Complications of injectable testosterone undecanoate in routine clinical practice

Objective: Injectable testosterone undecanoate (TU) was marketed within the last decade, but its complications in routine clinical practice are not well defined. Design and methods: Prospective observational study of consecutive TU injections in an Andrology Clinic to estimate the incidence of i) immediate cough/syncope due to pulmonary oil microembolisation (POME), ii) post-injection haematoma and iii) the prevalence of secondary polycythaemia. Results: In 3022 injections given to 347 patients over 3.5 years, POME was observed after 56 injections (66% mild, 19% severe; 40% with onset before injection completed) in 43 patients. The incidence of 19 (95% CI 14-24) per 1000 injections did not differ between three experienced nurse injectors, but recurrences were more frequent than by chance. No post-injection haematoma was reported including after 269 injections to men taking antiplatelet, anticoagulant or both drugs (upper 95% confidence limit 1%) with 56 not withholding drugs prior to TU administration (upper 95% confidence limit 5.4%). Mean haematocrit was 0.44 +/- 0.04 (S.D.) with 25 (7%) >0.50, 14 (4%) >0.52 and 3 (1%) >0.54. Conclusion: TU injections produce a low incidence of POME with injections by experienced nurses, but recurrence is more frequent than by chance. Post-injection haematoma was not observed even among men using anticoagulant and/or antiplatelet drugs, and polycythaemia was a minor problem rarely requiring treatment other than optimising inter-injection interval.