Side effects of vinpocetine include nausea, sleep disturbances, pain in the stomach, dizziness and headache, as listed by WebMD. Patients may also experience flushing of the face or nervousness.
Vinpocetine may slow blood clotting, potentially increasing the risk of bleeding during surgery, according to WebMD. Patients should not use the medication within the two weeks leading up to surgery, and patients with bleeding disorders should avoid the medication. Vinpocetine also may weaken the immune system, making patients more vulnerable to infections. Cancer patients, HIV patients and other individuals with weakened immune systems should consult a health care provider before taking the medication.
A study of Alzheimer's patients taking 60 milligrams of vinpocetine per day over the course of a year revealed no harmful effects, as stated by WebMD. Due to the lack of available research on the medication's safety, women who are pregnant or breast-feeding should avoid vinpocetine. Patients should not take vinpocetine if they are already taking anticoagulants or anti-platelet medications such as aspirin, ibuprofen, heparin and naproxen. The medication also interacts with warfarin, increasing the latter drug's time in the body and increasing risk of bruising. Individuals should consult a doctor if they experience severe or persistent side effects while taking vinpocetine.