Pentagastrin Injection BP

Pentagastrin BP 0.025% w/v

Solution for Injection.

Pentagastrin Injection BP is used for the diagnostic testing of gastric secretion.

For administration either subcutaneously or by continuous intravenous infusion.

Adults (including the elderly) and Children

The following procedure is adopted for testing gastric secretion with Pentagastrin Injection BP:

The patient receives no medication (eg. antacids, etc.) that might affect the results of the test for 24 hours and no food for 12 hours before the test. On the morning of the test a radio-opaque tube (Leven no. 7 or Ryles`s 12 – 16Fr.) is passed into the patients by the way of the nose. Radiological observation is used to ensure that the tube is correctly positioned in the lower part of the body of the stomach.

The tube is securely fastened to the patient`s nose and forehead with adhesive tape to ensure that it is not displaced. The patient lies on his left side.

The gastric juices are then collected by applying continuous suction (at 30-50 mm Hg below atmospheric pressure) to this tube, supplemented by manual suction. The patient takes occasional deep breaths to improve collection. The basal secretion is obtained by collecting samples at 15 minute intervals over an hour.

Pentagastrin Injection BP is then given, either at a dose of:

(a) 6 micrograms/kg bodyweight subcutaneously, or

(b) 0.6 micrograms/kg/hour as a continuous intravenous infusion. A tuberculin syringe is used to give a dose correct to 0.01 ml.

If dilution is required normal saline may be used.

Specimens of the gastric juices are again collected over periods of 10 or 15 minutes. The volume of the sample is measured and it is immediately filtered through gauze into a bottle. The acidity of each sample is determined by titration.

When the patient has previously shown a severe idiosyncratic response to the drug, Pentagastrin Injection BP should not be administered.

As pentagastrin stimulates gastric acid secretion it should be used with caution in patients with acute or bleeding peptic ulcer disease, though there is no clinical evidence to contraindicate use.

None known.

Pregnancy: Pentagastrin Injection BP should not be administered during pregnancy.

Lactation: no special precautions are required.

No precautions are required.

At the recommended dosage the incidence of side effects is extremely small, although very occasionally an individual may respond with hypotension and associated dizziness and faintness. Other unwanted effects reported are mild abdominal discomfort, abdominal cramps, nausea, vomiting, flushing, sweating, headaches, drowsiness or exhaustion, heaviness or weakness of the legs, allergic reactions, bradycardia, tachycardia, anxiety and panic attacks. These effects disappear once administration of `Pentagastrin Injection BP` has ceased.

The form of presentation makes it unlikely that overdosage will occur, and no such occurrence has been reported. As maximal secretory response is produced by the normal dosage, increased dosage would be expected to have no sequel other than an accentuation of the known side effects.

Pentagastrin is a synthetic pentapeptide containing the carboxyl terminal tetrapeptide responsible for the actions of natural gastrins. The most prominent action of pentagastrin is to stimulate the secretion of gastric acid, pepsin and intrinsic factor. Additonally, it stimulates pancreatic secretion, inhibits absorption of water and electrolytes from the ileum, contracts the smooth muscle of the lower oesophageal sphincter and stomach (but delays gastric emptying time), relaxes the sphincter of Oddi and increases blood flow in the gastric mucosa.

Pentagastrin stimulates gastric acid secretion approximately ten minutes after subcutaneous injection, with peak response occurring in most cases twenty to thirty minutes after administration. Duration of activity is usually between sixty and eighty minutes.

Pentagastrin is rapidly absorbed after administration. Pentagastrin has a short half-live (10 minutes or less) in the circulation. It is metabolised primarily in the liver and excretion is mainly by the kidneys.

Pentagastrin is a drug on which extensive clinical experience has been obtained. All relevant information for the prescriber is provided elsewhere in the Summary of Product Characteristics.

Sodium chloride Ph.Eur

Water for Injections Ph.Eur

Ammonium bicarbonate BP

N. Ammonia solution } pH Adjustment

N. Hydrochloric acid }

Final Excipient Composition in Solution

Sodium chloride

Water

Ammonium chloride

None known.

24 months

Store in a refrigerator. Do not freeze. Keep container in the outer carton.

2 ml glass ampoules in boxes of 5.

If dilution is required Sodium Chloride Injection BP may be used. This solution should be prepared immediately before it is required for use.

Cambridge Laboratories Limited

Deltic House

Kingfisher Way

Silverlink Business Park

Wallsend

Tyne & Wear

NE28 9NX

PL 12070/0020

First authorisation 9/2/73

Renewed 15/10/95

March 2005