More fun with pesticides: Here's some info on the infamous Paraquat and Diquat, pesticides/herbicides, which can cause the symptoms outlined below, and which are also chemically similar to our other favorite chemical, MPP+ (the derivative of MPTP, which caused pd in a number of young people who were trying to home-brew some heroin-like drug, MTPP, and screwed up the process and ended up with toxic MPTP). Wendy T ******************** Subj: twitching - paraquat & diquat Date: 95-06-29 17:43:56 EDT From: [log in to unmask] (Tebay, Wendy) To: [log in to unmask] (athome) --PART.BOUNDARY.claven.2fdd.2ff31d8c.0001 Content-Type: text/plain; charset=us-ascii Commercial Products Paraquat and diquat are identified chemically as DIPYRIDYLS. Paraquat is a synthetic nonselective contact herbicide, usually marketed as the dichloride salt. Dimethyl sulfate salts are also produced. Liquid technical products range from 20% to 50% concentration. Names of liquid concentrates are: Ortho Paraquat CL, Ortho Paraquat Plus, Cekuquat, Crisquat, Herbaxon, Herboxone, Dextrone, Esgram, Gramocil, Gramoxone, Goldquat 276, Sweep, Osaquat Super, Gramonol, Toxer Total, Pillarxone, Pillarquat. Paraquat is commonly formulated in combination with other herbicides: With diquat: Actor, Preeglone, Preglone, Priglone, Weedol (a 2.5% soluble granule formulation). With monolinuron: Gramonol With diuron: Gramuron, Paracol, Totacol, Dexuron With simazine: Terraklene, Pathclear Diquat is usually prepared as the dibromide monohydrate salt, 20% to 25% in liquid concentrates. Deiquat and reglon alternative common names. Commercial products are: Ortho Diquat, Aquacide, Dextrone, Reglone, Reglox, Weedtrine-D. Combinations with paraquat are listed above. Diquat is still used as a water herbicide, but it is now applied as a dessicant and terrestrial herbicide as well. --PART.BOUNDARY.claven.2fdd.2ff31d8c.0001 Content-Type: text/plain; charset=us-ascii Diquat Diquat is somewhat less damaging to skin than paraquat, but irritant effects may appear following dermal contamination with the concentrate. There is probably significant absorption of diquat across abraded or ulcerated skin. Systemically absorbed diquat is not selectively concentrated in lung tissue, as is paraquat, and pulmonary injury by diquat is less prominent. However, diquat has severe toxic effects on the central nervous system that are not typical of paraquat poisoning although brain injury has been observed postmortem in some fatal paraquat poisonings. Renal damage is an important feature of poisonings by both agents. The kidney is the principal excretory pathway for diquat absorbed into the body. Early symptoms of poisoning by ingested diquat are similar to those from paraquat, reflecting its corrosive effect on tissues: burning pain in the mouth, throat, chest, and abdomen. Intense nausea, vomiting, and diarrhea are characteristic. If the dosage was small, these symptoms maybe delayed 1-2 days. Blood may appear in the vomitus and feces. Intestinal ileus, with pooling of fluid in the gut, has characterized several human poisonings by diquat. Dehydration, hypotension, and tachycardia may result and shock is a common cause of death. Agitation, restlessness, disorientation, and psychotic behavior have been early manifestations of some diquat poisonings. Tonic-clonic seizures and coma may supervene. Proteinuria, hematuria, and pyuria may progress to renal failure and azotemia. Elevations of serum alkaline phosphatase, AST, ALT, and LDH reflect liver injury. Jaundice may develop. If the patient survives several hours or days, circulatory function may fail due to toxic myocardiopathy, or broncho-pneumonia may develop. Over the past decade, the great majority of poisonings by paraquat and diquat have been caused by ingestion - with suicidal intent in most cases. Nearly all of the few poisonings caused by occupational exposure have been survived, but the mortality rate among persons who have swallowed paraquat or diquat remains distressingly high (60%). Avoidance of this mortality will probably have to rely on preventive strategies or on stopping gastrointestinal absorption very soon after the toxicant has been ingested. Even though intestinal absorption of dipyridyls is relatively slow, lethal uptake by critical organs and tissues apparently occurs within 18 hours, possibly within 6 hours, following ingestion of toxic quantities of paraquat and diquat. Dipyridyls have large volumes of distribution. Once distribution to tissues has occurred, measures to remove dipyridyls from the blood are very inefficient in reducing the total body burden. --PART.BOUNDARY.claven.2fdd.2ff31d8c.0001 Content-Type: text/plain; charset=us-ascii Paraquat Particularly in concentrated form, paraquat causes injury to tissues with which it comes into contact. It leaves the skin of the hands dry and fissured, sometimes resulting in loss of fingernails. Prolonged contact with skin may cause blistering and ulceration, with subsequent absorption of paraquat in sufficient dosage to cause systemic poisoning. Prolonged inhalation of spray droplets may cause nosebleed. Eye contamination results in severe conjunctivitis and sometimes protracted and even permanent corneal opacification. When ingested in adequate dosage (see below), paraquat has life-threatening effects on the gastrointestinal tract, kidney, liver, heart, and other organs. The first