Consumer medicine information

Loniten

Minoxidil

BRAND INFORMATION

Brand name

Loniten

Active ingredient

Minoxidil

Schedule

S4

 

Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Loniten.

SUMMARY CMI

Loniten®

Consumer Medicine Information (CMI) summary

The full CMI on the next page has more details. If you are worried about using this medicine, speak to your doctor or pharmacist.

1. Why am I using Loniten?

Loniten contains the active ingredient minoxidil. Loniten is used to lower high blood pressure, also called hypertension.

For more information, see Section 1. Why am I using Loniten? in the full CMI.

2. What should I know before I use Loniten?

Do not take if you have ever had an allergic reaction to minoxidil or any of the ingredients listed at the end of the CMI.

Do not take if you have had phaeochromocytoma (rare tumour of the adrenal gland) or pulmonary hypertension (high blood pressure in the vessels of the lung).

Talk to your doctor if you have any other medical conditions, take any other medicines, or are pregnant or plan to become pregnant or are breastfeeding.

For more information, see Section 2. What should I know before I use Loniten? in the full CMI.

3. What if I am taking other medicines?

Some medicines may interfere with Loniten and affect how it works.
A list of these medicines is in Section 3. What if I am taking other medicines? in the full CMI.

4. How do I use Loniten?

  • The usual adult dosage range of Loniten is between 5 mg and 40 mg per day. The maximum recommended dosage is 100 mg per day.

More instructions can be found in Section 4. How do I use Loniten? in the full CMI.

5. What should I know while using Loniten?

Things you should do
  • Remind any doctor, pharmacist or dentist you visit that you are using Loniten.
Things you should not do
  • Do not stop taking this medicine or lower the dosage, without checking with your doctor.
  • Do not give Loniten to anyone else, even if they have the same condition as you.
  • Do not take Loniten to treat any other complaints unless your doctor tells you to.
Driving or using machines
  • Be careful driving or operating machinery until you know how Loniten affects you.
Looking after your medicine
  • Keep your tablets in a cool dry place where the temperature stays below 25°C.

For more information, see Section 5. What should I know while using Loniten? in the full CMI.

6. Are there any side effects?

Common side effects include unusual growth, thickening and darkening of fine body hair or changes in hair colour.
Serious side effects include puffiness or swelling of your face, eyes, ankles, hands or feet; weight gain; increase in heart rate; dizziness or light headedness (particularly when standing up from a sitting position); tiredness; muscle aches; constipation, diarrhoea, nausea or vomiting; stomach pain or signs of indigestion; rash; breast tenderness; frequent infections such as fever, severe chills, sore throat or mouth ulcers as a result of a decrease in white blood cell levels; bleeding or bruising more easily.

Tell your doctor or go to the hospital immediately if you notice onset or worsening of angina (chest pain, or a feeling of tightness or pressure in the chest); pain behind the breast bone, sometimes spreading to the neck and shoulders and sometimes accompanied by fever; shortness of breath; difficulty breathing; peeling skin or skin redness; severe blisters and bleeding in lips, mouth, nose and genitals.

For more information, including what to do if you have any side effects, see Section 6. Are there any side effects? in the full CMI.



FULL CMI

Loniten® (lon-e-ten)

Active ingredient(s): minoxidil (min-ox-ee-dil)


Consumer Medicine Information (CMI)

This leaflet provides important information about using Loniten. You should also speak to your doctor or pharmacist if you would like further information or if you have any concerns or questions about using Loniten.

Where to find information in this leaflet:

1. Why am I using Loniten?
2. What should I know before I use Loniten?
3. What if I am taking other medicines?
4. How do I use Loniten?
5. What should I know while using Loniten?
6. Are there any side effects?
7. Product details

1. Why am I using Loniten?

Loniten contains the active ingredient minoxidil.

Loniten lowers high blood pressure. High blood pressure is also called hypertension.

Loniten works by relaxing the muscles of your blood vessels. This makes it easier for your blood to flow around your body and results in a decrease in your blood pressure.

Loniten is reserved for use in severe cases of high blood pressure where it is used in combination with other blood pressure lowering medicines.

