Loniten

Loniten is part of the drug class:

• Pyrimidine derivatives

Minoxidil is a vasodilator that relaxes (widens) blood vessels and improves blood flow.

Minoxidil is used to treat severely high blood pressure (hypertension) that is causing symptoms or damaging your vital organs. Minoxidil is usually given together with two other medicines to help prevent serious side effects.

Minoxidil tablets should not be used to promote scalp hair growth. Only the topical form of minoxidil (Rogaine) is recommended for that use.

Minoxidil may also be used for purposes not listed in this medication guide.

You should not use minoxidil if you are allergic to it, or if you have:

• pheochromocytoma (tumor of the adrenal gland).

To make sure minoxidil is safe for you, tell your doctor if you have:

• congestive heart failure;

• angina (chest pain), or if you have recently had a heart attack;

• kidney disease (or if you are on dialysis);

• asthma;

• migraine headaches; or

• epilepsy or other seizure disorder.

It is not known whether this medicine will harm an unborn baby. However, a newborn baby could have excessive hair growth if the mother has taken minoxidil during pregnancy. Tell your doctor if you are pregnant or plan to become pregnant.

Minoxidil can pass into breast milk and may harm a nursing baby. You should not breast-feed while using this medicine.

Do not give this medicine to a child without medical advice.

Other drugs may interact with minoxidil, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

In the U.S.

• Loniten

Available Dosage Forms:

• Tablet

Therapeutic Class: Antihypertensive, Peripheral Vasodilator

Loniten Tablets contain minoxidil, an antihypertensive peripheral vasodilator. Minoxidil occurs as a white or off-white, odorless, crystalline solid that is soluble in water to the extent of approximately 2 mg/mL, is readily soluble in propylene glycol or ethanol, and is almost insoluble in acetone, chloroform or ethyl acetate. The chemical name for minoxidil is 2,4-pyrimidinediamine,6-(1-piperidinyl)-,3-oxide (mw=209.25). The structural formula is represented at right:

Loniten Tablets for oral administration contain either 2.5 mg or 10 mg of minoxidil. Inactive ingredients: cellulose, corn starch, lactose, magnesium stearate, silicon dioxide.

Loniten Tablets are contraindicated in pheochromocytoma, because it may stimulate secretion of catecholamines from the tumor through its antihypertensive action. Loniten is contraindicated in those patients with a history of hypersensitivity to any of the components of the preparation.

There have been only a few instances of deliberate or accidental overdosage with Loniten Tablets. One patient recovered after taking 50 mg of minoxidil together with 500 mg of a barbiturate. When exaggerated hypotension is encountered, it is most likely to occur in association with residual sympathetic nervous system blockade from previous therapy (guanethidine-like effects or alpha-adrenergic blockage), which prevents the usual compensatory maintenance of blood pressure. Intravenous administration of normal saline will help to maintain blood pressure and facilitate urine formation in these patients. Sympathomimetic drugs such as norepinephrine or epinephrine should be avoided because of their excessive cardiac stimulating action. Phenylephrine, angiotensin II, vasopressin, and dopamine all reverse hypotension due to Loniten, but should only be used if underperfusion of a vital organ is evident.

Radioimmunoassay can be performed to determine the concentration of minoxidil in the blood. At the maximum adult dose of 100 mg/day, peak blood levels of 1641 ng/mL and 2441 ng/mL were observed in two patients, respectively. 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 ng/mL should be regarded as overdosage, unless the physician is aware that the patient has taken no more than the maximum dose.

Oral LD50 in rats has ranged from 1321 – 3492 mg/kg; in mice, 2456 – 2648 mg/kg.

Loniten Tablets are available as follows:

2.5 mg (white, round, scored, imprinted U/121 and 2½)

        Bottles of 100                NDC 0009-0121-01

10 mg (white, round, scored, imprinted Loniten 10)

        Bottles of 100                NDC 0009-0137-01

Store at controlled room temperature 20° to 25°C (68° to 77°F) [see USP].

PATIENT INFORMATION

Loniten Tablets contain minoxidil, a medicine for the treatment of high blood pressure in the patient who has not been controlled or is experiencing unacceptable side effects with other medications. It must usually be taken with other medicines.

Be absolutely sure to take all of your medicines for high blood pressure according to your doctor's instructions. Do not stop taking Loniten unless your doctor tells you to. Do not give any of your medicine to other people.

It is important that you look for the warning signals of certain undesired effects of Loniten. Call your doctor if they occur. Your doctor will need to see you regularly while you are taking Loniten. Be sure to keep all your appointments or to arrange for new ones if you must miss one.

Do not hesitate to call your doctor if any discomforts or problems occur.

The information here is intended to help you take Loniten properly. It does not tell you all there is to know about Loniten. There is a more technical leaflet that you may request from the pharmacist; you may need your doctor's help in understanding parts of that leaflet.

What is Loniten?

Loniten Tablets contain minoxidil which is a drug for lowering the blood pressure. It works by relaxing and enlarging certain small blood vessels so that blood flows through them more easily.

Why lower blood pressure?

