6 ADVERSE REACTIONS The following adverse reactions are described, or described in greater detail, in other sections: • Primary pulmonary hypertension [ see Warnings and Precautions ( 5.2 ) ] • Valvular heart disease [ see Warnings and Precautions ( 5.3 ) ] • Effect on the ability to engage in potentially hazardous tasks [ see Warnings and Precautions ( 5.5 ) ] • Withdrawal effects following prolonged high dosage administration [ see Drug Abuse and Dependence ( 9.3 ) ] The following adverse reactions to phentermine have been identified: Cardiovascular Primary pulmonary hypertension and/or regurgitant cardiac valvular disease, palpitation, tachycardia, elevation of blood pressure, ischemic events. Central Nervous System Overstimulation, restlessness, dizziness, insomnia, euphoria, dysphoria, tremor, headache, psychosis. Gastrointestinal Dryness of the mouth, unpleasant taste, diarrhea, constipation, other gastrointestinal disturbances. Allergic Urticaria. Endocrine Impotence, changes in libido.