Molecular structure of cimetidine
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Tagamet

Cimetidine is a histamine H2-receptor antagonist that inhibits the production of acid in the stomach. It is largely used in the treatment of heartburn and peptic ulcers. It is marketed by GlaxoSmithKline under the trade name Tagamet®, and was approved by the Food & Drug Administration for prescriptions starting January 1, 1979. more...

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Clinical Use

History and development

Cimetidine was the prototypical histamine H2-receptor antagonist from which the later members of the class were developed. Cimetidine was the culmination of a project at Smith, Kline & French (SK&F; now GlaxoSmithKline) to develop a histamine receptor antagonist to suppress stomach acid secretion.

At the time (1964) it was known that histamine was able to stimulate the secretion of stomach acid, but also that traditional antihistamines had no effect on acid production. In the process, the SK&F scientists also proved the existence of histamine H2-receptors.

The SK&F team used a rational drug-design structure starting from the structure of histamine - the only design lead, since nothing was known of the then hypothetical H2-receptor. Hundreds of modified compounds were synthesised in an effort to develop a model of the receptor. The first breakthrough was Nα-guanylhistamine, a partial H2-receptor antagonist. From this lead the receptor model was further refined and eventually led to the development of burimamide - the first H2-receptor antagonist. Burimamide, a specific competitive antagonist at the H2-receptor 100-times more potent than Nα-guanylhistamine, proved the existence of the H2-receptor.

Burimamide was still insufficiently potent for oral administration and further modification of the structure, based on modifying the pKa of the compound, lead to the development of metiamide. Metiamide was an effective agent, however it was associated with unacceptable nephrotoxicity and agranulocytosis. It was proposed that the toxicity arose from the thiourea group, and similar guanidine-analogues were investigated until the ultimate discovery of cimetidine.

Shortcomings

Cimetidine is a known inhibitor of many isozymes of the cytochrome P450 enzyme system (specifically CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4). This inhibition forms the basis of the numerous drug interactions that occur between cimetidine and other drugs. For example, cimetidine may decrease metabolism of some drugs, such as oral contraceptives.

Adverse drug reactions were also found to be relatively common with cimetidine.

The development of longer-acting H2-receptor antagonists with reduced adverse effects such as ranitidine proved to be the downfall of cimetidine and, whilst it is still used, it is no longer amongst the more widely used H2-receptor antagonists.

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Did this doctor cure his AIDS? When a doctor believes he was sick with AIDS or ARC and credits lysine, Tagamet and acyclovir for arresting it, we listened
From Saturday Evening Post, 10/1/86 by Cory SerVaas

DID THIS DOCTOR CURE HIS AIDS?

Truth being stranger than fiction, almost every day becomes more exciting than a soap opera in my office here at the SatEvePost Society. But for sheer excitement, this particular telephone conversation topped everything. The friendly, familiar voice of the doctor, with whom I had been tracking an AIDS related complex patient for many months--several years, really--was not telling me that he was indeed the patient. I was shocked, because Dr. "X' had always referred to the patient in the third person. Now he was him.

"But are you homosexual?' I asked.

"Well, bisexual,' he responded. "I have children.'

I knew that this compassionate-sounding doctor, whom I had never met, wanted the world to hear about the "cure' that had blessed him. His story is of such profound significance that I feel compelled to disseminate the information to our readers.

The story began several years ago when I heard via the medical grapevine that there was a doctor who had treated and AIDS related complex victim --who had been antibody positive for AIDS virus--and that this patient had fully recovered. He had become, in fact, a new man after taking lysine. When I tracked down the doctor, which was no easy feat, he gave me the story of how his "patient' was on very large doses of lysine. In subsequent conversations he had told me about adding acyclovir and Tagamet to the regimen.

"From a man who "looked like death warmed over,' this man was now lifting weights,' he told me. His telltale T-cell ratio had improved dramatically. His swollen lymph nodes were back to normal. His IGg had dropped from 2100 to 1800 and had been maintained there for about a year now, he said. His serum albumin rose from hypoalbuminemia to a normal level. His lymphocytes were fine. His immunity had come back. In fact, he recently had a hyperimmune reaction to monilia (a yeast infection), the doctor said.

