Side Effects of Lupron (leuprolide)

Lupron (leuprolide) is a man-made hormone used to treat prostate cancer, endometriosis, central precocious puberty (early onset of puberty), and fibroids. It is similar to but stronger than human gonadotropin releasing hormone (GnRH). 

GnRH is made in the hypothalamus (a part of the brain) and travels to the pituitary gland where it causes the production of luteinizing hormone (LH) and follicle stimulating hormone (FSH). LH and FSH are released by the pituitary into the blood and stimulate the production of testosterone by the testes in men and estrogens by the ovaries in women. 

The release of GnRH, LH and FSH is governed by negative feedback which means that when there is too much testosterone or estrogen being produced, the body sends a signal to the pituitary gland to reduce the production of GnRH which, in turn reduces the production of LH and FSH. 

This results in reduced production of testosterone and estrogen. When given continuously, Lupron initially increases the production of LH and FSH as well as testosterone and estrogen; however, after a few weeks of continuous Lupron, the levels of LH and FSH drop because the pituitary gland stops responding to GnRH and leuprolide. 

This leads to a decrease in the production of estrogen and testosterone. Testosterone promotes the growth of prostate cancer. Lupron is used in treating prostate cancer to slow the growth of the cancer. 

In children with central precocious puberty (puberty caused at an early age because of too much LH and FSH) Lupron, by suppressing LH and FSH, reduces the levels of estrogen and testosterone and allows for more normal timing of puberty. 

Estrogens promote the growth of fibroids (benign tumors of the uterus) and areas of endometriosis (abnormal uterine tissue that exists outside of the uterus). Lupron is used to reduce the production of estrogen and treat both fibroids and endometriosis. 

Common side effects of Lupron include

• aches and pain,
• fatigue,
• fluid retention (edema),
• headaches,
• hot flashes,
• chest pain, and
• irritation at the injection site.

Other important side effects of Lupron include

• impotence,
• shrinking of the testes, and
• breast enlargement in men (gynecomastia).

Serious side effects of Lupron include

• depression,
• rare cases of suicidal behavior,
• low blood pressure,
• convulsions, and
• joint pain and muscle aches.

No drug interaction studies have been done for Lupron. Lupron should not be administered to pregnant women because there is a high chance of harm to a fetus. The effects of Lupron on the infant have not been studied in women who are breastfeeding. Consult your doctor before breastfeeding.

The most common side effects of leuprolide are:

• aches and pain,
• fatigue,
• edema,
• headaches,
• hot flashes,
• chest pain, and
• irritation at the injection site.

Other important side effects of leuprolide include:

• impotence,
• shrinking of the testes, and
• breast enlargement in men (gynecomastia).

Depression, rare cases of suicidal behavior, low blood pressure, convulsions, joint pain and muscle aches have been reported in post-marketing surveillance.

Clinical Trials

• In the majority of patients testosterone levels increased above baseline during the first week, declining thereafter to baseline levels or below by the end of the second week of treatment.
• This transient increase was occasionally associated with a temporary worsening of signs and symptoms, usually manifested by an increase in bone pain.
• In a few cases a temporary worsening of existing hematuria and urinary tract obstruction occurred during the first week.
• Temporary weakness and paresthesia of the lower limbs have been reported in a few cases.
• Potential exacerbations of signs and symptoms during the first few weeks of treatment is a concern in patients with vertebral metastases and/or urinary obstruction which, if aggravated, may lead to neurological problems or increase the obstruction.
• In a comparative trial of Lupron Injection (leuprolide acetate) versus DES, in 5% or more of the patients receiving either drug, the following adverse reactions were reported to have a possible or probable relationship to drug as ascribed by the treating physician.
• Often, causality is difficult to assess in patients with metastatic prostate cancer.
• Reactions considered not drug related are excluded.

In this same study, the following adverse reactions were reported in less than 5% of the patients on Lupron.

Cardiovascular System—Angina, Cardiac arrhythmias, Myocardial infarction, Pulmonary emboli;

Gastrointestinal System—Diarrhea, Dysphagia, Gastrointestinal bleeding, Gastrointestinal disturbance, Peptic ulcer, Rectal polyps;

Endocrine System—Libido decrease, Thyroid enlargement;

Musculoskeletal System—Joint pain;

Central/Peripheral Nervous System—Anxiety, Blurred vision, Lethargy, Memory disorder, Mood swings, Nervousness, Numbness, Paresthesia, Peripheral neuropathy, Syncope/blackouts, Taste disorders;

Respiratory System—Cough, Pleural rub, Pneumonia, Pulmonary fibrosis;

Integumentary System— Carcinoma of skin/ear, Dry skin, Ecchymosis, Hair loss, Itching, Local skin reactions, Pigmentation, Skin lesions;

Urogenital System—Bladder spasms, Dysuria, Incontinence, Testicular pain, Urinary obstruction;

Miscellaneous—Depression, Diabetes, Fatigue, Fever/chills, Hypoglycemia, Increased BUN, Increased calcium, Increased creatinine, Infection/inflammation, Ophthalmologic disorders, Swelling (temporal bone).

