---
name: pharmacovigilance-guide-0c6576730fe3
description: "Adverse drug event detection, safety signal mining, and drug monitoring"
metadata:
  openclaw:
    emoji: "⚠️"
    category: "domains"
    subcategory: "pharma"
    keywords: ["pharmacovigilance", "adverse-events", "drug-safety", "faers", "signal-detection", "disproportionality"]
    source: "wentor"
---

# Pharmacovigilance Guide

A skill for computational pharmacovigilance research, covering adverse drug event (ADE) databases, signal detection algorithms, disproportionality analysis, and safety surveillance methods used in post-market drug monitoring.

## Adverse Event Data Sources

### Key Databases

| Database | Operator | Coverage | Access |
|----------|----------|----------|--------|
| FAERS (FDA Adverse Event Reporting System) | FDA | US spontaneous reports | Free quarterly downloads |
| EudraVigilance | EMA | European reports | Research access via application |
| VigiBase | WHO-UMC | Global (150+ countries) | Research license |
| VAERS | CDC/FDA | US vaccine adverse events | Free download |
| MAUDE | FDA | Medical device reports | Free download |

### Loading FAERS Data

```python
import pandas as pd
import zipfile
import os

def load_faers_quarter(data_dir: str, year: int, quarter: int) -> dict:
    """
    Load FAERS quarterly data files into DataFrames.
    Downloads available from: fis.fda.gov/extensions/FPD-QDE-FAERS/FPD-QDE-FAERS.html
    Returns dict of DataFrames for each file type.
    """
    prefix = f"faers_ascii_{year}Q{quarter}"
    tables = {}

    file_map = {
        "DEMO": "demographics",    # Patient demographics
        "DRUG": "drugs",            # Drug information
        "REAC": "reactions",        # Adverse reactions (MedDRA terms)
        "OUTC": "outcomes",         # Patient outcomes
        "INDI": "indications",     # Drug indications
        "THER": "therapy",          # Therapy dates
        "RPSR": "report_sources",   # Report source
    }

    for suffix, name in file_map.items():
        filepath = os.path.join(data_dir, f"{suffix}{year}Q{quarter}.txt")
        if os.path.exists(filepath):
            tables[name] = pd.read_csv(
                filepath, sep="$", encoding="latin-1",
                low_memory=False, on_error="warn"
            )

    return tables

# Example: Load and inspect
faers = load_faers_quarter("./faers_data", 2024, 3)
print(f"Reports: {len(faers['demographics']):,}")
print(f"Drug-reaction pairs: {len(faers['reactions']):,}")
```

## Signal Detection Methods

### Disproportionality Analysis

Disproportionality measures compare the observed frequency of a drug-event pair against the expected frequency under independence:

```python
import numpy as np
from scipy.stats import chi2

def compute_disproportionality(a: int, b: int, c: int, d: int) -> dict:
    """
    Compute disproportionality measures from a 2x2 contingency table:

              Event+    Event-
    Drug+       a          b
    Drug-       c          d

    a: reports with both the drug and the event
    b: reports with the drug but not the event
    c: reports with the event but not the drug
    d: reports with neither
    """
    n = a + b + c + d
    expected = (a + b) * (a + c) / n if n > 0 else 0

    # Reporting Odds Ratio (ROR)
    ror = (a * d) / (b * c) if b * c > 0 else float("inf")
    ln_ror = np.log(ror) if ror > 0 and ror != float("inf") else 0
    se_ln_ror = np.sqrt(1/a + 1/b + 1/c + 1/d) if min(a, b, c, d) > 0 else float("inf")
    ror_lower = np.exp(ln_ror - 1.96 * se_ln_ror)

    # Proportional Reporting Ratio (PRR)
    prr = (a / (a + b)) / (c / (c + d)) if (a + b) > 0 and (c + d) > 0 else 0

    # Information Component (IC, Bayesian shrinkage)
    ic = np.log2((a + 0.5) / (expected + 0.5)) if expected > 0 else 0

    # Chi-squared with Yates correction
    chi2_val = (n * (abs(a * d - b * c) - n / 2) ** 2) / (
        (a + b) * (c + d) * (a + c) * (b + d)
    ) if min(a + b, c + d, a + c, b + d) > 0 else 0

    return {
        "a": a, "b": b, "c": c, "d": d,
        "expected": round(expected, 2),
        "ROR": round(ror, 3),
        "ROR_lower_95": round(ror_lower, 3),
        "PRR": round(prr, 3),
        "IC": round(ic, 3),
        "chi2": round(chi2_val, 3),
        "signal": ror_lower > 1 and a >= 3 and chi2_val > 3.84,
    }
```

