File size: 3,786 Bytes
327b23d | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 | """Drug-dose adjustment given patient BBB permeability + drug BBB classification.
Pure-function logic. Researcher-persona module — does NOT touch the fusion
engine. Output is a research suggestion, NOT medical advice.
Decision matrix:
BBB intact (perm < 0.2) -> factor=1.0, risk=low
BBB leaky, drug BBB-permeable -> factor=max(0.3, 1 - 0.7*perm),
risk=high if perm > 0.6 else moderate
BBB leaky, drug NOT permeable -> factor=max(0.6, 1 - 0.4*perm),
risk=moderate
drug_permeable=None (unknown) -> treat as permeable (safer)
"""
from __future__ import annotations
from dataclasses import dataclass
from typing import Literal
RiskLevel = Literal["low", "moderate", "high"]
@dataclass(frozen=True)
class DoseAdjustment:
recommended_dose_mg: float
adjustment_factor: float # 0..1; 1.0 = no change
risk_level: RiskLevel
rationale: str
# Threshold below which BBB is considered intact and no adjustment applies.
_INTACT_THRESHOLD = 0.2
# Floor on the adjustment factor (we never recommend going below this fraction
# of the baseline dose — anything more aggressive belongs to a clinician).
_PERMEABLE_DRUG_MIN_FACTOR = 0.3
_NON_PERMEABLE_DRUG_MIN_FACTOR = 0.6
# Slope on the linear adjustment.
_PERMEABLE_DRUG_SLOPE = 0.7
_NON_PERMEABLE_DRUG_SLOPE = 0.4
def adjust(
baseline_dose_mg: float,
bbb_permeability_score: float,
drug_bbb_permeable: bool | None = None,
) -> DoseAdjustment:
"""Return a DoseAdjustment for the (patient, drug) pair."""
if baseline_dose_mg <= 0.0:
raise ValueError(f"baseline_dose_mg must be > 0; got {baseline_dose_mg}")
if not 0.0 <= bbb_permeability_score <= 1.0:
raise ValueError(
f"bbb_permeability_score must be in [0, 1]; got {bbb_permeability_score}"
)
if bbb_permeability_score < _INTACT_THRESHOLD:
return DoseAdjustment(
recommended_dose_mg=baseline_dose_mg,
adjustment_factor=1.0,
risk_level="low",
rationale=(
f"BBB permeability score {bbb_permeability_score:.2f} is below the "
f"intact threshold ({_INTACT_THRESHOLD:.2f}). No dose adjustment "
"recommended. Research suggestion, not medical advice."
),
)
# Treat unknown permeability conservatively as 'permeable'.
permeable = True if drug_bbb_permeable is None else bool(drug_bbb_permeable)
if permeable:
factor = max(
_PERMEABLE_DRUG_MIN_FACTOR,
1.0 - _PERMEABLE_DRUG_SLOPE * bbb_permeability_score,
)
risk: RiskLevel = "high" if bbb_permeability_score > 0.6 else "moderate"
permeable_note = (
"Drug is BBB-permeable" if drug_bbb_permeable is True
else "Drug BBB permeability is unknown (treated as permeable for safety)"
)
else:
factor = max(
_NON_PERMEABLE_DRUG_MIN_FACTOR,
1.0 - _NON_PERMEABLE_DRUG_SLOPE * bbb_permeability_score,
)
risk = "moderate"
permeable_note = "Drug is normally BBB-excluded"
recommended = baseline_dose_mg * factor
rationale = (
f"BBB permeability score {bbb_permeability_score:.2f} indicates "
f"compromised barrier. {permeable_note}; recommended dose reduced "
f"to {factor*100:.0f}% of baseline ({recommended:.1f} mg of "
f"{baseline_dose_mg:.1f} mg). Risk level: {risk}. "
"Research suggestion, not medical advice."
)
return DoseAdjustment(
recommended_dose_mg=float(recommended),
adjustment_factor=float(factor),
risk_level=risk,
rationale=rationale,
)
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