Drowsiness, dizziness, lightheadedness, nausea, constipation, increased appetite, weight gain, dry mouth, headache, or redness/pain/swelling at the injection site may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly. Dizziness and lightheadedness can increase the risk of falling. Get up slowly when rising from a sitting or lying position. Remember that your doctor has prescribed Zyprexa Relprevv because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using Zyprexa Relprevv do not have serious side effects. Olanzapine extended-release injection is designed to release medication slowly over 2 to 4 weeks. If the medication releases too quickly, your drug levels may be too high.very drowsy/hard to wake up, severe dizziness, slowed breathing, new or worsening mental/mood changes (such as confusion, agitation, nervousness, aggression), restlessness, muscle stiffness/spasm, shaking (tremor), unusual weakness, difficulty walking or speaking, balance problems, seizure. Zyprexa Relprevv may rarely make your blood sugar rise, which can cause or worsen diabetes. Weight gain from Zyprexa Relprevv may increase the risk of this side effect. Tell your doctor right away if you have symptoms of high blood sugar such as increased thirst/urination. If you already have diabetes, check your blood sugar regularly as directed and share the results with your doctor. Your doctor may need to adjust your diabetes medication, exercise program, or diet. Zyprexa Relprevv may cause significant weight gain and a rise in your blood cholesterol (or triglyceride) levels, especially in teenagers. 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.) Tell your doctor right away if you have any serious side effects,yellowing of the eyes/skin, difficulty swallowing, severe stomach/abdominal pain, trouble urinating, interrupted breathing during sleep. Zyprexa Relprevv may rarely cause a very serious condition called neuroleptic malignant syndrome (NMS).fever, muscle stiffness/pain/tenderness/weakness, severe tiredness, severe confusion, sweating, fast/irregular heartbeat, dark urine, signs of kidney problems (such as change in the amount of urine). Olanzapine may rarely cause a condition known as tardive dyskinesia. In some cases, this condition may be permanent. Tell your doctor right away if you develop any unusual/uncontrolled movements (especially of the face or tongue). In rare cases, olanzapine may increase your level of a certain substance made by the body (prolactin). For females, this increase in prolactin may result in unwanted breast milk, missed/stopped periods, or difficulty becoming pregnant. For 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 right away. A very serious allergic reaction to Zyprexa Relprevv is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction,fever, swollen lymph nodes, 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. 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.. Why Buy Zyprexa Relprevv from Universal Drugstore? We are the global leader in online prescription drug savings with almost 20 years of experience supplying prescription and over the counter drugs to our international customers..