Didrex

Pronounced: DIE-drecks
Generic name: Phentermine hydrochloride
Other brand name: Ionamin, Bontril, Fastin, Tenuate

Why is Didrex prescribed?

Didrex, an appetite suppressant, is prescribed for short-term use (a few weeks) as part of an overall weight reduction program that also includes dieting, exercise, and counseling. The drug is for use only by excessively overweight individuals who have a condition--such as diabetes, high blood pressure, or high cholesterol--that could lead to serious medical problems.

Most important fact about Didrex

Be sure to use this drug only as directed. It will lose its effect after a few weeks, and should be discontinued when this happens. If you try to boost its effectiveness by increasing the dose, you will run the risk of serious side effects and dependence on the drug.

How should you take Didrex?

Take Didrex before breakfast or up to 2 hours after breakfast. Tablets can be broken in half, if necessary.

Take Ionamin before breakfast or 10 to 14 hours before you go to bed. Ionamin capsules should be swallowed whole.

--If you miss a dose...

Skip the missed dose completely; then take the next dose at the regularly scheduled time.

--Storage instructions...

Store at room temperature.

What are the side effects of Didrex?

Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking this medication.

Side effects may include:

• Changes in sex drive
• constipation
• diarrhea
• dizziness
• dry mouth
• exaggerated feelings of depression or elation
• headache
• high blood pressure
• hives
• impotence
• inability to fall or stay asleep
• increased heart rate
• overstimulation
• restlessness
• stomach or intestinal problems
• throbbing heartbeat
• tremors
• unpleasant taste

Why should Didrex not be prescribed?

If you are sensitive to or have ever had an allergic reaction to phentermine hydrochloride or other drugs that stimulate the nervous system, you should not take this medication. Make sure your doctor is aware of any drug reactions you have experienced.

Do not take this drug if you have hardening of the arteries, symptoms of heart or blood vessel disease, an overactive thyroid gland, the eye condition known as glaucoma, or high blood pressure. Also avoid this drug if you are agitated, have ever abused drugs, or have taken an MAO inhibitor, including antidepressant drugs such as Nardil and Parnate, within the last 14 days.

Special warnings about Didrex

This drug can cause a rare but potentially fatal condition called primary pulmonary hypertension. Call your doctor immediately if you develop such warning signs as chest pain, shortness of breath, fainting spells, or swollen ankles.

This drug may affect your ability to perform potentially hazardous activities. Therefore, you should be extremely careful if you have to drive a car or operate machinery.

You can become psychologically dependent on this drug. Consult your doctor if you rely on this drug to maintain a state of well-being.

If you stop taking this drug suddenly after you have taken high doses for a long time, you may find you are extremely fatigued or depressed, or that you have trouble sleeping.

If you continually take too much of any appetite suppressant it can cause severe skin disorders, a pronounced inability to fall or stay asleep, irritability, hyperactivity, and personality changes.

Even if your blood pressure is only mildly high, be careful taking this drug.

Possible food and drug interactions when taking Didrex

Remember that this drug should never be combined with the weight-loss drug fenfluramine (Pondimin); very dangerous side effects could result. This drug may also react badly with alcohol. Avoid alcoholic beverages while you are taking it.

If Didrex is taken with certain other drugs, the effects of either can be increased, decreased, or altered. It is especially important that you check with your doctor before combining this drug with the following:

• Drugs that boost serotonin levels, such as the antidepressants Luvox, Paxil, Prozac, Celexa, and Zoloft
• Drugs classified as MAO inhibitors, including the antidepressants Nardil and Parnate
• Diabetes medications such as insulin and Micronase
• High blood pressure medications such as guanethidine (Ismelin)

Special information if you are pregnant or breast feeding

The effects of this drug during pregnancy have not been adequately studied. If you are pregnant, plan to become pregnant, or are breast feeding, notify your doctor immediately.

Recommended dosage

ADULTS

Didrex

The usual dose is 1 capsule or tablet a day, taken before breakfast or up to 2 hours after breakfast. Some people need only half a tablet each day. Others may find it more effective to take half a tablet twice daily.

Ionamin

The usual dose is 1 capsule a day, taken before breakfast or 10 to 14 hours before bedtime.

CHILDREN

This drug is not recommended for use in children under 16 years of age.

Overdosage

Any medication taken in excess can have serious consequences. An overdose of this drug can be fatal. If you suspect an overdose, seek emergency medical treatment immediately.

Symptoms of Didrex overdose may include:

• abdominal cramps
• aggressiveness
• confusion
• diarrhea
• exaggerated reflexes
• hallucinations
• high or low blood pressure
• irregular heartbeat
• nausea
• panic states
• rapid breathing
• restlessness
• tremors
• vomiting

Fatigue and depression may follow the stimulant effects of this drug.

In cases of fatal poisoning, convulsions and coma usually precede death.