# Intravenous acetylcysteine Intravenous acetylcysteine Status: LIVE Price: $0.005 USDC `GET /api/calc/acetylcysteine_iv` HTML: https://magentlab.com/docs/acetylcysteine-iv Markdown: https://magentlab.com/docs/acetylcysteine-iv.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Compute intravenous acetylcysteine milligrams from body weight using the Prescott 1979 paracetamol (acetaminophen) poisoning schedule: 150 mg/kg over 15 minutes, then 50 mg/kg over 4 hours, then 100 mg/kg over 16 hours (300 mg/kg over 20.25 hours). ## When to use When an agent needs published Prescott 1979 intravenous acetylcysteine milligram-per-kilogram arithmetic and must not invent an oral protocol, a nomogram reading, or a prescription. ## When not to use - Not a medical device. A licensed clinician remains responsible for interpretation. - Not a prescription. magent does not choose a vial, concentration, or infusion pump setting. - Not a Rumack–Matthew nomogram. magent does not plot a nomogram image. - magent does not interpret a plasma acetaminophen (paracetamol) concentration and does not decide whether to treat. - This is the Prescott 1979 intravenous 15-minute load, then 4 hours, then 16 hours. It is not an oral protocol. ## Formula ``` load_mg = weight_kg * 150; infusion_4h_mg = weight_kg * 50; infusion_16h_mg = weight_kg * 100; total_mg = weight_kg * 300; load_minutes = 15; infusion_4h_hours = 4; infusion_16h_hours = 16; total_hours = 20.25 ``` ## Citation [Intravenous N-acetylcysteine: the treatment of choice for paracetamol poisoning](https://doi.org/10.1136/bmj.2.6198.1097) Prescott LF, Illingworth RN, Critchley JA, Stewart MJ, Adam RD, Proudfoot AT Br Med J. 1979;2(6198):1097-1100 DOI: [10.1136/bmj.2.6198.1097](https://doi.org/10.1136/bmj.2.6198.1097) ## Worked example ### 70 kg intravenous schedule Given: `weight_kg=70` 1. load_mg = 70 * 150 = 10500.0 mg over 15 minutes 2. infusion_4h_mg = 70 * 50 = 3500.0 mg over 4 hours 3. infusion_16h_mg = 70 * 100 = 7000.0 mg over 16 hours 4. total_mg = 70 * 300 = 21000.0 mg over 20.25 hours ### 50 kg intravenous schedule Given: `weight_kg=50` 1. load_mg = 50 * 150 = 7500.0 mg over 15 minutes 2. infusion_4h_mg = 50 * 50 = 2500.0 mg over 4 hours 3. infusion_16h_mg = 50 * 100 = 5000.0 mg over 16 hours 4. total_mg = 50 * 300 = 15000.0 mg over 20.25 hours ## Also searched as - acetylcysteine dose - intravenous acetylcysteine - paracetamol poisoning acetylcysteine - acetaminophen poisoning acetylcysteine - Prescott acetylcysteine - N-acetylcysteine infusion - acetylcysteine loading dose ## Parameters - `weight_kg` (number, required): Weight in kilograms (1-200). ## Bulk (POST) POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement. Method: `POST /api/calc/acetylcysteine_iv` Max items: 25 Price: unit_amount + extra_item_amount * (n - 1) (unit 5000 atomic, extra 2000 atomic) Status: PREVIEW - 1 to 25 items. Each item uses the same keys as the GET query parameters. - POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows. - The first invalid item fails the whole request (index in the 400 JSON). You are not charged. - HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row. - Catalog misses (empty matches, found=false) stay paid 200s inside that slot. - x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items. Example request: ```json { "items": [ { "weight_kg": "70" }, { "weight_kg": "70" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/acetylcysteine-iv Example 200: ```json { "count": 2, "path": "/api/calc/acetylcysteine_iv", "items": [ { "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.", "citation": { "authors": "Prescott LF, Illingworth RN, Critchley JA, Stewart MJ, Adam RD, Proudfoot AT", "doi": "10.1136/bmj.2.6198.1097", "id": "prescott-1979", "pmid": "519312", "source": "Br Med J. 1979;2(6198):1097-1100", "title": "Intravenous N-acetylcysteine: the treatment of choice for paracetamol poisoning" }, "formula": "acetylcysteine_iv", "formula_expression": "load_mg = weight_kg * 150; infusion_4h_mg = weight_kg * 50; infusion_16h_mg = weight_kg * 100; total_mg = weight_kg * 300; load_minutes = 15; infusion_4h_hours = 4; infusion_16h_hours = 16; total_hours = 20.25", "infusion_16h_hours": 16, "infusion_16h_mg": 7.0e3, "infusion_4h_hours": 4, "infusion_4h_mg": 3.5e3, "load_mg": 1.05e4, "load_minutes": 15, "total_hours": 20.25, "total_mg": 2.1e4, "weight_kg": 70.0 }, { "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.", "citation": { "authors": "Prescott LF, Illingworth RN, Critchley JA, Stewart MJ, Adam RD, Proudfoot AT", "doi": "10.1136/bmj.2.6198.1097", "id": "prescott-1979", "pmid": "519312", "source": "Br Med J. 1979;2(6198):1097-1100", "title": "Intravenous N-acetylcysteine: the treatment of choice for paracetamol poisoning" }, "formula": "acetylcysteine_iv", "formula_expression": "load_mg = weight_kg * 150; infusion_4h_mg = weight_kg * 50; infusion_16h_mg = weight_kg * 100; total_mg = weight_kg * 300; load_minutes = 15; infusion_4h_hours = 4; infusion_16h_hours = 16; total_hours = 20.25", "infusion_16h_hours": 16, "infusion_16h_mg": 7.0e3, "infusion_4h_hours": 4, "infusion_4h_mg": 3.5e3, "load_mg": 1.05e4, "load_minutes": 15, "total_hours": 20.25, "total_mg": 2.1e4, "weight_kg": 70.0 } ] } ``` ## Response fields - `formula` (string): acetylcysteine_iv - `formula_expression` (string): Exact expression used - `weight_kg` (number): Input weight in kg - `load_mg` (number): Loading dose in milligrams (150 mg/kg over 15 minutes), 1 decimal - `infusion_4h_mg` (number): First infusion milligrams (50 mg/kg over 4 hours), 1 decimal - `infusion_16h_mg` (number): Second infusion milligrams (100 mg/kg over 16 hours), 1 decimal - `total_mg` (number): Total milligrams (300 mg/kg over 20.25 hours), 1 decimal - `load_minutes` (integer): Loading infusion duration in minutes (15 as published) - `infusion_4h_hours` (integer): First infusion duration in hours (4) - `infusion_16h_hours` (integer): Second infusion duration in hours (16) - `total_hours` (number): Total protocol duration in hours (20.25) - `citation` (object): Prescott et al. 1979 citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.", "citation": { "authors": "Prescott LF, Illingworth RN, Critchley JA, Stewart MJ, Adam RD, Proudfoot AT", "doi": "10.1136/bmj.2.6198.1097", "id": "prescott-1979", "pmid": "519312", "source": "Br Med J. 1979;2(6198):1097-1100", "title": "Intravenous N-acetylcysteine: the treatment of choice for paracetamol poisoning" }, "formula": "acetylcysteine_iv", "formula_expression": "load_mg = weight_kg * 150; infusion_4h_mg = weight_kg * 50; infusion_16h_mg = weight_kg * 100; total_mg = weight_kg * 300; load_minutes = 15; infusion_4h_hours = 4; infusion_16h_hours = 16; total_hours = 20.25", "infusion_16h_hours": 16, "infusion_16h_mg": 7.0e3, "infusion_4h_hours": 4, "infusion_4h_mg": 3.5e3, "load_mg": 1.05e4, "load_minutes": 15, "total_hours": 20.25, "total_mg": 2.1e4, "weight_kg": 70.0 } ``` ## Errors - HTTP 400 `invalid_acetylcysteine`: Acetylcysteine inputs must match Prescott 1979 weight from that intravenous protocol. Returned before settlement; you are not charged. - HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged. - HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged. - HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged. Shared HTTP 402 and 503: https://magentlab.com/docs/payments ## Related tools - [King's College criteria](https://magentlab.com/docs/kings-college) — Apply the O'Grady 1989 King's College poor-prognosis criteria for fulminant hepatic failure, with separate acetaminophen and non-acetaminophen trees using prothrombin time in seconds. - [Fomepizole](https://magentlab.com/docs/fomepizole) — Compute adult IV fomepizole loading and maintenance milligrams from body weight using the AACT 1999 ethylene glycol guideline schedule, with a 12-hour or 4-hour interval from the hemodialysis flag. - [Estimated ethanol](https://magentlab.com/docs/estimated-ethanol) — Estimate fasting theoretical blood ethanol (Co) from ingested ethanol grams and sex-specific Watson 1980 total body water, using the Watson 1981 Widmark update. ## Payment Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. - GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall). - HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote. - Sign accepts[0] (exact, EIP-3009) with validBefore = now + maxTimeoutSeconds (600 seconds), or accepts[1] (batch-settlement deposit/voucher) on product GET. Ping and POST {items} stay exact. Magent retries transient facilitator 429/5xx before answering. - Retry the same URL with PAYMENT-SIGNATURE (base64 JSON of accepted and payload). Magent attaches canonical extensions.bazaar on CDP verify/settle; echoing 402 bazaar is optional. - Success is HTTP 200 JSON plus PAYMENT-RESPONSE. exact settles before the tool. batch-settlement verifies (and deposit-settles) before the tool and commits the charge after HTTP 2xx. HTTP 503: retry the same PAYMENT-SIGNATURE. Mint a new exact nonce only after a new HTTP 402. - offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront. - offered `batch-settlement` on eip155:8453: Payment-channel vouchers claimed later in batches. Exact stays accepts[0]. Same-path POST {items} is still exact. extra.assetTransferMethod=eip3009 extra.paymentFlow=authorization. - not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search. Same-path POST {items} is still scheme exact: one EIP-3009 authorization for GET unit plus $0.002 per extra item. That is not x402 batch-settlement (payment channels / vouchers). Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments Stdio MCP (one process per host): https://magentlab.com/docs/mcp ## Guarantees - HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. HTTP 402 never includes the tool JSON. - exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE. - HTTP 402 is unpaid only. Do not sign a second authorization because of a 503. - Execution is timeout-bounded and concurrency-capped. - Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.