Goserelin- Indications, Dosage, Risks, and Interactions

Overview:

The Goserelin implant is used to treat the symptoms of advanced prostate cancer (cancer that develops in the prostate gland) and in conjunction with radiation therapy and other drugs to treat localized prostate cancer. In certain women, it is also used to treat severe breast cancer. Additionally, it is used to treat abnormal uterine bleeding as well as endometriosis, a condition in which the tissue that lines the uterus develops in other parts of the body, such as ovaries and fallopian tube, causing pain, heavy or irregular menstruation, or periods, and other symptoms.

Drug Group:

The Goserelin implant includes a group of drugs known as gonadotropin-releasing hormone (GnRH) agonists. It functions by lowering the body's levels of specific hormones. It prevents testosterone production in men, which may encourage the development of cancerous cells. Goserelin reduces estradiol production in women to levels resembling the postmenopausal phase, which may inhibit the proliferation of cancer cells. Hormone levels return to normal after the drug is stopped.

How Does Goserelin Work?

Our bodies produce molecules called hormones. Hormones serve as messengers and aid in regulating the function of cells and organs. Drugs used in hormonal therapy alter how hormones are produced or function in the body. Prostate cancer requires the hormone testosterone to spread. The testicles produce almost all of the testosterone in males.

Goserelin is a luteinizing hormone blocker, a form of hormone treatment. This indicates that it inhibits the pituitary gland's ability to release luteinizing hormone (LH). The male sex hormone, which is testosterone, is no longer produced by the testicles as a result. Hormone therapy for prostate cancer aims to lower or stop the body's production of testosterone, which slows down or stops the development of the tumor.

Indication for the Drug:

• Goserelin is indicated in prostatic carcinoma. It is recommended for the palliative treatment of advanced prostate cancer.

• Stage T2b-T4 (stage B2-C) localized prostate cancer is approved for the use of Goserelin in combination with Flutamide. Flutamide and Goserelin should be administered for eight weeks before the start of radiation therapy and throughout radiation therapy.

• Goserelin is recommended as an endometrial-thinning medication prior to endometrial ablation for dysfunctional uterine bleeding.

• Goserelin is approved for the palliative treatment of progressed and advanced breast cancer in pre- and perimenopausal women. It may be possible to determine whether Goserelin medication will be effective by looking at the estrogen and progesterone receptor levels. The syringe's built-in automated safety mechanism helps to reduce the risk of needlestick injuries.

• Goserelin is prescribed to treat endometriosis, which includes reducing lesions and relieving pain throughout treatment. Women over the age of 18 who received treatment for endometriosis for six months had a successful experience with Goserelin.

Dosage of the Drug:

Goserelin is available as an implant that a doctor or nurse will place in the stomach area using a syringe subcutaneously (under the skin) in a hospital or medical facility. A 3.6 mg Goserelin implant is typically placed every four weeks, and a 10.8 mg (milligrams) Goserelin implant is typically placed every 12 weeks. The ailment being treated and how the patient reacts to the drug will determine how long the patient needs to receive treatment.

The doctor will decide how long individuals should utilize the Goserelin implant. In the initial weeks following implant installation, Goserelin may increase specific hormones. Throughout this period, the doctor will keep a close eye on the patient for any new or worsening symptoms.

• Dosage for Endometriosis - An implant containing 3.6 mg of Goserelin should be placed every 28 days for a maximum of six months for the treatment of endometriosis.

• Dosage for Breast Cancer Palliative Care - A 3.6-mg implant placed every 28 days is the normal prescribed Goserelin dosage for the palliative treatment of breast cancer.

• Dosage for Uterine Bleeding - One or two 3.6-mg implants of Goserelin are typically advised for treating uterine hemorrhage. Patients will normally have endometrial ablation four weeks after getting a single implant. During this treatment, the uterine lining is removed. If patients have two implants, the second one will be released four weeks after the first one. The endometrial ablation usually follows two to four weeks later.

• Dosage for Prostate Cancer - A 3.6-mg implant of Goserelin is typically advised for prostate cancer treatment. This should be followed by a 10.8 mg Goserelin implant after 28 days. This treatment will start eight weeks before radiation therapy.

