PTCB Pharmacology #2 3

Question 1

Which of the following best describes a drug's "half-life"?

Accepted Answer

Time required for the plasma drug concentration to decrease by 50%

Answer

Half-life (t½) is the time required for the plasma concentration of a drug to decrease by 50%. It determines dosing frequency — drugs with short half-lives require more frequent dosing.

Question 2

Fluoroquinolone antibiotics (e.g., ciprofloxacin) work by:

Accepted Answer

Inhibiting DNA gyrase and topoisomerase IV

Answer

Fluoroquinolones inhibit DNA gyrase (topoisomerase II) and topoisomerase IV, enzymes essential for bacterial DNA replication, repair, and transcription.

Question 3

A drug's "volume of distribution" (Vd) indicates:

Accepted Answer

The extent to which the drug distributes throughout the body relative to plasma

Answer

Volume of distribution (Vd) is a theoretical volume that relates plasma concentration to total drug in the body. A high Vd indicates extensive tissue distribution (lipophilic drugs); a low Vd indicates drug stays in plasma.

Question 4

Which of the following is a tetracycline antibiotic?

Accepted Answer

Doxycycline

Answer

Doxycycline is a tetracycline antibiotic that inhibits protein synthesis by binding to the 30S ribosomal subunit. It is used for atypical pneumonia, Lyme disease, acne, and malaria prophylaxis.

Question 5

Which of the following drug classes are typically used as "rescue" medications for acute asthma attacks?

Accepted Answer

Short-acting beta-agonists (SABA)

Answer

Short-acting beta-agonists (SABAs) like albuterol are quick-relief/rescue medications for acute asthma. Inhaled corticosteroids are controller/maintenance therapy; LABAs are never used as monotherapy or rescue.

Pharmacy Practice Test

Pharmacy Practice Test

PTCB Pharmacology #2 3