GONADORELIN Powder for solution for injection Ref.[9559] Active ingredients: Gonadorelin

Posology

Adults and Elderly

100 micrograms, subcutaneously or intravenously. In females for whom the phase of the menstrual cycle can be established, the test should be performed in the early follicular phase (days 1-7).

Paediatric population

The safety and efficacy of gonadorelin in children under one year have not been established. No data are available.

Route of administration

For subcutaneous and intravenous administration.

For instructions on reconstitution before administration, see section 6.6.

Test Methodology

To determine the status of the gonadotropin secretory capacity of the anterior pituitary, a test procedure requiring seven venous blood samples for LH is recommended.

Procedure:

1. Venous blood samples should be drawn at -15 minutes and immediately prior to gonadorelin administration. The LH baseline is obtained by averaging the LH values of the two samples.
2. Administer a bolus of gonadorelin subcutaneously or intravenously.
3. Draw venous blood samples at 15, 30, 45, 60 and 120 minutes after administration.
4. Blood samples should be handled as recommended by the laboratory that will determine the LH content. It must be emphasised that the reliability of the test is directly related to the inter-assay and intra-assay reliability of the laboratory performing the assay.

Interpretation of test results: Interpretation of the LH response requires an understanding of the hypothalamic-pituitary physiology, knowledge of the clinical status of the individual patient, and familiarity with the normal ranges and the standards used in the laboratory performing the LH assays.

Figure 1. Normal male LH response after gonadorelin 100 micrograms subcutaneous administration 10th and 90th percentiles:

Figure 2. Normal male LH response after gonadorelin 100 micrograms intravenous administration 10th and 90th percentiles:

Figure 3. Normal female LH response after gonadorelin 100 micrograms subcutaneous administration 10th and 90th percentiles:

Figure 4. Normal female LH response after gonadorelin 100 micrograms intravenous administration 10th and 90th percentiles:

Figures 1-4 represent the LH response curves after gonadorelin administration in normal subjects. The normal LH response curves were established between the 10th percentile (B line) and 90th percentile (A line) of all LH responses in normal subjects analysed from the results of clinical studies.

Individual patient responses should be plotted on the appropriate curve. A subnormal response in patients is defined as three or more LH values which fall below the B line of the normal LH response curve.

In cases where there is a blunted or borderline response, the gonadorelin test should be repeated.

The gonadorellin test complements the clinical assessment of patients with a variety of endocrine disorders involving the hypothalamic-pituitary axis. In cases where there is a normal response, it indicates the presence of functional pituitary gonadotropes. The single injection test does not determine the patho-physiological cause for the subnormal response and does not measure pituitary gonadotropic reserve.

Gonadorelin has been administered parenterally in doses up to 3 mg bd for 28 days without any signs or symptoms of overdosage. In cases of overdosage or idiosyncrasy, symptomatic treatment should be administered as required.

Shelf life

Unopened: 3 years.

After reconstitution: 24 hours.

Store below 25°C.

Gonadorelin is supplied in a USP Type I clear glass vial with grey butyl rubber stopper and aluminium collar.

Preparation for single injection administration: Reconstitute 100 micrograms vial with 1.0 ml of sterile water for injections. Prepare solution immediately before use. After reconstitution, refrigerate and use within 1 day. Discard unused reconstituted solution.