Morning Rounds \u00b7 Pharmacokinetics \u00b7 Round 03<\/title>\n<link href=\"https:\/\/fonts.googleapis.com\/css2?family=Playfair+Display:ital,wght@0,400;0,600;0,700;1,400;1,600&family=Source+Serif+4:ital,wght@0,300;0,400;0,600;1,400&display=swap\" rel=\"stylesheet\">\n<style>\n#npk03 *,#npk03 *::before,#npk03 *::after{box-sizing:border-box;margin:0;padding:0}\n#npk03{\n --ob:#1A5F7A;--ob-light:#236E8C;--ob-pale:#E6F3F7;--ob-dark:#114455;\n --correct:#2D6B47;--correct-bg:#EAF6EF;--correct-border:#3A9960;\n --wrong:#B83232;--wrong-bg:#FDF0F0;--wrong-border:#E53935;\n --ink:#0F2A35;--ink-mid:#2A4D5A;--ink-soft:#5A7D8A;\n --line:#B8D8E3;--cream:#F2F8FA;--warm:#F8FCFD;\n font-family:'Source Serif 4',Georgia,serif;\n font-size:16px;color:var(--ink);background:var(--cream);\n line-height:1.7;padding:0 0 64px;\n}\n#npk03 .mr-header{background:linear-gradient(135deg,var(--ob-dark) 0%,var(--ob) 60%,var(--ob-light) 100%);color:#E4F4F9;padding:36px 24px 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.mr-band-c{background:var(--correct-bg);color:var(--correct)}\n#npk03 .mr-band-w{background:var(--wrong-bg);color:var(--wrong)}\n#npk03 .mr-band-s{background:var(--ob-pale);color:var(--ob)}\n#npk03 .mr-retry{display:block;margin:18px auto 4px;background:transparent;border:2px solid var(--ob);color:var(--ob);border-radius:8px;padding:9px 28px;font-family:'Playfair Display',serif;font-size:0.92rem;font-weight:700;cursor:pointer;}\n#npk03 .mr-retry:hover{background:var(--ob);color:#E4F4F9}\n@media(max-width:480px){\n #npk03 .mr-title{font-size:1.4rem}\n #npk03 .mr-num{font-size:1.7rem}\n #npk03 .mr-stem{font-size:0.9rem}\n #npk03 .mr-opt-text{font-size:0.86rem}\n}\n<\/style>\n\n<div id=\"npk03\">\n\n <div class=\"mr-header\">\n <div class=\"mr-series-tag\">Numerical Series · Pharmacokinetics<\/div>\n <div class=\"mr-eyebrow\">Morning Rounds · Round 03 of 07<\/div>\n <div class=\"mr-title\">Volume of Distribution &<br><em>The Loading Dose<\/em><\/div>\n <div class=\"mr-subtitle\">Five calculations · Vd, loading dose, apparent volume & what drug distribution tells you clinically<\/div>\n <div class=\"mr-chips\">\n <span class=\"mr-chip\">5 Questions<\/span>\n <span class=\"mr-chip\">+4 \/ −1 scoring<\/span>\n <span class=\"mr-chip\">Options reshuffled<\/span>\n <\/div>\n <\/div>\n\n <div class=\"mr-sentinel\" id=\"npk03-sentinel\"><\/div>\n\n <div class=\"mr-progress\" id=\"npk03-progress\">\n <div class=\"mr-prog-inner\">\n <div class=\"mr-pips\" id=\"npk03-pips\"><\/div>\n <\/div>\n <\/div>\n\n <div class=\"mr-body\">\n <div id=\"npk03-cases\"><\/div>\n <div class=\"mr-submit-wrap\">\n <button class=\"mr-btn\" id=\"npk03-submit\">Submit for Debrief<\/button>\n <\/div>\n <div class=\"mr-score\" id=\"npk03-score\">\n <div class=\"mr-score-in\">\n <div class=\"mr-score-ey\">Round Complete<\/div>\n <div class=\"mr-ring\" id=\"npk03-ring\">\n <div class=\"mr-ring-in\">\n <span class=\"mr-ring-pct\" id=\"npk03-pct\">0%<\/span>\n <span class=\"mr-ring-sub\">net<\/span>\n <\/div>\n <\/div>\n <div class=\"mr-score-title\">Your Debrief<\/div>\n <div class=\"mr-score-net\" id=\"npk03-net\"><\/div>\n <div class=\"mr-verdict\" id=\"npk03-verdict\"><\/div>\n <div class=\"mr-bands\">\n <span class=\"mr-band mr-band-c\" id=\"npk03-ct-c\"><\/span>\n <span class=\"mr-band mr-band-w\" id=\"npk03-ct-w\"><\/span>\n <span class=\"mr-band mr-band-s\" id=\"npk03-ct-s\"><\/span>\n <\/div>\n <button