Dextroamphetamine 

Why would this drug be used? 

Dextroamphetamine is sometimes used in treating chronic cancer pain, when large doses of opioids (morphine-like drugs) are required to control the pain. Dextroamphetamine helps to counter the extreme sleepiness caused by the pain medicine, allowing the person to have relief from pain and still be awake. It is approved for use in attention-deficit disorders and narcolepsy, and may be used for other purposes.     

How does this drug work? 

Dextroamphetamine stimulates the brain and nervous system, making the person feel  more awake. Exactly how it does that is not well understood.    

Before taking this medicine 

Tell  your doctor:       

• If you are allergic to anything, including medicines, dyes, additives, or foods, especially if  you have reacted to yellow dye or aspirin. 
• If you have any medical conditions such as kidney disease, liver disease (including hepatitis), heart disease, congestive heart failure, diabetes, gout, or infections. These conditions  may require that your doctor watch  you more closely during your treatment. 
• If you have high blood pressure. This drug  may raise blood pressure and also block the actions of blood pressure medicines. You may not be able  to take this drug. If you do your doctor will likely want to watch you closely during treatment. 
• If you have heart disease or hardening  of the arteries. You may not be able to take this drug, since it may stress the heart  and cause heart attacks or strokes. 
• If  you have heart rhythm problems, cardiomyopathy, abnormal heart structure,  or if there have been sudden, unexpected deaths  in your family. This drug can worsen heart problems. 
• If  you or a relative  have movement tics (repeated muscle twitches that are hard to control), verbal tics (repeated sound  or words that are hard to control),  or Tourette's syndrome. You may not be able to take this drug, because it may worsen these symptoms. 
• If you  have glaucoma. This drug may worsen the problem. 
• If you have an overactive thyroid. This drug can worsen the symptoms. 
• If  you have taken any antidepressants of  the MAO inhibitor type in the past 2 weeks (see drug interactions, below). This drug can cause a serious increase in body temperature  and blood pressure. 
• If  you have trouble with addiction, alcohol, or drug abuse now or have had one in the past. Dextroamphetamine can be habit forming, especially for those who have had problems before. 
• If you have had seizures. This drug  may make  you more likely to have them again. 
• If you have anxiety, tension, or agitation. You may  not be able to take this drug, since it can make these symptoms worse. 
• If you have serious mental illness, especially psychosis, agitation, bipolar disorder (manic-depressive illness), or depression. This drug can worsen  your symptoms. You should also tell the doctor if any family members have  one or more  of these illnesses. 
• If you are pregnant, trying to get pregnant,  or if there is  any chance of pregnancy. There  may be an increased risk of harm to the fetus  if a woman takes this drug during pregnancy. Also,  the infant may have withdrawal symptoms after birth. 
• If you are breast-feeding. The drug passes into breast milk and may affect the baby. 
• About any other prescription  or over-the-counter medicines  you are taking, including vitamins and herbs. In fact, keeping a written list of each of these medicines (including  the doses of each and  when you take them) with you in case of emergency may help prevent complications  if you get sick. 

• Dextroamphetamine can block the effects of blood pressure medicines (anti-hypertensive drugs). 
• Dextroamphetamine can increase the effects of tricyclic antidepressants such as amitriptylene, nortriptylene, desiprimine, and doxepin, including their side effects on the heart and circulation. 
• Dextroamphetamine may block the drowsiness caused by antihistamines, which includes most over-the-counter (non-prescription) sleeping medicines. 
• Dextroamphetamine can slow the absorption of certain anti-seizure drugs from the stomach, such as phenobarbital, ethosuximide, and phenytoin. 
• Any medicine that raises blood pressure can affect it more if you are taking dextroamphetamine. Cold, sinus, or allergy medicines containing pseudoephedrine (decongestants) and pain medicines containing caffeine may cause even more of an increase in heart rate and blood pressure, as well as other stimulant effects. 
• Antacids and stomach alkalizers (like sodium bicarbonate) may speed the absorption of dextroamphetamine from the stomach. Any medicine that makes the urine less acid, such as acetazolamide (Diamox) and some types of diuretics (water pills) slow down the body's effort to get rid of dextroamphetamine Both types of agents may increase the action of dextroamphetamine and worsen its side effects. 
• Propoxyphene (Darvon) can also increase the effects of dextroamphetamine. 
• Lithium, haloperidol, and chlorpromazine (used for mental health conditions and sometimes nausea) may block the effects of dextroamphetamine. 
• Drugs that make the urine more acid make the body get rid of dextroamphetamine faster, which means it may not work as it should. 
• Anything that makes the stomach more acid can slow down dextroamphetamine absorption, such  as guanethidine, reserpine, glutamic acid hydrochloride, and large doses  of ascorbic acid (vitamin C). This makes dextroamphetamine work  more slowly. 
• If monoamine oxidase (MAO) inhibitors, such as isocarboxazid (Marplan), phenelzine (Nardil), selegiline (Eldepryl),  and tranylcypromine (Parnate),  are taken within 2 weeks  of taking dextroamphetamine, they can rarely cause  a serious reaction with high blood pressure and life-threatening increases in body temperature. These drugs can also slow down  the body's attempts to get rid  of the dextroamphetamine.
• Check with your doctor, nurse, or pharmacist about whether other medicines, vitamins, herbs, and supplements can cause problems with  this medicine. 