• Dosage for Treating Advanced Prostate Cancer With Palliative Care - An implant containing 3.6 mg of Goserelin should be placed every 28 days as the standard suggested dosage for the palliative treatment of advanced prostate cancer. A 10.8-mg implant placed every 12 weeks is an alternative.

For Patients

What Is Goserelin?

A hormone-like substance called Goserelin is present in the body. It decreases the body's production of sex hormones. While using this medication, both men and women will have decreased amounts of testosterone and estrogen. This medication is injected either once every month or once every 12 weeks into males to treat prostate cancer. Women with endometriosis, dysfunctional uterine hemorrhage, or advanced breast cancer are exclusively treated with a monthly injection.

What Should Patients Inform Their Doctor About Before Using Goserelin?

If an individual has any of the following conditions, they need to inform their doctor about the same:

• Bone issues.

• Heart disease and diabetes (low blood sugar level).

• Record of irregular heartbeat, unusual or allergic response to Goserelin, other medications, foods, colors, or preservatives

• Pregnancy or trying to become pregnant.

• Nursing a child.

• List all of the pharmaceuticals, herbs, over-the-counter remedies, and nutritional supplements patients take for their health to their doctor. Also, let them know whether you smoke, consume alcohol, or engage in illicit drug usage.

How Should Patients Use Goserelin?

This medication is intended for subcutaneous injection. It is administered by a medical expert in a hospital or clinic environment. Regarding the administration of this medication to children, consult a pediatrician. One might need to take extra care. If patients believe they have taken too much of this medication, call an emergency room or a poison control center right away. Patients should note that this medication is solely for them. Do not give this medication to anyone else.

How Long Will Patients Have to Take Goserelin?

Goserelin is designed to be used for an extended period of time. If patients and their doctors decide that taking it for a long time is safe and beneficial for them, they can probably continue using it.

Missing Dose: It is crucial not to skip a dose. If patients are unable to keep a scheduled appointment, they should call their doctor or other healthcare providers.

Overdosing: Patients do not need to remember to take individual dosages because the Goserelin implant delivers the medication to their body over a predetermined period of time. There is no need to schedule an appointment to have the implant removed because it will dissolve over time.

To continue the treatment, their doctor might wish to install another implant.

The Goserelin implant is made to continue dispensing the medication for a few days after the next dose is scheduled. Delaying the appointment for the subsequent Goserelin implant is not advised. Patients will nevertheless continue to receive the medication for a brief period if they choose. Patients should try as hard as they can to follow a four-week or 12-week regimen, depending on their prescription dosage.

What Risks Should Patients Be Aware of While Taking Goserelin?

Visit a physician or other healthcare professional regularly to monitor progress. During the first few weeks of treatment, the symptoms may seem to worsen. If they do not begin to improve or worsen following this period, notify your doctor or healthcare provider.

• If patients use this medication for a long period, their bones could become weaker. Individuals run a greater risk of losing bone mass if they smoke or drink alcohol frequently. The risk of bone loss may also be increased by having a family history of the disease, using corticosteroids frequently, or using medications to treat seizures (convulsions). Consult your doctor for advice on maintaining bone health.

• Women taking this medication should no longer experience monthly menstruation. If they continue to menstruate, they should let their doctor know. While using this medication and for 12 weeks after discontinuing it, women should not get pregnant.

• If a woman wants to get pregnant or believes she might already be pregnant, she should tell her doctor. An unborn child could have major negative effects. For more information, patients should consult a physician or pharmacist. Breastfeeding a baby while taking this medication is not advised.

• Men who want to father a child should let their doctors know. This drug may reduce sperm counts. Patients should consult a physician or pharmacist for more information.

• This medication may cause blood sugar to rise. If someone has diabetes, check with your healthcare provider to see if dietary or medication modifications are necessary.

What Side Effects Does Goserelin Have on Patients?

The following are Goserelin side effects that should be reported as soon as possible to a physician or other healthcare provider:

• Skin rashes, itching, hives, swelling of the face, lips, or tongue.