class=\"mr-retry\" id=\"npk03-retry\">↻ New Round<\/button>\n <\/div>\n <\/div>\n <\/div>\n\n<\/div>\n\n<script>\n(function () {\n 'use strict';\n\n var NS = 'npk03';\n var TOTAL = 5;\n var MAX = 20;\n var LTRS = ['A','B','C','D'];\n\n var QS = [\n\n {\n id: 1,\n tag: 'Vd — Basic Calculation',\n stem: 'A <strong>70 kg<\/strong> patient receives an IV bolus dose of <strong>500 mg<\/strong> of a drug. The plasma concentration immediately after injection is <strong>10 mg\/L<\/strong>. What is the <strong>volume of distribution (Vd)<\/strong> of this drug?',\n correct: '50 litres',\n opts: [\n '50 litres',\n '5 litres',\n '500 litres',\n '0.71 L\/kg'\n ],\n exp: 'The fundamental Vd formula:<span class=\"calc\">Vd = Dose ÷ C<sub>0<\/sub><br>Vd = 500 mg ÷ 10 mg\/L<br>Vd = <strong>50 litres<\/strong><\/span>Interpretation: 50 L in a 70 kg patient = <strong>0.71 L\/kg<\/strong>. This is actually close to total body water (~42 L), suggesting moderate tissue distribution. The trap option 0.71 L\/kg is the <em>per-kilogram<\/em> expression of the same answer — not wrong mathematically, but the question asks for Vd in litres, not per-kg. Key reference points to memorise:<br><br>• Vd ~3–5 L → drug stays in plasma (e.g. heparin, warfarin)<br>• Vd ~15 L → distributes into extracellular fluid (e.g. gentamicin)<br>• Vd >40 L → extensive tissue distribution (e.g. chloroquine >200 L, amiodarone >5000 L)'\n },\n\n {\n id: 2,\n tag: 'Loading Dose — Calculation',\n stem: 'A patient requires rapid digitalization. The target plasma concentration of digoxin is <strong>1.5 μg\/L<\/strong>. The volume of distribution of digoxin is <strong>500 L<\/strong> and its oral bioavailability is <strong>60%<\/strong>. What is the approximate <strong>oral loading dose<\/strong> required?',\n correct: '1250 μg (1.25 mg)',\n opts: [\n '1250 μg (1.25 mg)',\n '750 μg (0.75 mg)',\n '500 μg (0.5 mg)',\n '2083 μg (2.08 mg)'\n ],\n exp: 'Loading dose formula:<span class=\"calc\">Loading Dose = (Target C<sub>p<\/sub> × Vd) ÷ Bioavailability (F)<br>= (1.5 μg\/L × 500 L) ÷ 0.60<br>= 750 μg ÷ 0.60<br>= <strong>1250 μg = 1.25 mg<\/strong><\/span>Why divide by bioavailability? An oral dose is not fully absorbed. If you gave 750 μg orally, only 60% (= 450 μg) would reach systemic circulation — not enough. You must give <em>more<\/em> to compensate for the absorption loss. The trap 750 μg is the IV loading dose (100% bioavailability). 2083 μg arises from dividing by 0.36 instead of 0.6 — a unit confusion error. Digoxin’s massive Vd (~500 L) is why its loading dose seems enormous relative to maintenance.'\n },\n\n {\n id: 3,\n tag: 'Vd — Clinical Interpretation',\n stem: 'Drug X has a volume of distribution of <strong>3.5 L<\/strong> in a 70 kg adult. Drug Y has a Vd of <strong>700 L<\/strong> in the same patient. Which statement correctly interprets these values?',\n correct: 'Drug X is largely confined to plasma; Drug Y is extensively distributed into tissues and intracellular compartments, making it difficult to remove by haemodialysis',\n opts: [\n 'Drug X is largely confined to plasma; Drug Y is extensively distributed into tissues and intracellular compartments, making it difficult to remove by haemodialysis',\n 'Drug X has higher potency than Drug Y because a smaller volume is needed to achieve the same plasma concentration',\n 'Drug Y has a higher plasma concentration than Drug X at the same dose because it distributes into a larger apparent volume',\n 'Both drugs distribute similarly; the difference in Vd simply reflects their different molecular weights rather than tissue binding'\n ],\n exp: 'Total plasma volume in a 70 kg adult ≈ <strong>3 litres<\/strong>. A Vd of 3.5 L means Drug X barely leaves the bloodstream — it is highly protein-bound in plasma or too large to cross membranes (e.g. heparin, monoclonal antibodies).