Adverse Reactions & Pharmacovigilance

Type A Adverse Reaction

TRTip A Advers Reaksiyon
Also known as:Augmented reaction · Dose-related adverse reaction

An adverse drug reaction resulting from an exaggeration of a drug's known pharmacological action; it is dose-related, predictable and usually common but rarely fatal.

In depth

In the Rawlins–Thompson classification, type A (augmented) reactions make up the large majority of ADRs. They may be an excess of the primary therapeutic effect, such as bleeding with anticoagulants, hypoglycaemia with insulin or sulfonylureas and bradycardia with beta-blockers, or an effect at a secondary target, such as the anticholinergic effects of tricyclic antidepressants.

Risk rises whenever drug exposure or sensitivity increases: renal or hepatic impairment, older age, drug–drug interactions, pharmacogenomic variants (e.g., CYP2C9 and VKORC1 with warfarin) and narrow-therapeutic-index drugs. Most type A reactions are preventable and are managed by dose reduction, dosing-interval adjustment or monitoring rather than by withdrawing the drug.

Clinical pearl

Before attributing a new symptom to disease progression, check renal function, recent dose changes and newly added interacting drugs; many type A reactions are preventable.

Example drugs

Warfarin insulin glibenclamide Digoxin Atenolol Amitriptyline
TRIn Turkish

Tip A Advers Reaksiyon

İlacın bilinen farmakolojik etkisinin aşırı ölçüde ortaya çıkmasından kaynaklanan, doza bağımlı, öngörülebilir, genellikle sık görülen ancak nadiren ölümcül olan advers ilaç reaksiyonudur.

Rawlins–Thompson sınıflamasında tip A (augmented, artmış) reaksiyonlar advers ilaç reaksiyonlarının büyük çoğunluğunu oluşturur. Antikoagülanlarla kanama, insülin veya sülfonilürelerle hipoglisemi, beta blokörlerle bradikardi gibi birincil tedavi etkisinin aşırılığı ya da trisiklik antidepresanların antikolinerjik etkileri gibi ikincil bir hedefteki etki biçiminde ortaya çıkabilir.

İlaç maruziyetini veya duyarlılığını artıran her durumda risk yükselir: böbrek veya karaciğer yetmezliği, ileri yaş, ilaç–ilaç etkileşimleri, farmakogenomik varyantlar (ör. varfarin için CYP2C9 ve VKORC1) ve dar terapötik indeksli ilaçlar. Tip A reaksiyonların çoğu önlenebilir; yönetimde ilacın kesilmesinden çok doz azaltma, doz aralığının ayarlanması veya izlem öne çıkar.

Yeni bir belirti hastalığın ilerlemesine bağlanmadan önce böbrek fonksiyonu, son doz değişiklikleri ve yeni eklenen etkileşimli ilaçlar gözden geçirilmelidir; tip A reaksiyonların çoğu önlenebilir.

Diğer adları:Artmış (augmented) reaksiyon · Doza bağımlı advers reaksiyon
Updated 24.09.2026 0 views Educational reference — verify against current sources before clinical use.

Read next

Type B Adverse ReactionTip B Advers Reaksiyon

An adverse drug reaction that is not expected from the drug's known pharmacology, is largely independent of dose, and is uncommon but frequently serious.

 Adverse Drug ReactionAdvers İlaç Reaksiyonu

A noxious and unintended response to a medicinal product in which a causal relationship with the drug is at least a reasonable possibility.

 Narrow Therapeutic Index DrugDar Terapötik İndeksli İlaç

A drug for which small differences in dose or blood concentration may lead to serious therapeutic failure or serious adverse drug reactions.

 Drug–Drug Interactionİlaç–İlaç Etkileşimi

A change in the magnitude or duration of a drug's effect, or in its concentrations, caused by the concurrent or prior administration of another drug.

 Renal Dose AdjustmentBöbrek Fonksiyonuna Göre Doz Ayarlaması

The modification of the dose or dosing interval of a drug that is cleared, or has active or toxic metabolites cleared, by the kidneys, to prevent accumulation and toxicity in renal impairment.

 Therapeutic Drug MonitoringTerapötik İlaç İzlemi

The measurement of drug concentrations in blood at defined times, interpreted in the clinical context, to individualise dosing so as to maximise efficacy and minimise toxicity.