Correct Answer: D. 0.5 mg daily before bedtime for 7 days
Alprazolam is a short-acting benzodiazepine (BZD) with a half-life of 6–12 hours, making it suitable for short-term anxiolytic and hypnotic use. According to KD Tripathi and Indian prescribing guidelines, the standard therapeutic dose for anxiety and insomnia is 0.5–1 mg daily, typically administered at bedtime to exploit its sedative properties and minimize daytime impairment. The key discriminator here is duration and frequency: alprazolam should be prescribed for short-term use only (7–14 days maximum) to prevent dependence, a critical concern in Indian clinical practice where benzodiazepine misuse is increasingly recognized. Option D specifies 0.5 mg once daily at bedtime for 7 days—this adheres to the lowest effective dose principle, respects the short-term prescribing window mandated by Indian guidelines and the Narcotic Drugs and Psychotropic Substances (NDPS) Act, and minimizes the risk of tolerance and withdrawal. The bedtime timing is optimal because it aligns with the drug's pharmacokinetics (peak effect in 1–2 hours) and the patient's sleep-wake cycle, reducing next-day residual effects. This is the safest, most rational prescription pattern in Indian clinical practice.
Why the other options are wrong
A. 0.5 mg BD for 7 days — Twice-daily dosing (BD) is inappropriate for alprazolam in insomnia/anxiety because it increases total daily exposure (1 mg/day) and cumulative CNS depression. More critically, BD scheduling violates the principle of using the minimum effective dose and accelerates tolerance and dependence risk. Indian guidelines recommend once-daily dosing at bedtime for short-term use, not divided doses. B. 1/2 mg HS for 7 days — While 'HS' (hora somni, at bedtime) is correct timing, the notation '1/2 mg' is ambiguous and non-standard in Indian prescription writing. This violates the Drugs and Cosmetics Rules and NDPS guidelines, which mandate clear, unambiguous dosing to prevent medication errors and misuse. Prescribers must write '0.5 mg' explicitly, not fractions, especially for controlled substances. C. 1 mg OD before bedtime for 7 days — A 1 mg once-daily dose exceeds the recommended starting dose for most patients and increases the risk of next-day sedation, cognitive impairment, and dependence. Indian prescribing practice and KD Tripathi recommend starting with 0.5 mg daily; 1 mg is reserved for patients with severe anxiety or established tolerance, not first-line therapy. This violates the 'start low, go slow' principle.
High-Yield Facts
- Alprazolam half-life: 6–12 hours (short-acting BZD); suitable for once-daily bedtime dosing.
- Standard dose: 0.5–1 mg daily; start with 0.5 mg to minimize dependence risk and next-day impairment.
- Maximum duration: 7–14 days for short-term use; longer courses require specialist review and risk NDPS Act violations.
- Bedtime timing: Optimal for insomnia; peak effect 1–2 hours aligns with sleep onset and reduces daytime residual effects.
- Prescription notation: Write '0.5 mg' explicitly, never fractions ('1/2 mg'), per Indian Drugs and Cosmetics Rules and NDPS guidelines.
- Dependence risk: Increases with higher doses, frequent dosing (BD/TDS), and duration >2 weeks; once-daily short-term use minimizes this.
Mnemonics
SAFE-BZD (Benzodiazepine Prescribing in India) Start low (0.5 mg), Avoid BD/TDS, For short-term (≤14 days), Explicit notation (not fractions). Use at Bedtime, Zero tolerance for >2 weeks, Document NDPS compliance. OD HS Rule Once Daily at Hora Somni (bedtime) = standard for short-acting BZDs like alprazolam in Indian practice. Avoids BD traps and NDPS scrutiny.
NBE Trap
NBE pairs benzodiazepine dosing with frequency notation (BD vs. OD) to test whether students understand that short-acting BZDs like alprazolam should be dosed once daily at bedtime, not divided throughout the day. Students who default to "more frequent = better control" or who confuse alprazolam with long-acting agents (e.g., diazepam) fall into the BD trap.
Clinical Pearl
In Indian outpatient practice, a patient presenting with acute anxiety or insomnia should receive alprazolam 0.5 mg at bedtime for 7 days with explicit counseling on non-renewal and dependence risk. This approach satisfies NDPS compliance, minimizes next-day impairment (critical for working patients), and sets the stage for non-pharmacological follow-up (CBT, sleep hygiene) after the short course ends.
_Reference: KD Tripathi Pharmacology Ch. 12 (Anxiolytics & Hypnotics); Harrison Ch. 387 (Sleep Disorders); Indian Drugs and Cosmetics Rules 1945 & NDPS Act 1985 (Controlled Substance Prescribing)_