I am a male patient on lanreotide (Somatuline) experiencing dull right‑sided penile pain that begins just before ejaculation and persists briefly afterward; could this be a side effect of the drug or what other causes should be considered?

Evaluation of Right-Sided Penile Pain During Ejaculation in a Patient on Lanreotide

Your right-sided penile pain occurring just before and during ejaculation is unlikely to be directly caused by lanreotide, as this medication is not documented to cause painful ejaculation; instead, you should be evaluated for more common causes including prostatitis, ejaculatory duct pathology, or benign prostatic hyperplasia.

Understanding Your Symptom

Painful ejaculation (dysorgasmia) is more common than many realize, affecting 1-25% of men worldwide, and has significant impact on quality of life and sexual function 1. The timing of your pain—beginning just before ejaculation and persisting briefly afterward—suggests involvement of the ejaculatory ducts, prostate, or seminal vesicles rather than a medication effect 1.

Lanreotide and Sexual Function

• Lanreotide (a somatostatin analog) does not have documented associations with painful ejaculation in the medical literature 2, 3.
• The most common side effects of lanreotide are gastrointestinal discomfort, gallstone formation risk, and glucose metabolism changes—not genitourinary pain 2.
• While some medications can affect male sexual function through various mechanisms (hormonal suppression, direct gonadotoxic effects, or effects on ejaculatory function), lanreotide does not fit these patterns 4.

More Likely Causes to Investigate

Prostatitis-Related Pain

• Approximately 18-20% of sexually active men with lower urinary tract symptoms experience painful ejaculation, which is considered a prostatitis-like symptom 5.
• Men with painful ejaculation typically have more severe urinary symptoms and greater overall bother compared to those without this complaint 5.
• A history of urinary tract infection is more common (12% vs 7%) in men with ejaculatory pain 5.

Benign Prostatic Hyperplasia (BPH)

• BPH can present with painful ejaculation, particularly when associated with prostatic inflammation 5.
• Men with both BPH and painful ejaculation have higher rates of erectile dysfunction (72% vs 57%) and reduced ejaculate volume (75% vs 56%) compared to those with urinary symptoms alone 5.

Ejaculatory Duct Obstruction

• Obstruction or inflammation of the ejaculatory ducts can cause localized pain during the ejaculatory process 1.
• This can result from infection, inflammation, or structural abnormalities 1.

Recommended Evaluation Approach

You need a focused urological evaluation that includes:

• Detailed sexual and urinary history to distinguish between different ejaculatory disorders and identify any lower urinary tract symptoms 6.
• Digital rectal examination to assess for prostatic tenderness, nodules, or enlargement 5.
• Urinalysis and urine culture to rule out urinary tract infection, which is more common in men with painful ejaculation 5.
• Post-ejaculatory urinalysis if indicated, to assess for inflammatory cells or infection 1.
• Consideration of prostate-specific antigen (PSA) testing if clinically appropriate based on age and examination findings 5.
• Transrectal ultrasound may be warranted if ejaculatory duct obstruction is suspected 1.

Treatment Considerations

Treatment should be directed at the underlying cause once identified 1:

• If prostatitis is diagnosed: antibiotics for bacterial infection or alpha-blockers and anti-inflammatory medications for chronic prostatitis/chronic pelvic pain syndrome 1.
• If BPH is contributing: alpha-blockers may help, though be aware that some (particularly tamsulosin and silodosin) can cause ejaculatory dysfunction including retrograde ejaculation 7.
• If no clear organic cause is found: referral to a mental health professional with sexual health expertise should be considered, as psychological factors can contribute 6.

Critical Pitfall to Avoid

Do not assume this is simply a medication side effect and ignore it—painful ejaculation warrants proper urological evaluation as it may indicate treatable conditions like infection, inflammation, or structural abnormalities 1. The symptom is often underreported due to its sensitive nature, so your willingness to seek evaluation is appropriate 1.