What is langcare-drug-interactions?

A clinical medication-safety checker that looks for important interactions between active medicines. It considers how medicines are processed in the body and effects such as bleeding, heart-rhythm changes, serotonin syndrome, or sedation.

Use it to examine active prescriptions and reported medicines, check allergies and kidney or liver information, classify interaction severity, and explain the likely mechanism and action.

It helps clinicians find risky combinations before prescribing a new medicine or reviewing an existing medication list.

langcare-drug-interactions — Skill by langcare/langcare-mcp-fhir

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add langcare/langcare-mcp-fhir --skill drug-interactions

Clone the repo

git clone --depth 1 https://github.com/langcare/langcare-mcp-fhir

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/langcare/langcare-mcp-fhir/drug-interactions/github.svg)](https://agentmods.dev/skills/langcare/langcare-mcp-fhir/drug-interactions)

Your own site

<a href="https://agentmods.dev/skills/langcare/langcare-mcp-fhir/drug-interactions"><img src="https://agentmods.dev/badge/skills/langcare/langcare-mcp-fhir/drug-interactions/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/langcare/langcare-mcp-fhir/drug-interactions"><img src="https://agentmods.dev/badge/skills/langcare/langcare-mcp-fhir/drug-interactions.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 59 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 705 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00059	$0.00705
Opus 5.5	$0.00024	$0.00282
Sonnet 5.5	$0.00012	$0.00141
Haiku 4.5	$0.00006	$0.00071

Measured 2mo ago against content hash 971124dfe094, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

langcare-drug-interactions scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

cma/skills/medication-management/drug-interactions/SKILL.md · 64 lines

How it starts

The opening of the file, as written. The whole thing — 64 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Drug Interaction Checker

When to Use This Skill

Use when a clinician needs to evaluate the active medication list for drug-drug interactions, particularly before prescribing a new medication or during medication reconciliation.

Clinical Workflow

Use fhir_search to pull all active MedicationRequest and MedicationStatement resources
Use fhir_search to pull active AllergyIntolerance for drug allergy cross-check
Use fhir_search to pull relevant Observation resources (renal function, hepatic function) for dose adjustment context
Map each medication to its CYP450 substrate/inhibitor/inducer profile (see references/cyp450-table.md)
Identify pharmacokinetic interactions (CYP inhibition/induction affecting drug levels) and pharmacodynamic interactions (additive/synergistic effects: QT prolongation, serotonin syndrome, bleeding risk, CNS depression)
Classify interactions by severity: contraindicated, major, moderate, minor
Present findings with mechanism, clinical significance, and recommended action

FHIR Resources

MedicationRequest -- Active prescriptions with medication codes
MedicationStatement -- Patient-reported medications including OTC and supplements
AllergyIntolerance -- Drug allergy cross-reference
Observation -- Renal function (CrCl/eGFR), hepatic function (ALT, AST) for dose adjustment context

FHIR Query Examples

Pull All Active Medications

fhir_search(resourceType="MedicationRequest", queryParams="patient=[patient-id]&status=active&_count=100")

Pull Patient-Reported Medications (OTC, supplements)

fhir_search(resourceType="MedicationStatement", queryParams="patient=[patient-id]&status=active&_count=100")

Pull Renal Function for Dose Context

fhir_search(resourceType="Observation", queryParams="patient=[patient-id]&code=33914-3&_sort=-date&_count=1")

Clinical Guidelines

FDA drug interaction guidance for labeling
AHA/ACC guidelines on QT-prolonging drug combinations
Beers Criteria for potentially inappropriate drug combinations in elderly

Read the full file on GitHub · 64 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

references/cyp450-table.md 3.3 KB

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 64 lines · 59 tokens per session scan A 971124dfe094

Subscribe to this mod's changes

langcare-drug-interactions is a skill published in the GitHub repository langcare/langcare-mcp-fhir (71 stars, last pushed 6mo ago), licensed MIT. It adds 59 tokens to every session and 705 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Scientific

langcare-drug-interactions next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
langcare-drug-interactionslangcare/langcare-mcp-fhir	Skill	71	6mo ago	MIT	A	59	Claude Code, Codex
instrument-data-to-allotropeanthropics/knowledge-work-plugins	Skill	35k	2d ago	Apache-2.0	A	123	Claude Code
exploratory-data-analysisK-Dense-AI/scientific-agent-skills	Skill	56k	4d ago	MIT	A	83	Claude Code
matlabK-Dense-AI/scientific-agent-skills	Skill	56k	4d ago	MIT	A	44	Claude Code
phylogeneticsK-Dense-AI/scientific-agent-skills	Skill	56k	4d ago	MIT	A	71	Claude Code, Codex
research-engineerdavila7/claude-code-templates	Skill	33k	yesterday	MIT	A	43	Claude Code, Codex
mapping-to-snomedmaziyarpanahi/openmed	Skill	5.8k	yesterday	Apache-2.0	A	205	Claude Code