Ask your doctor if you have any questions about why Loniten has been prescribed for you.

Your doctor may have prescribed Loniten for another purpose.

2. What should I know before I use Loniten?

Warnings

Do not take Loniten if:

  1. you are allergic to minoxidil, or any of the ingredients listed at the end of this leaflet.
Some of the symptoms of any allergic reaction may include:
  • shortness of breath
  • wheezing or difficulty breathing
  • swelling of the face, lips, tongue or other parts of the body
  • rash, itching or hives on the skin.
Always check the ingredients to make sure you can use this medicine.
  1. you have or have had any of the following medical conditions:
  • phaeochromocytoma (a rare tumour of the adrenal gland, which sits near the kidney)
  • pulmonary hypertension (high blood pressure in the vessels of the lung) due to a narrowing of the valve between the main blood vessels from the lung and the heart.
  1. you are pregnant.
  2. you are not using any form of contraception and could fall pregnant.

Check with your doctor if you:

  • have allergies to:
    - any other medicines, foods, preservatives or dyes.
  • have or have had any other medical conditions especially:
    - unstable or mild hypertension
    - symptoms of heart failure
    - a heart attack
    - fast heart rate
    - chest pain
    - renal failure
    - regular dialysis
    - liver disease.
  • take any medicines for any other condition

If you have not told your doctor or pharmacist about any of the above, tell them before you start taking Loniten.

During treatment, you may be at risk of developing certain side effects. It is important you understand these risks and how to monitor for them. See additional information under Section 6. Are there any side effects?

Pregnancy and breastfeeding

Check with your doctor if you are pregnant or intend to become pregnant. Loniten is not recommended for use during pregnancy.

Talk to your doctor if you are breastfeeding or intend to breastfeed. Loniten is not recommended while you are breast feeding. Loniten passes into breast milk. It is not known whether this will have any effect on the baby.

If you have not told your doctor about any of the above, tell them before you start taking Loniten.

Your doctor will discuss the risks and benefits of taking Loniten during pregnancy or while you are breast-feeding.

3. What if I am taking other medicines?

Tell your doctor or pharmacist if you are taking any other medicines, including any medicines, vitamins or supplements that you buy without a prescription from your pharmacy, supermarket or health food shop.

Some medicines may interfere with Loniten and affect how it works.

These include:

  • guanethidine (a type of medicine used to treat high blood pressure).

Check with your doctor or pharmacist if you are not sure about what medicines, vitamins or supplements you are taking and if these affect Loniten.

Your doctor and pharmacist have more information on medicines to be careful with or avoid while taking Loniten.

4. How do I use Loniten?

How much to take

  • The usual adult dosage range of Loniten is between 5 mg and 40 mg per day.
  • The maximum recommended dosage is 100 mg per day.

Your doctor will adjust the dose to suit your individual needs. Dosage adjustments are usually made at intervals of 3 days or longer.

Your doctor or pharmacist will tell you how many tablets you will need to take each day. This depends on your condition and whether or not you are taking any other medicines.

Follow all directions given to you by your doctor or pharmacist carefully.

They may differ from the information contained in this leaflet.

If you do not understand the instructions on the bottle, ask your doctor or pharmacist for help.

How to take Loniten

Swallow Loniten tablets with a glass of water.

How long to take Loniten

Loniten helps control your high blood pressure, but does not cure it. Therefore, you must take Loniten every day.

Continue taking the tablets for as long as your doctor or pharmacist tells you.

Do not stop taking it unless your doctor or pharmacist tells you to.

If you forget to take Loniten

Loniten should be taken regularly at the same time each day.

If it is almost time for your next dose, skip the dose you missed and take your next dose when you are meant to.

Otherwise, take it as soon as you remember, and then go back to taking your medicine as you would normally.

Do not take a double dose to make up for the dose you missed.

This may increase the chance of you getting an unwanted side effect.

If you are not sure what to do, ask your doctor or pharmacist.

If you have trouble remembering to take your medicine, ask your pharmacist for some hints.