Dr. "X' told me it had all started in 1981 with swollen lymph glands. Then in December of '83 he had a mononucleosis--type of episode, with a blistering rash and a sudden increase in swollen lymph glands. In November of '84 he had a positive HTLV III (AIDS virus) antibody test, and that's when he started the lysine.

"How much had he been taking?' I asked. (This was, of course, when the "patient' was still in the third person.)

"Oh, we've had him up to 15 grams when some of these things flared up.'

"Did you keep him off arginine?' I asked.

"We did tell him to avoid peanuts and chocolate and Jell-O,' the doctor replied. "But you know, being single and getting a lot of prepared food, I'm sure he got things that were high in arginine. I think this may be one of the problems we have all along in proving the effectiveness of lysine. There's probably arginine in many things that people eat and don't even know about. But we're pretty sure that his herpes infections were improved on the lysine.'

"Do herpes and AIDS go together pretty much?'

"Oh, very definitely. Herpes is a forerunner of it. I've got a boy with hemophilia who is also lymphopenic (too few white blood cells called lymphocytes) and leukopenic (too few white blood cells called leukocytes) and he presented with herpes zoster. Now he's at "X' hospital, and he's never had an HTLV III run, but I'm pretty sure he's immunocompromised and has AIDS. He is at the age that he probably did get the contaminated factor VIII through an I.V. transfusion. They've never checked him there. They don't see any need to do that.

"They think it'll create hysteria. Until they see definite symptoms, they don't see any need to do that.'

"But is he sexually active?' I asked.

"Oh, no,' he assured me, "he's only 12 years old.'

"But once he's sexually active,' I suggested, "it would be very important for a patient to know he's contagious. He could be a carrier.'

"Carriers can be two things,' the doctor said. "They can have the virus and not be AIDS positive, and they can be both. And some people with HTLV III positive titers go through periods of shedding the virus and not shedding the virus, just like herpes. They probably just go into quieter stages.'

"Do you see a close relationship between the herpes virus and the AIDS virus?' I asked.

"I definitely think they are very closely related. There is no question about that. I have here an article, "Defective Regulation of the Epstein-Barr (herpes) Virus Infection in Patients with Acquired Immune Deficiency Syndrome.' (The EB virus belongs to the herpes family of viruses and is also the cause of infectious mononucleosis. It is also believed to cause Burkitt's lymphoma.) Non-Hodgkins lymphomas in homosexual men may be related to errors in regulation of the Epstein-Barr (EB) virus because of defective T-calls. The EB virus and all the herpes viruses are immunosuppressors themselves. They may all go together like twiddle dee dee and twiddle dee dum. There was a report released from Los Angeles that in a lot of gays, one of the initial presentations was herpes encephalitis. When you get a young 25-, 26-, or 27-year-old man who presents with some signs of encephalitis and, if you think it is herpes encephalitis, you definitely have to assume he has AIDS until proven otherwise.

"Oh, yes,' he continued, "there is a very close relationship. In fact, prophylaxis against the herpes virus may be reducing one of the factors that causes the progression with the person who is infected with HTLV III on to AIDS.'

"How did you happen to have this patient?'

"Well, you see, in 1970 I was in cancer research, and I had one of the highest number of pneumocystis pneumonia patients in the world. I was one of the few people in this area who had much experience with pneumocystis when this stuff (AIDS) started breaking out, and basically I just slipped into it because I had been asked by an internist to consult on a patient. When I was asked to present ideas on treatment, I said, "Well, there are only a few things that we've got. We've got lysine.' I have read about lysine, and I also know that topical zinc has helped. I know that zinc is an immune stimulator. I know that there has been some suggestion about the increase in immunity with Tagamet. Of course, at the time acyclovir was still experimental. Everything seemed to fall in place at just about the time we got ready to treat this guy-- acyclovir came on the market in oral form. Just about then the detail man walked in with a couple boxes of acyclovir. All sort of coincidental.'

