Parkinson's disease-BPT

Parkinsonism Dr.Rathnakar U.P. MD.DIH.PGDHM

BPT 20 NOV 2013

Contents •

Examples of antiparkinsonian drugs

•  Adverse

effects effects of levodopa levodopa

•

Basis for combining levodopa with carbidopa

•

Drugs used in drug-induced parkinsonism and their mechanism of action

PD [Poverty of movements, tremors and rigidity]

Clinical features Clinical  features of PD Parkinson's disease (PD) is the second commonest neurodegenerative disease, exceeded only by Alzheimer's disease (AD). 5 million persons in the world suffer from this disorder.

Pathophysiology of PD

•

"Dopaminergic" pathology

Degeneration of dopaminergic neurons in SN [Deficiency of DA] • “Non-dopaminergic"

pathology

Over activity cholinergic neurons,

DA and Ach in PD DA

Antichlonergics

DA

Ach

Ach

 Normal DA=Ach

DA

DA

PD Deficiency of DA Relative excess of Ach

Ach

Treatment PD Dopaminergics Anticholinergics

Sites of action of drugs used to treat Parkinson's disease

2

Carbidopa Benserazide

Entacapone Tolcapone

2

1

0 Stupid

Dopamine

Levodopa DDC

3-MDOPA COMT

BBB

BBB 3

Selegiline Rasagiline

Levodopa

Tolcapone

Dopamine

DOPAC MAOB

3MT COMT

5 6

4

DA agonists

3

D1 & D2 Receptors

DA facilitator Amantadine

• • • •

Anticholinergics Trihexyphenidyl Procyclidine Biperiden Antihistaminics

Drugs for PD I.Drugs affecting brain dopaminergic system

II.Drugs affecting brain cholinergic system

1. DA prec precur urso sorr- Levodopa

1. Cen Central tral ant antic icho holi line nerg rgic icss

2. DDC inhibi inhibitor torss-Carbidopa

Trihexyphenydyl, procyclidine, biperiden

3. DA agon agonis iststsBromocriptine

2. Antihistaminics

4. MAO-B MAO-B inhibi inhibitor torssSelegiline

Orphenadrine, promethazine

5. COMT COMT inhibi inhibitors tors-Entacapone 6. DA facili facilitat tatoror-Amantadine

Levodopa

Levodopa Pharmacological actions • CNS

• CVS

1. Normal pe persons-n s-no effect

1. Tachycardia

2. PD: PD: Exce Excell llen entt clin linica ical improvement initiallyrigidity, hypokinesia, Tremors other nonmotor symptoms later 3. Psychosis 4. Sexual activity↑

2. Postural hypotension[central action] 3. Tolerance develops • Endocrine Prolactin↑

Levodopa ADEs At initiation of therapy

Prolonged therapy

•  Nausea & vomiting

• Abnormal movements

• Postural hypotension • Cardiac arrhythmias

[dyskinesia]-chorea, grimacing. Worsen with time

• Exacerbation of angina

• Dose limiting

• Alteration of taste

• Behavioral-Anxietydepression-psychosis • End of dose effect • On-off phenomenon [worsening and improvement in a few minutes-progressive minutes-progressive degeneration]

Centrally acting anticholinergics • Restore Ach/ DA  balance in striatum

• Trihexyphenidil

• Tremor is benefitted more than rigidity

• Biperiden

• Less effective than L.dopa

• Promethazine

• Cheap, less side effects • Atropine like side effects

• Procyclidine • Orphenadrine

Drug induced Parkinsonism [Extrapyramidal symptoms]

Drug induced extrapyramidal e xtrapyramidal reaction •  Antipsychotics  Antipsychotics •  Antiemetic

-

- Phenothiazines Phenothiazines Metoclopramide Metoclopramide

•

Tt of acute reactions - Promethazine Promethazine 25 mg.i.v

•

Other drugs-Anticholinergics drugs-Anticholinergics & antihistaminics with antiucholinergic activity

Physiotherapy and Parkinson’s Disease •

The main areas in which physiotherapists help people with Parkinson's Disease are:

•

posture,

•

range of movement,

•

walking and turning,

•

balance and transfers.

http://www.parkinsons.ie/aboutparkinsons_treatments_physio2