<br><br>A Vd of 700 L is physically impossible as a real volume — it is <strong>apparent<\/strong>. It tells us the drug is avidly sequestered in tissues, and very little remains in plasma. Clinical consequence: <strong>haemodialysis cannot remove drugs with large Vd<\/strong> because dialysis only cleans the plasma compartment. With 700 L Vd, almost nothing is in plasma to be filtered. This is why haemodialysis is ineffective for tricyclic antidepressant or chloroquine overdose. The trap about potency conflates concentration with efficacy — Vd says nothing about potency.'\n },\n\n {\n id: 4,\n tag: 'Loading Dose — Why It Is Used',\n stem: 'A patient is started on amiodarone for a ventricular arrhythmia. The drug has a half-life of <strong>40–55 days<\/strong> and a Vd of approximately <strong>5000 L<\/strong>. A large loading dose is given over several days before switching to maintenance dosing. What is the primary pharmacokinetic reason for giving a loading dose?',\n correct: 'Without a loading dose, it would take 4–5 half-lives (up to 275 days) to reach therapeutic steady-state concentrations; the loading dose rapidly fills the large volume of distribution to achieve target plasma levels immediately',\n opts: [\n 'Without a loading dose, it would take 4–5 half-lives (up to 275 days) to reach therapeutic steady-state concentrations; the loading dose rapidly fills the large volume of distribution to achieve target plasma levels immediately',\n 'The loading dose is required because amiodarone has poor oral bioavailability and the extra dose compensates for first-pass metabolism in the liver before systemic absorption',\n 'Loading doses are given for drugs with short half-lives to prevent plasma concentrations from falling below the minimum effective concentration between doses',\n 'The loading dose saturates plasma protein binding sites, thereby increasing the free fraction of the drug available to reach the site of action in cardiac tissue'\n ],\n exp: 'This question links two concepts: <strong>half-life determines time to steady state<\/strong>, and <strong>Vd determines the loading dose magnitude<\/strong>.<span class=\"calc\">Time to steady state = 4–5 × t½<br>= 4–5 × 40–55 days<br>= <strong>160–275 days<\/strong> without a loading dose<\/span>Waiting 6–9 months for an antiarrhythmic to work is clinically unacceptable. The loading dose bypasses this delay by <strong>rapidly saturating the huge Vd<\/strong> (5000 L for amiodarone — one of the largest of any drug). Once distribution equilibrium is achieved, a small maintenance dose replenishes only what is eliminated. Trap C is backwards: loading doses are used for drugs with <em>long<\/em> half-lives, not short ones. Short half-life drugs reach steady state quickly on their own.'