Parlodel general information
What is Parlodel used for?
Hormones are important chemical messengers that are produced by the glands of our body that make up the endocrine system. Hormones are secreted into the blood and circulate around the body until they reach their target tissue. There are many different types of hormone that act on specific cells to produce a response that affects a body function or process.
Prolactin is a hormone produced by the pituitary gland, which is a small gland in the base of the brain. The pituitary gland produces several other important hormones, including growth hormone. Dopamine is a hormone that is also a neurotransmitter. It is a chemical messenger produced in the hypothalamus of the brain and allows brain cells to communicate. Dopamine also regulates many vital processes, including secretion of hormones like prolactin and growth hormone, and muscle function and movement.
Parlodel tablets 2.5mg are used to treat various conditions that are mediated by dopamine. These include infertility, galactorrhoea (excess breast milk production) and menstrual disorders caused by high levels of prolactin (hyperprolactinaemia). Acromegaly is a condition of excess growth caused by too much growth hormone. Parkinson’s disease is a neurological condition related to low levels of dopamine in the brain. Parlodel tablets 2.5mg work through a common mechanism of action to treat these conditions.
Prolactin and breast milk production
The primary role of prolactin is to induce milk production (lactation) in response to suckling. Prolactin regulates milk production in breast tissue by stimulating milk-producing breast cells to proliferate. The amount of prolactin produced is regulated by dopamine, which binds to specific receptors in the pituitary gland and switches off prolactin production, which in turn shuts down breast milk production. There are some situations where the mother does not wish to breastfeed. In other situations, suppression of milk production is needed, such as after a stillbirth. Too much prolactin can cause over-production of breast milk, a condition known as galactorrhoea. Parlodel tablets 2.5mg can be used to suppresses lactation and help dry up milk supply and unwanted milk production.
Prolactin is involved in the regulation of both the female and male reproductive process. If too much prolactin is produced (hyperprolactinaemia), normal reproductive functioning is suppressed, which can result in infertility.
High levels of prolactin in women, disrupts the menstrual cycle by inhibiting the production of other hormones needed for ovulation and preparation for pregnancy. Ovulation is regulated by a coordinated release of various hormones from the ovaries, pituitary gland and hypothalamus in the brain, which includes positive and negative feedback loops. The hypothalamus releases Gonadotropin-Releasing Hormones (GnRH) that stimulates the secretion of Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) by the pituitary gland. FSH stimulates the growth of the egg follicle in the ovaries, which begins to produce oestrogen. As the most mature ovarian follicle ripens and oestrogen levels increase, oestrogen has a positive effect on the pituitary and stimulates a surge in LH, which triggers ovulation. Once a ruptured egg follicle has released a mature egg it begins to produce progesterone, which stimulates the endometrium (lining of the uterus) to prepare for a pregnancy. High levels of prolactin block the regulation of hormone release that leads to ovulation, and this can result in an inability to conceive, causing infertility.
Testosterone, generally considered to be a male hormone, is also produced in small amount in the ovaries. Polycystic ovary syndrome (PCOS) is a hormonal condition where too much testosterone is produced in the ovaries. High levels of testosterone disrupt the menstrual cycle and can be a cause of infertility. Eggs are produced and mature but fail to be released, resulting in a build-up of mature eggs. Other symptoms of PCOS include irregular periods, unwanted facial hair and acne.
Prolactin is also produced in men. High levels of prolactin are linked to hypogonadism, which is a loss of normal function of the testes in producing the hormone testosterone. The effects of hypogonadism in men include low sperm count (oligospermia), reduced libido and erectile dysfunction (impotence), which can cause infertility.
Hyperprolactinaemia disrupts hormonal regulation of the menstrual cycle which can result in irregular cycles (oligomenorrhoea). These are menstrual cycles that last more than the usual average of 28 days and means that they are fewer and usually lighter. This can lead to amenorrhoea, which is the failure to have a menstrual cycle.
Pituitary tumours that secrete prolactin are often the cause of hyperprolactinaemia. Prolactinoma is a benign tumour of the pituitary gland that produces prolactin. The major effect of a prolactinoma is the disruption of oestrogen production in women and testosterone production in men. A large prolactinoma can cause headache and visual disturbances, as it can press on the optic nerve.
Growth hormone is a hormone produced by the pituitary gland that has many effects throughout the body. Growth hormone regulates normal growth processes in children and maintains body tissues in adults. If too much growth hormone is produced in adults when the body tissues are no longer growing, it can result in acromegaly, a condition where the hands face, and feet become enlarged. Acromegaly is usually caused by a benign pituitary tumour called an adenoma that produces growth hormone.