• Bone discomfort due to allergic reactions.

• Breathing difficulties.

• Alterations to vision.

• Chest discomfort.

• Feeling dizzy or lightheaded.

• Fever.

• Chills.

• Pain.

• Swelling.

• Numbness and tingling in the hands or feet.

Typically, the side effects listed below may not necessitate medical attention; however, if they persist or are unpleasant, patients should inform their doctor or other qualified healthcare providers.

• Altered sex drive or behavior.

• Both male and female breast size changes.

• Mood or emotion changes.

• Headache.

• Hot flashes.

• Irritation from the injection site.

• Hunger loss.

• Skin issues include dry skin and acne.

• Vaginal dryness.

For Doctors

Pharmacodynamics:

Initially, goserelin therapy raises the levels of testosterone (or estradiol in females), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) in the blood. Chronic treatment, however, results in pituitary down-regulation within two to four weeks, which prolongs gonadotropin suppression. Testosterone levels in men decrease to castrate levels, which resemble those following surgical castration. The accessory sex organs regress as a result. Clinical studies have demonstrated that with ongoing treatment, testosterone levels can be sustainedly suppressed for more than two years.

Goserelin reduces ovarian size and function, shrinks the uterine and mammary glands, and may even regress hormone-responsive cancers in females by bringing estradiol down to postmenopausal levels in three weeks. Within four weeks, serum levels of FSH and LH also decrease to follicular phase levels, though some women may not experience this suppression. After the last injection, hormone levels usually return to normal in 12 weeks.

Mechanism of Action:

A synthetic decapeptide analog of gonadotropin-releasing hormone (GnRH) is called Goserelin. If Goserelin is taken in its biodegradable version, it inhibits the release of pituitary gonadotropin. As a result, the levels of serum testosterone and LH are persistently suppressed. In both animal and in vitro investigations, Goserelin administration caused the hormonally sensitive rat mammary tumor and Dunning prostate tumor to regress or be inhibited in their growth.

Pharmacokinetics:

Goserelin's pharmacokinetics have been studied in healthy male and female volunteers and patients. In these investigations, Goserelin was given subcutaneously in doses of one 250 mcg (aqueous solution) dosage plus one or more 3.6 mg depot doses.

Absorption:

Due to fast absorption, the blood levels of radiolabeled medication peaked between 0.5 and 1.0 hours after Gosarline dosage. Throughout the first eight days, Goserelin is released from the depot at a significantly slower pace; however, for the remaining 28 days of the dosage period, It is released more quickly and continuously.

The treatment of Goserelin every 28 days caused testosterone levels to be lowered to and maintained in the range typically found in surgically castrated men, despite the fact that Goserelin's rate of release had changed. However, a few patients' minimal serum levels were raised throughout clinical trials. This range can be explained by interpatient variability.

Metabolism:

The primary method of clearance for Goserelin is by its metabolism, which is accomplished by hydrolyzing its C-terminal amino acids. One healthy male volunteer's urine contained the predominant component of five to 10 fragments, while the major component circulating in serum looked to be one to seven fragments. Humans produce a restricted profile of metabolites from the metabolism of Goserelin that is similar to that of other species. Every human metabolite has also been discovered in toxicology species.

Distribution:

Following subcutaneous administration of a 250 mcg aqueous solution of Goserelin, the apparent volumes of distribution for males and females, respectively, were 44.1 and 20.3 liters. One sample of Goserelin was discovered to have a 27.3 percent plasma protein binding rate.

Excretion:

Goserelin is excreted relatively quickly after subcutaneous administration of the solution formulation, thanks to a combination of hepatic metabolism and urine excretion. Goserelin is eliminated in urine in excess of 90 percent of a subcutaneous radiolabeled solution formulation dosage. Goserelin, which has not been altered, accounts for around 20 percent of the dosage in urine. When given subcutaneously, Goserelin had a significantly higher total body clearance in females than in males.

What Are the Contraindications of the Drug?

• Hypersensitivity: In the medical literature, anaphylactic responses to Goserelin have been documented. Patients with a known hypersensitivity to the gonadotropin-releasing hormone, gonadotropin-releasing hormone agonist analogs, or any of the components in Goserelin should not use the medication.