\n },\n\n {\n id: 5,\n tag: 'Vd — Back-Calculating from Loading Dose',\n stem: 'A drug is given as an IV loading dose of <strong>300 mg<\/strong> to achieve a target plasma concentration of <strong>6 mg\/L<\/strong>. The bioavailability is 100% (IV route). What is the <strong>volume of distribution<\/strong>, and what does this value suggest about the drug\\'s distribution pattern?',\n correct: 'Vd = 50 L; the drug distributes into total body water, suggesting moderate tissue penetration beyond the plasma compartment',\n opts: [\n 'Vd = 50 L; the drug distributes into total body water, suggesting moderate tissue penetration beyond the plasma compartment',\n 'Vd = 50 L; since this equals plasma volume, the drug is confined entirely to the intravascular compartment with no tissue distribution',\n 'Vd = 1800 L; the drug is extensively sequestered in peripheral tissues with minimal plasma concentration at equilibrium',\n 'Vd = 18 L; the drug distributes only into extracellular fluid and does not penetrate intracellular compartments'\n ],\n exp: '<span class=\"calc\">Vd = Dose ÷ C<sub>0<\/sub><br>= 300 mg ÷ 6 mg\/L<br>= <strong>50 litres<\/strong><\/span>Now interpret 50 L in a 70 kg patient:<br><br>• Plasma volume ≈ 3 L → drug not confined to plasma<br>• Extracellular fluid ≈ 15 L → drug not just in ECF<br>• Total body water ≈ 42 L → 50 L exceeds this<br><br>A Vd of 50 L means the drug distributes into <strong>total body water and modestly into some tissues<\/strong> — moderate penetration. The trap B is a critical error: plasma volume is ~3 L, not 50 L. A drug confined to plasma would have Vd ~3–5 L. Trap C (1800 L) would require the calculation 300 ÷ 0.167, which is not what the numbers give. 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#npk03 .mr-opt-text{font-size:0.86rem}\n}\n<\/style>\n\n<div id=\"npk03\">\n\n <div class=\"mr-header\">\n <div class=\"mr-series-tag\">Numerical Series · Pharmacokinetics<\/div>\n <div class=\"mr-eyebrow\">Morning Rounds · Round 03 of 07<\/div>\n <div class=\"mr-title\">Volume of Distribution &<br><em>The Loading Dose<\/em><\/div>\n <div class=\"mr-subtitle\">Five calculations · Vd, loading dose, apparent volume & what drug distribution tells you clinically<\/div>\n <div class=\"mr-chips\">\n <span class=\"mr-chip\">5 Questions<\/span>\n <span class=\"mr-chip\">+4 \/ −1 scoring<\/span>\n <span class=\"mr-chip\">Options reshuffled<\/span>\n <\/div>\n <\/div>\n\n <div class=\"mr-sentinel\" id=\"npk03-sentinel\"><\/div>\n\n <div class=\"mr-progress\" id=\"npk03-progress\">\n <div class=\"mr-prog-inner\">\n <div class=\"mr-pips\" id=\"npk03-pips\"><\/div>\n <\/div>\n <\/div>\n\n <div class=\"mr-body\">\n <div id=\"npk03-cases\"><\/div>\n <div class=\"mr-submit-wrap\">\n <button class=\"mr-btn\" id=\"npk03-submit\">Submit for Debrief<\/button>\n <\/div>\n <div class=\"mr-score\" id=\"npk03-score\">\n <div class=\"mr-score-in\">\n <div class=\"mr-score-ey\">Round Complete<\/div>\n <div class=\"mr-ring\" id=\"npk03-ring\">\n <div class=\"mr-ring-in\">\n <span class=\"mr-ring-pct\" id=\"npk03-pct\">0%<\/span>\n <span class=\"mr-ring-sub\">net<\/span>\n <\/div>\n <\/div>\n <div class=\"mr-score-title\">Your Debrief<\/div>\n <div class=\"mr-score-net\" id=\"npk03-net\"><\/div>\n <div class=\"mr-verdict\" id=\"npk03-verdict\"><\/div>\n <div class=\"mr-bands\">\n <span class=\"mr-band mr-band-c\" id=\"npk03-ct-c\"><\/span>\n <span class=\"mr-band mr-band-w\" id=\"npk03-ct-w\"><\/span>\n <span class=\"mr-band mr-band-s\" id=\"npk03-ct-s\"><\/span>\n <\/div>\n <button class=\"mr-retry\" id=\"npk03-retry\">↻ New Round<\/button>\n <\/div>\n <\/div>\n <\/div>\n\n<\/div>\n\n<script>\n(function () {\n 'use strict';\n\n var NS = 'npk03';\n var TOTAL = 5;\n var MAX = 20;\n var LTRS = ['A','B','C','D'];\n\n var QS = [\n\n {\n id: 1,\n tag: 'Vd — Basic Calculation',\n stem: 'A <strong>70 kg<\/strong> patient receives an IV bolus dose of <strong>500 mg<\/strong> of a drug. The plasma concentration immediately after injection is <strong>10 mg\/L<\/strong>. What is the <strong>volume of distribution (Vd)<\/strong> of this drug?',\n correct: '50 litres',\n opts: [\n '50 litres',\n '5 litres',\n '500 litres',\n '0.71 L\/kg'\n ],\n exp: 'The fundamental Vd formula:<span class=\"calc\">Vd = Dose ÷ C<sub>0<\/sub><br>Vd = 500 mg ÷ 10 mg\/L<br>Vd = <strong>50 litres<\/strong><\/span>Interpretation: 50 L in a 70 kg patient = <strong>0.71 L\/kg<\/strong>. This is actually close to total body water (~42 L), suggesting moderate tissue distribution. The trap option 0.71 L\/kg is the <em>per-kilogram<\/em> expression of the same answer — not wrong mathematically, but the question asks for Vd in litres, not per-kg. Key reference points to memorise:<br><br>• Vd ~3–5 L → drug stays in plasma (e.g. heparin, warfarin)<br>• Vd ~15 L → distributes into extracellular fluid (e.g. gentamicin)<br>• Vd >40 L → extensive tissue distribution (e.g. chloroquine >200 L, amiodarone >5000 L)'\n },\n\n {\n id: 2,\n tag: 'Loading Dose — Calculation',\n stem: 'A patient requires rapid digitalization. The target plasma concentration of digoxin is <strong>1.5 μg\/L<\/strong>. The volume of distribution of digoxin is <strong>500 L<\/strong> and its oral bioavailability is <strong>60%<\/strong>. What is the approximate <strong>oral loading dose<\/strong> required?',\n correct: '1250 μg (1.25 mg)',\n opts: [\n '1250 μg (1.25 mg)',\n '750 μg (0.75 mg)',\n '500 μg (0.5 mg)',\n '2083 μg (2.08 mg)'\n ],\n exp: 'Loading dose formula:<span class=\"calc\">Loading Dose = (Target C<sub>p<\/sub> × Vd) ÷ Bioavailability (F)<br>= (1.5 μg\/L × 500 L) ÷ 0.60<br>= 750 μg ÷ 0.60<br>= <strong>1250 μg = 1.25 mg<\/strong><\/span>Why divide by bioavailability? An oral dose is not fully absorbed. If you gave 750 μg orally, only 60% (= 450 μg) would reach systemic circulation — not enough. You must give <em>more<\/em> to compensate for the absorption loss. The trap 750 μg is the IV loading dose (100% bioavailability). 2083 μg arises from dividing by 0.36 instead of 0.6 — a unit confusion error. Digoxin’s massive Vd (~500 L) is why its loading dose seems enormous relative to maintenance.'\n },\n\n {\n id: 3,\n tag: 'Vd — Clinical Interpretation',\n stem: 'Drug X has a volume of distribution of <strong>3.5 L<\/strong> in a 70 kg adult. Drug Y has a Vd of <strong>700 L<\/strong> in the same patient. Which statement correctly interprets these values?',\n correct: 'Drug X is largely confined to plasma; Drug Y is extensively distributed into tissues and intracellular compartments, making it difficult to remove by haemodialysis',\n opts: [\n 'Drug X is largely confined to plasma; Drug Y is extensively distributed into tissues and intracellular compartments, making it difficult to remove by haemodialysis',\n 'Drug X has higher potency than Drug Y because a smaller volume is needed to achieve the same plasma concentration',\n 'Drug Y has a higher plasma concentration than Drug X at the same dose because it distributes into a larger apparent volume',\n 'Both drugs distribute similarly; the difference in Vd simply reflects their different molecular weights rather than tissue binding'\n ],\n exp: 'Total plasma volume in a 70 kg adult ≈ <strong>3 litres<\/strong>. A Vd of 3.5 L means Drug X barely leaves the bloodstream — it is highly protein-bound in plasma or too large to cross membranes (e.g. heparin, monoclonal antibodies).