Six public APIs, no keys and no paywall. Queries are scoped to title and abstract rather than full text, because a full-text hit on Curcuma in a reference list is not evidence of anything. Everything retrieved is then passed through an interaction-vocabulary gate: a paper is admitted only if it actually describes an interaction, not merely because it names a plant and a drug in the same abstract. What survives is ranked against an eight-level evidence hierarchy, so a randomised trial outranks a review that cites it.
Expectorant botanicals promote productive cough while centrally acting antitussives suppress it, so the two purposes conflict; sedating antitussives also add to botanical CNS depression.
Expected clinically: Sputum retention, ineffective cough clearance, additive drowsiness.