The Half Decent Pharmaceutical Chemistry Blog

Those of you who read my last post may have realised there was something wrong. The thing is last week-end has been rather…eventful. It’s also hard for me to find where I should start, so, in a pretty common way, let’s begin from the end. Sunday, 7:15 pm: the weekend finishes with a massacre of cells, killed by a 0.01 M hydrochloric acid in 10% SDS solution, which is obviously the last step of any MTT assay (in case you noticed it, yes: I haven’t done anything but that for the last three weeks and there’s a chance I’ll go on with cytotoxicity for some time). Four hours before, 3:15 pm, I enjoyed the traditional, graduate student, Sunday afternoon: working in the lab. It was my first time in this particular lab, as I had already lost my virginity in Amsterdam (where else?), where Saturdays and Sundays were days like the others (not always, fortunately), only that I need to get in from the main reception to tell the security people not to shoot me.
I said I enjoyed that because I only add to dissolve some MTT and treat my cells with it, while no one was there, so I could pump the radio which, indeed, was turned to a massively high volume in order to have a real-time, full coverage of all the matches being played in the Italian first division.  
On Saturday, though, things got even better: on that day, in fact, I not only had to write the SNS weekly post, but I also travelled from Bologna to Piacenza (approximately 154 km by train) at noon for an important business (well, I had to collect some money for one of my relatives). At 5:00 pm it was time to get back. Altogether I spent 4 hours on a train.
In the morning, after the weekly shopping, I drew the reaction for the post (making quite a lot of mistakes). The post was written at 8:00 pm, after the supper.

Sounds very grumpy, doesn’t it? So, I believe I need something to help me increase my stamina. These days, luckily, pharmacies are literally clogged up with integrators and similar, over-the-counter products. Interestingly (and worryingly), most of these products stress their natural origin.

Ginseng, for example, has now become a popular remedy to fight fatigue. Yeah, perhaps I should do like other millions of exhausted people and give it a try. The dried roots of Panax Ginseng and Quinquefolius are remarkably rich in ginsenoides and sesquiterpene alcohols. Hold on: although ginseng has always had a huge importance in traditional, Chinese medicine, but, despite its success in Western countries, it’s not featured by either the American and European pharmacopoeia. In fact, its sole clinical role undoubtedly recognized is that of being an adaptogen, a weird word, created by environmentalists and people who think HIV was created in a secret lab by some evil organization, which means it helps you adapt well to stress and fatigue.
It’s, however, became such a popular drug, over the years, that many alternative clinical applications have been deeply investigated and, as result, ginseng is proposed as a (complementary) cure for hypertension, gastritis, insomnia and neurasthenia. But these are just opinions, not facts.
What’s more, you take this kind of substances thinking its totally safe because it’s natural or, if it’s just a multivitamin, at the worst, it’ll produce no effect whatsoever. And this is such a wrong way of thinking! Would you take a synthetic, evil, antiviral if you knew, at worst, it’ll just travel through your bloodstream and kidney? Of course you wouldn’t because it’d be not only pointless, but also potentially dangerous, because, albeit not acting on its target, the molecule will nonetheless have to be filtered and excreted by kidneys and, perhaps, metabolised in the liver.

It’s estimated that 50% of those who regularly consume integrators, are either doing something useless or inappropriate. I’m not advocating for a total, draconian ban of these preparation but it’s fundamental to underline (especially in this critical period of the year, when it’s cold and flu is about to arrive) that, although they are sold without prescription, you should always ask your doctor whether it’s a good idea or a waste of time (and money). Don’t trust pharmacists.

Me? Well, I’ve eventually selected a natural, energetic drink, with a much better flavour than ginseng, called beer. Actually, I’m having my daily dose right now. So, cheers!

Working at the chemist’s had its pros and cons, of course. I’ve already (endlessly) described the boring days spent doing, well, absolutely nothing. What I’ve never mentioned, so far, is the “student” discount I was kindly awarded: in a nutshell, it consisted of a whopping 20% discount on any product, from prescription drugs to OTCs, I wanted to buy.
Predictably, I fully utilized it, buying as many products (not only drugs, but also toothpastes, mouthwashes, etc.) as possible, including a friend of mine’s prescript alendronate.

If you ever came across bisphosphonates, you’d instantly realize this friend is likely to be an old lady. In case, on the contrary, this name didn’t sound familiar to you, somebody could draw question marks over your head now, staring at the monitor with an expression getting little by little more inquisitive.