If you take too much Loniten

If you think that you have taken too much Loniten, you may need urgent medical attention.

You should immediately:

  • phone the Poisons Information Centre
    (by calling 13 11 26), or
  • contact your doctor, or
  • go to the Emergency Department at your nearest hospital.

You should do this even if there are no signs of discomfort or poisoning.

5. What should I know while using Loniten?

Things you should do

Tell any other doctors, dentists, and pharmacists who are treating you that you are taking Loniten.

If you are about to be started on any new medicine, tell your doctor, dentist or pharmacist that you are taking Loniten.

If you plan to have surgery that needs a general anaesthetic, tell your doctor or dentist that you are taking Loniten.

If you become pregnant while taking Loniten, tell you doctor.

While you are taking Loniten your doctor may recommend that you reduce the amount of salt in your diet.

If you feel that you are gaining weight due to the retention of water, tell your doctor. Your doctor may need to adjust the medicines you are taking.

Things you should not do

  • Do not give Loniten to anyone else, even if they have the same condition as you.
  • Do not take Loniten to treat any other complaints unless your doctor or pharmacist tells you to.
  • Do not stop taking Loniten, or lower the dosage, without checking with your doctor or pharmacist.

Driving or using machines

Be careful before you drive or use any machines or tools until you know how Loniten affects you.

As with some other blood pressure lowering medicines, Loniten may cause dizziness or light-headedness in some people.

Make sure you know how you react to Loniten before you drive a car, operate machinery, or do anything else that could be dangerous if you are dizzy or light-headed.

Looking after your medicine

  • Keep your tablets in a cool dry place where the temperature stays below 25°C.

Follow the instructions in the carton on how to take care of your medicine properly.

Store it in a cool dry place away from moisture, heat or sunlight; for example, do not store it:

  • in the bathroom or near a sink, or
  • in the car or on window sills.

Do not use this medicine after the expiry date.

Keep it where young children cannot reach it.

When to discard your medicine

Getting rid of any unwanted medicine

If you no longer need to use this medicine or it is out of date, take it to any pharmacy for safe disposal.

6. Are there any side effects?

All medicines can have side effects. If you do experience any side effects, most of them are minor and temporary. However, some side effects may need medical attention.

See the information below and, if you need to, ask your doctor or pharmacist if you have any further questions about side effects.

Less serious side effects

Less serious side effectsWhat to do
  • unusual growth, thickening and darkening of fine body hair. This is usually first noticed on or around your face about 3 to 6 weeks after you start to take Loniten. This effect may slow after long-term use and will be reversed approximately 1 to 3 months after stopping Loniten therapy.
  • changes in hair colour.
Speak to your doctor if you have any of these side effects and they worry you.

Serious side effects

Serious side effectsWhat to do
  • puffiness or swelling of your face, eyes, ankles, hands or feet
  • weight gain
  • increase in heart rate
  • dizziness or light headedness (particularly when standing up from a sitting position)
  • tiredness
  • muscle aches
  • constipation, diarrhoea, nausea or vomiting
  • stomach pain or signs of indigestion
  • rash
  • breast tenderness
  • frequent infections such as fever, severe chills, sore throat or mouth ulcers as a result of a decrease in white blood cell levels
  • bleeding or bruising more easily.
Tell your doctor as soon as possible if you notice any of these serious side effects.
  • onset or worsening of angina (chest pain, or a feeling of tightness or pressure in the chest)
  • pain behind the breast bone, sometimes spreading to the neck and shoulders and sometimes accompanied by fever
  • shortness of breath
  • difficulty breathing
  • peeling skin or skin redness
  • severe blisters and bleeding in lips, mouth, nose and genitals.
Call your doctor straight away, or go straight to the Emergency Department at your nearest hospital if you notice any of these more serious side effects.

Tell your doctor or pharmacist if you notice anything else that may be making you feel unwell.

Other side effects not listed here may occur in some people.

Do not be alarmed by this list of possible side effects.

You may not experience any of them.