Might supplemental lysine and a low-arginine diet help prevent AIDS-antibody-positive individuals from converting to full-blown AIDS? When an AIDS-positive individual starts to show signs of AIDS related complex, might the regimen tried by our Dr. "X' prevent progression or reverse those symptoms?

We promised to maintain the Dr. "X' anonymity, but we could relay to any callers the regimen that he used. He is convicted that it worked for him. For further information call 317-636-8881, Extension 259.

Physicians or persons who are HTLV III (AIDS virus) antibody-positive who might like to receive our previous Saturday Evening Post articles about the herpes virus and lysine are invited to write to the Saturday Evening Post Society, Dept. A, 1100 Waterway Blvd., Indianapolis, IN 46202.

An interesting piece in the AIDS/ herpes puzzle is that a herpes zoster infection (shingles) in a seemingly healthy homosexual man under age 50 may be on occasion a harbinger of AIDS. This statement came from Dr. Alvin Friedman-Kien of the New York University Medical Center at the annual meeting of the Society for Investigative Dermatology.

He reported that of 48 patients with localized herpes zoster infections and no known immunodeficiencies or signs of AIDS or AIDS related complex, 35 had antibodies to HTLV III and 41 had risk factors for AIDS.

Herpes zoster infections as an early clinical sign of impending AIDS were studied after it was discovered that the rate of herpes zoster infection was seven times higher in pre-AIDS patients than in that of control subjects of the same age.

An AIDS-antibody-positive person with risk factors for AIDS might be willing to try the lysine therapy which has, for Dr. Richard Griffith, helped in treatment of early herpes zoster.

If the Post weren't edited in Indianapolis we probably would never have come upon the lysine story. It is a story as fascinating, we believe, as the story of vitamin C and scurvy, and it has as much worldwide significance. The story involves the kids who die with immune deficiencies from kwashiorkor in Ethiopia. It also involves poverty's children who don't die in Central and South America because of high-lysine corn.

It is as global as the saga of vitamin C saving the lives of the "limeys' who are citrus fruit while at sea and the North American Indians who survived with vitamin C from evergreen trees.

Lysine has been an interest to our researchers at the Post because men in our state with the highest credentials use it successfully.

Dr. Richard Griffith found it works about 90 percent of the time for his herpes patients. He also uses it for herpes zoster (shingles) patients. "Even antibiotics don't work all the time--they're about 85 percent effective,' Dr. Griffith says.

But to begin the story, we have to start with a young Californian, Chris Kagan, who came to Indianapolis to seek research funding from Eli Lilly and Company, because he had studied lysine and its activity in preventing the growth of the herpes virus. Dr. Kagan, a radiologist, had an opportunity to put his theory to test one day when a hapless herpes patient came in with fever blisters (herpes simplex I) that had spread around his entire mouth. The seeping, bloody crevices were so painful that the poor man could hardly swallow the barium solution he had been asked to take. With compassion, Dr. Kagan asked him to take lysine for a week and report back. When he returned, his mouth was entirely healed.

After several more successful experiments with lysine for herpes of the mouth, Dr. Kagan was encouraged to persuade some clinical researchers to work on his theory. In the petri dish, the herpes virus would not grow. However, the herpes virus would multiply rapidly when fed a sister amino acid that has almost a mirror image configuration to L-lysine. The amino acid that the herpes virus happens to thrive on is called arginine. If lysine, being so similar, could keep the virus from finding enough arginine to survive, why then couldn't more lysine and less arginine stop the herpes virus in the human body--right in its tracks?

Dr. Richard Griffith, now professor of medicine at the Indiana University School of Medicine, was then a researcher at Eli Lilly's. He liked the large volume of research work that Chris Kagan had brought him concerning the behavior of herpes virus in the laboratory. He brought not just one paper by Dr. Robert Tankersley, a first, but about 40 other scientific papers that had replicated and verified the original work.

Dr. Griffith, who worked on the Lilly Research Unit at what is now Wishard Hospital, of Indiana University School of Medicine, and Dr. Kagan persuaded Dr. Arthur Norins, professor of dermatology, to try lysine on his herpes patients. It worked.

