Toxicology

Toxicology

TRToksikoloji

The science that studies the adverse effects of chemical, physical or biological agents on living organisms, including their mechanisms, detection, risk assessment and the management of poisoning.

In depth

A founding principle, attributed to Paracelsus, is that the dose makes the poison: almost any substance can cause harm at sufficient exposure, and harm depends on dose, route, duration of exposure and individual susceptibility. Toxicokinetics describes the absorption, distribution, metabolism and excretion of a toxicant at harmful exposures, whereas toxicodynamics describes its interaction with biological targets.

Major branches are clinical toxicology (diagnosis and treatment of the poisoned patient), regulatory and preclinical toxicology (safety assessment of medicines and chemicals before human exposure), and forensic, environmental and occupational toxicology. In drug development, repeat-dose, genotoxicity, reproductive toxicity and carcinogenicity studies define the safety profile that supports first-in-human dose selection and label warnings.

Clinical pearl

In Turkey, the National Poison Information Centre (Ulusal Zehir Danışma Merkezi, UZEM) gives 24-hour telephone advice via the 114 line; early consultation supports risk assessment and timely access to antidotes.

TRIn Turkish

Toksikoloji

Kimyasal, fiziksel veya biyolojik etkenlerin canlı organizmalar üzerindeki zararlı (advers) etkilerini; bu etkilerin mekanizmalarını, saptanmasını, risk değerlendirmesini ve zehirlenmelerin tedavisini inceleyen bilim dalıdır.

Toksikolojinin Paracelsus'a atfedilen temel ilkesi "zehri belirleyen dozdur" önermesidir: hemen her madde yeterli maruziyette zarar verebilir ve zararın ortaya çıkışı doza, uygulama yoluna, maruziyet süresine ve bireysel duyarlılığa bağlıdır. Toksikokinetik, toksik maddenin zararlı maruziyet düzeylerindeki absorpsiyon, dağılım, metabolizma ve atılımını; toksikodinamik ise biyolojik hedeflerle etkileşimini tanımlar.

Başlıca alt dalları klinik toksikoloji (zehirlenen hastanın tanı ve tedavisi), düzenleyici ve klinik öncesi toksikoloji (ilaç ve kimyasalların insan maruziyeti öncesinde güvenlilik değerlendirmesi) ile adli, çevresel ve mesleki toksikolojidir. İlaç geliştirmede tekrarlı doz, genotoksisite, üreme toksisitesi ve karsinojenite çalışmaları, insanda ilk doz seçimine ve ürün bilgilerindeki uyarılara dayanak oluşturan güvenlilik profilini belirler.

Türkiye'de Ulusal Zehir Danışma Merkezi (UZEM), 114 numaralı hat üzerinden 7/24 telefonla danışmanlık verir; erken danışma, risk değerlendirmesini ve antidotlara zamanında erişimi kolaylaştırır.

Diğer adları:Zehirbilim
Updated 24.09.2026 0 views Educational reference — verify against current sources before clinical use.

Read next

ToxicityToksisite

The capacity of a substance to cause harmful effects in a living organism, or the harmful effect itself; it depends on dose, route, duration of exposure and the susceptibility of the exposed individual.

 ToxidromeToksidrom

A constellation of signs and symptoms (vital signs, mental status, pupils, skin and bowel sounds) characteristic of poisoning by a particular class of agents, used to identify the likely cause at the bedside.

 AntidoteAntidot

A substance that counteracts the effects of a poison or drug overdose by preventing its absorption, binding or inactivating it, antagonising it at its site of action, enhancing its elimination or reversing its toxic effects.

 Median Lethal DoseMedyan Letal Doz

The dose of a substance expected to cause death in 50% of a test animal population under defined conditions of species, route and observation period; a statistical measure of acute toxicity.

 Preclinical StudyKlinik Öncesi Çalışma

Laboratory and animal investigation of a drug candidate's pharmacology, pharmacokinetics and toxicity, carried out before first administration to humans to justify and design safe clinical trials.

 Clinical PharmacologyKlinik Farmakoloji

It is the branch of science that comprehensively examines the relationship of drugs that have reached the clinical trial phase on volunteer patients and healthy individuals in all aspects.