4. Phentermine
• Phentermine is presumed addicting
• No human evidence of addiction
• Obesity treatment specialists have seen neither
addiction nor withdrawal
• Patients taking phentermine can cease abruptly
without symptoms other than hunger
• Some patients experience lower energy levels
5. Withdrawal Study Rationale
• Amphetamine addiction, abuse and withdrawal
syndromes now well described.
• If phentermine is addicting, abrupt cessation
should induce amphetamine-like withdrawal.
• Use addiction metrics to assess symptoms in
phentermine-treated patients.
6. Research Setting
• Private, Fee-for-service, Obesity Medicine
specialty practice
• Metropolitan Sacramento, California, USA
• In operation, with same MD 24 years
• Treatment modalities:
– Low carbohydrate, optimum protein: 100%
– Behavior, Lifestyle modification: 100%
– Pharmacotherapy: 95%
– Phentermine: 90%
7. Research Plan
•
•
•
•
Prospective Interventional Clinical trial
Patients phentermine-treated for > 1 year.
Consent to cease phentermine ~ 48 hours
Examine for signs of Abuse, Addiction,
Phentermine cravings.
• Examine for withdrawal symptoms while on
drug (D0) and at ~ 24 hours (D1) and
~ 48 hours (D2) after abrupt cessation.
19. Conclusions
• Abrupt cessation of phentermine treatment
does not produce amphetamine-like
withdrawal.
• Fear of inducing addiction is an inappropriate
justification for withholding phentermine
treatment for obesity.
20. WITH THANKS TO:
Frank Greenway, MD
Pennington Biomedical Research Center
Baton rouge, Louisiana, USA
Manit Srisurapanont, MD, PhD
Chang Mai University
Chang Mai, Thailand
Richard Atkinson, MD
Editor, International Journal of Obesity
21. Phentermine Rx Weight Loss
1 Year
Mean Wt. Loss = 18.7 %
Mean Wt. Loss = 17.7 Kg
Hendricks, Obesity 2011; 19(12):2351-60.
22. Phentermine & Weight Loss
No phentermine Rx
Phentermine Rx
Hendricks, Obesity 2011; 19(12):2351-60.