Reporting side effects

After you have received medical advice for any side effects you experience, you can report side effects to the Therapeutic Goods Administration online at www.tga.gov.au/reporting-problems. By reporting side effects, you can help provide more information on the safety of this medicine.

Always make sure you speak to your doctor or pharmacist before you decide to stop taking any of your medicines.

7. Product details

This medicine is only available with a doctor's prescription.

What Loniten contains

Active ingredient
(main ingredient)
10 mg minoxidil
Other ingredients
(inactive ingredients)
microcrystalline cellulose
colloidal anhydrous silica
lactose monohydrate
maize starch
magnesium stearate

Do not take this medicine if you are allergic to any of these ingredients.

What Loniten looks like

Loniten tablets are white in colour and have a circular, half oval shape.

One side of the tablet is scored and marked with U and 137; the other side is marked with the number 10.

Loniten 10 mg tablets: AUST R 12309.

Who distributes Loniten

Pfizer Australia Pty Ltd
Sydney, NSW
Toll Free Number: 1800 675 229
www.pfizermedinfo.com.au

This leaflet was prepared in May 2022.

® Registered Trademark

© Pfizer Australia Pty Ltd 2022

Published by MIMS October 2023

BRAND INFORMATION

Brand name

Loniten

Active ingredient

Minoxidil

Schedule

S4

 

1 Name of Medicine

Minoxidil.

2 Qualitative and Quantitative Composition

Loniten (minoxidil) 10 mg tablets.

Excipient(s) with known effect.

Lactose monohydrate.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Loniten 10 mg tablets are white, circular, half oval, scored tablets marked “10” on one side and “U/137” on the other side.

4 Clinical Particulars

4.1 Therapeutic Indications

Indicated as adjunctive therapy in adults with severe refractory hypertension which has failed to respond to extensive multiple therapy.
When used in combination with an accompanying diuretic and beta-blocker, minoxidil (Loniten) has been shown to reverse encephalopathy and retinopathy in severe hypertensives.

4.2 Dose and Method of Administration

Dosage.

The usual adult dosage range of Loniten is 5 to 40 mg per day. The maximum recommended dosage is 100 mg per day.
Loniten therapy can be initiated with a single or divided daily dosage. If the desired reduction in diastolic pressure is greater than 30 mmHg, divided dosage will minimise diurnal fluctuations. Dosage adjustments should be made at intervals of 3 days or longer.
A more rapid reduction of pressure can be achieved using continuous blood pressure monitoring and incremental doses of 5 mg every 6 hours.
Dosage requirements may be lower in patients with renal failure or undergoing chronic dialysis.
For patients with hepatic impairment dosage adjustment should be considered, starting therapy at a reduced dose once daily and titrating up to the lowest effective dose to obtain desired therapeutic effect (see Section 5.2 Pharmacokinetic Properties, Special populations).
Prior to introducing Loniten, it is recommended that the antihypertensive therapy be adjusted to a regimen consisting of a diuretic and a beta-adrenergic blocking agent. When other sympathetic nervous system suppressants are used, the initial dosage of Loniten should be reduced.

Children and adolescents (patients over 12 years of age).

Initial dosage.

5 mg as a single daily dosage.

Incremental increases.

5 to 10 mg per day at 3 day intervals until 50 mg per day is reached; then in increments of 25 mg per day up to a maximum of 100 mg per day.

Concomitant medications.

Diuretics.

Loniten must be given with sufficient diuretic therapy to maintain salt and water balance in all patients who are not on dialysis. When excessive water retention results in a weight gain exceeding 2.0 to 2.5 kg while on a thiazide or chlorthalidone, a more potent diuretic, e.g. frusemide, should be used.

Sympathetic nervous system suppressants.

Initially most patients will require a sympathetic nervous system suppressant to limit a Loniten induced rise in heart rate. The preferred agent is a beta-blocker equivalent to an adult propranolol dosage of 80 to 160 mg per day. Higher doses may be required when pretreated patients have an increase in heart rate exceeding 20 beats per minute or when simultaneous introduction causes an increase exceeding 10 beats/minute. When beta-blockers are contraindicated, methyldopa or clonidine may be used instead and should be started 24 hours prior to Loniten.

