PENTAGASTRIN TEST

Purpose

Stimulation of thyroid follicular cells to screen for cancer of the medullary thyroid. Pentagastrin only induces calcitonin in tumour-derived secretions and hyperplastic follicular cells.

Product

Pentagastrin (Peptavlon®, 500µg / 2ml vial).

Dose

0.5 µg Peptavlon®/kg body weight, to be diluted in 5 ml normal saline immediately before administration.

Protocol

• Samples (dry tubes) at time intervals: -5 min (T-5) and 0 (T0).
• Slow IV injection (over exactly 3 minutes).
• Samples (dry tubes) taken either according to the doctor's instructions or T+3, T+5 and T+10 min after the beginning of injection.

Samples

After centrifugation of the samples, draw off the serum and freeze at –20°C.

Assay

Calcitonin.

Side effects

• Gastrointestinal symptoms: cramp, nausea, vomiting.
• Cardiovascular symptoms: tachycardia, bradycardia, hypotension, hot flushes.
• Dizziness, faintness, sleepiness, headaches, impaired visual function, sweating.
• Allergic reaction.

Contraindications

• Pregnancy.
• Coronary heart disease.
• Allergy.
• Severe asthma.
• Recent digestive tract bleeding problems.