Chronotherapy applies circadian biology to optimize drug administration timing for better therapeutic outcomes and fewer side effects. For B. Pharm students, understanding chronopharmacology — the interaction of circadian rhythms with pharmacokinetics and pharmacodynamics — is essential for designing dosing schedules, time-controlled formulations, and clinical studies. Key concepts include circadian rhythms, clock genes (CLOCK, PER, BMAL1), drug absorption, hepatic metabolism (CYP enzymes), transporter activity (P-gp), and pulsatile or delayed-release systems. Practical examples cover statins, antihypertensives, glucocorticoids, and chrono-modulated chemotherapy. Mastery helps improve efficacy, reduce toxicity, and inform formulation strategies. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the primary goal of chronotherapy in clinical pharmacology?
- To increase pill count
- To optimize the timing of drug administration to improve efficacy and reduce adverse effects
- To shorten drug development time
- To increase drug cost for better marketability
Correct Answer: To optimize the timing of drug administration to improve efficacy and reduce adverse effects
Q2. Which biological rhythm is most relevant to chronotherapy for daily dosing schedules?
- Ultradian rhythm
- Circadian rhythm
- Infradian rhythm
- Seasonal rhythm
Correct Answer: Circadian rhythm
Q3. Which of the following genes are principal components of the molecular circadian clock?
- TP53 and RB1
- ACE and AGTR1
- CLOCK and BMAL1
- HER2 and EGFR
Correct Answer: CLOCK and BMAL1
Q4. Chronopharmacokinetics primarily studies which aspect?
- Daily variations in drug target expression only
- Time-dependent changes in drug absorption, distribution, metabolism, and excretion
- Manufacturing timelines for timed-release tablets
- Species differences in drug response
Correct Answer: Time-dependent changes in drug absorption, distribution, metabolism, and excretion
Q5. Which commonly prescribed lipid-lowering drug is recommended to be taken at night for optimal effect?
- Amlodipine
- Simvastatin
- Omeprazole
- Metformin
Correct Answer: Simvastatin
Q6. Nighttime dosing of which antihypertensive strategy has been shown to better blunt the morning blood pressure surge?
- Switching to short-acting beta-agonists
- Administering antihypertensives at bedtime
- Taking all doses with a high-fat meal
- Using twice-daily dosing exclusively in the morning
Correct Answer: Administering antihypertensives at bedtime
Q7. For patients with nocturnal asthma symptoms, chronotherapy suggests optimizing timing of which therapy?
- Daily long-term antibiotics
- Inhaled corticosteroids given at night or as evening dosing
- Proton pump inhibitors before breakfast
- Statins at midday
Correct Answer: Inhaled corticosteroids given at night or as evening dosing
Q8. Which dosing strategy reduces morning stiffness in rheumatoid arthritis by aligning prednisone release with circadian inflammation?
- Immediate-release prednisone taken at noon
- Modified-release prednisone administered at bedtime to release in early morning
- Single high-dose prednisone injection once weekly
- Prednisone given only when symptoms occur
Correct Answer: Modified-release prednisone administered at bedtime to release in early morning
Q9. Which pharmacokinetic parameter commonly shows circadian variation due to fluctuating hepatic enzyme activity?
- Volume of distribution only
- Clearance (hepatic metabolism)
- Tablet disintegration time
- Active transport by renal glomerulus only
Correct Answer: Clearance (hepatic metabolism)
Q10. Which formulation approach is specifically designed to achieve time-specific drug release for chronotherapy?
- Immediate-release tablets
- Pulsatile (time-controlled) release systems with a defined lag time
- Liquid suspensions for rapid absorption
- Uncoated granules for continuous release
Correct Answer: Pulsatile (time-controlled) release systems with a defined lag time
Q11. Which clinical measurement is considered a reliable marker of circadian phase for chronotherapy planning?
- Fasting blood glucose at noon
- Dim light melatonin onset (DLMO)
- Red blood cell count
- Serum creatinine at bedtime
Correct Answer: Dim light melatonin onset (DLMO)
Q12. The main therapeutic objective of aligning drug dosing with biological rhythms is to:
- Increase drug manufacturing complexity
- Improve therapeutic index by maximizing benefit and minimizing toxicity
- Make dosing regimens more confusing
- Reduce the number of available drug formulations
Correct Answer: Improve therapeutic index by maximizing benefit and minimizing toxicity
Q13. Which clinical event has a well-documented circadian peak influencing chronotherapy for cardiovascular drugs?
- Late-night hypoglycemia
- Early morning myocardial infarction and stroke
- Afternoon anaphylaxis
- Midday seizure clusters
Correct Answer: Early morning myocardial infarction and stroke
Q14. Which major drug-metabolizing enzyme exhibits circadian variation that can affect drug clearance?
- Lipase
- CYP3A4
- Amylase
- Renin
Correct Answer: CYP3A4
Q15. How does drug half-life influence the importance of dosing time in chronotherapy?