4.3 Contraindications

Loniten is contraindicated in phaeochromocytoma and pulmonary hypertension secondary to mitral stenosis.
Loniten is contraindicated in those patients with a history of hypersensitivity to any of the components of the preparation.

4.4 Special Warnings and Precautions for Use

Salt and water retention.

If used alone, Loniten can cause a significant retention of salt and water, producing dependent oedema; puffiness of face, eyes or hands, neck vein distention, hepatojugular reflux. Haemodilution may occur leading to a temporary decrease in haematocrit, haemoglobin and erythrocyte count, which then recovers to pretreatment levels. Chest X-rays may show evidence of pulmonary vascular engorgement. The clinical condition of some patients with symptomatic heart failure may deteriorate under these circumstances. The patient's bodyweight, fluid and electrolyte balance should be monitored, and if there is evidence of fluid retention, then diuretic treatment alone or in combination with restricted salt intake will minimise this response.
Refractoriness to these measures may require temporary discontinuation of Loniten therapy for 1 or 2 days, during which there may be partial loss of blood pressure control.
Salt and water retention in excess of 2 to 2.5 kg of weight gain may diminish the effectiveness of Loniten; therefore, patients should be carefully instructed about compliance to diuretic usage and limitation of their sodium intake (see Section 4.2 Dose and Method of Administration).

Tachycardia.

Reflex tachycardia and possibly angina pectoris may develop in patients with unsuspected coronary artery disease, unless protected against Loniten induced tachycardia with beta-adrenergic blocking drugs or other suitable sympathetic nervous system suppressants. Patients with unstable angina pectoris or angina pectoris of recent onset should be protected with these agents before starting Loniten therapy.

Orthostatic hypotension.

The blood pressure lowering effect of Loniten is additive to concurrent antihypertensive agents. The interaction of Loniten with agents that produce orthostatic hypotension may result in excessive blood pressure reduction (see Section 4.5 Interactions with Other Medicines and Other Forms of Interactions).

Hypertension.

In patients with pulmonary hypertension associated with mitral valve regurgitation, caution is necessary to avoid excessive tachycardia.
Loniten is not recommended for the treatment of patients with labile or mild hypertension.
Loniten should not be used for extended therapy in hypertension readily ameliorated by surgery, e.g. coarctation of the aorta, primary aldosteronism, or unilateral, large vessel renal artery stenosis.

Hypertrichosis.

Elongation, thickening and enhanced pigmentation of fine body hair (hypertrichosis) unassociated with endocrine abnormalities, is seen in most patients. It is usually first noticed in the facial area 3 to 6 weeks after starting therapy, may recede slightly during prolonged therapy, and is reversed 1 to 3 months after Loniten is discontinued. All patients should be fully informed of this possible effect before commencing Loniten therapy.

Cardiac lesions.

Right atrial lesions have been found in dogs treated with minoxidil at dosages as low as 0.5 mg/kg/day. Similar lesions have been produced with the 4-hydroxy metabolite (20 mg/kg/day) in the beagle dog; however, studies in other species with either minoxidil or the 4-hydroxy metabolite have not produced these changes.
In addition haemorrhagic lesions of the coronary arteries were observed mainly in the right atrium of dogs (and the left atrium of mini-pigs).
In dogs, mini-pigs, rats and hamsters necrosis of the papillary muscles and, in some cases, subendocardial areas of the left ventricle were observed following a few days treatment. Beta-adrenergic receptor blockade reduced the incidence and severity of the alterations.
There was no evidence in 78 autopsied patients that similar lesions have occurred in humans receiving minoxidil. However studies to date cannot exclude the possibility of such lesions occurring in man.

ECG alterations.

Approximately 60% of patients exhibit ECG alterations in the direction and magnitude of their T-waves soon after starting Loniten therapy. Large changes may encroach on the ST segment, but the ST segment is not independently altered and there is no evidence of myocardial ischaemia. These asymptomatic changes usually disappear with continuing Loniten treatment. The ECG reverts to the pretreatment state if Loniten is discontinued.

