Stomach acid and Sinemet

[reverett123]

Going through the closet and found this abstract.


1: Rinsho Shinkeigaku. 1994 Mar;34(3):264-6.

[Gastric acid secretion and absorption of levodopa in patients with Parkinson's
disease--the effect of supplement therapy to gastric acid]

[Article in Japanese]

Yazawa I, Terao Y, Sai I, Hashimoto K, Sakuta M.

Department of Neurology, Japanese Red Cross Medical Center.

Since an oral regimen of levodopa has been instituted for treatment of
Parkinson's disease, its absorption and metabolism has been well demonstrated.
However, its chemical characteristics of high solubility in acid solution and low
solubility in water have not been well known. We paid attention to this
characteristic and studied the relationship between its absorption and gastric
acid secretion in 38 patients with Parkinson's disease who became refractory to
therapy of levodopa. We measured the pH and amount of collected fasting gastric
juice. Gastric acid secretion was decreased in 22 patients (58%). In ten of these
22 patients, 30 ml of lemon juice was prescribed in every administration of
levodopa as a supplement to gastric acid for two weeks. Increases of L-dopa
concentration after 60 min. and 180 min. were observed after lemon juice
supplement therapy. Among the Parkinson symptoms, rigidity, akinesia, and small
step gait were improved in every case except one patient who showed decrease of
L-dopa concentration at 180 minutes. However, improvement of tremor was less
remarkable. We consider this supplement therapy to gastric acid is one of the
effective and useful methods in the management of Parkinson's disease.


PMID: 8200147 [PubMed - indexed for MEDLINE]

[RLSmi]

This observation would seem to be most applicable to regular, non-controlled release L-dopa preparations which are apparently dissolved and absorbed more readily in the low pH environment of the stomach. It would appear that most of a slow-release preparation would pass into the more alkaline duodenum and jejunum of the small intestine while releasing the medication. The lower solubility of L-dopa at that higher pH may be part of the "controlled release" phenomenon.

Taking a little lemon juice (or vinegar) along with regular carbidopa/levodopa, especially on an empty stomach, would appear to be a good way to a fast "on". Also, avoiding taking antacids around meds time would certainly be smart.

Robert

[Ibken]

especially as i've been thinking about digestive enzymes effect on meds - and wondering if any white rats have sniffed this one out? :rolleyes:

ibby

[reverett123]

Since a sizable number of the patients had low stomach acid and the assumption is that that is representative, what other nutrients depend upon stomach acid for proper absorption?

[RLSmi]

The classic deficiency of vitamin B12 (cobalamin) absorption called pernicious anemia is often seen in elderly persons resulting from loss of acid-secreting cells of the stomach which also secrete a protein called "intrinsic factor". Intrinsic factor is required for the efficient intestinal absorption of cobalamin. Injection of B12 effectively circumvents the deficiency. The same problem is encountered by persons who have partial or total removal of their stomach, for instance to treat stomach cancer or to bypass the stomach for weight loss.

Robert

[jim3416]

B12 deficiency due to loss of intrinsic factor can also be autoimmune - I forget whether the autoimmunity is against only the protein, or the cells themselves though.

The fraction of B12 converted into methyl-cobalamin, which I've read is the main or perhaps form used by the brain, may also be insufficient for optimal brain function, given all the heavy metals we accumulate in a lifetime, stress weakening the HPA axis, loss of a regular light/dark cycle affecting the SCN, pineal, pituitary, and other things.