Parkinson’s disease is a progressive neurological disorder, which affects movement, balance, walking and coordination of the body. It usually starts with tremor of the hands, and movement is slow and jerky (bradykinesia). Eventually, the bowels and bladder are affected and walking and talking become difficult, as non-motor symptoms develop, including mood changes and loss of cognitive function. Parkinson’s is caused by loss of brain cells in a specific area of the brain called the substantia nigra. These are the cells that produce dopamine, the neurotransmitter that is involved in motor function as well as memory, learning and decision making. Symptoms of Parkinson’s are related to loss of dopamine production and Parlodel tablets 2.5mg are used to help improve symptoms of Parkinson’s, but cannot cure the disease.
How does Parlodel work?
Parlodel tablets 2.5mg contain bromocriptine, a dopamine agonist that is used to treat a variety of endocrinological and neurological conditions that are mediated by dopamine. Bromocriptine in Parlodel tablets 2.5mg works by binding to dopamine receptors in various parts of the brain and activating the dopaminergic (stimulates dopamine receptors) pathways.
Stimulation of dopamine receptors by Parlodel tablets 2.5mg increases dopamine release, which inhibits prolactin synthesis and secretion from the anterior pituitary gland. Inhibition of prolactin secretion by bromocriptine releases the suppression caused by high prolactin levels on the normal functioning of the reproductive glands, which is a cause of infertility and menstrual problems. This action of bromocriptine also reduces breast milk production, which is dependent on prolactin to stimulate lactation.
Two tumours of the pituitary gland contain dopamine receptors. Dopamine binds to these receptors and causes the overproduction of pituitary hormones. A prolactinoma produces prolactin, and a pituitary adenoma produces growth hormone. Bromocriptine in Parlodel tablets 2.5mg binds to dopamine receptors in the tumour cells, which causes the tumour to shrink and returns the levels of prolactin and growth hormone to normal.
Stimulation of the dopamine receptors in the brain mimics the effect of dopamine. Bromocriptine in Parlodel tablets 2.5mg binds to dopamine receptors in the substantia nigra of the brain. This is the region of the brain where nerve cells are lost, causing symptoms of Parkinson’s disease. This action of Bromocriptine in Parlodel tablets 2.5mg helps improve symptoms associated with Parkinsonism.
What does Parlodel contain?
Parlodel tablets 2.5mg contain the active ingredient bromocriptine, a dopamine agonist that is used to treat a group of endocrinological and neurological conditions mediated by dopamine. They also contain lactose, maize starch, disodium edetate, maleic acid, colloidal anhydrous silica, and magnesium stearate.
What are the side effects of Parlodel?
Most medications have some side effects, but they are not experienced by everyone. Some side effects are commonly experienced when taking Parlodel tablets 2.5mg, but others are not so common, and you should discuss any problems or concerns with your primary care physician.
Common side effects when taking Parlodel include headache, drowsiness, nausea, constipation, nasal congestion.
When should Parlodel not be used?
Have a talk with your primary healthcare physician before taking Parlodel tablets 2.5mg so that you have a full understanding of what this medicine is for and how to use it. There are some reasons for not taking a medication; these are called contraindications, and for Parlodel you should consider the following before taking Parlodel:
- Have you ever had an unusual reaction or an allergy when taking Parlodel?
- Are you pregnant or breastfeeding?
- Do you have any problems with your kidneys or your liver?
- Do you have uncontrolled high blood pressure (hypertension)?
- Have you had high blood pressure during pregnancy, such as pre-eclampsia, or just after delivery?
- Do you have heart disease, stroke or other severe cardiovascular conditions, or heart valve disease?
- Do you have serious mental health problems or a psychiatric disorder?
What medications interact with Parlodel?
Some medicines interact with Parlodel tablets 2.5mg and may affect the way it works, or are affected by Parlodel or increase side effects; you should discuss possible interactions with your primary care physician. These may include macrolides antibiotics like erythromycin, the antifungal ketoconazole, ergot alkaloids like ergotamine for migraine, HIV medication like ritonavir, antihypertensive drugs for lowering blood pressure, antihypertensive drugs for lowering blood pressure, octreotide for acromegaly, phenothiazine butyrophenone and thioxanthene antipsychotics, the antiemetics metoclopramide and domperidone, reserpine and methyldopa for high blood pressure, the antipsychotic pimozide, oestrogens, thyrotropin releasing hormone.
If other medications may interact with Parlodel, your doctor will discuss these with you.
How should Parlodel be taken and for how long?
You should take your Parlodel tablets 2.5mg swallowed whole with a glass of water and with food, once, twice or three times daily, depending on what you are being treated for and your doctor’s recommendations. Your doctor will usually increase your dose gradually, starting with one tablet at bedtime, until you have reached the appropriate dose for your condition and to keep any side-effects to a minimum. You should continue to take your Parlodel 2.5 mg tablets for as long as recommended by your doctor, which may be for up to two weeks, or until your medication has improved your condition.
Missed dose of Parlodel
If you miss a dose of Parlodel tablets 2.5mg take it as soon as you remember, unless it is time to take the next dose, then skip the missed dose. Do not take a double dose.
How should Parlodel be stored?
You should store your Parlodel tablets 2.5mg below 25°C in a cool dry place.