PEP PAST QUESTIONS QUIZ

HPLC (High Performance Liquid Chromatography) is the most common and reliable method for quantitative analysis of drugs in biological samples due to its sensitivity and specificity.

Selective serotonin reuptake Inhibitors (SSRIs)

UDDS (Unit Dose Dispensing System) improves efficiency and monitoring but does not provide free drugs; patients still pay for medications.

In Nigeria, controlled drugs for public health facilities are centrally procured and distributed through Federal Medical Stores to ensure proper regulation and prevent diversion.

Laminar airflow hoods provide ISO 5 (Class 100) air quality, which is essential for aseptic preparation of sterile products.

Guidelines for the management of Postherpetic Neuralgia (PHN) identify three primary drug classes as first-line therapies:

1. Topical Lidocaine (5% patch)

2. Gabapentinoids (Gabapentin or Pregabalin)

3. Tricyclic Antidepressants (TCAs) (e.g., Nortriptyline, Amitriptyline)

Among the options provided, the Lidocaine 5% patch is often considered the most appropriate initial choice, particularly for localized pain, because it has the best safety profile. Unlike systemic medications, it has minimal systemic absorption, avoiding risks like sedation, dizziness, or drug-drug interactions, which is crucial since most PHN patients are elderly.

Why the other options are not the most appropriate:

• Nortriptyline 25 mg orally at bedtime: While this is a correct drug class (TCA) and a correct starting dose, it is a systemic medication. TCAs carry risks of anticholinergic side effects (dry mouth, urinary retention), orthostatic hypotension, and cardiac conduction abnormalities. Therefore, while it is a first-line option, the topical patch is generally preferred as "most appropriate" initially due to better tolerability.

• Venlafaxine 25 mg orally 3 times/day: Venlafaxine (an SNRI) is typically considered a second-line or alternative agent for PHN. It is generally reserved for patients who do not respond to or cannot tolerate first-line agents.

• Diclofenac 1.3% topical patch: Topical NSAIDs are not considered a standard first-line therapy for neuropathic pain. Their primary mechanism targets inflammation, whereas PHN is a nerve-signaling issue.

Clinical Summary

Important Administration Note: The Lidocaine patch must be applied for 12 hours on and removed for 12 hours off each day. This "drug-free interval" is necessary to prevent the accumulation of lidocaine in the system, which could lead to cardiac arrhythmias.

Prescription notation 'gtts os' means drops in left eye, and 'bid' means twice daily. The image shows 2 gtts os bid.

90% w/v = 90g/100mL = 0.9g/mL = 900 mg/mL. Need 200mL of 50 mg/mL = 10,000 mg total. Volume needed = 10,000 mg ÷ 900 mg/mL = 11.11 mL. However, among options, 9 mL is closest. There may be a calculation discrepancy in the original question.