Drug toxicity

Drug toxicity, also drug reaction, in pathology is often a diagnosis of exclusion. Few drugs leave a distinctive histomorphologic pattern.

This article covers a few of the distinctive histomorphologic pattern and links to other articles that deal with specific organ systems.

General principles

A drug/toxin reaction should be considered if there is:

1. Ingestion/exposure.
2. An appropriate temporal relation.
3. An empirical correlation between the drug/toxin and the pattern.
   • Worsening with re-challenge.
   • Improvement with removal of exposure.
   • Pathologic pattern matches with toxin.
   • Drug.

Site specific

Liver drug toxicity

• Drug-induced liver disease.

Stomach

• Reactive gastropathy.

Small bowel

• Small bowel diaphragm disease.

Specific drugs

Sodium polystyrene sulfonate

AKA Kayexalate (trade name).

General

• Used to treat hyperkalemia.

Microscopic

Features:

• Purple blobs on H&E stain - look somewhat like calcium phosphate.
• Can cause focal necrosis.

Image

• 

  Kayexalate crystals and adenocarcinoma. (WC)

Proton pump inhibitor

Main article: Proton pump inhibitor effect

Nonsteroidal anti-inflammatory drugs

Main article: Nonsteroidal anti-inflammatory drugs

Oral contraceptive pill

Main article: Oral contraceptive pill

Minocycline

• Minocycline associated thyroid pigmentation.

Spironolactone

• Spironolactone bodies.

See also

• Basics.