THE FOLLOWING ARTICLE APPEARED IN THE

AUGUST 1999 ISSUE

THE POISON SLEUTHS

DEATH BY DIGITALIS

-Dr. Anil Aggrawal

"Good morning doctor. Oh, my God, what are you doing today? You have the dead body of a young man today. What happened to him? Please tell me."

"Good morning Tarun. The name of this young man is Surendra, and he died early this morning in the hospital. He was a business partner of Lokesh. They were in the business of assembling computers and distributing them to the customers. Lokesh has done an assorted medley of jobs before coming to this business, not the least significant of which was his brief stint as a pharmacist. He in fact is a qualified pharmacist and had tried his hand at that job in the beginning. But when he couldn't succeed in that job, he changed to other professions, changing them frequently, until finally he settled in the business of computers about a year back. It is said that his company Goodwin Computers Ltd was doing a business of several lakhs."

"Do all these facts have a bearing on Surendra's death?"

"I am coming to that. Lately Goodwin Computers Ltd was running in a loss. Surendra found out that Lokesh was illegally siphoning off a major chunk of money to his own personal company Lokesh Computers Ltd, which he had floated simultaneously only about a couple of months back. Surendra realized that very soon, he would siphon off all the money from their joint company to his own personal company. So he was clamouring for a dissolution of their joint company and to give him his due share. It is estimated that Goodwin Computers Ltd was worth about 50 to 60 Lakhs, so obviously Surendra's share was about 30 Lakhs. Lokesh always denied that he was illegally siphoning off money as alleged by Surendra. Ultimately to sign the deal, Lokesh agreed to come over to Surendra's house yesterday evening. After the initial pleasantries, Surendra offered Lokesh drinks which he readily agreed to. They were sitting in the drawing room. After the first drink, Surendra went inside to the bedroom to phone a nearby restaurant for some food. When he returned he found that Lokesh had prepared the second drink for both of them. They were to have dinner after that, after which Surendra and Lokesh would sign the deal to dissolve the company and share the proceeds. Surendra was himself trained in law, and had already prepared the deal. After Surendra finished his second drink, Lokesh got a call on his mobile and he expressed his desire to go to his home for some little work. He said that he would be back within 15 minutes. Just after Lokesh left, Surendra felt a nauseating feeling; in fact he vomited once or twice. But he thought that it was probably because of alcohol. But soon he complained of diarrhoea, fatigue and marked muscular weakness. He knew something was wrong with him, so he phoned his doctor. His doctor advised him immediate hospitalization. In the hospital, he became drowsy and restless. He complained of several strange visual symptoms. He had blurred vision and complained of seeing big dark circles. He also said that things were appearing yellowish to him. The symptoms rather confused the doctors. They were still investigating his case, when today morning Surendra suddenly expired. Surendra's parents have alleged that he has been poisoned and that is why the police has handed over his body to me for post-mortem. My job of course is to find out if indeed he has been poisoned."

"What do you make out of this case doctor? Is it really a case of poisoning?"

"Tarun, I have made a detailed study of Surendra's symptoms. And again and again my mind is coming back to one poison only - Digitalis. Indeed his characteristic visual symptoms are leading me to that. Of course I will have to do the detailed autopsy to find out if indeed it was digitalis which killed him."

"Digitalis! Never heard of it being used as a poison. What is it anyway?"

"Tarun, Digitalis is a drug which is given usually to heart patients. And regarding its use as a poison, it has been used several times before for killing people. The effects of this drug are best known to doctors. Indeed one of the first murderers to use digitalis to eliminate his victims was a doctor."

"Oh, looks like we are again on to one of your exciting stories. Please tell me about digitalis from the beginning doctor."

"Tarun, Digitalis comes from a plant called Foxglove. Its botanical name is Digitalis purpurea, and it has beautiful bell-shaped purple flowers.

In fact the species name purpurea is derived from the purple color of its flowers. The term foxglove actually is a corruption of "folks-glove", which means "fairies glove". The name comes from the finger like appearance of its flowers. Because of the same appearance, it is called fingerhut in German, which literally means "finger hat" or "thimble". The botanical name digitalis is also derived in a similar fashion. In Latin digitus actually means a finger or toe. You may be interested to know that since early man counted on his "fingers", even the numerals 0-9 came to be known as digits, and from this comes our modern word "digital calculator". Isn't it interesting that as widely different terms as digitalis and digital calculator have similar origins?"

"It surely is. Since when is this plant known to mankind?"

"Tarun, the plant foxglove has been known to man since antiquity and has been used by herb doctors and wise old women (The proverbial "Dadi Ma")(Note to Non-Hindi Readers: Dadi Ma is a word of affection used widely in India for wise, loving grandmother) in multifarious concoctions. But it was used systematically for the first time by a young English doctor William Withering (1741-1799) in 1776.