• Pregnancy: Unless Goserelin is being taken for palliative treatment of advanced breast cancer, it is not advised to take the drug while pregnant. If Goserelin is given to a pregnant woman, the fetus could suffer injury. The patient should be informed of any potential risks to the fetus if this medication is used while pregnant. Due to anticipated hormone changes brought on by the medication, there is an elevated risk of miscarriage.

Warnings and Precautions:

• Tumor Flare- Like other GnRH agonists, Goserelin initially causes temporary increases in serum estrogen and testosterone levels in women with breast cancer. During the first weeks of treatment, some patients may experience a temporary worsening of symptoms or the appearance of new signs of breast or prostate cancer. A small percentage may also experience a brief increase in bone pain, which can be managed symptomatically. In prostate cancer patients, isolated cases of ureteral blockage and spinal cord compression have occurred. If renal impairment arises from these complications, urgent orchiectomy is typically recommended, especially in severe prostate cancer cases.

• Diabetes and Hyperglycemia- Men taking GnRH (gonadotropin-releasing hormone) agonists have had hyperglycemia and an elevated chance of acquiring diabetes. Hyperglycemia may signal the onset of diabetes mellitus or a decline in the glycemic control of diabetic patients. Patients taking a GnRH agonist should routinely have their blood sugar and glycosylated hemoglobin (HbA1c) checked, and they should be managed according to standard procedures for treating hyperglycemia or diabetes.

• Hypersensitivity- GnRH (gonadotropin-releasing hormone) agonist analogs have been linked to hypersensitivity, antibody production, and acute anaphylactic reactions. One patient revealed low-titer binding to Goserelin; out of 115 women treated with the drug globally, they were evaluated for the development of binding to Goserelin after treatment with the drug. The Goserelin binding component of this patient's plasma, which was collected after treatment, did not precipitate with rabbit anti-human immunoglobulin polyvalent sera, according to additional testing. These results imply the potential for antibody production.

• Pregnancy and Effect on Women of Childbearing Potential- Before starting Goserelin for benign gynecological disorders, pregnancy must be ruled out. Women capable of becoming pregnant should use reliable non-hormonal contraception during treatment and for 12 weeks after discontinuation. While Goserelin typically prevents menstruation and slows ovulation, pregnancy prevention is not guaranteed. Chronic use may affect reproductive function due to its anti-gonadotrophic effects. Goserelin can harm a fetus and has been associated with increased pregnancy loss in animal studies. Patients should be informed of the potential risks if the medication is used during pregnancy, particularly for palliative breast cancer treatment.

• Cervical Resistance- Cervical resistance may rise as a result of Goserelin's pharmacologic effects on the uterus and cervix. As a result, caution is advised when dilatation of the cervix is necessary for endometrial ablation.

• Injection Site Injury- Site Injury reports of Goserelin-related injection site injuries and vascular injuries, including discomfort, hematoma, bleeding, and hemorrhagic shock, necessitating blood transfusions and surgical intervention, have been made. Goserelin administration to patients with low BMI (body mass index) or those taking full-dose anticoagulation should be done with extra caution.

• Hypercalcemia- In some prostate and breast cancer patients who started treatment with Goserelin and had bone metastases, hypercalcemia has been documented, just like with other GnRH (gonadotropin-releasing hormones) agonists or hormonal therapies (antiestrogens, estrogens, etc.). If hypercalcemia does occur, the proper treatments should be started right away.

• Cardiovascular Conditions- The use of GnRH (gonadotropin-releasing hormone) agonists by men has been linked to an elevated risk of stroke, myocardial infarction, and sudden cardiac death. According to the provided odds ratios, the risk appears to be minimal, yet it should be carefully considered, along with cardiovascular risk factors, when choosing a prostate cancer treatment. Patients receiving a GnRH agonist should be managed in accordance with current clinical practice and should be watched for symptoms and signs that indicate the onset of cardiovascular disease.

