Antiparkinsonism drugs levodopa

Amantadine is less effective than levodopa in the treatment of Fhrkinson s disease but more effective than die anticholinergics. Amantadine may be given alone or in combination witii an antiparkinsonism drug witii anticholinergic activity. Amantadine is also used as an antiviral drug (see Chap. 14). 

Chap. 31), and during lactation. Levodopa is used cautiously in patients with cardiovascular disease, bronchial asthma, emphysema, peptic ulcer disease, renal or hepatic disease and psychosis. Levodopa and combination antiparkinsonism drugs (eg, carbidopa/levodopa) are classified as Pregnancy Category C and are used with caution during pregnancy and lactation. 

Do not abruptly discontinue use of the antiparkinsonism drugs Neuroleptic malignant-like syndrome may occur when the antiparkinsonism drugs are discontinued or the dosage of levodopa is reduced abruptly. The nurse carefully observes the patient and reports the following symptoms muscular rigidity, elevated body temperature, and mental changes... 

Opioids, antiepileptics, levodopa, antiparkinsonism drugs, psychotropic drugs, anticholinergics Corticosteroids, diuretics... 

BETA-BLOCKERS ANTIPARKINSON S DRUGS - LEVODOPA t hypotensive effect Additive hypotensive effect however, overall, adding beta-blockers to levodopa can be beneficial (e.g. by reducing the risk of dopamine-mediated risk of arrhythmias) Monitor BP at least weekly until stable... 

THIAZIDES ANTIPARKINSON S DRUGS-LEVODOPA t hypotensive effect Additive effect Monitor BP at least weekly until stable. Warn patients to report symptoms of hypotension (light-headedness, dizziness on standing, etc.)... 

PHENYTOIN ANTIPARKINSON S DRUGS - LEVODOPA Possibly 1 levodopa levels Uncertain Watch for poor response to levodopa and consider increasing its dose... 

BACLOFEN ANTIPARKINSON S DRUGS -LEVODOPA Reports of CNS agitation and 1 efficacy of levodopa Uncertain Avoid co-administration... 

VITAMIN B6 ANTIPARKINSON S DRUGS-LEVODOPA 1 efficacy of levodopa (in the absence of a dopa decarboxylase inhibitor) A derivative of vitamin B6 is a co-factor in the peripheral conversion of levodopa to dopamine, which l amount available for conversion in the CNS. Dopa decarboxylase inhibitors inhibit this peripheral reaction Avoid co-administration of levodopa with vitamin B6 co-administration of vitamin B6 with co-beneldopa or co-careldopa is acceptable... 

When levodopa is given without a peripheral decarboxylase inhibitor, anorexia and nausea and vomiting occur in about 80% of patients. These adverse effects can be minimized by taking the drug in divided doses, with or immediately after meals, and by increasing the total daily dose very slowly antacids taken 30-60 minutes before levodopa may also be beneficial. The vomiting has been attributed to stimulation of the chemoreceptor trigger zone located in the brain stem but outside the blood-brain barrier. Fortunately, tolerance to this emetic effect develops in many patients. Antiemetics such as phenothiazines should be avoided because they reduce the antiparkinsonism effects of levodopa and may exacerbate the disease. 

Levodopa Levodopa degraded in gut prior to reaching sites of absorption. Agents that alter gastrointestinal motility may alter degree of intraluminal degradation. Antiparkinsonism effect of levodopa susceptible to inhibition by other drugs. Clonidine [NE] Inhibits antiparkinsonism effect. 

The use of dopaminergic agents in combination with antimuscarinic drugs is common in the treatment of parkinsonism. Bromocriptine does not complicate treatment with antimuscarinic drugs or amantadine. If combined with levodopa, bromocriptine should be used in reduced doses to avoid intolerable adverse effects. Confusion, delusions, and hallucinations occur more frequently with bromocriptine than with levodopa. Bromocriptine does not require bioactivation for its antiparkinson effects. The answer is (C). 

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