Warning: Difference of up to 20% Bioequivalency for Generic Drugs

[Guest guest]

Friends,

The following is a warning for those trying to withdraw from psychotropic drugs, especially if using a generic version of the drug.

It is advised to NOT switch from one generic version to another. The reason is outlined in this report from the medical journal, The Lancet:

The Lancet: Volume 355 Issue 9217 Page 1822

Controlled withdrawal for psychotropic drugs

Sir--I welcomed the letter by Allan Young and Haddad (April 1, p 1184)1 and agree that discontinuation symptoms after taking psychotropic drugs requires further study. However, there are some measures that could be taken immediately. Such measures could alleviate side effects that can occur even whilst the patient is taking the drug. These measures also apply to a host of other medications. Fluoxetine (Prozac, Eli Lilly, Basingstoke, UK) is usually prescribed in 20 mg capsules, which means that patients, following a supervised withdrawal scheme, cannot readily break down their dose into ever lessening amounts. Unless a syrup is taken and the patient is able to work out some difficult arithmetic, withdrawal schemes are difficult to follow. Paroxetine has the advantage of being presented in 20 mg or 30 mg scored tablets so withdrawal programmes are easier to devise. Since patent expiry, fluoxetine is now available in at least 12 generic formats.2 Generic drugs, for licensing purposes, are allowed up to 20% difference in bioequivalence from the brand original.3 Therefore, even patients on continuous therapy, could, if dispensed products emanating from different manufacturers, receive back to back prescriptions where the medicine given varies up to 40% in dose. So, in some cases, we are likely to see discontinuation symptoms in patients still on medication. I recommend that patients receive continuity of supply from the dispenser, with no intermanufacturer switching. I would also recommend that tablets come in a scored formulation so that slow and consistent withdrawal can be followed. Gillian S Wade

Celtic Dimensions, Morawelon, Gwynedd LL53 6EB, UK (e-mail:celtic_dimensions@...)

1 Young A, Haddad P. Discontinuation symptoms and psychotic drugs. Lancet 2000; 355: 1184.

2 Chem Drug Gener List April­Sept 2000: 25.

3 Generic medicine--can quality be assured? Drug Ther Bull 1997; 35: 9­11. [PubMed]

The Avenging Angel

Please sign the petitions at:

http://www.petitiononline.com/lilpro

http://www.petitiononline.com/oky71.html

http://www.petitiononline.com/effexor

Please report all adverse drug reactions to:

http://www.fda.gov/medwatch/index.html

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[Guest guest]

Friends,

The following is a warning for those trying to withdraw from psychotropic drugs, especially if using a generic version of the drug.

It is advised to NOT switch from one generic version to another. The reason is outlined in this report from the medical journal, The Lancet:

The Lancet: Volume 355 Issue 9217 Page 1822

Controlled withdrawal for psychotropic drugs

Sir--I welcomed the letter by Allan Young and Haddad (April 1, p 1184)1 and agree that discontinuation symptoms after taking psychotropic drugs requires further study. However, there are some measures that could be taken immediately. Such measures could alleviate side effects that can occur even whilst the patient is taking the drug. These measures also apply to a host of other medications. Fluoxetine (Prozac, Eli Lilly, Basingstoke, UK) is usually prescribed in 20 mg capsules, which means that patients, following a supervised withdrawal scheme, cannot readily break down their dose into ever lessening amounts. Unless a syrup is taken and the patient is able to work out some difficult arithmetic, withdrawal schemes are difficult to follow. Paroxetine has the advantage of being presented in 20 mg or 30 mg scored tablets so withdrawal programmes are easier to devise. Since patent expiry, fluoxetine is now available in at least 12 generic formats.2 Generic drugs, for licensing purposes, are allowed up to 20% difference in bioequivalence from the brand original.3 Therefore, even patients on continuous therapy, could, if dispensed products emanating from different manufacturers, receive back to back prescriptions where the medicine given varies up to 40% in dose. So, in some cases, we are likely to see discontinuation symptoms in patients still on medication. I recommend that patients receive continuity of supply from the dispenser, with no intermanufacturer switching. I would also recommend that tablets come in a scored formulation so that slow and consistent withdrawal can be followed. Gillian S Wade

Celtic Dimensions, Morawelon, Gwynedd LL53 6EB, UK (e-mail:celtic_dimensions@...)

1 Young A, Haddad P. Discontinuation symptoms and psychotic drugs. Lancet 2000; 355: 1184.

2 Chem Drug Gener List April­Sept 2000: 25.

3 Generic medicine--can quality be assured? Drug Ther Bull 1997; 35: 9­11. [PubMed]

The Avenging Angel

Please sign the petitions at:

http://www.petitiononline.com/lilpro

http://www.petitiononline.com/oky71.html

http://www.petitiononline.com/effexor

Please report all adverse drug reactions to:

http://www.fda.gov/medwatch/index.html

Send and receive Hotmail on your mobile device: Click Here