Your doctor has prescribed Loniten to lower your blood pressure and protect vital parts of your body. Uncontrolled blood pressure can cause stroke, heart failure, blindness, kidney failure, and heart attacks.

Most people with high blood pressure need to take medicines to treat it for their whole lives.

Who should take Loniten?

There are many people with high blood pressure, but most of them do not need Loniten. Loniten is used ONLY when your doctor decides that:

1. your high blood pressure is severe;
2. your high blood pressure is causing symptoms or damage to vital organs; and
3. other medicines did not work well enough or had very disturbing side effects.

Loniten should be taken only when a doctor prescribes it. Never give any of your Loniten Tablets, or any other high blood pressure medicine, to a friend or relative.

Pregnancy: In some cases doctors may prescribe Loniten for women who are pregnant or who are planning to have children. However, its safe use in pregnancy has not been established. Laboratory animals had a reduced ability to become pregnant and a reduced survival of offspring while taking Loniten. If you are pregnant or are planning to become pregnant, be sure to tell your doctor.

How to take Loniten.

Usually, your doctor will prescribe two other medicines along with Loniten. These will help lower blood pressure and will help prevent undesired effects of Loniten.

Often, when a medicine like Loniten lowers blood pressure, your body tries to return the blood pressure to the original higher level. It does this by holding on to water and salt (so there will be more fluid to pump) and by making your heart beat faster. To prevent this, your doctor will usually prescribe a water tablet to remove the extra salt and water from your body (a diuretic: dye-u-RET-tic) and another medicine to slow your heart beat.

You must follow your doctor's instructions exactly, taking all the prescribed medicines, in the right amounts, each day. These medicines will help keep your blood pressure down. The water tablet and heart beat medicine will help prevent the undesired effects of Loniten.

Loniten Tablets come in two strengths (2½ milligrams and 10 milligrams) that are marked on each tablet. Pay close attention to the tablet markings to be sure you are taking the correct strength. Your doctor may prescribe half a tablet; the tablets are scored (partly cut on one side) so that you can easily break them.

When you first start taking Loniten, your doctor may need to see you often in order to adjust your dosage. Take all your medicine according to the schedule prescribed by your doctor. Do not skip any doses. If you should forget a dose of Loniten, wait until it is time for your next dose, then continue with your regular schedule. Remember: do not stop taking Loniten, or any of your other high blood pressure medicines, without checking with your doctor. Make sure that any doctor treating or examining you knows that you are taking high blood pressure medicines, including Loniten.

WARNING SIGNALS

Even if you take all your medicines correctly, Loniten Tablets may cause undesired effects. Some of these are serious and you should be on the lookout for them. If any of the following warning signals occur, you must call your doctor immediately:

1. Increase in heart rateYou should measure your heart rate by counting your pulse rate while you are resting. If you have an increase of 20 beats or more a minute over your normal pulse, contact your doctor immediately. If you do not know how to take your pulse rate, ask your doctor. Also ask your doctor how often to check your pulse.
   
2. Rapid weight gain of more than 5 poundsYou should weigh yourself daily. If you quickly gain five or more pounds, or if there is any swelling or puffiness in the face, hands, ankles, or stomach area, this could be a sign that you are retaining body fluids. Your doctor may have to change your drugs or change the dose of your drugs. You may also need to reduce the amount of salt you eat. A smaller weight gain (2 to 3 pounds) often occurs when treatment is started. You may lose this extra weight with continued treatment.
   
3. Increased difficulty in breathing, especially when lying down. This too may be due to an increase of body fluids. It can also happen because your high blood pressure is getting worse. In either case, you might require treatment with other medicines.
   
4. New or worsening of pain in the chest, arm, or shoulder or signs of severe indigestionThese could be signs of serious heart problems.
   
5. Dizziness, lightheadedness or faintingThese can be signs of high blood pressure or they may be side effects from one of the medicines. Your doctor may need to change or adjust the dosage of the medicines you are taking.
   

OTHER UNDESIRED EFFECTS

Loniten Tablets can cause other undesired effects such as nausea and/or vomiting that are annoying but not dangerous. Do not stop taking the drug because of these other undesired effects without talking to your doctor.

Hair growth: About 8 out of every 10 patients who have taken Loniten noticed that fine body hair grew darker or longer on certain parts of the body. This happened about 3 to 6 weeks after beginning treatment. The hair may first be noticed on the forehead and temples, between the eyebrows, or on the upper part of the cheeks. Later, hair may grow on the back, arms, legs, or scalp. Although hair growth may not be noticeable to some patients, it often is bothersome in women and children. Unwanted hair can be controlled with a hair remover or by shaving. The extra hair is not permanent, it disappears within 1 to 6 months of stopping Loniten. Nevertheless, you should not stop taking Loniten without first talking to your doctor.

A few patients have developed a rash or breast tenderness while taking Loniten Tablets, but this is unusual.

Rx only

810 384 620
692167
March 2002

Use is not recommended. -According to some authorities: Use is not recommended unless potential benefit outweighs potential risk. Excreted into human milk: Yes Comments: The effects in the nursing infant are unknown.