INTRODUCTION : Diagnostic agents are the substances used to examine the body in order to detect impairment of its normal functions. Usually these agents find no other use in medicine. Diagnostic agents are divided according to the use as drugs used as X-ray contrast media drugs used to test organ functions drugs used to determine blood volume and haemopoietic function and drugs used for miscellaneous agents.

1. DIAGNOSTIC
AGENTS
BY
SRIRAM THIRUNAVUKKARASU,
PHARM.D,
PGP COLLEGE OF PHARMACY,
NAMAKKAL

2. INTRODUCTION :
Diagnostic agents are the substances used to examine the body in order to detect
impairment of its normal functions. Usually these agents find no other use in medicine.
Diagnostic agents are divided according to the use as
• drugs used as X-ray contrast media
• drugs used to test organ functions
• drugs used to determine blood volume and haemopoietic function and
• drugs used for miscellaneous agents.

3. DRUGS USED IN X-RAY CONTRAST MEDIA :
 Any substance which when administered to a patient improves the visualization of an
organ or tissue is called a contrast media.
 Having property of opacifying X-ray radiations
 Either inorganic as well as organic

4. DRUGS USED IN
X RAY CONTRAST MEDIA
A) Positive contrast media
(absorb X-rays)
(eg: Radio opaques)
1.i}Heavy Metals & their
salts(Inorganic)Eg:BaSO4
2.ii}Iodized oils
3.iii}Iodinated organic compounds (Organic)
a) water soluble contrast media
b) water insoluble contrast media
B) Negative contrast media
(Transparent to X-rays)
Eg: Air, Oxygen, Nitrogen etc.
CLASSIFICATION:

5. IODINATED ORGANIC COMPOUND:
-Most widely used
-Tetra iodo-phenolphthalein was 1st agent
-Amount of iodine is important for opacity
a) Water soluble contrast media:
Eg: Diatrizoate sodium, Diatrizoate meglumine, Sodium iothalamate, Metrizoic acid,
Iodipamide, Ipodate sodium, Iodohippurate sodium.
• Mainly used for urography & angiography
• Administered by retrograde method (i.e. By mechanical means)
• Mild toxicity

6. Diatrizoate sodium:
• Sodium salt of substituted triiodo benzoic acid
• Iodine content: 62%
• Used for angiography & urography
• Also available as meglumine salt
Sodium Iothalamate:
• Structural isomer of diatrizoic acid One actamide (CH CONH-)
group replaced by methyl carbamoyl (-CONHCH)group
• Available as meglumine salt
• Used in angiography
• Chem. Name: sodium 3-acetamido-2,4,6-triiodo- 5-(methyl
carbamoyl)benzoate
3,5-Bis(acetylamino)-2,4,6-triiodobenzoic acid
sodium;3-acetamido-2,4,6-
triiodo-5-(methyl
carbamoyl)benzoate

7. b) Water insoluble contrast media:
Eg: Iopanoic acid, Propyliodone, Iophendylate, Iocetamic acid, Iodoxamide.
• very slightly water soluble,
• mainly used for cholecystography, bronchography and myelography,
• patient should not drink or eat before Six hrs.
Iopanoic acid:
3-amino-α-ethyl-2,4,6-triiodobenzenepropanoic acid

8. According to their test functionalities as :
• Gall bladder function, cholecystography and cholangiography:
eg: Iocetamic acid, Iodipamide, Tyropanoate sodium.
• Gastric function: eg: Pentagastrin, Congored.
• Liver function: eg. Indocyanine green.
• Ophthalmic diagnostic aid: eg. Fluorescein sodium.
• Pancreatic function: eg. Bentiromide.
• Intestinal function: eg. Barium sulfate, Xylose.
• Kidney function: eg. Aminohippurate sodium, Indigotin disulfonate,
Phenolsulphophthalein.
• Lymphatic system: eg. Isosulfan blue.
• Bronchial airway hyperacidity: eg. Methacholine.
• Drug – hyper sensitivity: eg. Benzyl penicilloyl polylysine.
• Drugs used in X- ray contrast medium: eg. Diatriazoic acid, Iocetamic acid, Iothalamic
acid, Propyliodone.
• Miscellaneous: eg. Erythrosin sodium, Evans blue.

9. Gastric Function
Congo Red
Congo Red is the sodium salt of benzidinediazo-bis-1-naphthylamine-4-sulfonic acid; a diazo
dye that is red in alkaline solution and blue in acid solution
SYNTHESIS:

10. Gall Bladder Function:
Tyropanoate Sodium
Use: It is an oral radio - opaque agent used in cholecystography.

11. Iocetamic acid:
Use: It is an oral cholecystographic agent used for radiographic visualization of gall bladder.

12. Liver Function
A. Indocyanine Green
Use: It is used to determine cardiac output, hepatic function and liver blood flow. It is
also used to measure plasma volume and regional blood flow in various organs
including kidney, eye and lungs.

13. Ophthalmic Diagnostic Aids
A. Fluorescein Sodium
Use: It is used in ophthalmic practice for detecting corneal lesions and foreign bodies in the
eyes.
Pancreatic Function
Bentiromide
Bentiromide is a peptide used as a screening test for exocrine pancreatic insufficiency and
to monitor the adequacy of supplemental pancreatic therapy

14. THANK YOU…..