• Effect on the QT/QTc Interval- The QT/QTc interval may be prolonged by androgen deprivation therapy. In patients with congenitally long QT syndrome, congestive heart failure, frequent electrolyte disorders, and individuals using medications known to lengthen the QT interval, healthcare providers should assess the advantages of androgen deprivation therapy against any potential dangers. Any abnormalities in the electrolyte should be treated. Think about routine electrolyte and ECG monitoring.

Nonclinical Toxicology- Carcinogenesis, Mutagenesis, Impairment of Fertility

• Carcinogenesis- An increased incidence of pituitary adenomas was seen in male and female rats given subcutaneous Goserelin implantation once every four weeks for a year and recovery for 23 weeks. Following subcutaneous Goserelin implant in rats over a period of 72 weeks in males and 101 weeks in females at identical dose levels, a higher incidence of pituitary adenomas was also noted. The applicability of rat pituitary adenomas to people has not been proven. Mice were given Goserelin subcutaneous implants every three weeks for two years, and this led to a rise in the incidence of histiocytic sarcomas of the vertebral column and femur. The available animal data could not be used to derive human dose or exposure multiples.

• Mutagenesis- There is no evidence of mutagenic potential from experiments on mammalian and bacterial systems regarding point mutations and cytogenetic effects. Regarding fertility, Goserelin's endocrine activity caused gonadal inhibition in male and female rats. In males, it led to atrophic changes in the testes, epididymis, seminal vesicles, and prostate gland, with complete suppression of spermatogenesis. In females, ovarian activity was suppressed, reducing the size and weight of ovaries and secondary sex organs, halting follicular growth at the antral stage, and diminishing the corpora lutea. These effects were largely reversible several weeks after discontinuation, except for the testes. However, fertility was impaired, as reduced ovulation, implantation, and live fetuses were observed in pregnancies following the cessation of Goserelin. In dogs, after a year of continuous Goserelin administration, reproductive organ effects were reversible upon discontinuation. However, animal data could not be used to determine human exposure or dose equivalents.

Results From Clinical Studies:

• Prostatic Cancer, Stage B2-C- In a multicenter trial of 466 individuals with bulky prostate tumors (stage B2 or C), the effects of hormonal therapy combined with radiation were examined. Results showed a significant reduction in local failure and a tendency for fewer distant metastases in patients treated with Goserelin and Flutamide before and during radiation compared to radiation alone. Those receiving combination therapy had a notably longer median time without disease and longer disease-free survival when normal PSA levels were required.

• Endometriosis- Controlled clinical studies have shown Goserelin to be as effective as Danazol in reducing the size of endometrial lesions and alleviating symptoms such as dysmenorrhea, dyspareunia, and pelvic discomfort. In one study, 63 percent of Goserelin-treated patients and 42 percent of Danazol-treated patients had endometrial lesions reduced by 50 percent or more. In another study, 62 percent of Goserelin-treated patients and 51 percent of Danazol-treated patients saw a similar reduction.

The clinical implications of reduced endometriotic lesions remain unclear, as symptom severity does not always correlate with laparoscopic staging of endometriosis. Goserelin caused amenorrhea in all treated women within eight weeks of the first dose, with menstruation typically returning eight weeks after therapy ended. Clinical symptoms decreased by an average of 84 percent by the end of treatment, with significant improvements seen within four weeks. Some women may experience vaginal bleeding during the first two months, likely due to estrogen withdrawal, which typically resolves on its own. There is insufficient evidence to determine the impact of Goserelin on pregnancy rates.

• Breast Cancer- A randomized clinical trial compared Goserelin and oophorectomy in premenopausal women with progesterone receptor-positive or advanced estrogen receptor-positive breast cancer. The median time to treatment failure was 6.7 months for Goserelin and 5.5 months for oophorectomy. Both groups showed similar subjective responses, with 48 percent of Goserelin patients and 50 percent of oophorectomy patients reporting improvements in pain control and performance status. Results were comparable in uncontrolled trials involving both hormone receptor-positive and negative breast cancer.

• Prostate Cancer- Goserelin and orchiectomy both produced equivalent long-term endocrine responses and objective responses in controlled investigations of individuals with advanced prostatic cancer. In a comparison trial, the length of survival was comparable across the two treatment arms.

