Dizziness, drowsiness, fatigue, nausea, constipation, runny nose, increased appetite, weight gain, nervousness, acne, dry skin, difficulty concentrating, decreased sexual ability/desire or difficulty sleeping may occur. If any of these effects persist or worsen, contact your doctor or pharmacist promptly. To minimize dizziness and lightheadedness, get up slowly when rising from a seated or lying position. Remember that your doctor has prescribed this medication because he or she 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. Tell your doctor immediately if any of these serious side effects occur: severe dizziness, fast/pounding/irregular heartbeat, mental/mood changes, fever, muscle stiffness/spasms/twitching, sweating, uncontrolled muscle movements (e.g., tongue and facial muscles), drooling, difficulty swallowing, seizures, frequent falls, signs of infection (such as fever, persistent sore throat). Seek immediate medical attention if any of these unlikely but serious side effects occur: chest pain, fainting, weakness on one side of the body, numbness in the face/arms/legs, sudden vision changes, slurred speech, confusion, breast lumps, change in amount of urine. This medication may in rare instances increase your blood level of a certain hormone (prolactin). In females, an increase in prolactin levels may result in unwanted breast milk, the end of menstruation or difficulty becoming pregnant. In males, it may result in decreased sexual ability, inability to produce sperm, or enlarged breasts. If you develop any of these symptoms, tell your doctor immediately. This drug may infrequently make your blood sugar level rise, therefore causing or worsening diabetes. This high blood sugar can rarely cause serious conditions such as diabetic coma. Tell your doctor immediately if you develop symptoms of high blood sugar, such as unusual increased thirst and urination. If you already have diabetes, be sure to check your blood sugar level regularly. This drug may also cause significant weight gain and a rise in your blood cholesterol (or triglyceride) levels. These effects, along with diabetes, may increase your risk for developing heart disease. Discuss the risks and benefits of treatment with your doctor. (See also Notes section.) For males, in the very unlikely event you have a painful or prolonged erection lasting 4 or more hours, stop using this drug and seek immediate medical attention, or permanent problems could occur. A serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: 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. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.