Questions and Answers
Two days ago my 64 year-old mother died. She has had Parkinson's for about 5 years but it seemed to advance quickly with her. My dad also has Parkinson's (about 12 years) but the progression is so slow that he maintains a fairly normal life.
Last Wednesday (8/26) my mom was admitted to the hospital for dehydration. She had experienced diarrhea and vomiting for two days. While in the hospital, she was mistakenly given 3 times her normal dosage of Sinemet (1.5 pills three times daily instead of 0.5 pills three times daily). In addition, even though she was admitted for dehydration, she was only given 2 liters of I-V fluids. By Friday evening, she had to be rushed to the emergency room of a "more significant" hospital. Once there, she took 8 liters of I-V fluids and seemed to be improving. On Saturday morning, she was given her usual dosage of Sinemet, Eldepryl, and Requip with her breakfast around 8:00a.m. She ate well and for two hours were very encouraged with her progress. At about 10:00a.m. she began showing signs of dyskinesia. Within 10-15 minutes, it was so severe that doctors were alerted to a drastic reduction in her oxygen absorption. They immediately recommended that she be put on a ventilator. Although stabilized several times over the next few days, she eventually died.
We really don't know the exact reason that she died. Have you any thoughts as to why or what might have brought this on? Is it possible that the Sinemet overdose could be lethal? I'm confused with all of this and am hoping that you will be able to shed at least some light as to what might have happened.
Hi Norman ... very sorry to hear of your loss.
I can only comment on the pharmacology.
Sinemet is a combination of two drugs, carbidopa and levodopa. The preparation comes in several strengths, 10/100, 25/100 and 25/250 (all in milligrams). The usual treatment schedule is one tablet, of whatever strength has been found necessary, thrice daily. Your mother's regular dose of half a tablet three times daily is quite small. Perhaps initial therapy started higher (you'd have to check her medical records) and had to be reduced because of side-effects. There is some evidence of this in her use of the two other antiparkinson agents as adjuncts.
In contrast to your mother's low dosage is the requirement of some patients for up to a maximum of eight tablets daily. Even her tripled dosage is about half way along the range.
One effect, the on/off effect, may have come into play. This may occur after long treatment when near normal activity may rapidly convert to a severe degree of parkinson for from 30 minutes to 3 or 4 hours. Such episodes may occur once a day or 10 or more times daily during waking hours.
A recognised side-effect of Sinemet is dyskinesias - when it does occur in an otherwise uneventful course of therapy, it is usually a sign that dosage should be reduced. Other events in overdosage include cardiac arrythmias which are carefully monitored for and appropriately treated should they occur.
Complicating all of this, as if it weren't complex enough, is your mother's state of hydration. The drug compartmentalizes among the various compartments of the body - its effective concentration (for both desired and undesirable effects) depending to a large extent on the amount of water in the body.
Sorry, not a satisfactory answer, but the best I can offer.
Best wishes.