• Thinning of the Endometrium- A prospective, randomized, double-blind study of 358 premenopausal women with dysfunctional uterine hemorrhage compared the effects of two depot injections of Goserelin versus placebo, administered four weeks apart. Two weeks after the second injection, 155 women from each group underwent endometrial ablation. The median endometrial thickness was significantly lower in the Goserelin group compared to the placebo group before surgery. At 24 weeks post-ablation, the incidence of amenorrhea was similar between the two groups.

In a separate open-label, randomized trial, premenopausal women with dysfunctional uterine hemorrhage received either one or two Goserelin depot injections before Nd:YAG laser ablation. The group receiving two injections had a significantly lower median endometrial thickness before surgery compared to the group with one injection. At 24 weeks, there was no difference in amenorrhea rates. Six months after surgery, 53 % of the 74 patients who completed the trial had hypomenorrhea, while 20 % had normal menstrual cycles.

Interaction of Goserelin With Other Drugs:

There has not been any official research conducted on drug interactions. No verified interactions between Goserelin and other medications have been reported. Pituitary-gonadal suppression is the outcome of administering Goserelin at therapeutic levels. Due to this suppression, diagnostic testing of pituitary-gonadotropic and gonadal activities performed throughout treatment and up until the resumption of menstruation may produce false results. Usually, 12 weeks after treatment is stopped, normal function returns.

However, take care not to combine this medication with any of the following drugs:

• Cisapride.

• Dronedarone.

• Thioridazine.

• Pimozide.

The following medicines or drugs may also interact with this drug:

• Drugs that lengthen the QT period (an abnormal heart rhythm).

Uses of Goserelin in Specific Populations:

• Usage in Lactating Patients- Whether Goserelin is excreted in human milk is unknown. Lactating rats secrete Goserelin in their milk. Given that many medications are excreted in human milk and that the drug may have major negative effects on nursing infants, a choice should be made regarding whether to stop breastfeeding or stop taking the medication while also considering how important the medication is to the mother.

• Usage in Pregnant Patients- Goserelin is classified as Pregnancy Category D for pregnant individuals with advanced breast cancer and Category X for those with endometriosis or a thinned endometrium. It is not recommended during pregnancy unless used for the palliative treatment of advanced breast cancer, as its use in pregnant women has not been adequately studied.

Goserelin can harm a fetus, as shown by its mechanism of action and reports of increased pregnancy loss in animal studies. It crosses the placenta when administered subcutaneously to rats and rabbits. In these studies, Goserelin increased preimplantation loss and resorptions and caused dose-dependent umbilical hernias in offspring. Patients should be informed of the potential risks to the fetus, including a higher risk of miscarriage due to hormone changes.

• Usage in Patients With Renal Insufficiency- In clinical trials with the solution formulation of Goserelin, male patients with impaired renal function, as opposed to subjects with normal renal function, had a decreased total body clearance, an increased serum elimination half-life, and decreased creatinine clearance from the body. It is uncertain how decreased Goserelin clearance brought on by compromised renal function affects the efficacy and toxicity of medications in females. There is no evidence from pharmacokinetic investigations in patients with renal impairment that the dose should be adjusted when using the depot formulation.

• Usage in Geriatric Patients- There is no need to change the dosage when giving Goserelin to male geriatric patients. Women over 65 have not been investigated with Goserelin.

• Usage in Pediatric Patients- Pediatric patients' safety and efficacy have not been confirmed.

• Usage in Obese Patients- With each kilogram of body weight added, there was a roughly 1 to 2.5 percent drop in the AUC after the administration of a 10.8 mg depot. Testosterone levels in obese patients who have not shown a therapeutic response need to be closely watched.

• Usage in Patients With Hepatic Insufficiency- When treated with a 250 mcg subcutaneous formulation of Goserelin, normal subjects and patients with mild hepatic impairment had comparable total body clearances and serum elimination half-lives. According to a pharmacokinetic study, people with somewhat impaired liver function do not require a dose change. Goserelin pharmacokinetic data in patients with severe hepatic insufficiency are lacking.