E-DRUG: Heart drug withdrawn from U.S.A.

[srahmad@essential.org]

E-DRUG: FDA Talk Paper on Heart Drug Withdrawal
-----------------------------------------------
T98-33                        
June 8, 1998                  
                  ROCHE LABORATORIES ANNOUNCES 
          WITHDRAWAL OF POSICOR FROM THE MARKET

Roche Laboratories of Nutley, NJ has announced that it is voluntarily 
withdrawing the heart drug, Posicor (mibefradil), from the market as a 
result of new information about potentially harmful interactions with 
other drugs.

In many cases, drug interactions can be addressed by appropriate 
labeling changes and public education, but due to the complexity of 
the prescribing information needed in this case, and seriousness of 
side effects, FDA and Roche agreed that it would be difficult to 
administer Posicor safely. The following may be used to respond to 
inquiries.

Posicor is a calcium-channel blocker, chemically unlike the other 
approved products in this class. Posicor was approved in June of last 
year, to be used in the treatment of patients with hypertension and 
chronic stable angina.

Posicor reduces the activity of certain liver enzymes that are 
important in helping the body eliminate many other drugs. Inhibiting 
these enzymes can cause some of these other drugs to accumulate in the 
body to dangerous levels.

When Posicor entered the market in August of 1997, its 
enzyme-inhibiting properties were described in the labeling. The
labeling specifically listed three drugs (astemizole, cisapride, and 
terfenadine) that could be expected to accumulate to dangerous levels 
if Posicor was coadministered.

In December, after learning of several cases in which patients 
suffered serious adverse reactions after taking Posicor with one or 
more of the other drugs, FDA strengthened the labeling of Posicor, and 
two more drugs (lovastatin and simvastatin) were added to the label's 
list of those that should never be coadministered with Posicor. FDA 
also issued a public warning about this problem and the company issued 
a Dear Doctor letter to physicians.

>From spontaneous reports and ongoing trials, FDA and Roche have 
continued to learn of adverse reactions related to coadministration of 
Posicor with several other drugs. At present, more than 25 drugs are 
known to be potentially dangerous if used with Posicor -- a number and 
diversity of drugs that cannot be practically addressed by standard 
label warnings.

Since Posicor has not been shown to offer special benefits (such as 
treating patients who do not respond to other antihypertensive and 
anti-anginal drugs), the drug's problems are viewed as an unreasonable 
risk to consumers.

Patients now taking Posicor should not simply discontinue treatment 
because stopping medications can be risky. Instead, patients should 
promptly consult with their physicians about appropriate alternative 
therapy. In addition, patients now taking Posicor should not add any 
new medication to their current treatment without consulting their 
physicians.

Roche Laboratories is providing information in a "Dear Doctor" letter 
to physicians, pharmacists, nurse practitioners, and other health care 
professionals. Questions about the withdrawal of Posicor can be 
addressed to Roche's 24-hour hotline at 1-800-205-4611.

The following is a list of drugs that depend on the same liver enzyme 
as Posicor (mibefradil). Use of them in combination with Posicor could 
be dangerous.

  Generic name         Trade Name 
  ------------         ----------
  amiodarone            Cordarone 

  astemizole            Hismanal 

  bepridil              Vesture 

  cisapride             Propulsid 

  cyclosporine          Neoral, Sandimmune 

  cyclophosphamide      Cytoxan 

  desipramine           Norpramin 

  erythromycin          Erythrocin, Ilosone, others 

  etoposide             VePesid 

  flecainide            Tambocor 

  flutamide             Eulexin 

  halofantrine          Halfan 

  ifosfamide            Ifex 

  imipramine            Tofranil 

  lovastatin            Mevacor 

  mexiletine            Mexitil 

  pimozide              Orap 

  propafenone           Rythmol 

  quinidine             Cardioquin, Quinaglute, Quinidex, others 

  simvastatin           Zocor 

  tacrolimus            Prograf 

  tamoxifen             tamoxifen 

  terfenadine           Seldane 

  thioridazine          Mellaril 

  vinblastine           Velban 

  vincristine           Oncovin 



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