Pericarditis, pericardial effusion and tamponade.

There have been multiple reports of pericarditis occurring in association with Loniten.
Pericardial effusion, and occasionally tamponade, has been detected in 3% to 4% of patients treated with a Loniten containing regimen. In more than one-half of these cases, the effusion had been evident pretrial or occurred among chronic dialysis patients. Most of the effusions in nondialysis patients were attributed to factors such as uraemia, massive volume overload, congestive heart failure, and open A-V shunt, or an infectious, autoimmune or connective tissue disease. Loniten treated patients should be closely monitored for any suggestion of a pericardial effusion and echocardiography should be carried out if suspicion arises. More vigorous diuretic therapy, dialysis, pericardiocentesis, or surgery may be required. If effusion persists, withdrawal of Loniten should be considered in light of other means of controlling the hypertension and the patient's clinical status.

Myocardial infarction.

Patients who have had a myocardial infarction should be only treated with Loniten after a stable postinfarction state has been established.

Use in renal impairment.

Those patients with renal failure or on haemodialysis may require smaller doses of Loniten (see Section 4.2 Dose and Method of Administration).

Use in hepatic impairment.

For patients with hepatic impairment dosage adjustment should be considered, starting therapy at a reduced dose once daily and titrating up to the lowest effective dose to obtain desired therapeutic effect. (See Section 4.2 Dose and Method of Administration).

Use in the elderly.

No data available.

Paediatric use.

No data available.

Effects on laboratory tests.

No data available.

4.5 Interactions with Other Medicines and Other Forms of Interactions

Guanethidine.

While minoxidil itself does not cause orthostatic hypotension, its administration to patients already receiving guanethidine can result in profound orthostatic effects. If possible, guanethidine should be discontinued well before minoxidil is begun. If this is not feasible, minoxidil therapy should be instituted in the hospital and the patient monitored carefully for orthostatic events.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

No data available.
(Category C)
Minoxidil has been associated with hypertrichosis in the newborn infant following exposure in utero.
Loniten is not recommended during pregnancy and in women of childbearing potential not using contraception.
Minoxidil has been reported to be excreted in human milk. A risk to the suckling child cannot be excluded, therefore it is not recommended for nursing mothers unless the expected benefits outweigh any potential risk.

4.7 Effects on Ability to Drive and Use Machines

No studies on the effect of minoxidil on the ability to drive or use machines have been performed. The ability to drive or operate machinery may be influenced by the individual response to treatment, particularly at the start of therapy.

4.8 Adverse Effects (Undesirable Effects)

Most patients receiving Loniten have experienced a diminution of pre-existing adverse medical events attributable to their disease or previous therapy. New events or events likely to increase include: peripheral oedema associated with or independent of weight gain; increases in heart rate; hypertrichosis; a temporary decline in haemoglobin and haematocrit; and a temporary rise in creatinine and BUN.
Infrequently reported side effects include hypotension, gastrointestinal intolerance, rash and breast tenderness. See Table 1.

Reporting suspected adverse effects.

Reporting suspected adverse reactions after registration of the medicinal product is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions at www.tga.gov.au/reporting-problems.

4.9 Overdose

Signs and symptoms.

Hypotension resulting from the administration of minoxidil has occurred on only a few occasions. When exaggerated hypotension is encountered it is most likely to occur when minoxidil is used in association with antihypertensive agents which block sympathetic nervous system responses (guanethidine-like effects of alpha-adrenergic blockage) and compensatory mechanisms. Sinus tachycardia has also been reported.

Treatment of overdosage.

Due to patient to patient variation in blood levels, it is difficult to establish an overdosage warning level. In general, a substantial increase above 2000 nanogram/mL should be regarded as overdosage, unless the physician is aware that the patient has taken no more than the maximum dose. Treatment is primarily symptomatic and supportive. Consider administration of activated charcoal in the event of a potentially toxic ingestion. Activated charcoal is most effective when administered within 1 hour of ingestion. In patients who are not fully conscious or have impaired gag reflex, consideration should be given to administering activated charcoal via nasogastric tube once the airway is protected. Recommended treatment for hypotension is intravenous administration of normal saline. Sympathomimetic drugs, such as noradrenaline, should be avoided because of their excessive cardiac stimulating action. Phenylephrine, angiotensin II and vasopressin, which reverse the effect of Loniten, should be used only if inadequate perfusion of a vital organ is evident.
For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action.

