When amphetamines are abused, the resulting effects may include nervousness, loss of appetite, high blood pressure, and vomiting. increased appetite, sleepiness, and euphoria. heart disease, high blood pressure, impaired circulation, and erectile problems in men. restlessness, insomnia, loss of appetite, heartbeat irregularities, and nervousness. restlessness, insomnia, muscle tension, heartbeat irregularities, and high blood pressure