Sensitive to drugs

When I first developed muscle spasms around my eyes in February 2002, I didn’t have the internet. I remember a health professional telling me I was “sensitive to drugs” when I told her that an antidepressant I had been given had made me feel “caffeinated”. She noted that I was “restless sitting in the chair|”. I learnt much later from a patient forum that this restlessness was called akathisia – a drug-induced movement disorder. I began to look up the drugs I had been given as my movement disorder worsened. I probably came across stuff about CYP2D6 and genetic vulnerability when I was reading about adverse reactions to antidepressants and I started getting worried about Parkinson’s.

Obviously I was concerned about risk to my children. I thought two of them had shown signs of adverse reactions to prescription drugs. In 2012 I had a genetic test done.

There are many drugs that can cause parkinson’s & many that can make the symptoms worse. Some people have very serious issues of toxicity/lack of efficacy. The risk increases when more than one drug is being taken. When your symptoms get worse or you develop new ones, the first thing to suspect is any recent addition/change in drug treatment.


I am back after 3 years of absence from this Forum redpoppy Jun '18
The fact that the Parkinson’s medication does not seem to do anything much for me is frustrating. I have just discovered that I have polymorphisms in the genes which are involved in drug metabolizing enzymes, CYP 450, hence my poor metabolism of levodopa. I wonder whether other people too find they do not respond too well to the Parkinson’s drugs


Totally confused Norman oct 2020
I am newly diagnosed; I have been prescribed Half Sinemet as well as an anti sickness drug. Prior to diagnosis I was a shuffler and has relatively minor tremors. However, in the few short months I am now getting to feel out of sorts and my symptoms have gotten markedly worse. Can anyone give me a few tips please as to how to deal with my worsening symptoms.


The relevance of cytochrome P450 polymorphism in forensic medicine and akathisia-related violence and suicide S.J.M.Eikelenboom-Schieveld, Y.Lucire, J.C.Fogleman Journal of Forensic and Legal Medicine Vol. 41, July 2016, p. 65–71

Many drugs that cross the blood–brain barrier and a quarter of the medicines in general use are metabolized by the highly polymorphic cytochrome P450 system. Blood levels of prescribed medicines can be pushed towards toxicity because of genetically determined metabolizing capacity, high doses, and interactions with co-prescribed CYP450 inhibitors and synergies.…CYP450 status is an important factor that differentiates those who can tolerate a drug or combination of drugs from those who might not. Testing for cytochrome P450 identifies those at risk for such adverse drug reactions.

https://books.google.co.uk/books?id=g815isikVSAC&pg=PA340&lpg=PA340&dq=marsden+parkinson’s+disease&source=bl&ots=L0baMLPG_G&sig=Ny1IBLXm8joR2iMU-4nkR2GovM0&hl=en&sa=X&ved=0ahUKEwjr06-Oiu_QAhWsKsAKHZ9TCggQ6AEIODAG#v=onepage&q=marsden%20parkinson’s%20disease&f=false
Marsden’s Book of Movement Disorders I. Donaldson, C. D.Marsden, S. Schneider, K.P.Bhatia OUP 2012

p.218 A scenario for the cause of Parkinson’s disease might be as follows: patients with Parkinson’s disease may be vulnerable by virtue of inheritance of a relative inability to dispose of toxins (eg. Cyp2D6)

https://books.google.co.uk/books?id=ntQe9RooZ9kC&pg=PA88&lpg=PA88&dq=akathisia+relentless+discomfort&source=bl&ots=EBipm4R2iS&sig=ACfU3U1MG-oA_tE_wmroyr3zHkO1Xpwhbg&hl=en&sa=X&ved=2ahUKEwiO7YOy16vqAhWEURUIHZJ-AckQ6AEwDXoECAgQAQ#v=onepage&q=akathisia%20relentless%20discomfort&f=false

& see p.48 on susceptibility to TD (tardive dyskinesia)

Chapter 11 Movement Disorders Induced by Selective Serotonin Reuptake Inhibitors and other Antidepressants K.J. Barucha & K.D.Sethi (in Drug-Induced Movement Disorders ed. K.D. Sethi Marcel Dekker 2004)

The movement disorders induced by the older tricyclic and newer SSRIs are commonly caused by pharmacokinetic drug interactions, some of which occur in the context of a deficiency in the cytochrome p-450 enzyme system.
…The enzyme CYP2D6 is involved in the metabolism of SSRIs, and its role in PD has also been studied. Tsuneoka and coworkers, in a Japanese study, have shown that genetic polymorphism of the CYP2D6 gene has been associated with increased susceptibility to Parkinson’s Disease…These authors suggest that the Hhal polymorphism in the CYP2D6 gene is part of the molecular basis of Parkinson’s Disease …It will be interesting to see if patients with PD who develop motor worsening with SSRIs have this genetic mutation