Alendronate belongs to the family of bisphosphonates, a group of molecules which bear a close resemblance to pyrophosphoric acid, although, instead of the P-O-P bond, they present a P-C-P. These are, indeed, superb drugs, from every point of view. First of all, they are almost completely free from adverse effects: yes, oesophageal irritation and gastro-oesophageal reflux might result, but only if the patient isn’t following some simple instructions: plainly, bisphosphonates have to be taken on a fasting state, with lots of water and avoiding lying down for at least 30 minutes after they were administered.
Fasting is of paramount importance because an incredibly low 10% of a tablet is actually absorbed and, generally speaking, food unsurprisingly reduces oral absorption. Water, on the other hand, plays a key role, enhancing motility. Walking after taking bisphosphonates can help as well.

Bisphosphonates are useful in pretty much any severe condition affecting bones: ectopic calcification, malignancy-associated hypercalcaemia, Paget’s disease, etc. However, alendronate seems particularly effective in the treatment of osteoporosis (either female and male), with a remarkably time-lasting effect, despite its function was once believed to be solely the inhibition of bone resorption. through depressed hydroxyapatite crystals metabolism. If that were the sole effect, though, how could you explain why the action of alendronate in increasing the density of bone minerals lasts for more than 2 years?

Recent trials have highlighted a wider spectrum of pathways where bisphosphonates act, including inhibition of glycolysis, cell growth and marked alterations of phosphatases in bone cells. Not to mention those not related to bone homeostasis.

All this amazing-ness, though, doesn’t come cheap. Alendronate, for example, isn’t paid by the Italian Health Service, so, when prescribed by a physician, you have to pay approximately € 24 for only four tablets, although you should bear in mind that, according to clinical protocols, 10mg are an average daily dose, which is, moreover, often administered as a single one, once a week.

To sum up, that period at the chemist’s might have been not that useless, especially if I gave up everything and became a drug seller: first, I’ve practiced a lot with handmade dose bags and, then, trained myself as a pusher, although bisphosphonates are a lot cooler than, say, heroin, aren’t they?

Although last week I didn’t do anything cool at the chemist’s, I learnt something new. Fortunately, I know nothing about diets and dietary fibres (at least from a clinical point of view), because I’ve never needed them. So, I got really curious when I read we had an order for 150 g of something called glucomannan: never heard of this (judging from the name) polysaccharide. Mind you, at that time I completely ignored it had anything to do with diets.

Actually, even if you’ve spent most of your life being on diet so far, there’s still a chance you never heard of or tried glucomannan per se or as an ingredient of a main course. But it’s pity because, in my opinion, it can be considered the most exotic (and, thus, glamorous) dietary fibre out there. This polysaccharide is extracted from the root (the corm, in particular) of Amorphophallus Konjac, which is native to eastern Asia, where, unsurprisingly, it’s wildly used not only in traditional, home-made remedies, but also with food. The best-known examples of the use of A. Konjac in oriental cuisine are Shirataki noodles, which I’ve never tried, to tell you truth, but now I look forward to eating.
The corm contains lignin, cellulose and other fibres, too, but they are lost during the extraction and purification of glucomannan.

Although there are undoubtedly similarities between this fibre and cellulose, a striking difference is that the former is soluble in water. What’s more, it’s capable of absorbing up to 80- or 100-times its weight in liquids, yielding a gel-like structure. This results form the deacetylation of the positions 6C in the main chain, which therefore yields new centres to form H-bonds with other molecules of polysaccharide. This helps explain why it’s often administered to obese people: this gel floats in their intestine giving them a sense of satiety.

From a chemical point of view, glucomannan is a glucose and mannose polymer (the ratio is 1:1.6), with beta 1-4 bonds between the two sugars. Although the structure is rather linear (compared to other polysaccharides), 11 – 16 monosaccharides side chains appear every 50 – 60 units, in this case through beta 1-3 linkages.

However, obese people aren’t the only to receive benefits from a regular use of glucomannan: as a fibre, it promotes defecations (relieving constipation). Moreover, it has shown to remarkably reduce serum cholesterol levels (even after a short amount of time) and lipids intake. 

So, the only time when it’s highly recommended to make dose bags is when a drug, sold as tablets with a certain dosage, is to be administered to a baby, for which the dose must be significantly reduced.

Sure, you might point out that nowadays for a lot of drugs we can get a wide range of dosages, some of which explicitly designed for kids (something often clearly stated: it’s not uncommon to read “Baby” – or things like that- on the box).
This, however, is much more usual for over-the-counter preparations or, to state the obvious, types of drugs, which are normally given to young children as well as adults.

