The effective control of Parkinson’s disease requires that we are stabilised by taking a combination of medication at set times as this optimises symptom control. There is usually a period of trial and error but once an individual patient is stabilised on a particular medicine or combination of medicines it is important that the same medicine is dispensed on each occasion.
Each patient needs to have confidence in the dispensed medicines and therefore if different generic medicine is dispensed the patient may become anxious as to whether the medicine will control their symptoms and/or whether they will suffer side effects.
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 in the brain is known as “bioavailability” and this is important as it determines how effective the medicine will be. Bioavailability can vary between branded and generic medicines and even different generic medicines with the same amount of active ingredient. This is because the formulation and other ingredients in the medicine affect the absorption and metabolism of the drug.
I was diagnosed with Parkinson’s in May 2013 and at that time my consultant stressed that I should not change the brand of medication prescribed as it could lead to side effects so, when in January 2021 I got home from the pharmacy to unpack my medication and found I had been given a different brand I was concerned. I rang the surgery and spoke to the prescribing nurse and expressed my concerns at the change of brand without any notification or discussion. She explained it was probably a financial decision on the doctor’s part and said there shouldn’t be any problem as the ingredients were the same so suggested I try the brand I had been given and contact them again should I suffer any adverse side effects!
I was not prepared to do this so contacted the doctor who was very helpful and explained that a locum doctor had processed my repeat prescription request and as the software programme offered a cheaper alternative to my brand he made the change. My doctor apologised and said this should not have been done without notifying me and discussing the matter and agreed to make a note on my file that the brand I am prescribed should not be changed and asked me to return the medicine I had been given and it would be replaced with my correct brand.