# Microgram: naranjo-causality

`station__algovigilance__microgram-naranjo-causality` · native (always callable) · domain `algovigilance` · pv-relevance `pv-core`

Naranjo Adverse Drug Reaction Probability Scale. Ten yes/no/unknown questions about the drug-event temporal and clinical relationship, producing a probability category: definite, probable, possible, or doubtful.

## Agent metadata

- `idempotent`: true
- `read_only`: true
- `expected_latency_ms`: 60 ms (last measured)
- `cost_tokens_estimate`: 48 tokens (~192 bytes)

## Compose with

After invoking this tool, a natural next step is [`station__algovigilance__microgram-meddra-soc-router`](/tools/algovigilance__microgram-meddra-soc-router). The recommended chain is hand-authored in the catalog's `pipes_to` graph.

## Input schema

- `previous_reports` *string* (required) — Are there previous conclusive reports on this reaction? (yes/no/unknown)
- `after_drug` *string* (required) — Did the adverse event appear after the drug was administered? (yes/no/unknown)
- `improved_on_discontinuation` *string* (required) — Did the AE improve when the drug was discontinued or a specific antagonist was administered? (yes/no/unknown)
- `reappeared_on_readministration` *string* (required) — Did the AE reappear when the drug was re-administered? (yes/no/unknown)
- `alternative_causes_ruled_out` *string* (required) — Are there alternative causes that could on their own have caused the reaction? (yes/no/unknown) — note: 'yes' means alternative causes EXIST (worse for causality).
- `reappeared_with_placebo` *string* (required) — Did the reaction reappear when a placebo was given? (yes/no/unknown)
- `drug_detected_in_blood` *string* (required) — Was the drug detected in blood (or other fluids) in toxic concentrations? (yes/no/unknown)
- `dose_dependent` *string* (required) — Was the reaction more severe when dose increased / less severe when dose decreased? (yes/no/unknown)
- `prior_similar_reaction` *string* (required) — Did the patient have a similar reaction to the same/similar drug previously? (yes/no/unknown)
- `confirmed_by_objective_evidence` *string* (required) — Was the AE confirmed by any objective evidence (lab values, vital signs, imaging)? (yes/no/unknown)

## Example call

```json
POST /api/mcp
Content-Type: application/json

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "station__algovigilance__microgram-naranjo-causality",
    "arguments": {
      "previous_reports": "",
      "after_drug": "",
      "improved_on_discontinuation": "",
      "reappeared_on_readministration": "",
      "alternative_causes_ruled_out": "",
      "reappeared_with_placebo": "",
      "drug_detected_in_blood": "",
      "dose_dependent": "",
      "prior_similar_reaction": "",
      "confirmed_by_objective_evidence": ""
    }
  }
}
```

## Related

- [/tools](/tools) — all 3062 tools
- [/tools/algovigilance__microgram-naranjo-causality](/tools/algovigilance__microgram-naranjo-causality) — HTML page
- [/tools/algovigilance__microgram-naranjo-causality/json](/tools/algovigilance__microgram-naranjo-causality/json) — JSON form (agent-friendly)
- [/api/mcp](/api/mcp) — endpoint
- [/AGENTS.md](/AGENTS.md) — agent guide