Interview with Michael Anchors, M.D., Ph.D., about Phen-Pro (1997)

Michael Anchors, M.D., Ph.D., the author of “Safer Than Phen-Fen” dicusses the use of combining phentermine with Prozac and other SSRIs to help patients lose weight.

Michael Anchors, M.D., Ph.D. is the author of the book titled “Safer Than Phen-Fen”. He is a clinical professor of medicine at Georgetown University and operates a family practice in Maryland. Dr. Anchors can be reached as follows:

Michael Anchors, MD, PhD
16220 Frederick Rd Ste 210
Gaithersburg, MD 20877
(301) 990-6061
(301) 990-6064 Fax
.(JavaScript must be enabled to view this email address)
www.phenpro.com

Hobbs:      What is the drug combination that you are using for weight loss?

Anchors:   Phentermine and Prozac (Phen-Prozac).

Hobbs:      When did you start using Phen-Prozac?

Anchors:   March 1995.

Hobbs:      How many patients have you treated with Phen-Prozac?

Anchors:   About 620.

Hobbs:      Do you ever use phentermine alone?

Anchors:   No. Phentermine alone isn’t very effective. Patients lost a little weight at first, but gained it back even when they kept taking it. Phen-Prozac works much better.

Hobbs:      Did you ever prescribe Fen-Phen?

Anchors:   No. I considered fenfluramine to have unnecessary risks such as primary pulmonary hypertension (PPH) and possible heart valve damage. In fact, in the book (page 59) I predicted that we would see cases of heart valve damage in some people taking fenfluramine.

Hobbs:      Does Prozac increase the risk of PPH?

Anchors:   No. Eli Lilly, the company that manufactures Prozac, has received only 8 reports of PPH in people taking Prozac out of 19 million users worldwide. This is even fewer cases than would be expected in the general population. The reason is that Prozac does not force the release of serotonin like fenfluramine does. It only blocks the reuptake. Prozac is also more than 98% protein-bound in the blood, whereas fenfluramine is much less protein-bound and so is more available to cause trouble.

Hobbs:      Will you comment on the letter from Bostwick and Brown (1996) regarding a toxic reaction from combining phentermine and Prozac.

(Reference: Bostwick JM, Brown TM. A toxic reaction from combining fluoxetine and phentermine [letter]. Journal of Clinical Psychopharmacology, 1996 Apr, 16(2):189-90.)

Anchors:   First of all the phentermine was started at a dose of 30 mg, which should not be done. And second, the “toxic reaction” occurred 8 days after the Prozac was stopped.

Hobbs:      How does Phen-Prozac compare in to Fen-Phen as far as efficacy?

Anchors:   I believe they are equally effective.

Hobbs:      How does Phen-Prozac compare to Redux as far as efficacy?

Anchors:   I think that Phen-Prozac or Fen-Phen, for that matter, is more effective than Redux. I’ve treated a number of patients who failed to lose weight with Redux, but were successful with Phen-Prozac.

Hobbs:      How do they compare as far as side effects?

Anchors:   Phen-Prozac generally causes fewer side effects than Fen-Phen. And Phen-Prozac is better tolerated than either phentermine or Prozac alone.

Hobbs:      Have you had any problems with anxiety using Phen-Prozac?

Anchors:   Rarely. It’s probably because I start with a small dose of phentermine and gradually increase it and I only use 10 mg of Prozac.

Hobbs:      If Fen-Phen didn’t work for someone, is it likely that Phen-Prozac might work?

Anchors:   I have some patients who did not lose weight with Fen-Phen, but did lose weight with Phen-Prozac. I think it is certainly worth a try.

Hobbs:      What percentage of your Phen-Prozac patients have lost weight?

Anchors:   Most of them. Only 10 out of 620 failed to lose when following the program. A few dozen more failed to lose weight because they didn’t take the medicines as prescribed, ate when they weren’t hungry or didn’t exercise.

Hobbs:      How did you decide to use Phen-Prozac rather than Fen-Phen?

Anchors:   There were a couple reasons. First, fenfluramine is not covered by most insurance plans, but Prozac is. Second, fenfluramine has a shorter half-life, so it has to be taken two or three times per day, whereas Prozac only has to be taken once per day. Prozac also generally has fewer side effects than fenfluramine.

Hobbs:      What is the dose of Phen-Prozac that you use?

Anchors:   30 mg of phentermine plus 10 mg of Prozac. But I always have patients start with only 15 mg of phentermine for the first week or two and then increase it to 30 mg to reduce the initial side effects.

Hobbs:      Why do you think it is that only 10 mg of Prozac is necessary when combined with phentermine, whereas using Prozac alone seems to require at least 60 mg?

