Taste Alteration with Antiparkinsonian Medications
Yes, antiparkinsonian medications can cause taste alterations, though this is primarily documented as a side effect of levodopa therapy rather than a direct pharmacologic effect, and patients should be monitored for changes in taste and smell that may contribute to nutritional decline.
Evidence for Taste Changes in Parkinson's Disease Treatment
Documented Side Effects of Antiparkinsonian Drugs
Changes in taste and smell have been reported by Parkinson's disease patients as contributing factors to weight loss, alongside other gastrointestinal side effects of antiparkinsonian medications 1.
Side effects of drugs prescribed for PD that influence nutritional status include nausea, vomiting, abdominal pain, dyspepsia, constipation, weight decrease, dry mouth, diarrhea, anorexia, and GI disorders 1.
The ESPEN guideline specifically recommends monitoring side effects of antiparkinsonian drugs that might influence nutritional status and intervening on an individually tailored basis 1.
Distinguishing Disease from Drug Effects
Taste dysfunction occurs in approximately 27% of patients with clinically defined Parkinson's disease, independent of age, disease severity, or smell sense 2.
The impairment of taste in PD most likely signifies involvement of the frontal operculum or orbitofrontal cortex, though confounding by drug effects and changes in salivary constitution could not be excluded completely 2.
Taste threshold is significantly impaired in non-demented PD patients, with no important correlation between taste and smell dysfunction 2.
Clinical Management Approach
Monitoring Strategy
Assess nutritional status regularly, as weight loss is common in Parkinson's disease patients and may be exacerbated by taste alterations 3.
Monitor for specific side effects including changes in taste perception, dry mouth, and anorexia when prescribing levodopa or other antiparkinsonian agents 1.
Increasing doses of levodopa and levodopa equivalent doses are associated with increased risk for malnutrition, requiring closer nutritional monitoring 1.
Nutritional Interventions
Optimize antiparkinsonian treatment to ameliorate motor symptoms that contribute to dysphagia and nutritional problems 1.
Increased fiber and fluid intake, along with probiotics, can help manage constipation that may compound nutritional issues 3.
For levodopa specifically, give attention to homocysteine levels and vitamin B status, as levodopa use may be associated with impaired nutritional status 1, 4.
Important Caveats
The distinction between disease-related taste dysfunction and medication-related effects is challenging, as both the underlying Parkinson's disease and its treatments can contribute to taste alterations 2.
Dry mouth from antiparkinsonian medications can secondarily affect taste perception 1.
While taste alterations are documented, they appear less prominent than the well-established olfactory dysfunction in Parkinson's disease 2.
Medication adjustments should balance the management of taste-related side effects against the critical need for adequate motor symptom control 1.