Endocrine Abstracts

Background: Clinical experience has shown that men over 60 years of age frequently (40%) require extended intervals of greater than 12 weeks between administrations of Nebido. No work has assessed whether this is specific to men over 60 years of age.

Methods: We analysed men on Nebido over 60 years (n=12, mean age 66 years) and compared them with a BMI matched group aged 40–60 years. We assessed testosterone levels, injection intervals, PSA and haematocrit over the first 4 injections.

Results: Baseline mean serum testosterone in the over 60 age group was 4.13 nmol/l (range 1.5–12.1) and in the 40–60 age group was 5.85 nmol/l (range 0.4–16.1).

Over 60 age group: 3 out of 12 patients had an elevated trough testosterone pre-2nd injection (21.3, 22.2, 24.2 nmol/l) and had next injection interval extended to 15, 15, 24 weeks respectively.

4 out of 12 patients had elevated trough testosterone levels pre-3rd injection (23.9, 17.2, 17.5, 17.8). Two of these patients stopped Nebido due to elevated testosterone levels and polycythaemia. One patient stopped due to interval extending greater than 24 weeks.

1 out of 9 patients who continued with Nebido had an elevated trough testosterone level pre-4th injection (18.9 nmol/l) and had next injection interval extended to 20 weeks.

3 out of 12 patients developed polycythaemia, 2 requiring venesection.

1 out of 12 patients developed an elevated PSA above the normal range.

40–60 age group: No patients required the injection interval extending. No patients developed polycythaemia. No patients developed a raised PSA.

Conclusions: This is the first study to compare injection frequency and side effects in men over 60 with men of 40–60 years. Of the men aged over 60 years, 33.3% had elevated testosterone levels pre 3rd injection and 25% developed polycythaemia compared to no men aged 40–60. We have shown that the necessity for 12 weekly injections for men over 60 years is significantly decreased. Particularly careful monitoring for polycythaemia in this group is necessary.