Medication ,everyone with PD should be aware of this.

Branded medicines undergo a rigorous

process of clinical trials assessing safety and

effectiveness before they are approved for

human use.

However, generic medicines can

be approved on the basis of

pharmacokinetic studies carried out on a

minimal number of healthy volunteers,

Generic medicines have the same active

ingredient as the branded medicine.

However, they are not always identical to

the branded medicine.

The amount of drug that finally reaches the site of action is

known as the ‘bioavailability’.

Thebioavailability is very important, because

this will determine how effective the

medicine will be. Too little drug reaching

the target could lead to less effective

treatment, but too much could increase side

effects. The bioavailability can vary between

branded and generic medicines, and

between different generic medicines, with

the same amount of active ingredient. This

is because the formulation and excipients

(other ingredients included in the medicine)

affect the absorption and metabolism of the

drug.

where they are shown to be ‘bioequivalent’

to the branded medicine. This means that

the rate and extent of their bioavailability

lies within ‘acceptable predefined limits’

compared with the original branded

medicine. For a generic medicine to be

considered bioequivalent, the European

Medicines Agency (EMEA) requires the

measures of bioavailability (area under the

curve and Cmax) to be within 0.8 and 1.25 of

the original medicine’s values.

Thus, the relative bioavailability of the generic

medicine can lie anywhere between 80%

and 125% of the original medicine’s values.

Bearing in mind that patients can be

switched with each prescription

Patients with certain conditions requiring

carefully balanced combinations of

medications would also be

disproportionately affected by medicine

substitutions. For example, people with

Parkinson’s disease often take a

combination of medications, which must be

taken at the correct time for them to avoid

worsening of their symptoms. Patients

with Parkinson’s disease could be

understandably concerned about apparent

changes in their medication. In addition,

changes in formulation type could affect

symptom control

[Leyther]

This is a very good point.

In the UK it is becoming the norm for health authorities to cut costs by only allowing the cheaper generic medicines to be prescribed.

Often to the detriment of the patient. I have several friends who this has happened to and it can be difficult to get them changed to the original manufacturer if you have a problem.

Persistence with your neuro / gp is required to get them to write expressing that you must have the correct drug.

Interestingly my selegeline has always been generic and the patented original doesnt work for me !!!

[MagicMax]

Great info. Now I understand why sinemet was giving me stomach aches until my pharmacy switched me to the Teva brand. Thank you.

[jernor]

Thank you so much for such an informative article!

[Kat00]

Great information!

[Hidden]

Thanks. This is helpful.

[Hikoi]

Thanks PP

I find it difficult to know if it is a change in maufacturer or just the day to day changes living with PD that I notice. I did mention this to my doctor and she was quick to offer me non generic by writing it on the prescription. I am sad to read that others are not as fortunate with their GP. I wasn't aware that some Health Authorities were only allowing generics to be prescribed.