In an additional clinical trial and from long-term observation of both studies, the following additional adverse events (excluding those considered not drug related) were reported for patients receiving Lupron.

Cardiovascular System—Bradycardia, Carotid bruit, Extrasystole, Palpitations, Perivascular cuffing (eyes), Ruptured aortic aneurysm, Stroke, Tachycardia, Transient ischemic attack;

Gastrointestinal System—Flatus, Dryness of mouth and throat, Hepatitis, Hepatomegaly, Occult blood (rectal exam), Rectal fistula/erythema;

Endocrine System—Libido increase, Thyroid nodule;

Musculoskeletal System—Ankylosing spondylosis, Arthritis, Blurred disc margins, Bone fracture, Muscle stiffness, Muscle tenderness, Pelvic fibrosis, Spasms/cramps;

Central/Peripheral Nervous System—Auditory hallucinations/tinnitus, Decreased hearing, Decreased reflexes, Euphoria, Hyperreflexia, Loss of smell, Motor deficiency;

Respiratory System—Chest tightness, Decreased breathing sounds, Hemoptysis, Pleuritic chest pain, Pulmonary infiltrate, Rales/rhonchi, Rhinitis, Strep throat, Wheezing/bronchitis;

Integumentary System—Boil (pubic), Bruises, Hives, Keratosis, Mole, Shingles, Spiders;

Urogenital System— Blisters on penis, Inguinal hernia, Penile swelling, Post void residual, Prostatic pain, Pyuria;

Miscellaneous—Abdominal distention, Facial swelling/edema, Feet burning, Flu, Eyelid growth, Hypoproteinemia, Accidental injury, Knee effusion, Mass, Pallid, Sallow, Weakness.

Postmarketing

During postmarketing surveillance which includes other dosage forms and other patient populations, the following adverse events were reported.

Symptoms consistent with an anaphylactoid or asthmatic process have been rarely (incidence rate of about 0.002%) reported. Rash, urticaria, and photosensitivity reactions have also been reported.

Localized reactions including induration and abscess have been reported at the site of injection.

Symptoms consistent with fibromyalgia (e.g., joint and muscle pain, headaches, sleep disorders, gastrointestinal distress, and shortness of breath) have been reported individually and collectively.

Cardiovascular System -Hypotension, Myocardial infarction;

Endocrine System -Diabetes;

Gastrointestinal System -Hepatic dysfunction;

Hemic and Lymphatic System -Decreased WBC;

Integumentary System -Hair growth;

Central/Peripheral Nervous System -Convulsion, Spinal fracture/paralysis, Hearing disorder;

Miscellaneous -Hard nodule in throat, Weight gain, Increased uric acid;

Musculoskeletal System -Tenosynovitis-like symptoms;

Respiratory System -Respiratory disorders.

Changes in Bone Density: Decreased bone density has been reported in the medical literature in men who have had orchiectomy or who have been treated with an LH-RH agonist analog. In a clinical trial, 25 men with prostate cancer, 12 of whom had been treated previously with leuprolide acetate for at least six months, underwent bone density studies as a result of pain. The leuprolide-treated group had lower bone density scores than the nontreated control group. It can be anticipated that long periods of medical castration in men will have effects on bone density.

Pituitary apoplexy: During post-marketing surveillance, rare cases of pituitary apoplexy (a clinical syndrome secondary to infarction of the pituitary gland) have been reported after the administration of gonadotropin-releasing hormone agonists. In a majority of these cases, a pituitary adenoma was diagnosed, with a majority of pituitary apoplexy cases occurring within 2 weeks of the first dose, and some within the first hour. In these cases, pituitary apoplexy has presented as

• sudden headache,
• vomiting,
• visual changes,
• ophthalmoplegia,
• altered mental status, and
• sometimes cardiovascular collapse.

Immediate medical attention has been required.

See other Lupron Depot and Lupron Injection package inserts for other events reported in the same and different patient populations.

Drug/Laboratory Test Interactions

Administration of leuprolide acetate in therapeutic doses results in suppression of the pituitary-gonadal system. Normal function is usually restored within 4 to 12 weeks after treatment is discontinued.