Why would a man receive a Medroxyprogesterone Acetate (MPA) injection?

Medroxyprogesterone Acetate (MPA) Injections in Men: Clinical Applications

Medroxyprogesterone acetate (MPA) injections in men are primarily used to reduce sexual urges and behaviors in cases of inappropriate sexual behavior, particularly in men with dementia or for chemical castration in certain legal contexts.

Primary Clinical Indications

1. Management of Inappropriate Sexual Behavior in Dementia

• MPA effectively reduces disruptive sexual behaviors in men with dementia who exhibit problematic sexual behaviors such as public masturbation or inappropriate sexual advances 1
• Treatment results in rapid cessation of sexual acting out (within 2 weeks) by reducing testosterone levels by approximately 90% 1
• Can be considered a first-line treatment for sexual acting out in men with dementia when other management approaches have failed 1

2. Male Hormonal Contraception (Investigational)

• MPA has been studied in combination with testosterone for male contraception 2, 3
• When combined with testosterone undecanoate (TU), MPA can effectively suppress spermatogenesis to azoospermia or severe oligozoospermia 3
• However, MPA alone with methyltestosterone was found ineffective for male contraception at standard doses 2

Mechanism of Action

• MPA works primarily by:
  • Suppressing luteinizing hormone (LH) and follicle-stimulating hormone (FSH) 1
  • Dramatically reducing serum testosterone levels (approximately 90% reduction) 1
  • Inhibiting sexual drive and behavior through hormonal suppression 1

Administration Protocol

• Standard dosing for behavioral management:

  • Typically administered as intramuscular injections
  • Dosage varies based on indication and patient response
  • Effects on testosterone levels are seen within 2 weeks of initiation 1

• For investigational male contraception:

  • Combination therapy with testosterone undecanoate (TU) at 8-week intervals has shown efficacy 3
  • Doses of 150-300mg DMPA combined with 1000mg TU have been studied 3

Monitoring and Follow-up

• Regular monitoring of:

  • Serum testosterone levels
  • Luteinizing hormone (LH) levels
  • Clinical response (reduction in target behaviors)
  • Potential side effects

• Upon discontinuation:

  • Testosterone and LH levels typically return to baseline 1
  • Sexual behaviors may return but often at reduced levels 1

Important Considerations and Caveats

• MPA is not FDA-approved specifically for behavioral management in men
• Treatment should be initiated only after other non-pharmacological approaches have failed
• Informed consent should be obtained when possible, or appropriate surrogate decision-making for patients with dementia
• Regular assessment for potential side effects is essential
• The treatment is generally reversible upon discontinuation 1

Contraindications and Precautions

• History of thromboembolic disorders
• Liver dysfunction
• Known hypersensitivity to MPA
• Undiagnosed vaginal bleeding (not applicable to male patients)

While MPA has shown efficacy in reducing inappropriate sexual behaviors in men with dementia and has investigational applications in male contraception, its use should be carefully considered within appropriate clinical contexts and with proper monitoring.