Dr. Griffith taught his residents in the dermatology department to use it in their practices. Dr. Fred Hibbeln, an Indianapolis dermatologist, is having success using it. One of his patients was a microbiologist at Eli Lilly and Company. She wanted to prove to him that lysine would work. She knew she could induce a case of faver blisters if she ate chocolate-covered peanuts. But this time she took lysine first, and when she challenged herself with the chocolate-coated peanuts, no fever blisters appeared. When she tried it without lysine, the blisters returned. Dr. Hibbeln prescribes 1000 mg of lysine three times a day for his herpes patients. He now also includes acyclovir with the supplemental lysine.

From there the story moves to the University of Notre Dame, where Dr. Bernard Vagner was having success giving lysine to his mononucleosis (another herpes family illness) patients. To his delight, he was able to keep them in classes. "It is so very important to keep these young people in their classes when they are competing for professional schools in a very competitive institution like Notre Dame,' he said. Even to keep them from having to go to bed between classes was a major change from the usual treatment for mononucleosis.

Now our story jumps to Purdue University, where Dr. Edwin Mertz was persevering with his high-lysine corn and had managed to get Central and South American farmers using it to prevent kwashiorkor in children. For them, high-lysine corn meant the difference between life and death. He had a slight commercial problem at first--the corn didn't weigh quite as much as regular hybrid corn. However, as one farmer pointed out, "The corn may not weigh as much per bushel, but my children weigh more.' Our regular readers know that Dr. Norman Borlaug, who won the Nobel Prize for bringing India out of starvation with his short-stemmed wheat, is now with the Rockefeller Foundation and evangelizing to get South American farmers to grow Dr. Mertz' high-lysine corn.

Dr. Mertz hadn't known about Indiana University's work with lysine and herpes. The Society remedied this breakdown in communications and held a lysine symposium in conjunction with Indiana University. Many disciples of Dr. Mertz, the Indiana contingent, and many others from around the country came to report their findings.

Dr. Rosemary Newman and her husband, Dr. Walter Newman, at Montana State University, have developed high-lysine, hulless barley; other grains; and even a bacteria to manufacture lysine in yeast for making high-lysine baladi bread for Egyptians.

We wanted to know: How could we help the kwashiorkor children in Ethiopia by bringing high-lysine corn there? They do not die from kwashiorkor, but they die from measles, mumps, or whatever comes along, because they have no immune mechanism left. In the same way, AIDS patients die from anything that comes along, because their immune mechanisms are destroyed. The kwashiorkor kids also die from a cancer similar to the Kaposi's sarcoma, if they don't die from measles first. Many die from pneumonia, and others from cholera, because like AIDS victims, they have no way to fight it.

At home, the most intriguing and haunting question remains for us to research: Would changing an AIDS-antibody-positive patient to a lysine-supplemented, low-arginine diet have an effect on the AIDS virus?

We hope doctors and patients who would like to read our previous articles on lysine as an anti-viral substance will write for copies. Please address:

Lysine Request SatEvePost Society 1100 Waterway Blvd. Indianapolis, IN 46202

Photo: Dr. "X' could hardly take care of his patients. After work he'd fall into bed, exhausted. His antibody test for AIDS was positive and symptoms were appearing.

Photo: From looking like "death warmed over,' our Dr. "X' is now running and lifting weights. The AIDS symptoms have disappeared after his regimen of lysine, Tagamet, and acyclovir.

Photo: Professor Richard Griffith's work at Indiana University has shown lysine to be effective about 90 percent of the time in treating his herpes patients.

Photo: When herpes hampered an X-ray examination, and lysine provided prompt relief, Dr. Chris Kagan brought his theory to Dr. Arthur Norins (opposite), dermatology professor at Indiana University.

Photo: Dr. Edwin Mertz discovered the genetic mutation that made high-lysine corn possible. Then he helped make it a commercially viable product.

Photo: Dr. Frederick Hibbeln has been using lysine for herpes infections for about eleven years. He gives 1000 mg three times a day. Now that acyclovir (Zovirax) is available he uses it in conjunction with lysine.

COPYRIGHT 1986 Saturday Evening Post Society
COPYRIGHT 2004 Gale Group

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