DMPS In Metal Chelation

DMPS was developed in the former Soviet Union in
1958. It became available to the Western world in 1978 and is since
synthesized and produced by the German pharmaceutical company
Heyl, Berlin...


DMPS Bioavailability
The metabolism of DMPS, being hydrophilic in nature, has been thoroughly studied. DMPS undergoes both renal and biliary excretion and is excreted largely through the urine. DMPS is distributed in both an intracellular and extracellular manner. DMPS does not cross the blood brain barrier and does not re-distribute arsenic, lead or inorganic mercury to the brain [2][3][4]. Adverse reactions are known but are relatively rare. About 90% of DMPS is eliminated via the kidneys. After 24h about 80% of the dose received has been excreted. DMPS does not accumulate in tissue even after repeated use. Since the kidneys are the main organs of excretion for DMPS and its complexes, patients with a limited kidney function should not be chelated with this antidote if serum creatinine values exceed 2.5mg/dl. Animal studies on the acute and chronic toxicity of DMPS have been carried out and results illustrate the safety of this agent and its wide therapeutic window. DMPS is not mutagenic and seems to have no teratogenic effects. It is not carcinogenic.
(intravenous or intramuscular). Heyl does not recommend that DMPS is used in combination with other chelating agents.

Side Effects
Numerous human studies have failed to uncover any significant adverse impacts of DMPS upon human renal function. Minor effects such as local irritation at the site of parenteral infusion or hypotension with overly rapid infusion of the agent have been reported [7]. Adverse reactions during treatment with DMPS include gastrointestinal discomfort, skin reactions, mild neutropenia and elevated liver enzymes. Some patients, especially those with allergic asthma symptoms, may develop hypersensitivity to DMPS. If this occurs, DMPS treatment must be discontinued [8]. Does DMPS treatment affect existing amalgam fillings or be contraindicated in a patient with amalgam fillings? Dr. J. Ruprecht, previous research scientist at Heyl, Berlin stated that this is 'highly unlikely. DMPS does not come in contact with fillings and even if it would, the level found in blood would not be sufficient to affect the amalgam'. DMPS may be given to patients with fillings.

Oral VS Intravenous Use
The bioavailability of oral DMPS is about 50%. Table 1 indicates that oral administration of arsenic (As) binding exceeds the estimated 50%. For mercury (Hg) and lead (Pb), the 50% estimate seems right.

The peak excretion time of DMPS is between 1-2 hours
after the injection has been completed. During that time, the patient should wait in the office and drink at most 300ml water.
If possible, the patient should hold off urination for maximal 2 hours, after which some urine is taken into a normal urine cup.

Paravenous infiltration of DMPS is harmless but creates
discomfort and an itching sensation at the injection site for half an hour approximately.

9.
Occasionally, side effects are observed such as allergic reactions, and skin rashes.
10. If DMPS is injected or infused too quickly, blood pressure may drop. Observe patient.

DMPS easily binds with zinc. Skin problems can develop if
the patient is borderline zinc deficient before treatment start. 14. If the patient's zinc status indicates a need for supplementation, zinc and vitamin B6 should be given daily for one to two weeks prior to treatment. Stop supplementation at least 24hrs before the DMPS treatment and resume 24hrs later.

Material for Urine Metal Testing
Baseline Urine: This urine shows the metal excretion before chelation and is used to rule out immediate exposure through food, water, medication etc.
Acute Toxicity: 24hr urine collection is recommended. Of that the laboratory needs 5-7ml . The total volume of the 24hr urine collection must be recorded and provided to the laboratory. ask the patient to lie down [12]. If this does not alleviate the problem, discontinue the treatment.

1.
Check and write down blood pressure.

DMPS-Protocol for Oral Use
The Challenge or Provocation Test