Lupron, with the active ingredient leuprolide acetate, is a form of hormone-based treatment for prostate cancer. This medication is a type of androgen deprivation therapy (ADT), designed to slow the disease’s progression. It functions by reducing the body’s production of testosterone, a hormone that can fuel the growth of prostate cancer cells. Lupron is not a cure, but a method to manage the cancer, particularly in its advanced stages.
The Mechanism of Lupron
Lupron is a synthetic version of a natural hormone called Gonadotropin-Releasing Hormone (GnRH). Normally, GnRH is released in pulses, signaling the pituitary gland to produce luteinizing hormone (LH), which then signals the testicles to produce testosterone. Lupron works by mimicking GnRH but in a continuous, rather than pulsatile, manner.
This constant stimulation initially causes a surge in LH and testosterone during the first few weeks, an effect known as a “testosterone flare.” This temporary increase can worsen symptoms before they improve, so doctors often prescribe an anti-androgen drug at the start of therapy to counteract this flare.
Following this surge, the continuous presence of Lupron desensitizes the pituitary gland. The receptors shut down from overstimulation, leading to a dramatic drop in LH production. Without the LH signal, the testicles reduce their testosterone production to castrate levels (50 ng/dL or less). This state is reversible if the drug therapy is discontinued.
Application in Prostate Cancer Therapy
The goal of Lupron is to starve cancer cells of the testosterone they use to grow. Lowering testosterone can slow tumor growth, cause tumors to shrink, and help alleviate symptoms of advanced disease, such as bone pain.
It is a standard treatment for men with advanced or metastatic prostate cancer, where the disease has spread beyond the prostate gland. In these cases, hormone therapy is used to control the cancer’s progression for as long as possible.
For men with high-risk or locally advanced prostate cancer, Lupron is often used with radiation therapy. Administering Lupron before and during radiation can shrink the prostate and make the treatment more effective. It may also be used after surgery for early-stage prostate cancer to lower the risk of the cancer returning.
Administration and Dosing Schedule
Lupron is administered as a depot injection, meaning the medication is suspended in a solution for slow release over time. The injection is given either into a muscle (intramuscularly) or under the skin (subcutaneously) in a doctor’s office.
The medication comes in several dosing schedules to ensure testosterone levels remain suppressed. Common formulations include:
- A 7.5 mg injection given once a month
- A 22.5 mg injection every three months
- A 30 mg injection every four months
- A 45 mg injection every six months
Adherence to the prescribed schedule is necessary for the treatment’s effectiveness. Consistent administration ensures that testosterone production stays at a low, castrate level.
Physiological Effects of Treatment
Lowering testosterone causes widespread physiological effects. One of the most common is the onset of hot flashes or sweats, similar to menopause. Fatigue, general weakness, and weight gain are also frequently reported.
Musculoskeletal health can be impacted, with a loss of muscle mass and a decrease in bone mineral density over time. This bone thinning increases the risk of osteoporosis and fractures, and joint pain is another common complaint. A loss of libido and erectile dysfunction are very common, and shrinkage of the testicles also occurs.
The initial testosterone flare can temporarily worsen symptoms like bone pain, difficulty urinating, or new nerve-related issues.
The hormonal changes can also lead to mood swings, irritability, and feelings of depression. There are potential metabolic consequences, including an increased risk of developing diabetes and elevated cholesterol levels. Some studies have noted an increased risk of cardiovascular events like heart attack and stroke.
Monitoring and Managing Care
Regular monitoring is part of managing care for individuals on Lupron. The main tool for tracking effectiveness is the Prostate-Specific Antigen (PSA) blood test, as a falling PSA level indicates the treatment is working. Doctors also periodically test testosterone levels to confirm they are maintained in the castrate range.
Managing side effects is central to maintaining quality of life. For bone health, providers may recommend weight-bearing exercises, calcium, and Vitamin D supplements to mitigate bone density loss. A balanced diet and regular physical activity can help manage weight gain and fatigue.
Patients should report any new or worsening symptoms to their healthcare team, including mood changes or depression. Discussing side effects allows the medical team to suggest interventions, from lifestyle adjustments to additional medications, to help manage the impacts of treatment.