Parkinsonian-like

Another indication of the importance of DA in motor control is the observation that in humans its precursor levodopa, and DA agonists like bromocriptine, not only overcome the akinesia of Parkinsonism but in excess will actually cause involuntary movements, or dyskinesia (Chapter 14). Also it is well known that DA antagonists like chlorpromazine and haloperidol produce Parkinsonian-like symptoms in humans (and catalepsy in animals) and, as indicated above, reduce the dyskinesia of Huntington s Chorea. Thus DA seems to sit on a knife edge in the control of motor function (Fig. 7.8). 

Decker M., Keating G., Freeman A., Rye D. (2000). Parkinsonian-like sleep-wake... 

The only common side effect associated with IFN-y is the characteristic flu-like symptoms. However, in rare instances and at high doses, adverse clinical reactions have been noted. These have included heart failure, central nervous system complications (confusion disorientation, Parkinsonian-like symptoms), metabolic complications (e.g. hyperglycaemia), and various other symptoms. 

D2-dopamine receptor Parkinsonian-like motor impairment [68]... 

Baik, J. H., Picetti, R., Saiardi, A. etal. Parkinsonian-like locomotor impairment in mice lacking dopamine D2 receptors. Nature 377 424—428,1995. 

Restlessness, drowsiness, fatigue, lassitude, insomnia, headache, confusion, dizziness, mental depression Extrapyrainidal Reactions Acute dystonic reactions. Parkinsonian-like symptoms Endocrine Disturbances... 

Antipsychotic drugs include the older phenothiazines and butyrophenones, as well as newer atypical drugs. All of these can cause CNS depression, seizures, and hypotension. Some can cause QT prolongation. The potent dopamine D2 blockers are also associated with parkinsonian-like movement disorders (dystonic reactions) and in rare cases with the neuroleptic malignant syndrome, characterized by "lead-pipe" rigidity, hyperthermia, and autonomic instability (see Chapter 29 Antipsychotic Agents Lithium). 

Nigrostriatal tract Substantia nigra and striatum. Motor control. Hypoactivity implicated in parkinsonian-like side effects of antipsychotics. 

In workers with chronic inhalation exposure, iron deficiency and liver cirrhosis are commonly observed. Chronic inhalation exposure also affects the CNS, resulting in Parkinsonian-like symptoms. Mental aberrations are also observed. The psychiatric disturbance has been called manganese madness . Symptoms include confusion, unusual behavior, and sometimes hallucinations. Apathy, difficulty with speech, and loss of balance are most common. Other symptoms include difficulty with fine motor movement, anxiety, and pain. Manganese intoxication can result in a syndrome of parkinsonism and dystonia. If these extrapyramidal findings are present, they are likely to be irreversible... 

Manganese Nausea, vomiting, dermatitis, hair color changes, hypocholesterolemia, growth retardation, defective carbohydrate and protein metabolism Parkinsonian-like symptoms, hyper irritability, hallucinations, libido disturbances, ataxia Increased decreased biliary excretion high iron or vitamin C intake... 

Adverse Effects The major side effects of metoclopramide include extrapyramidal effects. Dystonias, usually occurring acutely after intravenous administration, and parkinsonian-like symptoms that may occur several weeks after initiation of therapy generally respond to treatment with antichohn-eigic or antihistaminic drugs and are reversible upon metoclopramide discontinuation. Tardive dyskinesia also can occur with chronic treatment (months to years) and may be irreversible. Metoclopramide can elevate prolactin levels by blocking the inhibitory effect of dopamine on pituitary lactotropes. Methemoglobinemia has been reported in premature and fuU-term neonates receiving metoclopramide. 

Although ethosuximide is thought to be the least toxic of the succinimides, it can cause gastrointestinal disturbances and dose-related CNS effects, such as drowsiness, dizziness, ataxia, sleep disturbances and depression. Idiosyncratic hypersensitivity reactions include severe rashes, leukopenia, agranulocytosis (some fatal), systemic lupus erythematosus, and parkinsonian-like symptoms. In addition to being less toxic than trimethadione, ethosuximide offers a wider range of protection against different kinds of absence seizures. 

Other reports in patients taking levodopa alone describe reductions in the levodopa dosage of up to 30% and 70% during concurrent treatment with methyldopa. Another report states that the control of Parkinson s disease improved during the concurrent use of methyldopa in some patients taking levodopa alone, hut the dyskinesias were worsened in others. Methyldopa on its own can cause a reversihle parkinsonian-like syn-drome. " ... 

Reserpine and other rauwolfia alkaloids deplete the brain of monoamines, including dopamine, thereby reducing their effects. This can lead to parkinsonian-like symptoms, and may oppose the actions of administered levodopa. There are not only sound pharmacological reasons for believing this to be an interaetion of elinieal importance, but a reduction in the antiparkinsonian activity of levodopa has been observed in patients given reserpine. The rauwolfia alkaloids should be avoided in patients with Parkinson s disease, whether or not they are taking levodopa. 

The production of stereotype gnawing in animals by amphetamine and the Parkinsonian-like symptoms by 4-methoxyphenylethylamine are mutually... 

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