Minoxidil general information
What is Minoxidil used for?
High blood pressure or hypertension is described as the silent killer as it usually has no symptoms, so you will only know if you have high blood pressure by having a check. If left untreated, hypertension can lead to cardiovascular disease, a term that covers a range of heart and circulation problems, including heart failure, stroke and heart attack. If hypertension is treated but does not respond to standard high blood pressure medication used for lowering high blood pressure, the condition can worsen and bring with it additional health risks such as end-organ damage of the kidneys, eyes and brain.
Minoxidil tablets 10mg are an antihypertensive medication used to treat severe hypertension when other treatments have not succeeded in lowering high blood pressure. It is used in conjunction with other antihypertensives such as diuretics (water tablets) and beta-blockers.
What is blood pressure?
Blood pressure is the force of your heart pumping blood around the body, combined with the resistance of the artery walls to the blood, as it is forced into the circulation. Two blood pressure measurements indicate whether your blood pressure is within the normal range. Systolic pressure measures the force generated by the heart contracting with each heartbeat as it pumps blood out into the arteries. Diastolic pressure is the resting phase between each heartbeat when the heart muscle relaxes and the heart fills with blood. When your blood pressure is measured, it is expressed as systolic pressure (the highest measure) over diastolic pressure (the lowest measure).
What is severe hypertension?
Hypertension is defined as high blood pressure when your body is relaxed and at rest and is caused by constriction and narrowing of the arteries. This increases the resistance of the arteries to the blood flowing through them, so that more force is needed to pump blood around the body, putting a strain on the heart by increasing its workload and its need for more oxygen. If hypertension is not well controlled and has not responded to at least three different types of medication to bring your blood pressure down so that it remains high over an extended period of time, it becomes a chronic condition known as severe refractory (difficult to treat) hypertension. This can cause damage to blood vessels, especially smaller blood vessels, such as those in the kidneys, brain and eyes, which can lead to serious conditions like kidney damage, vision loss and brain injury.
You may start to notice symptoms if your condition has progressed to this stage. They include headache, shortness of breath, chest pains and nosebleeds.
End organ damage
Changes in blood flow to the end organs like the kidneys, eyes and brain are normally regulated by the small blood vessels that supply them. As pressure increases, they constrict, as pressure decreases, they dilate. Continued high blood pressure causes the blood vessel to go into spasm resulting in damage to the vessel and thickening of the vessel wall, causing further narrowing and restriction of blood flow. Fluid is pushed out of the blood into the surrounding tissue, which causes oedema (swelling) and can lead to ischemia (cell death).
Hypertensive encephalopathy is a rare but severe result of chronic high blood pressure in the brain and usually develops suddenly. It can lead to seizures, coma, and can be fatal.
Hypertensive retinopathy is damage to the retina at the back of the eye due to high blood pressure. This can result in double vision, busting of the blood vessels, and, ultimately vision loss.
Minoxidil tablets 10mg are used to treat severe chronic refractory hypertension to relieve symptoms of hypertensive encephalopathy and hypertensive retinopathy.
How does Minoxidil work?
Minoxidil tablets 10mg are a generic of the medication of Loniten, and they contain minoxidil, a vasodilator that is used to treat severe refractory hypertension to lower blood pressure.
Minoxidil acts directly on the smooth muscle cells in the walls of small peripheral arteries (arterioles) that supply blood to the end organs, including the brain, kidneys and eyes. As a result of continued high blood pressure, these arterioles become narrowed and constricted, which restricts the blood flow. Minoxidil causes the smooth muscle cells to relax and this allows the blood vessels to widen (vasodilation), which reduces resistance to blood flow in the peripheral arteries and arterioles by allowing blood to flow more freely.
Other effects of Minoxidil include increased contraction of the heart muscle, which consequently increases the heartbeat. Minoxidil also interacts with the control of water and salt excretion by the kidneys, causing increased water and salt retention. These effects are countered by using other medications in addition to Minoxidil including a diuretic and a beta-blocker.
What does Minoxidil contain?
Minoxidil tablets 10mg contain the active ingredient minoxidil, a vasodilator that is used to treat severe refractory hypertension to lower blood pressure. They also contain colloidal silicon dioxide, corn starch, lactose anhydrous, magnesium stearate and microcrystalline cellulose.
What are the side effects of Minoxidil?
Most medications have some side effects, but they are not experienced by everyone. Some side effects are commonly experienced when taking Minoxidil, but others are not so common, and you should discuss any problems or concerns with your primary care physician.
Common side effects when taking Minoxidil include peripheral oedema (swelling around hands and feet due to water retention), weight gain, increased heart rate, hypertrichosis (increased hair growth) and changes in hair colour, gastrointestinal problems (nausea, diarrhoea).
When should Minoxidil not be used?
Have a talk with your primary healthcare physician before taking Minoxidil 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 Minoxidil you should consider the following before taking Minoxidil:
- Have you ever had an unusual reaction or an allergy when taking Minoxidil?
- Are you pregnant or breastfeeding?
- Do you have any problems with your kidneys or your liver?
- Do you have phaeochromocytoma (a tumour of the adrenal glands)?
- Do you have angina or have recently had a heart attack or stroke?
What medications interact with Minoxidil?
Some medicines interact with Minoxidil and may affect the way it works, or are affected by Minoxidil or increase side effects; you should discuss possible interactions with your primary care physician. These may include other medications for high blood pressure, like betanidine or guanethidine.
If other medications may interact with Minoxidil, your doctor will discuss these with you.
How should Minoxidil be taken and for how long?
You should take your Minoxidil tablets 10mg swallowed whole with a glass of water once daily. Your doctor may increase your dose depending on how well you respond, and you will be monitored regularly. You should continue to take your Minoxidil tablets 10mg for as long as recommended by your doctor, which may be long term as it controls your hypertension but does not cure it.
Missed dose of Minoxidil
If you miss a dose of Minoxidil 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 Minoxidil be stored?
You should store your Minoxidil tablets 10mg below 25°C in a cool dry place.