Interactions with foods 

Fruit juices and other acid substances can slow the absorption of dextroamphetamine from the stomach. Check with your doctor, nurse, or pharmacist about whether other foods may be a problem. 

How is this drug taken or given? 

• This drug  comes in tablets  and time-released capsules.  The time-released capsules may be taken once a day, while the tablets are  usually taken 2 to 3 times a day. Your dose depends on your condition and your response to the medicine. Dextroamphetamine may be taken  with or without food (see interactions with foods, above).  The first dose is usually taken before breakfast, with  a second dose 4 to 6 hours later. If a third dose is needed, it is usually taken later in the afternoon. Take the last dose of the  day at least 6 hours before bedtime to reduce the chance of interfering  with sleep. To avoid overdose, don't crush, chew,  or dissolve time-released pills. 
• Take this drug exactly as directed by your doctor. If you do not understand the instructions, ask  your doctor or nurse to explain them to you. 
• Keep the medicine  in a tightly closed container away from light, heat, and moisture. Keep out of  the reach of children, pets,  and others.  Do not let anyone else to  take your medicine. When no longer needed, this drug should be flushed down  the toilet  or discarded in a safe way so that pets, children, and others cannot get  to it. 

Precautions 

• This medicine can cause dizziness and impair your ability to perform some tasks.  Do not drive, operate machinery,  or perform other activities that require alertness until you know how you react to this medicine. 
• Call your doctor if  you notice abnormal movement, uncontrolled shaking, hallucinations (seeing or hearing things that aren't there), unusual thoughts  and behavior, such as hostility, suspiciousness, mania, aggression, or other signs of losing touch with reality. 
• Dextroamphetamine speeds up the heart and raises the blood pressure, and  may rarely cause stroke or heart attack. If  you notice chest pain, pounding heart, shortness of breath, severe headache, have trouble speaking or moving, or feel faint, call your doctor right away. 
• Don't  stop taking dextroamphetamine all at once  if you have taken it  for a long time. Withdrawal symptoms  that may occur after prolonged use include extreme tiredness, mental depression, changes in sleep. Talk to your doctor or nurse about reducing the dose gradually. 
• This is a controlled substance, and  may be habit-forming. Take it only as directed by  your doctor. Dextroamphetamine may cause psychological dependence (which can lead to addiction). Some signs of psychological dependence are a strong desire to keep taking the medicine, and wanting to take larger doses. Talk with your  doctor if you think this has happened to you. 
• If you  are taking dextroamphetamine along with pain medicines  for chronic cancer pain, keep in mind that most cancer pain can be controlled.  Keep your doctor or nurse informed about how well your pain medicines are working and any side effects you are having. Your cancer team may need to adjust your medicines several times before they find  the medicines that work best for you. 
• If you have chronic (long term) cancer pain, talk with your doctor or nurse about taking your pain medicines on a regular schedule to keep  it from worsening. If you wait until  the pain  is bad, it takes more medicine  to get it under control. If pain comes back between doses, talk to  your cancer team  about changing  your medicine or adding an extra one for "breakthrough" pain. 
• If you think you  or someone else may have taken an overdose of dextroamphetamine, get  emergency help right away.  Symptoms of overdose may include: nausea, vomiting, diarrhea, cramps, high blood pressure, tremor, fast  or irregular heartbeat, hallucinations, confusion, seizures, and eventually low blood pressure and fainting  or passing out. 
• Dextroamphetamine interferes with lab tests for corticosteroids in the blood and steroids in the urine. Before lab work is done, let the doctor know  that you are taking this medicine. 

Possible side effects 

Common

• high blood pressure* 
• faster heart rate 
• restlessness
• trouble sleeping 
• mood changes 
• headache
• diarrhea

Less common 

• dry mouth 
• loss of appetite 
• constipation
• tremor
• withdrawal symptoms if drug stopped suddenly after being taken  a long time* 

Rare

• impotence
• changes in sexual desire 
• blurred vison 
• abnormal movements* 
• shaking or tremors* 
• losing touch  with reality* 
• hallucinations
• shortness  of breath*
• chest pain* 
• skin welts (hives) 
• stroke* 
• heart attack* 
• sudden death