Loniten selectively relaxes arteriolar smooth muscle which reduces peripheral vascular resistance and lowers systemic blood pressure. This is accomplished without a diminution of nutritional flow to body tissues or interference with normal vasomotor reflexes.
Loniten does not directly stimulate the heart or electrolyte reabsorption of the kidney. However, Loniten administration elicits a reflex mediated increase in cardiac output; salt and water retention; and a rise in plasma renin activity. These effects are diminished by the simultaneous administration of diuretics and beta-adrenergic blocking agents.

Clinical trials.

No data available.

5.2 Pharmacokinetic Properties

Absorption.

Gastrointestinal absorption is rapid and amounts to at least 95% of the administered dose. Serum levels of the parent drug peak within the first hour.

Distribution.

Loniten does not bind to plasma proteins, or enter the central nervous system, or accumulate in body tissues.
The plasma elimination half-life of Loniten is approximately 4-4.5 hours but the duration of its hypotensive action may exceed 24 hours. This disparity between blood level and pharmacological effect and the large volume of distribution indicates extensive tissue localisation of the drug. However, on chronic treatment accumulation does not occur and the pharmacological effect is slowly reversible.
With an effective oral dose, blood pressure usually starts to decline within one half hour, reaches a minimum between 2 and 3 hours, and recovers at a rate of approximately 30%/day. During daily administration there is a cumulative effect which reaches a steady state after 3 to 7 days. The magnitude of the blood pressure response is related to the extent of the original diastolic elevation above 85 mmHg, and is proportional to the logarithmic function of the dose administered. When the desired diastolic reduction is greater than 30 mmHg, twice a day dosing is advised to keep the diurnal variation within 10 mmHg.

Metabolism.

Metabolism is predominantly by glucuronic acid conjugation.

Excretion.

Metabolites are excreted principally in the urine and can be removed by haemodialysis in anephric patients. Haemodialysis does not however, rapidly reverse the pharmacological effect of Loniten.

Special populations.

Hepatic impairment.

The pharmacokinetics of minoxidil has not been studied in patients with moderate to severe hepatic impairment. In a pharmacokinetic study in patients with mild cirrhosis, eight patients with biopsy proven mild cirrhosis and eight healthy subjects received minoxidil 5 mg. The elimination rate constant of minoxidil was significantly reduced by approximately 21% in patients with cirrhosis. Although not statistically significant, AUC increased approximately 50% in patients with cirrhosis relative to healthy controls. For patients with hepatic impairment dosage adjustment should be considered (see Section 4.2 Dose and Method of Administration).

5.3 Preclinical Safety Data

Genotoxicity.

No data available.

Carcinogenicity.

No data available.

6 Pharmaceutical Particulars

6.1 List of Excipients

Microcrystalline cellulose, lactose monohydrate, magnesium stearate, colloidal anhydrous silica, maize starch.

6.2 Incompatibilities

Incompatibilities were either not assessed or not identified as part of the registration of this medicine.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.

6.4 Special Precautions for Storage

Store below 25°C. Protect from moisture.

6.5 Nature and Contents of Container

The tablets are supplied in HDPE bottles of 100.

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of in accordance with local requirements.

6.7 Physicochemical Properties

Loniten (minoxidil) is an orally active peripheral vasodilator. The pure compound is soluble in water to the extent of approximately 2 mg/mL and is readily soluble in propylene glycol or ethanol.
Chemical name: 2,4-diamino-6-piperidino-pyrimidine-3-oxide.
Molecular formula: C9H15N5O.
Molecular weight: 209.25.

Chemical structure.


CAS number.

38304-91-5.

7 Medicine Schedule (Poisons Standard)

S4.

Summary Table of Changes