A randomised controlled clinical trial of antibiotic impregnation of testosterone pellet implants to reduce extrusion rate.
OBJECTIVE
Testosterone pellet implantation is a safe, effective and convenient form of depot androgen replacement, with extrusion of pellets following about 10% of procedures the most frequent adverse effect. This study aimed to determine whether extrusion rate could be reduced by antibiotic impregnation of pellets immediately prior to implantation.


METHODS
Prospective, randomised, parallel-group, open-label study design in a single centre. One hundred and eighty-six androgen-deficient men (400 implantation procedures) were randomised into either a group who had their pellets soaked for approximately 2 min in gentamicin solution prior to implantation, or a control group who had the standard implantation procedure.


METHODS
Extrusion, infection and/or bruising were evaluated prospectively by self-report from the participants, and retrospectively at subsequent implantation. Other variables (site, shaving, skin preparation, operator, pellet batch, bruising) were collected at implantation time.


RESULTS
The extrusion rate was 20% lower (odds ratio=0.80, 95% confidence interval (CI) 0.40-1.62) but not statistically different between the two groups (extrusion rate 23/205 (11.2%) for the control group vs 18/195 (9.2%) for the antibiotic-soak group, P=0.42). One operator experienced more total (P=0.0002) and infection-related (P=0.0008) extrusions and marginally more bruising (P=0.06) than other operators. The operator effect did not appear to be explained by differences in experience or implantation style. There was a 4.6-fold excess (95% CI 1.6-18.6) of multiple (19 vs 4 expected) over single (22 vs 10 expected) and no (359 vs 386 expected) extrusions. Extrusion was not related to batch number (P=0.15), location (P=0.15), shaving (P=0.32), old or new site (P=0.59), or the presence of suppuration or not (P=0.42); however, povidone-iodine skin disinfectant had statistically fewer extrusions than mixed alcohol solution.


CONCLUSIONS
Antibiotic impregnation prior to implantation does not significantly decrease testosterone pellet extrusion rate. An operator effect, not due to experience or procedural style, an excess of multiple extrusions and disinfectant effects were confirmed. Neither location, nor preparation of the site, nor pellet batch, influences extrusion rate.
Kelleher
S
S
Department of Andrology, Concord Hospital and ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139, Australia.
Conway
A J
AJ
Handelsman
D J
DJ
D000328:Adult; D000728:Androgens / Q000172:deficiency*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D004338:Drug Combinations; D004343:Drug Implants; D005548:Foreign-Body Migration / Q000517:prevention & control*; D005839:Gentamicins / Q000008:administration & dosage* / Q000627:therapeutic use; D012739:Gonadal Steroid Hormones / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013739:Testosterone / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D017211:Treatment Failure
D000728:Androgens; D000900:Anti-Bacterial Agents; D004338:Drug Combinations; D004343:Drug Implants; D005839:Gentamicins; D012739:Gonadal Steroid Hormones; D013739:Testosterone