phase of systemic poisoning consists of swelling, edema, and ulceration of the mucosal linings of the mouth, pharynx, esophagus, stomach, and intestine. Centrizonal hepatocellular injury along with damage to the proximal renal tubules, myocardium, and skeletal muscle (sometimes including focal necrosis) are the main features of the second phase. The nervous system and pancreas are affected in some cases. The third phase - injury to the lung - usually becomes evident 2-14 days following ingestion, although, in some cases, pulmonary edema has developed only a few hours after paraquat has been swallowed. Paraquat is selectively concentrated in lung tissue where it destroys lung parenchymal cells probably by generation of free-radical oxygen and subsequent lipid peroxidation. Hemorrhage, edema fluid, and leukocytes infiltrate the alveolar spaces, after which there is rapid proliferation of fibroblasts. Severe impairment of gas exchange causes death from anoxemia and tissue anoxia. Remarkably, essentially full recovery of pulmonary function occurs following paraquat poisonings which are survived. Although absorption across intact skin is slow, abraded or eroded skin allows efficient absorption. Fatal poisonings are reported to have occurred as a result of protracted dermal contamination by paraquat. The effect of paraquat on renal tubule cells is more likely to be reversible than the effect on lung tissue, but impaired renal function may play a critical role in determining the outcome of paraquat poisoning. Normal tubule cells actively secrete paraquat into the urine, clearing it efficiently from the blood. However, high blood concentrations poison the secretory mechanism and may destroy the cells. Because the kidney is almost the exclusive route of paraquat elimination from body tissues, renal failure fosters a buildup of tissue concentrations, including those in the lung. Unfortunately, this pathogenetic sequence may occur in the first several hours following paraquat ingestion, generating lethal concentrations of paraquat in lung tissue before therapeutic measures to limit absorption and enhance disposition have taken effect. It is probably for this reason that methods for enhancing paraquat disposition several hours following ingestion have had little influence on mortality. The hepatic injury from paraquat may be severe enough to cause jaundice, but hepatotoxicity is rarely a major determinant of clinical outcome. Elevated alkaline phosphatase, AST, ALT, and LDH are indications of hepatocellular insult; jaundice signifies more severe injury. Early symptoms and signs of poisoning by ingested paraquat are burning in the mouth, throat, chest, and upper abdomen, due to the corrosive effect of paraquat on the mucosal lining. Giddiness, headache, fever, myalgia, and diarrhea (sometimes bloody) occur. Pancreatitis may cause severe abdominal pain. Proteinuria, hematuria, pyuria, and azotemia reflect renal injury. Oliguria/anuria indicate acute tubular necrosis. Progressive decline in arterial oxygen tension and CO diffusion capacity commonly precede pulmonary symptomatology. Cough, dyspnea, and tachypnea usually appear 2-4 days following paraquat ingestion, but may be delayed as long as 14 days. Progressive cyanosis and air hunger reflect deteriorating gas exchange in the damaged lung. Coma usually precedes death. In some cases, the coughing up of frothy sputum (pulmonary edema) is the early and principal manifestation of paraquat lung injury. Clinical experience has offered a rough dose-effect scale on which to base prognosis in cases of paraquat ingestion (J.A. Vale, et al., Human Toxicology, 6:41-47, 1987): I. Less than 20 mg paraquat ion per kg body weight (less than 7.5 ml of 20% (w/v) paraquat concentrate). No symptoms, or only gastrointestinal symptoms occur. Recovery is likely. II. Twenty to 40 mg paraquat ion per kg body weight (7.5-15.0 ml of 20% (w/v) paraquat concentrate). Gastrointestinal, renal, hepatic and pulmonary damage by paraquat occurs. Pulmonary fibroplasia ensues. Death occurs in most cases, but may be delayed 2-3 weeks. III. More than 40 mg paraquat ion per kg body weight (more than 15.0 ml of 20% (w/v) paraquat concentrate). Multiple organ damage occurs as in class II, but is more rapidly progressive. Often characterized by marked ulceration of the oropharynx. Mortality is essentially 100% in 1-7 days. Although much concern has been expressed about the effects of smoking paraquat-contaminated marijuana, toxic effects by this mechanism have been either rare or nonexistent. Most paraquat that contaminates marijuana is pyrolyzed during smoking to dipyridyl. Dipyridyl is a product of combustion of leaf material itself (including marijuana) and presents little toxic hazard. It is tragic that use of paraquat as a suicidal agent has increased in recent years, particularly in Japan and also in developing countries. Several strategies are being tested to reduce the frequency of these occurrences: addition of emetics, stenching agents, gelling substances. --PART.BOUNDARY.claven.2fdd.2ff31d8c.0001 Content-Type: text/plain; charset=us-ascii Paraquat and Diquat ------------------------------------------------------------------------ Donald P. Morgan, M.D., Ph.D. Commercial Products Toxicology and Manifestations of Poisoning Confirmation of Absorption Treatment of EXTERNAL Poisoning Treatment of Poisoning by INGESTION