Misuse or abuse of amphetamine may cause serious (possibly fatal) heart and blood pressure problems. Amphetamine-type medications can be habit-forming. Use only as directed. If you use this drug for a long time, you may become dependent on it and may have withdrawal symptoms after stopping the drug. Consult your doctor or pharmacist for more details.

Loss of appetite, weight loss, dry mouth, stomach upset/pain, nausea/vomiting, dizziness, headache, diarrhea, fever, nervousness, and trouble sleeping may occur. If any of these effects last or get worse, tell your doctor promptly. Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. This medication may raise your blood pressure. Check your blood pressure regularly and tell your doctor if the results are high. Tell your doctor right away if you have any serious side effects, including: signs of blood flow problems in the fingers or toes (such as coldness, numbness, pain, or skin color changes), unusual wounds on the fingers or toes, mental/mood/behavior changes (such as agitation, aggression, mood swings, depression, abnormal thoughts, thoughts of suicide), uncontrolled movements, continuous chewing movements/teeth grinding, outbursts of words/sounds, change in sexual ability/desire, frequent/prolonged erections (in males). Get medical help right away if you have any very serious side effects, including: shortness of breath, chest/jaw/left arm pain, fainting, severe headache, fast/pounding/irregular heartbeat, seizures, swelling of the ankles/feet, extreme tiredness, blurred vision, weakness on one side of the body, trouble speaking, confusion. This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take (see Drug Interactions section). Get medical help right away if you develop some of the following symptoms: fast heartbeat, hallucinations, loss of coordination, severe dizziness, severe nausea/vomiting/diarrhea, twitching muscles, unexplained fever, unusual agitation/restlessness. A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before treatment with this medication. Ask your doctor when to start or stop taking this medication. Some products have ingredients that could raise your heart rate or blood pressure. Tell your pharmacist what products you are using, and ask how to use them safely (especially cough-and-cold products or diet aids). The risk of serotonin syndrome/toxicity increases if you are also taking other drugs that increase serotonin. Examples include street drugs such as MDMA/ "ecstasy," St. John's wort, certain antidepressants (including SSRIs such as fluoxetine/paroxetine, SNRIs such as duloxetine/venlafaxine), among others. The risk of serotonin syndrome/toxicity may be more likely when you start or increase the dose of these drugs. Dextroamphetamine is very similar to lisdexamfetamine. Do not use medications containing lisdexamfetamine while using dextroamphetamine. This medication may interfere with certain medical/lab tests (such as blood and urine steroid levels, brain scan for Parkinson's disease), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.