- Short half-life drugs are more sensitive to dosing time than long half-life drugs
- Long half-life drugs are always unaffected by dosing time
- Half-life has no relevance to dosing time
- Only prodrugs are affected by half-life in chronotherapy
Correct Answer: Short half-life drugs are more sensitive to dosing time than long half-life drugs
Q16. Chronomodulated chemotherapy has been studied to reduce toxicity. Which chemotherapeutic agent has been commonly evaluated in timed infusion trials?
- Metformin
- 5-fluorouracil (5-FU)
- Simvastatin
- Aspirin
Correct Answer: 5-fluorouracil (5-FU)
Q17. In ambulatory blood pressure monitoring, a “non-dipper” is defined as a patient whose nocturnal blood pressure fall is:
- Greater than 20%
- Less than 10%
- Exactly 15%
- Greater than 50%
Correct Answer: Less than 10%
Q18. The central “master clock” that synchronizes peripheral clocks is located in which brain region?
- Hippocampus
- Suprachiasmatic nucleus (SCN) of the hypothalamus
- Pons
- Cerebellum
Correct Answer: Suprachiasmatic nucleus (SCN) of the hypothalamus
Q19. Which gastrointestinal factor that varies by time of day can significantly affect oral drug absorption?
- Daily variation in gastric emptying rate
- Daily variation in bone density
- Daily variation in hair growth
- Daily variation in nail growth
Correct Answer: Daily variation in gastric emptying rate
Q20. Chronopharmacodynamics focuses on:
- Time-dependent changes in drug target sensitivity and physiological response
- Only the chemical stability of a drug
- Packaging design for timed-release products
- Market demand cycles for medications
Correct Answer: Time-dependent changes in drug target sensitivity and physiological response
Q21. To reduce morning cardiovascular risk, many guidelines suggest which timing strategy for at least one antihypertensive dose?
- All doses taken immediately after midday meal
- At least one antihypertensive dose taken at bedtime
- Administering doses only during physical exercise
- Avoid taking any antihypertensive at night
Correct Answer: At least one antihypertensive dose taken at bedtime
Q22. Which delivery technology is commonly used to provide a lag time followed by rapid drug release in chronotherapy?
- Immediate soluble powders
- Enteric-coated tablets with a timed inner core (lag-time pulsatile tablet)
- Standard compressed tablets with no coating
- Oral emulsions
Correct Answer: Enteric-coated tablets with a timed inner core (lag-time pulsatile tablet)
Q23. Which hormone, closely tied to the sleep–wake cycle, typically increases in the evening and is important in chronotherapy considerations?
- Cortisol
- Melatonin
- Insulin
- Aldosterone
Correct Answer: Melatonin
Q24. When designing a pharmacokinetic study to investigate dosing-time effects, what must be standardized to obtain reliable circadian comparisons?
- Only the pill color
- Dosing time and sampling schedule across subjects
- Brand of coffee consumed by subjects
- Room temperature during storage only
Correct Answer: Dosing time and sampling schedule across subjects
Q25. Which efflux transporter known to affect oral drug absorption displays circadian variation and can influence chronotherapy?
- SGLT2
- P-glycoprotein (P-gp)
- ACE
- GLUT4
Correct Answer: P-glycoprotein (P-gp)
Q26. Regarding sensitivity to dosing time, which statement is correct?
- Long half-life drugs are always more time-sensitive than short half-life drugs
- Short half-life drugs are typically more sensitive to dosing time than long half-life drugs
- Half-life does not affect time sensitivity
- Only topical drugs show time sensitivity
Correct Answer: Short half-life drugs are typically more sensitive to dosing time than long half-life drugs
Q27. Effective development of chronotherapeutic products requires integration of which disciplines?
- Only marketing and sales
- Pharmacology, pharmaceutics, and chronobiology
- Only clinical psychology
- Only mechanical engineering
Correct Answer: Pharmacology, pharmaceutics, and chronobiology
Q28. Which non-pharmacological chronotherapy used in mood disorders aligns light exposure with circadian rhythms?
- Deep brain stimulation
- Bright light therapy
- Transdermal patches
- Intradermal injections
Correct Answer: Bright light therapy
Q29. Which of the following drugs is a classic example where nocturnal dosing exploits peak nocturnal enzyme activity for effectiveness?
- Metoprolol
- Simvastatin taken at night for maximal HMG‑CoA reductase inhibition
- Amoxicillin at bedtime for viral infections
- Paracetamol only in the morning
Correct Answer: Simvastatin taken at night for maximal HMG‑CoA reductase inhibition
Q30. When comparing two dosing times in a clinical chronotherapy trial, which study design helps control inter-individual variability most effectively?
- Parallel-group randomized trial without crossover
- Crossover design where each subject receives both dosing times in different periods
- Uncontrolled observational case series
- Single-arm historical control study
Correct Answer: Crossover design where each subject receives both dosing times in different periods
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.
Mail- Sachin@pharmacyfreak.com