### Multi-Item Gamma Poisson Shrinker (MGPS)

The MGPS method (used by FDA) applies empirical Bayesian shrinkage to stabilize estimates for rare events:

```python
def empirical_bayes_geometric_mean(observed: np.ndarray,
                                     expected: np.ndarray) -> np.ndarray:
    """
    Simplified EBGM computation.
    Shrinks observed/expected ratios toward the overall mean,
    reducing false positives from small counts.
    """
    # Raw ratio
    rr = observed / np.maximum(expected, 0.01)

    # Empirical Bayes shrinkage (simplified two-component mixture)
    # Full implementation uses EM algorithm to fit mixture of gammas
    global_mean = np.mean(rr)
    shrinkage = expected / (expected + 1)  # more shrinkage for small expected
    ebgm = shrinkage * rr + (1 - shrinkage) * global_mean

    return ebgm
```

## MedDRA Terminology

### Medical Dictionary for Regulatory Activities

MedDRA provides the standardized terminology for adverse event coding:

```
Hierarchy (5 levels):
  System Organ Class (SOC)      -- e.g., "Cardiac disorders"
    High Level Group Term (HLGT) -- e.g., "Cardiac arrhythmias"
      High Level Term (HLT)      -- e.g., "Supraventricular tachyarrhythmias"
        Preferred Term (PT)      -- e.g., "Atrial fibrillation"
          Lowest Level Term (LLT) -- e.g., "Auricular fibrillation"
```

### Standardized MedDRA Queries (SMQs)

Pre-defined search strategies for known safety topics:

- **Anaphylactic reaction (SMQ)**: Broad and narrow search terms
- **Drug-induced liver injury (SMQ)**: Hy's Law criteria
- **Torsade de pointes / QT prolongation (SMQ)**: Cardiac safety signals
- **Rhabdomyolysis (SMQ)**: Muscle-related adverse events

## Temporal Pattern Analysis

### Time-to-Onset Analysis

```python
def time_to_onset_analysis(drug_start_dates: pd.Series,
                            event_dates: pd.Series) -> dict:
    """
    Analyze time-to-onset distribution for a drug-event pair.
    Useful for distinguishing causal signals from coincidental reports.
    """
    ttp = (event_dates - drug_start_dates).dt.days
    ttp = ttp[ttp >= 0]  # exclude negative (data quality issue)

    return {
        "n_reports": len(ttp),
        "median_days": ttp.median(),
        "mean_days": ttp.mean(),
        "q25_days": ttp.quantile(0.25),
        "q75_days": ttp.quantile(0.75),
        "within_30_days_pct": (ttp <= 30).mean() * 100,
        "within_90_days_pct": (ttp <= 90).mean() * 100,
    }
```

## Causality Assessment

Standard frameworks for evaluating whether a drug caused an adverse event:

| Method | Type | Key Criteria |
|--------|------|-------------|
| WHO-UMC | Algorithmic | Temporal, dechallenge, rechallenge, alternative causes |
| Naranjo Score | Scoring scale | 10 questions, score 0-13 (definite/probable/possible/doubtful) |
| Bradford Hill | Principles | Strength, consistency, specificity, temporality, biological gradient |

## Tools and Resources

- **openFDA API**: Direct access to FAERS data via REST
- **OHDSI / OMOP CDM**: Standardized observational health data for pharmacoepidemiology
- **PhViD (R package)**: Pharmacovigilance signal detection methods
- **EHRtemporalVariability**: R package for temporal data quality in EHR
- **VigiRank**: WHO-UMC signal prioritization algorithm
- **AEOLUS**: Standardized and cleaned version of FAERS data


---
Source attribution: wentorai
Original project: https://github.com/wentorai/research-plugins/blob/bf44b3cd617fa94c8a1b254c5d1987142ca3d631/skills/domains/pharma/pharmacovigilance-guide/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2026 Wentor AI

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Mega AI Hub resource metadata

Creator / publisher: wentorai
Original project: https://github.com/wentorai/research-plugins/blob/bf44b3cd617fa94c8a1b254c5d1987142ca3d631/skills/domains/pharma/pharmacovigilance-guide/SKILL.md
Attribution basis: Source repository record

Fields of work: Data & Analytics, Healthcare & Life Sciences
Roles: Clinical Research, Data Scientist, Health Informatics
Specialties: API, Database
Tools: Faers
Country applicability: United Kingdom, United States
Classification basis: Source catalog labels
Instruction SHA-256: 57ebc80961b00ef1512f20821abd3612560d22fa91f2ba69f939642b4422636a
