Ecopharmacology

Ecopharmacology

1. Scope: ecopharmacology and its toxicological foundation

• Ecopharmacology (synonyms: environmental pharmacology, pharmacoenvironmentology) is the study of the entry, environmental fate, and adverse ecological effects of pharmaceuticals and their metabolites released into the environment, together with strategies to minimise that impact. `[orientation — not in G&G Ch 76; see gaps]`
• Ecopharmacovigilance is the science/activities of detecting, assessing, understanding and preventing adverse effects of pharmaceuticals in the environment — the environmental analogue of pharmacovigilance. `[orientation — not in G&G Ch 76; see gaps]`
• The governing science is environmental toxicology — "the study of how chemicals in our environment adversely affect human health" — distinguished from occupational toxicology, "the study of how chemicals in the workplace affect human health" (G&G 14e Ch.76, p.1507).
• The Industrial Revolution and the growth of chemical industries raised human exposure to chemicals that were previously rare or absent, stimulating the discipline (G&G 14e Ch.76, p.1507).
• The drug ↔ environmental-toxicant asymmetry (key conceptual anchor for ecopharmacology): "Unlike drugs, which are given to treat a specific disease and should have benefits that outweigh the risks, environmental toxicants are usually only harmful" — and exposures to them are typically involuntary, with uncertainty about severity and low public willingness to accept the risk (G&G 14e Ch.76, p.1507).
  • Ecopharmacology sits at the intersection of these two worlds: a pharmaceutical is a deliberate benefit-risk agent in the patient but becomes an involuntary environmental toxicant once excreted or discarded — so its environmental assessment follows the toxicant paradigm (low-dose, chronic, involuntary), not the therapeutic one.
• The one explicit pharmaceuticals-in-environment statement in the source: under drinking-water regulation, "there is concern about pharmaceutical waste in the water supply, but [maximum contaminant levels] have not been set for these compounds" (G&G 14e Ch.76, p.1513) — i.e. pharmaceuticals are a recognised but unregulated water contaminant class.
• Drug ↔ toxicant duality is illustrated repeatedly within the chapter — several agents are simultaneously historic drugs and environmental toxicants, underscoring that the boundary is one of dose, route, and intent (Paracelsus: "the dose makes the poison") (G&G 14e Ch.76, p.1516):
  • Mercury — used therapeutically for centuries (treatment of syphilis), now an environmental neurotoxicant (G&G 14e Ch.76, p.1516).
  • Arsenic — arsphenamine (Ehrlich's "magic bullet" for syphilis) and arsenic trioxide (still used in acute promyelocytic leukaemia, see G&G Ch.70) versus arsenic as a drinking-water carcinogen (G&G 14e Ch.76, p.1518).
  • Thimerosal — an ethyl-mercury–releasing antimicrobial preservative in vaccines: a pharmaceutical excipient that is itself an organomercurial (G&G 14e Ch.76, p.1516).
  • Diethylstilbestrol — a synthetic estrogen drug that is also a Group 1 estrogenic carcinogen via estrogen-receptor signalling (G&G 14e Ch.76, Table 76–1, p.1510).
  • Oltipraz (antischistosomal drug) and celecoxib/aspirin/tamoxifen/raloxifene repurposed as chemopreventives — drugs acting on the environmental-carcinogenesis pathway (G&G 14e Ch.76, Table 76–2, pp.1511–1512).