Extrapyramidal reactions

When ondansetron is administered with rifampin, blood levels of ondansetron may be reduced, decreasing the antiemetic effect. Dimenhydrinate may mask the signs and symptoms of ototoxicity when administered with ototoxic drugp, such as the aminoglycosides (see Chap. 10), causing irreversible hearing damage. When lithium is administered with prochlorperazine, the risk of extrapyramidal reactions increases (see Chap. 32). 

GASTROINTESTINAL STIMULANTS. If drowsiness or dizziness occurs with the administration of metoclo-pramide, the patient will require assistance with ambulatory activities. The nurse observes patients receiving high or prolonged doses of this drug for adverse reactions related to the CNS (extrapyramidal reactions or tardive dyskinesia, see Chap. 32). The nurse reports any... 

Problems associated with these drugs include troublesome and potentially dangerous side effects, including extrapyramidal reactions, hypersensitivity reactions with possible liver dysfunction, marrow aplasia, and excessive sedation. 

Extrapyramidal reactions may occur with high doses these reactions usually respond to dose reduction. 

Chiidren In general, these products are not recommended for children younger than 12 years of age. Children seem more prone to develop extrapyramidal reactions, even at moderate doses. Therefore, use the lowest effective dosage. 

Children seem more prone to develop extrapyramidal reactions, even on... 

CNS When used to treat extrapyramidal reactions resulting from phenothiazines in psychiatric patients, antiparkinson agents may exacerbate mental symptoms and precipitate a toxic psychosis. 

Drug-induced extrapyramidal reactions 100 mg twice/day. Patients with suboptimal responses may benefit from 300 mg/day in divided doses. 

When stimulation of Gl motility might be dangerous (eg, in the presence of Gl hemorrhage, mechanical obstruction, or perforation) pheochromocytoma (the drug may cause a hypertensive crisis, probably because of release of catecholamines from the tumor control such crises with phentolamine) sensitivity or intolerance to metoclopramide epileptics or patients receiving drugs likely to cause extrapyramidal reactions (the frequency and severity of seizures or extrapyramidal reactions may be increased). 

Parkinsonism and drug-induced extrapyramidal reactions See amantadine in the... 

Pimozide, penfluridol and fluspirilene are di-phenylbutylpiperidine derivatives. Pimozide and penfluridol are antipsychotics with high potency but they give relatively few extrapyramidal problems and exhibit minimal other adverse effects. Fluspirilene has similar pharmacological activity although the risk for extrapyramidal reactions seems to be somewhat higher. 

Drug Chemical Classification Equivalent Oral Dose (mg) Sedation Side Effects Autonomic Extrapyramidal Reactions ... 

Extrapyramidal reactions Dystonias, akathisia, parkinsonism Dj-receptor block... 

Contraindications Concurrent use of medications likely to produce extrapyramidal reactions, G1 hemorrhage, GI obstruction or perforation, history of seizure disorders, pheochromocytoma... 

Extrapyramidal reactions have been described in older adults. 

Advanced Parkinson s disease (53%-17%) Orthostatic hypotension, extrapyramidal reactions, insomnia, dizziness, hallucinations Occasional... 

Drug-induced extrapyramidal reactions PO Initially, 2.5 mg 3 times/day. May increase by 2.5 mg daily as needed. Maintenance 10-20 mg/day in divided doses 3... 

More extrapyramidal reactions than chlorpromazine and promazine thiethylpera-zine would be less desirable than these agents in patients where the occurrence of a dystonic reaction would be hazardous (i.e., head and neck surgery patients, patients with severe pulmonary disease, patients with a history of dyskinetic reactions)... 

The most common extrapyramidal reaction is akathisia, characterized by motor restlessness and anxiety. Akinesia, marked by rigidity, tremor, i ncreased sal ivat ion, mask-like facial expression, and reduced voluntary movements, occurs less frequently. Dystonias, including torticollis, opisthotonos, and oculogyric crisis, occur rarely. 

Monitor the patient for extrapyramidal reactions and early signs of tardive dyskinesia and potentiallyfatal neuroleptic malignant syndrome (such as altered mental status, fever, irregular pulse or blood pressure, and muscle rigidity)... 

Anticholinergic (dry mouth, constipation, blurred vision, hypotension—more common with low-potency agents) Weight gain Extrapyramidal reactions (dystonia, rigidity, tremor, akathisia, greater risk with higher potency) Drowsiness... 

Extrapyramidal reactions (dystonia, rigidity, tremor akathisia) 0.5-3 bid/tid Same as for diphenhydramine Benztropine 0.5, 1, 1 mg elixir, injectable... 

Extrapyramidal reactions include parkinsonism, acute muscular dystonias, akathisia, tardive dyskinesia and malignant neuroleptic syndrome. They can also cause hypersensitivity reaction including cholestatic jaundice, skin rash, urticaria, photosensitivity and contact dermatitis. There is also blue pigmentation of skin, lenticular opacities on prolonged use of drug. 

Adverse effects include mania, insorrmia, nervousness, fatigue, drowsiness, nausea, extrapyramidal reactions and irritability. 

It is used in prophylaxis of influenza A virus, idiopathic parkinsonism and drug-induced extrapyramidal reactions. 

One common denominator of all antipsychotics is the biockade of centrai dopamine (DA) receptors. As a result, extrapyramidal reactions, particularly parkinsonian symptoms, are a major adverse effect of many of these drugs, as well as an important clue to their mechanism of action. True Parkinson s disease is caused by a DA deficiency in the nigrostriatal system. Further, crystallographic data have demonstrated that CPZ s molecular configuration is similar to that of DA, which could explain its ability to block this neurotransmitter s receptors. Drugs with similar structures that do not block DA receptors (e.g., promethazine, imipramine) do not have antipsychotic activity. Another example is the isomer of flupenthixol, which blocks DA receptors is an effective antipsychotic, but the isomer that does not is ineffective (7). The other family of dopamine receptors, D and Dg, have not yet been implicated in psychosis. 

Therapeutic doses of each usually evoke minimal or no extrapyramidal reactions. 

Lack of antipsychotics more serious complications, such as tardive dyskinesia, neuroleptic malignant syndrome, other extrapyramidal reactions, or significant hypotension... 

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