<br><br>A Vd of 700 L is physically impossible as a real volume — it is <strong>apparent<\/strong>. It tells us the drug is avidly sequestered in tissues, and very little remains in plasma. Clinical consequence: <strong>haemodialysis cannot remove drugs with large Vd<\/strong> because dialysis only cleans the plasma compartment. With 700 L Vd, almost nothing is in plasma to be filtered. This is why haemodialysis is ineffective for tricyclic antidepressant or chloroquine overdose. The trap about potency conflates concentration with efficacy — Vd says nothing about potency.'\n },\n\n {\n id: 4,\n tag: 'Loading Dose — Why It Is Used',\n stem: 'A patient is started on amiodarone for a ventricular arrhythmia. The drug has a half-life of <strong>40–55 days<\/strong> and a Vd of approximately <strong>5000 L<\/strong>. A large loading dose is given over several days before switching to maintenance dosing. What is the primary pharmacokinetic reason for giving a loading dose?',\n correct: 'Without a loading dose, it would take 4–5 half-lives (up to 275 days) to reach therapeutic steady-state concentrations; the loading dose rapidly fills the large volume of distribution to achieve target plasma levels immediately',\n opts: [\n 'Without a loading dose, it would take 4–5 half-lives (up to 275 days) to reach therapeutic steady-state concentrations; the loading dose rapidly fills the large volume of distribution to achieve target plasma levels immediately',\n 'The loading dose is required because amiodarone has poor oral bioavailability and the extra dose compensates for first-pass metabolism in the liver before systemic absorption',\n 'Loading doses are given for drugs with short half-lives to prevent plasma concentrations from falling below the minimum effective concentration between doses',\n 'The loading dose saturates plasma protein binding sites, thereby increasing the free fraction of the drug available to reach the site of action in cardiac tissue'\n ],\n exp: 'This question links two concepts: <strong>half-life determines time to steady state<\/strong>, and <strong>Vd determines the loading dose magnitude<\/strong>.<span class=\"calc\">Time to steady state = 4–5 × t½<br>= 4–5 × 40–55 days<br>= <strong>160–275 days<\/strong> without a loading dose<\/span>Waiting 6–9 months for an antiarrhythmic to work is clinically unacceptable. The loading dose bypasses this delay by <strong>rapidly saturating the huge Vd<\/strong> (5000 L for amiodarone — one of the largest of any drug). Once distribution equilibrium is achieved, a small maintenance dose replenishes only what is eliminated. Trap C is backwards: loading doses are used for drugs with <em>long<\/em> half-lives, not short ones. Short half-life drugs reach steady state quickly on their own.'