Anchors:    Only 10 mg is needed for weight loss, although a higher dose is needed to treat depression.

Hobbs:      Studies indicate that weight loss with Prozac alone only lasts for 6 months or so and then patients return to their previous weight. Have you had any problem with patients regaining a substantial amount of weight using Phen-Prozac?

Anchors:   No. I have never seen a patient gain weight on Phen-Prozac.

Hobbs:      What do you do when patients reach their target weight?

Anchors:   About 25% of patients are able to stop taking the medicines, and the other 75% still need a small dose to maintain their lower weight.

Hobbs:      What do you mean by a small dose?

Anchors:   Typically, 15 mg of phentermine plus 10 mg of Prozac every other day for some weeks of the month.

Hobbs:      Can other serotonin reuptake inhibitors (SSRI) be substituted for Prozac?

Anchors:   Yes. Phen-Zoloft, Phen-Trazodone, and Phen-Luvox all seem to work.

Hobbs:      How do you decide whether to use Prozac, Zoloft, trazodone or Luvox?

Anchors:   If a patient is controlling their depression with one particular SSRI I’ll keep them on that and just add the phentermine. Or if I start a patient on Phen-Prozac and they experience side effects I may switch them to another SSRI.

Hobbs:      For example?

Anchors:   Zoloft is a good choice when patients are also taking medications for other conditions because it is less likely to interfere with other drugs. Zoloft also loosens the stool which is useful for patients who experience too much constipation from phentermine.

If a patient has problems sleeping trazodone is a good choice. It’s also available as a generic so it’s cheap.

And Luvox is a good choice for patients who experience a decrease in libido from Prozac.

Hobbs:      What doses do you use?

Anchors:   When I use Phen-Trazodone I have them take the phentermine in the morning and 50 to 100 mg of trazodone at night.

When I use Phen-Luvox I have them take 25 to 50 mg of Luvox.

And with Zoloft I use 25 to 50 mg.

The dose of phentermine is always 30 mg.

Hobbs:      Do you ever combine phentermine with 2 SSRIs like Phen-Prozac-Trazodone or Phen-Trazodone-Luvox?

Anchors:   Yes. Sometimes I combine low dose Prozac with low dose trazodone in depressed patients, because trazodone helps them sleep.

Hobbs:      Have you tried any other combinations like Phen-Tryptophan or Phen-5HTP (5-hydroxytryptophan)?

Anchors:   No. I think that tryptophan is capable of causing heart valve disease for the same reason that fenfluramine does.

Hobbs:      What criteria do you use for trying a patient on Phen-Prozac?

Anchors:   The usual. I’ll try it only if they: 1) have failed to maintain weight loss by diet and exercise; 2) have a body mass index (BMI) greater than 30 or; 3) a BMI of 27 if they have obesity-related health problems. And, of course, they can’t have any contraindications to the medicines.

Hobbs:      Are there SSRIs or other antidepressants that don’t work?

Anchors:   Yes. Elavil??Ω (amitriptyline) and Pamelor??Ω (nortriptyline) don’t work because they stimulate appetite. Paxil??Ω doesn’t work either. Neither does Wellbutrin??Ω or Serzone??Ω.

Hobbs:      What other benefits have you found with Phen-Prozac?

Anchors:   Many of my patients have said they found it easier to stop smoking or drinking.

I’ve also found that phentermine is an effective treatment for attention deficit disorder (ADD). I discovered this after some of my Phen-Prozac patients told me that could concentrate better. So I tried substituting phentermine for Ritalin in young obese patients with ADD and I found that phentermine worked just as well an Ritalin and they lost weight. Dr. Rothman previously published a paper on using phentermine for ADD.

Rothman RB. Treatment of a 4-year-old boy with ADHD with the dopamine releaser phentermine [letter]. Journal of Clinical Psychiatry, 1996 Jul, 57(7):308-9.)

Anchors:   I’ve also found that Phen-Prozac works for obsessive-compulsive disorder (OCD). After taking Phen-Prozac for a while one of my patients confessed that she previously had a compulsion to buy compact discs and had purchased 10,000 of them! After taking Phen-Prozac her compulsion went away and she lost 94 lbs. Other patients have told me that have stopped using their credit cards compulsively.

And, as I mentioned before, Phen-Prozac seem to have an easier time stopping addictive behaviors like smoking, drinking and illicit drugs.

Dr. Michael Anchors on Phen-Prozac (updated in October 2000)

Hobbs:      How many patients have you treated with Phen-Prozac?

