially concerning?
- Excessive drooling and tearing
- Seizures and severe agitation indicating central toxicity
- Increased urine output
- Excessive appetite
Correct Answer: Seizures and severe agitation indicating central toxicity
Q33. The stereochemical relationship between hyoscyamine and scopolamine is best described as:
- Identical stereochemistry and same compound
- Completely unrelated chemical classes
- Different tropane alkaloids with distinct functional groups and effects
- Isomers differing only by a methyl group
Correct Answer: Different tropane alkaloids with distinct functional groups and effects
Q34. Which preservative approach is relevant for liquid formulations of hyoscyamine sulphate?
- Acidification to maintain solubility and stability
- Alkalinization to reduce solubility
- Adding strong oxidizers
- Removing all water to create emulsion
Correct Answer: Acidification to maintain solubility and stability
Q35. A pharmacy student should counsel patients taking hyoscyamine to avoid which activity due to blurred vision?
- Driving or operating heavy machinery
- Drinking milk
- Walking short distances
- Taking multivitamins
Correct Answer: Driving or operating heavy machinery
Q36. Which physical property of hyoscyamine sulphate aids in formulating oral tablets?
- High volatility
- Good aqueous solubility as a salt
- Extreme insolubility in acids
- Low melting point causing instability
Correct Answer: Good aqueous solubility as a salt
Q37. In HPLC assay, the hyoscyamine peak is identified by:
- Retention time matching reference standard and spectral confirmation
- Color change of mobile phase
- Change in column pressure only
- pH meter reading
Correct Answer: Retention time matching reference standard and spectral confirmation
Q38. Which is a typical sign of peripheral anticholinergic effect of hyoscyamine?
- Bradycardia with increased secretions
- Urinary retention and constipation
- Excessive sweating and salivation
- Hypersalivation and drooling
Correct Answer: Urinary retention and constipation
Q39. Which of the following best describes the legal classification of hyoscyamine in many jurisdictions?
- Over-the-counter vitamin
- Prescription-only anticholinergic drug
- Controlled narcotic schedule I
- Illegal recreational drug
Correct Answer: Prescription-only anticholinergic drug
Q40. Which symptom would you NOT expect in anticholinergic syndrome from hyoscyamine?
- Hyperthermia
- Mydriasis
- Diaphoresis (profuse sweating)
- Confusion and hallucinations
Correct Answer: Diaphoresis (profuse sweating)
Q41. When preparing hyoscyamine as a salt, conversion to the free base is achieved by:
- Treating with strong acid
- Basification with alkali
- Adding alcohol
- Heating at 500 °C
Correct Answer: Basification with alkali
Q42. Which combination increases risk of adverse anticholinergic effects when taken with hyoscyamine?
- Beta-blockers
- Other antimuscarinic agents like tricyclic antidepressants or antihistamines
- Insulin
- Antacids only
Correct Answer: Other antimuscarinic agents like tricyclic antidepressants or antihistamines
Q43. In formulation stability studies, a degradation product of hyoscyamine might be detected after exposure to:
- Neutral conditions only
- Light, heat and alkaline conditions
- Storage at -80 °C
- Vacuum with an inert gas
Correct Answer: Light, heat and alkaline conditions
Q44. A key distinguishing lab sign of tropane alkaloid intoxication is:
- Pinpoint pupils with increased secretions
- Dilated pupils with dry mucous membranes
- Hypothermia and profuse sweating
- Excessive salivation and frequent urination
Correct Answer: Dilated pupils with dry mucous membranes
Q45. Which of the following is a correct statement about scopolamine relative to hyoscyamine?
- Scopolamine is an analgesic unrelated to antimuscarinic effects
- Scopolamine (hyoscine) has stronger CNS depressant effects and is structurally related
- Scopolamine is identical to hyoscyamine
- Scopolamine is a peptide antibiotic
Correct Answer: Scopolamine (hyoscine) has stronger CNS depressant effects and is structurally related
Q46. For quality control, which reference standard is used to confirm hyoscyamine identity in pharmacopeial assays?
- Caffeine reference standard
- Certified hyoscyamine reference standard
- Sodium chloride standard
- Ascorbic acid standard
Correct Answer: Certified hyoscyamine reference standard
Q47. Which patient population requires caution or dose adjustment when prescribing hyoscyamine?
- Patients with well-controlled asthma only
- Elderly patients prone to confusion and urinary retention
- Young healthy adults with no comorbidities
- Patients on vitamin supplements
Correct Answer: Elderly patients prone to confusion and urinary retention
Q48. Which laboratory technique separates hyoscyamine based on polarity on a stationary phase?
- Thin layer chromatography (TLC)
- Complete blood count
- Electrocardiogram
- Thermogravimetric analysis
Correct Answer: Thin layer chromatography (TLC)
Q49. In toxicology, which supportive measure is commonly used for hyoscyamine overdose?
- Gastric decontamination and activated charcoal if early
- Immediate hemodialysis as first-line
- High-dose steroids
- No supportive care is needed
Correct Answer: Gastric decontamination and activated charcoal if early
Q50. Teaching point: the pharmacological antagonism produced by hyoscyamine is best described as:
- Noncompetitive irreversible antagonism at muscarinic receptors
- Competitive reversible antagonism at muscarinic receptors
- Agonist action at nicotinic receptors
- Irreversible acetylcholinesterase activation
Correct Answer: Competitive reversible antagonism at muscarinic receptors
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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