\n },\n\n {\n id: 5,\n tag: 'Vd — Back-Calculating from Loading Dose',\n stem: 'A drug is given as an IV loading dose of <strong>300 mg<\/strong> to achieve a target plasma concentration of <strong>6 mg\/L<\/strong>. The bioavailability is 100% (IV route). What is the <strong>volume of distribution<\/strong>, and what does this value suggest about the drug\\'s distribution pattern?',\n correct: 'Vd = 50 L; the drug distributes into total body water, suggesting moderate tissue penetration beyond the plasma compartment',\n opts: [\n 'Vd = 50 L; the drug distributes into total body water, suggesting moderate tissue penetration beyond the plasma compartment',\n 'Vd = 50 L; since this equals plasma volume, the drug is confined entirely to the intravascular compartment with no tissue distribution',\n 'Vd = 1800 L; the drug is extensively sequestered in peripheral tissues with minimal plasma concentration at equilibrium',\n 'Vd = 18 L; the drug distributes only into extracellular fluid and does not penetrate intracellular compartments'\n ],\n exp: '<span class=\"calc\">Vd = Dose ÷ C<sub>0<\/sub><br>= 300 mg ÷ 6 mg\/L<br>= <strong>50 litres<\/strong><\/span>Now interpret 50 L in a 70 kg patient:<br><br>• Plasma volume ≈ 3 L → drug not confined to plasma<br>• Extracellular fluid ≈ 15 L → drug not just in ECF<br>• Total body water ≈ 42 L → 50 L exceeds this<br><br>A Vd of 50 L means the drug distributes into <strong>total body water and modestly into some tissues<\/strong> — moderate penetration. The trap B is a critical error: plasma volume is ~3 L, not 50 L. A drug confined to plasma would have Vd ~3–5 L. Trap C (1800 L) would require the calculation 300 ÷ 0.167, which is not what the numbers give. Always: <strong>calculate first, then interpret against the compartment benchmarks<\/strong>.'\n }\n\n ];\n\n var answers = {}, answered = 0, shuffled = {}, done = false;\n\n function gid(s) { return document.getElementById(NS + '-' + s); }\n function byId(s) { return document.getElementById(s); }\n\n function shuffleArr(arr) {\n var a = arr.slice(), i, j, t;\n for (i = a.length - 1; i > 0; i--) {\n j = Math.floor(Math.random() * (i + 1));\n t = a[i]; a[i] = a[j]; a[j] = t;\n }\n return a;\n }\n\n function countVal(v) {\n var n = 0, k;\n for (k in answers) { if (answers[k] === v) n++; }\n return n;\n }\n\n function buildPips() {\n var cont = gid('pips'), i, q, wLine, wPip, line, pip;\n cont.innerHTML = '';\n for (i = 0; i < QS.length; i++) {\n q = QS[i];\n if (i > 0) {\n wLine = document.createElement('div');\n wLine.className = 'mr-pip-wrap';\n line = document.createElement('div');\n line.className = 'mr-pip-line';\n line.id = NS + '-pl' + q.id;\n wLine.appendChild(line);\n cont.appendChild(wLine);\n }\n wPip = document.createElement('div');\n wPip.className = 'mr-pip-wrap';\n pip = document.createElement('div');\n pip.className = 'mr-pip';\n pip.id = NS + '-pip' + q.id;\n pip.textContent = String(q.id);\n wPip.appendChild(pip);\n cont.appendChild(wPip);\n }\n }\n\n function build() {\n var cont, i, q, opts, card, top, numDiv, meta, tag, stem,\n rule, optsDiv, expDiv, lbl, txt, j, optEl, ltrSpan, txtSpan;\n\n cont = gid('cases');\n cont.innerHTML = '';\n answers = {}; answered = 0; shuffled = {}; done = false;\n gid('score').style.display = 'none';\n buildPips();\n\n for (i = 0; i < QS.length; i++) {\n q = QS[i];\n opts = shuffleArr(q.opts);\n shuffled[q.id] = opts;\n\n card = document.createElement('div');\n card.className = 'mr-case';\n\n top = document.createElement('div');\n top.className = 'mr-case-top';\n\n numDiv = document.createElement('div');\n numDiv.className = 'mr-num';\n numDiv.textContent = q.id < 10 ? 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