Which of the following statements about drug metabolism in pharmacokinetics is correct?

A. Right Pharmacy: While it is important for medications to be obtained from a reliable pharmacy, "Right Pharmacy" is not one of the 10 rights of medication administration. The focus is on ensuring the correct administration process by the nurse or healthcare provider.
B. Right Medication: This is one of the core rights and ensures that the patient receives the exact medication that was prescribed. Verification is essential to avoid medication errors and adverse drug events.
C. Right Physician: Although having accurate prescriptions from a qualified provider is essential, "Right Physician" is not part of the 10 rights. The emphasis is on correct administration to the patient, not the prescriber’s identity.
D. Right Time: Administering medication at the correct time is critical for maintaining therapeutic drug levels, preventing underdosing or overdosing, and optimizing effectiveness especially for time-sensitive medications like insulin or antibiotics.
E. Right Route: Ensuring the medication is given via the prescribed route (oral, IV, subcutaneous, etc.) is vital for proper absorption, action, and safety. Errors in route can lead to severe complications or therapeutic failure.
F. Right Dose: Administering the correct dose is fundamental to achieving the desired therapeutic effect and avoiding toxicity or subtherapeutic dosing. Dosage must always match what is prescribed and appropriate for the patient's age, weight, and condition.

A. Second-generation antihistamines have shorter half-lives and require more frequent dosing compared to first-generation antihistamines: Second-generation antihistamines typically have longer half-lives, allowing once-daily dosing. They are designed for sustained action with improved compliance and fewer side effects.
B. First-generation antihistamines block both histamine and muscarinic receptors, while second-generation antihistamines primarily block histamine receptors: First-generation agents, such as diphenhydramine, cross the blood-brain barrier and exert anticholinergic effects by blocking muscarinic receptors. Second-generation antihistamines are more selective for peripheral H1 receptors, resulting in fewer CNS and anticholinergic side effects.
C. First-generation antihistamines are less likely to cause sedation compared to second-generation antihistamines: First-generation antihistamines are more likely to cause sedation because they easily penetrate the blood-brain barrier and affect central H1 receptors, unlike second-generation agents.
D. Second-generation antihistamines cross the blood-brain barrier, causing significant central nervous system effects: These medications are designed not to cross the blood-brain barrier significantly, which is why they are much less sedating and have minimal CNS effects compared to first-generation antihistamines.