Lonamin, generically known as phentermine, is a drug that's often prescribed in combination with dietary modification and exercise for weight loss in obese people. This drug is marketed under other brand names such as Adipex, Supramine and Zantryl. Although phentermine is a member of the amphetamine family, a study by Ed J. Hendricks and Frank L Greenway, published in the American Journal of Therapeutics, suggests that phentermine does not cause substance dependence or withdrawal. The average course of therapy is three to six weeks.
Decreased Appetite and Weight Loss
A double-blind, randomized, placebo-controlled study by Kyoung Kon Kim, et al., published in the Yonsei Medical Journal, indicated that a 14-week treatment course with phentermine--combined with behavioral modification therapy that included counseling on diet and exercise--was significantly more effective at inducing weight loss than placebo. The average weight loss was 13.2 lbs., accompanied by a reduction in waist circumference of 2.4 inches. A study by Trevor Silverstone, published in "Psychopharmacology," suggests that phentermine treatment reduced appetite. This effect was measured by caloric intake during the 10 hours after drug administration; subjects consumed an average of 30 percent fewer calories after taking phentermine.
Dry Mouth, Unpleasant Taste, Vomiting, Constipation, Diarrhea
Mild side effects of phentermine therapy include dry mouth and unpleasant taste. Gastrointestinal effects may include vomiting, constipation or diarrhea. These side effects are generally rare. A study published in the Yonsei Medical Journal, by Kyoung Kon Kim et al., reported that compared to placebo, the only statistically significant side effects reported in the phentermine group were dry mouth and insomnia.
Chest Pain, Heart Palpitations, Dizziness, Swelling in Legs
Serious cardiovascular side effects from phentermine may include chest pain or heart palpitations, increased blood pressure or shortness of breath. Neurological side effects can include restlessness, dizziness, insomnia or tremor. Finally, there could be swelling in the legs or ankles, or the patient may have difficulty doing exercises that he was previously able to do. Should any of these side effects occur, a physician should be immediately notified because they could indicate a more serious condition.
Valvulopathy
Valvulopathy is heart disease involving the heart valves. The first reports of a link between appetite suppressants and valvulopathy came in 1997. The Food and Drug Administration then conducted studies, which suggested valvulopathy in 33 percent of the patients taking appetite suppressants such as phentermine. However, according to Yoon K Loke, et al, in a study published in the journal BioMed Central Clinical Pharmacology, there were many methodological issues with the FDA studies--including non-blinded investigators, the absence of control groups and a heterogeneous population. When pooling all studies on the topic and conducting a meta-analysis of the available data, Loke, et al. found that the risk of valvulopathy with appetite suppressants was less then 6 percent, and that none of the reported cases could be attributed directly to the drugs.
References
- "American Journal of Therapeutics"; A Study of Abrupt Phentermine Cessation in Patients in a Weight Management Program; Ed J. Hendricks and Frank L Greenway; March 2, 2010
- "Yonsei Medical Journal"; Effects on Weight Reduction and Safety of Short-Term Phentermine Administration in Korean Obese People; Kyoung Kon Kim, Hi-Jung Cho, Hee-Cheol Kang, Bang-Bu Youn, and Kyu-Rae Lee; October 31, 2006
- "Psychopharmacology"; The Anorectic Effect of a Long-acting Preparation of Phentermine (Duromine); Trevor Silverstone; 1972
- United States National Library of Medicine: National Institutes of Health: Phentermine
- "BioMed Central Clinical Pharmacology"; Appetite Suppressants and Valvular Heart Disease -- A Systematic Review; Yoon K Loke, Sheena Derry and Angharad Pritchard-Copley; August 23, 2002
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