He received his M.D. Degree from the University of Edinburgh in 1766, and in 1775 came to practice in Birmingham General Hospital. In those days, physicians usually picked their own drugs from the plants, and thus botany was a subject included in medical curriculum. Oddly in his studies at Edinburgh the one subject Withering loathed was botany! But one of his first patients, Miss Helena Cooke, a talented flower painter, changed his loathing into love. She encouraged the young doctor to collect plants for her. Later their love grew, and Withering married Miss Cooke! After marriage he moved to Birmingham to take up his job at Birmingham General Hospital. It may interest you to know that Erasmus Darwin, grandfather of the great biologist, Charles Darwin had actually recommended Withering for this position. His friends included such great luminaries as Joseph Priestley, the chemist and James Watt."

"That's interesting. How did Withering come to know of foxglove?"

"At Birmingham, one of Withering's Hospital associates named John Ash informed Withering that one Dr. Cawley, principal of Brasenose College of Oxford University, was cured of a heart disease with a secret formula used by an old woman of Shropshire. She was a lady called Mrs. Hutton, and used a decoction containing some 20 herbs. One of these 20 herbs was foxglove, and Withering quickly realized that out of all the 20 herbs, it was the foxglove which was doing the trick.

Legend has it that Withering paid Mrs. Hutton with several Gold coins for the secret of foxglove which Mrs. Hutton gave him."

"Oh, this is most interesting. So how does digitalis help the patient in the heart disease. And how come, a drug which is so useful in heart disease can act as a poison?"

"Tarun, all medicines are potentially poisons. Indeed the great Swiss physician and Chemist, Paracelsus (1495-1541) said that all substances are poisons. There is none, which is not. He said that the right dose differentiates a poison and a remedy. You have already seen in my earlier discussions how innocuous looking substances as chilli powder (see Science Reporter November 1997) and common salt (see Science Reporter March 1998) have been used to kill people. You asked how digitalis helps the patient in heart disease. Well, it increases the force of contraction of the heart. In technical language we say that digitalis has a positive inotropic effect on the heart. But in large doses digitalis can be fatal."

"Doctor, how much digitalis is fatal?"

"Tarun, first of all, I must tell you that digitalis is the name given to the dried leaf of the plant Digitalis purpurea. It contains two principal drugs digoxin and digitoxin. Digitoxin is more toxic than digoxin. While the fatal dose of digoxin varies from 5 to 25 mg, the fatal dose of digitoxin is just 3-5 mg. For this reason, digitoxin is not used by doctors in the treatment of heart disease, because if they used this drug, there would be more fatal accidents, than with digoxin. I must tell you that digoxin is commonly available in the market under the names of Cardioxin, Digitran-250, Digox, Digoxin and Lanoxin. Different drug companies market the same chemical compound, i.e. digoxin under different commercial names. This tablet is available as 0.25 mg tablets. So about 20-100 tablets would be fatal. A patient of heart disease would require about 3-6 tablets daily."

"How are you going to determine whether Surendra indeed died of digoxin poisoning?"

"Tarun, normally there should be no digoxin in the blood. But even if we presume, Surendra was taking digitalis for some heart ailment, his blood should show very low quantities of digoxin. These low levels are called the therapeutic levels. The therapeutic levels of digoxin in the blood of a patient taking digoxin as a remedy should be around 0.5 to 2.5 nanograms per ml (one nanogram is 10-9 of a gram). Toxic levels are about 3.0 ng/ml. And levels of 10-30 ng/ml are associated with severe poisoning. I have estimated the levels of digoxin in the blood of Surendra, and I have found levels of 35.6 ng/ml. There is indeed no doubt that Surendra had been given digitalis by Lokesh. Lokesh definitely wanted to eliminate Surendra, so he could not ask for his due share in their joint business. In fact, when Surendra went inside to order for food on phone, Lokesh quickly prepared his drink, and laced it with about 30 to 35 tablets of digoxin, which he had already brought with him. Surendra was already a little tipsy because of the first peg of alcohol which he had taken, so he couldn't notice the slight change in taste that must have been induced by the addition of these tablets. I am almost sure this is how Lokesh has killed Surendra. In fact, I have already instructed the police to search Lokesh's house thoroughly. Oh, here comes a policeman with something in his hand which he has found from Lokesh's house. Lo and behold, these are the strips of digoxin tablets. Lokesh would have tough time explaining to the police and the court what these digoxin tablets were doing in his home, especially when he is not suffering from any heart disease."

"That was very clever of you doctor. Without your clever deduction - especially your noticing the peculiar visual symptoms of Surendra at the time of his death- everybody would have thought Surendra died of some mysterious natural disease. This was a most interesting discussion doctor. Tell me what are you going to tell me the next time?"

"Tarun, next time, I would tell you about a very interesting poison- Yellow Kaner. "