Mga Pahina

PARKINSON'S DISEASE: MEDICATION SIDE EFFECTS

Many health professionals sooner or later help to care for someone with Parkinson’s disease (PD), a progressive disease for which there is no cure. Most of the one to one and one-half million people in the U.S. diagnosed with PD are older adults, but about fifteen percent are under age 60. Characteristic of PD is a gradual death of the dopamine-producing cells of the brain. This results in loss of motor functions, causing uncontrollable tremor (usually at rest), rigidity, slow movement (bradykinesia), poor balance, and inability to walk normally. Many people with PD fall frequently, due in part to this loss of motor function.


Medication side effects. Medications used to treat PD have improved greatly over the years, enhancing quality of life and lengthening the years of independent living for most people. Unfortunately, however, these medications frequently cause side effects that can be obstacles to good nutrition:

  • nausea 
  • constipation 
  • heartburn 
  • confusion 
  • depression 
  • fatigue 
  • loss of the senses of smell and taste 
  • loss of appetite 
  • dry mouth 
  • anorexia 
  • sleep disruption
These side effects, along with Parkinson symptoms, can lead to further complications, and these become increasingly common, particularly as the disease progresses:
  • unplanned weight loss 
  • increased fatigue 
  • orthostatic hypotension 
  • bone thinning 
  • nutrient depletion
Protein-levodopa interactions. Furthermore, those who use levodopa, considered the gold standard of PD medications, must deal with a major food-medication interaction, that of protein and levodopa. Most people with PD require levodopa (Dopar, Larodopa), or, most frequently, a combination of levodopa and carbidopa (Sinemet, Sinemet CR) or levodopa and benserazide (Madopar). However, dietary protein can block levodopa absorption, both from the gut and at the blood-brain barrier. Without the benefits of levodopa, the individual may be unable to move, self-feed, turn over in bed, use the toilet, or perform other normal activities of daily living.

Additional concerns include increasing disability, sensory changes, and changes to the gastrointestinal tract, particularly in middle and late stages of PD. Medications and disease progression can cause excessive urination, and/or urinary retention. In later stages, choking, dysphagia, and/or dementia may occur. Perhaps because of sensory changes, patients frequently develop a craving for sweets, eating them in preference to nutrient-dense, high-fiber foods; this can contribute to the constipation which is already prevalent due to the disease and/or its medications. These conditions are direct or indirect risk factors for malnutrition, dehydration, urinary tract infections, kidney stones, heat stroke, bone loss, bowel impaction, and/or unplanned weight loss.


Fracture risk. Bone loss and loss of muscle mass, combined with poor balance, shuffling gait, and increased incidence of falling, greatly increases the risk for bone fracture, and probably explains the rate of hip fractures in patients with PD. Indeed, when bone mineral density was compared with values for age-matched groups, PD patients had a higher incidence of severe osteoporosis.


Unplanned weight loss. Parkinson’s patients have been shown to have lower levels of fat-free mass yet similar resting metabolic rates versus a control group. The resulting sarcopenia (loss of muscle mass) may contribute to poor muscular control and incidence of falling. Furthermore, postoperative rehabilitation was found to be longer and less successful in male PD patients with hip fractures than in other patients with similar fractures.

Unplanned weight loss and low body mass index are significant predictors of morbidity and mortality in older adults; both are common in patients with PD. Because patients with PD may be at risk for bone fracture, and are more likely to experience unplanned weight loss, it is important that nutrition bolster bone strength and prevent loss of lean body mass. Yet, because of the numerous difficulties listed above, patients may not make food choices helpful to maintaining bone strength and muscle mass. Also, due to confusion, depression, fear of falling, fatigue, and social withdrawal, patients may not perform weightbearing physical activity, or receive exposure to sunlight, again implicated in bone health.


Xerostomia. Some further complications can occur. In my practice, I frequently observe patients with PD who have missing teeth. Many experience dry mouth, leading to a form of tooth decay that cannot always be treated; often, the tooth must be extracted. If bone loss in the jaw area also occurs, dentures and bridges may not fit properly, leading to poor mastication — another obstacle to good nutrition.


Loss of manual dexterity. Inability to finish meals on time is common and can lead to unplanned weight loss. This slowed eating can be due to poor coordination, and/or inability to properly use the muscles of the tongue and mouth in the chewing and swallowing process. When this is the case, I often counsel patients not to eat foods like tossed salads, which may be difficult to spear on a fork and place in the mouth; or foods which require a great deal of chewing. I encourage use of softer vegetables, juices, ground meats, finger foods, etc., instead.


Slowed peristalsis. PD and/or the medications used to treat PD may slow the body’s natural peristalsis, leading to difficulty swallowing, delayed stomach emptying, gastroesophageal reflux (acid reflux or heartburn), and constipation. All of these should be regarded as further barriers that must be overcome in order to obtain adequate nutrition.


Constipation. Overwhelmed by the progressive nature of the disease, and the need for frequent changes in type and amount of medications and their side effects, patients may sometimes ignore constipation. However, fecal impaction occurs often, and can be especially difficult for people with PD, who are often emotionally labile. Stresses and trauma can quickly lead to downward spirals in physical, mental and emotional health. Patients hospitalized with bowel impaction may not regain their former state of health, and in fact have been discharged to long-term-care facilities, unable to perform their usual activities of daily living any longer.