Anchors:   1058. This is the total of all my patients on “Phen-Pro”, which consists of phentermine plus one of the serotonin reuptake inhibitors (SSRIs). About 70 percent of my patients are on Phen-Prozac, 20 percent of Phen-Zoloft, 10 percent on Phen-Luvox and 10 percent on Phen-Trazodone.

Hobbs:      Have you tried Phen-Wellbutrin, Phen-Effexor, Phen-Serzone or Phen-Paxil?

Anchors:   Yes, I’ve tried all of these. Phen-Wellbutrin doesn’t work any better than phentermine alone. That is tachyphylaxis develops after 6 weeks. It makes sense that Wellbutrin would not work because it doesn’t work on serotonin. The 3 times I tried it Phen-Serzone was not tolerated. And in all of the patients I tried Phen-Effexor they developed nausea. But now that slow-release Effexor XR has become available, it might be worth a second look. And Phen-Paxil does not work.

Hobbs:      How do you decide whether to use Prozac, Zoloft, trazodone or Luvox?

Anchors:   If a patient is controlling their depression with one particular SSRI I’ll keep them on that and just add the phentermine. Or if I start a patient on Phen-Prozac and they experience side effects I may switch them to another SSRI.

Hobbs:      For example?

Anchors:    Zoloft is a good choice when patients are also taking medications for other conditions because it is less likely to interfere with other drugs. Zoloft also loosens the stool which is useful for patients who experience too much constipation from phentermine.

If a patient has problems sleeping trazodone is a good choice. It’s also available as a generic so it’s cheap.

And Luvox is a good choice for patients who experience a decrease in libido from Prozac.

Hobbs:      What doses do you use?

Anchors:   The same doses that I suggested in Safer Than Phen-Fen, that is 10 or 20 mg of Prozac; 25 or 50 mg of Zoloft; 25 or 50 mg of Luvox; or 25 or 50 mg of Trazodone. Padla’s study showed that higher doses cause less weight loss than lower doses. I’ve confirmed this to be true.

Hobbs:      Do you ever combine phentermine with two SSRIs like Phen-Prozac-Trazodone or Phen-Trazodone-Luvox?

Anchors:   Yes. Sometimes I combine low dose Prozac with low dose trazodone in depressed patients, because trazodone helps them sleep.

Hobbs:      What percentage of your Phen-Prozac patients have lost weight?

Anchors:   Twenty-eight percent of my patients reached ideal body weight; 50 percent lost a significant amount of weight but plateaued; and the remaining 22 percent did not take the medicine or were lost to follow-up. I’ve only had 14 patients out of 1058 ??Ω just over one percent ??Ω who took the medicine and did not lose weight.

Hobbs:      What do you do when patients reach their target weight?

Anchors:   About 25 percent of patients are able to stop taking the medicines, and the other 75 percent still need a small dose to maintain their lower weight.

Hobbs:      What do you mean by a small dose?

Anchors:   Typically, 15 mg of phentermine plus 10 mg of Prozac every other day for some weeks of the month.

Hobbs:      Do patients tend to regain weight after the initial 6 months of weight loss?

Anchors:   Except in one case, I have NEVER seen a patient regain more than 10 pounds while taking the medicines. The one exception was one of the six people who lost 150 pounds. She regained 70 lbs while taking up to 90 mg of phentermine and low-doses of an SSRI. This is the only time I have ever tried 90 mg of phentermine, but it just didn’t work. I have no idea what’s going on with her. She reached a plateau from the underside! I offered her gastroplasty surgery, but her insurance is foot-dragging, so we are really waiting for other medicines to come out.

Hobbs:      Have you tried 5-hydroxytryptophan (5-HTP) combined with phentermine?

Hobbs:      What dietary advice do you give?

Anchors:   I suggest my patients follow my 10 commandments. They are…

1. Eat only when hungry, eat slowly and stop when full.

2. Don’t even buy what you shouldn’t eat.

3. Get aerobic exercise.

4. Fill your plate with side-dishes first.

5. Eat less of foods from land animals.

6. Choose restaurants with smaller portions.

7. Eat foods that are spicier and more aromatic.

8. Reduce alcohol intake.

9. Drink two big glasses of water with each meal.

10. Don’t stay up late eating.

It is also equally important to remove any interfering drugs and behaviors. Follow-up is also very important. I used to have patients come in every month for follow-up, but now I follow-up with a majority of them via email. It works very well. Simply handing patients a prescription without instructions on diet and exercise just doesn’t work.

—END

Articles on the same subject can be found here:

• Interviews with Doctors

• Phentermine

• Phen-Pro (Phentermine-Prozac or other SSRIs)