Tweet. There are no known adverse reactions between Plavix (Clopidogrel) and eating grapefruit, or drinking grapefruit juice. Furthermore, there is no sufficient evidence that illustrates grapefruit juice, or the fruit itself would interfere with the effectiveness of Plavix.
Other, more minor side effects include constipation, headache, dry mouth and insomnia (because the chemicals in these drugs also influence sleep patterns). Herbal diet pills, even though they're all natural, can have potentially dangerous side effects depending upon their ingredients.
Common side effects in children and teenagers include upset stomach, decreased appetite, nausea or vomiting, dizziness, tiredness, and mood swings. Common side effects in adults include constipation, dry mouth, nausea, decreased appetite, dizziness, sexual side effects, and problems passing urine. You are encouraged to report negative side effects of prescription drugs to the FDA.