Gastroesophageal reflux disease. Heartburn and acid reflux are also quite common, and may cause patients to avoid eating in fear of the extreme discomfort. I encourage frequent small meals and snacks in this case, to avoid overfilling the stomach, and advise against eating anything for several hours before bedtime. Patients who use levodopa should be referred to a registered dietitian trained in Parkinson’s disease, as they may need low-protein snacks to avoid blocking levodopa absorption.


Protein redistribution. In later stages of PD, motor fluctuations are more prevalent, and protein-rich foods often become problematic, particularly as the individual is often taking levodopa more than three times a day and timing of meals and levodopa becomes difficult. At this time, protein redistribution diets are sometimes recommended.

One plan entails avoiding protein throughout the day, for better mobility; then eating the bulk of the day’s protein foods at the evening meal. There are several problems with this plan. Patients who try this plan find that reduced mobility at night leaves them unable to turn in bed, and sometimes tangled inextricably in their sheets. Also, they cannot get up to urinate at need. It is not uncommon for patients to decide to avoid protein at the evening meal as well as during the day, in order to gain mobility throughout the night. Protein-calorie malnutrition, and often hospitalization, are the results.

Another concern arises if the patient has diabetes. Proper control of blood sugar requires a balanced intake of protein, carbohydrate, and fat. Avoidance of protein leads to an eating plan that is unnaturally high in carbohydrates and/or fats, and this can disrupt blood sugar control.
Patients require understanding and guidance in order to meet their protein needs, and should be referred to a registered dietitian who understands PD. The dietitian can assess personal protein needs and develop an individualized eating plan that best meets each patient’s unique goals.


Dehydration. Mild to severe dehydration is also not uncommon, again, often due to polyuria, urine retention, and/or fear that one will be unable to reach the bathroom due to disability. Chronic dehydration can lead to urinary tract infections, kidney stones, kidney failure, heat stroke, and other conditions. I caution patients about such complications, and encourage them to drink as much water as possible when they take their medications. The ensuing "on time" with its increased mobility (as opposed to "off time" when medications wear off and mobility decreases) should be used to empty the bladder frequently. Then the bladder will be empty during "off time" when the patient is less able to move about. Patients with swallowing difficulties should see a speech pathologist, who can perform a swallowing evaluation and teach safe swallowing techniques, as well as a registered dietitian who can assess hydration needs and provide appropriate recommendations for fluid sources.


Nutrient needs. Patients also need to be well educated with regard to the need for food sources of fiber, both soluble and insoluble. Some individuals experience abnormal blood glucose levels, possibly due to medications, and soluble fiber can help to control this. Insoluble fiber is needed to combat constipation. Sources of calcium and vitamin D are important areas of discussion, too. Few older adults are aware that the recommended amounts of both nutrients have changed recently, and many people do not meet the current RDA levels. PD patients can have difficulty with these two nutrients, because milk, which is one of the most common sources of both calcium and vitamin D, is also high in protein, and can interfere with the absorption of levodopa.


Parkinson’s disease is highly individualized, presenting a distinct array of conditions for each patient. This may require extra care and attention on the part of the health care professional. As an example, protein redistribution may need to be carefully calculated for people who have elevated triglycerides or diabetes, and may not be possible at all for those with chronic obstructive pulmonary disease. For most patients, however, properly individualized meal planning provides for maximum levodopa utilization, and in some cases, may even allow for a reduction in the amount of levodopa used, with resulting reduction in adverse side effects. It is important to work closely with patients and physicians to achieve optimal results for each patient.

Health professionals working in gerontological care need to be well-informed about the nature of Parkinson’s disease, and the highly specialized nutrition needs of patients with PD. For example, timing of medications is crucial in hospitals and long-term-care institutions, as well as in home health care. Without antiparkinson medications, patients are unable to achieve the mobility they need in order to perform other functions, and risk for pressure ulcers, dehydration, and pneumonia is greatly increased. Meal timing is equally important, as the levodopa may not be absorbed if taken with protein foods. Delayed gastric emptying can affect protein-levodopa interactions, as well. Understanding of the need for protein redistribution diets is important.


Medical nutrition therapy is crucial for this population group and should begin as soon as possible following diagnosis of PD. Early intervention to educate patients and/or caregivers regarding need for an energy- and nutrient-dense diet, suitable sources of calcium and vitamin D, adequate hydration, and control of constipation, is of the utmost importance. Education of this type may aid in maintaining bone density and muscle mass, help prevent weight loss, dehydration, and fecal impaction, and assist in prevention of dental caries related to dry mouth.

Upon diagnosis of PD, patients should be referred to a registered dietitian for counseling. Further, as the patient’s abilities and needs change throughout the stages of this disease, dietitians should be part of the health care team, working to maintain adequate nutrition, checking for unplanned weight loss, and designing individualized nutrient-dense meals and snacks. Patients should be advised of the need for interaction with their dentists regarding dry mouth and need for oral hygiene. Neurologists, dentists, hospitals, home health and long-term-care agencies should be aware of the high risk for malnutrition and the many costs it brings to the patient and the health care system, as well as the ability of trained dietitians to provide the highly specialized medical nutrition therapy necessary to meet the challenges of patients with PD.

No comments:

Post a Comment