Constipation phentermine

Common adverse reactions seen with phentermine use include heart palpitations, tachycardia, elevated blood pressure, stimulation, restlessness, dizziness, insomnia, euphoria, dysphoria, tremor, headache, dry mouth, constipation, and diarrhea. Phentermine should be avoided in patients with unstable cardiac status, hypertension, hyperthyroidism, agitated states, or glaucoma. In combination with fenfluramine or dexfenfluramine, pulmonary hypertension and valvular heart disease have been reported. The risk of developing either serious adverse effect cannot be ruled out with use of phentermine alone. Since phentermine is related to the amphetamines, the... 

The newest appetite suppressant, sibutramine (Meridia), works by blocking the reuptake of both serotonin and norepinephrine. It does not stimulate nerve cells to release serotonin, as do fenfluramine and dexfenfluramine. Administered at 20 mg/ day, sibutramine effectively reduces weight in obese patients, but its use has not been assessed in eating disorder patients. The most common side effects of this medication are insomnia, dry mouth, and constipation. It has not been associated with the more serious heart and lung complications observed with fenfluramine and dexfenfluramine. Because sibutramine acts in part through modulation of norepinephrine, there is no rational basis for coadministering phentermine, which acts via this same mechanism. 

Phentermine is indicated only for short-term treatment, and tolerance often develops. Its common adverse effects are dry mouth, insomnia, increased blood pressure, and constipation (5). It is the subject of a separate monograph (p. 2804). 

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