Things are different when it comes to drugs such as antiseizure ones, although many children suffer from this disease and some of these drugs are effective for them. Still I sincerely doubt you’ll ever read (but do not hesitate to prove me wrong) “Paediatric Phenytoin” on as pale blue or pink box: it wouldn’t look too appropriate, would it?

A customer of the chemist’s where I’m working at the moment has a baby who suffers from seizures and one of the best option is certainly carbamazepine. Her family doctor, thus, prescribed it and, given that dosage for children has to be 15 – 25 mg/kg/d, my job was to make 40 (!) dose bags. A busy afternoon, that’s for sure.

I already wrote about carbamazepine on these pages, during last January’s psycho week, but, frankly, not enough. On this occasion, I thought of showing, with a 3D picture, how closely the structure of phenytoin reminds that of carbamazepine but, given that before graduation I’ll go on working with the crappiest PC of the Western world, it’s better to skip on that. Just take it for granted, please.

This similarity helps to explain why they both exert the same mechanism (inhibition of abnormally-firing neurons through sodium channels block). That, though, is only the main one, as carbamazepine, in addition, reduces synaptic transmission due to presynaptic effect and act centrally impairing noradrenaline release.

Although partial seizure remains the most indicated therapeutic field where carbamazepine plays a role (in which case up to 2 g on a daily basis could be administered to adults), it could be used to treat trigeminal neuralgia as well.

Besides ataxia and diplopia (or double vision), the two, most frequently reported, adverse effects, idiosyncratic toxicity may arise too: skin rash, agranulocytosis and aplastic anaemia occur primarily in elderly people taking carbamazepine for neuralgia.

For my job, I started from commercial 200 mg tablets because this formulation is paid entirely by the Italian National Health System, while the 100 mg/5 mL suspension isn’t. I felt I needed to point this out because, obviously, when I realised how time-consuming making all those dose bags would have been, I immediately considered other options.

As a reader recently proposed, turning all those dose bags into a liquid solution would make it faster to prepare for me and easier (and more accurate) to administer for the customer. What’s more, this time I would have had solely to dilute the original preparation. However, this poor baby has many other health problems and, perhaps, the mother has little money and tries her best to save it. How can you blame her?

Whatever, thing is these tablets also contain excipients: so, plainly, one has to weigh them to get the average weight (281 mg); then, given that one tablet contains the quantity of carbamazepine to make 8 dose bags, you can calculate how much powder you’ll put in each one (35 mg: actually 35.1, but the balance we use doesn’t allow such accurate determinations).

To sum up, I should have used 5 or 6 tablets (you often put an extra tablet, just in case you’d waste something) but I must have been thinking so much to number 8 that I pulverized 8 tablets.

Embarrassingly, I realised this only in the end, as I found myself with approximately a 850 mg surplus of drug.

Instead of throwing this whole lot away, I made a big dose bag and brought it home, where it is at the moment.

Now the question is: I’ll be in a place that may look like a lab until next Friday. Then I’ll spend the next 9 months, at least, in a molecular biology lab. What could I do with all this carbamazepine, given that, luckily, I don’t suffer from partial seizures? It’d be lovely to purify it but, unless molecular biologists have started using (don’t ask me why, please) rotavaps, I guess this is impossible. However, I’ve never told you that I’ll share the building with people doing EPR and close to other organic people, so maybe they have useful stuff and let me use it on lazy Saturday or Sunday afternoons.

Any ideas? Does anyone know the exact recipe to make carbamazepine suspension? Because I’m not going to taste it for the sugar content!

These days I’ve often asked myself if I could write something about food and pharmacology. Yes, there are undoubtedly blogs entirely dedicated to the relationship between science and food, but, still,  I just read something so amazing that has convinced it was time to give it try.

First, however, I must beg a favour: please, Mann Packing, finish to reconstruct your website as soon as possible and, most importantly, put the “Broccoli Town” back online! I just had a look at your old website during a lecture  and found it was brilliant: kids, I guess, liked and it was full of useful information, put in a rather funny fashion. Exactly the thing we need to spread a bit of scientific culture and let people know what they eat has a dramatic importance on their health.

Yup, the food I chose for this blogging experiment is broccoli.

Broccoli is a well-known member of the Brassicaceae: together with cabbage, cauliflower, Brussels sprouts, they are amongst the Cruciferae we should usually have on our tables and they are all wonderfully rich in anticancer, natural molecules, as well as other therapeutically useful substances.

But let’s focus on broccoli. So far it has been proved that it contains fibres, vitamin C,  molecules capable of lowering blood levels of LDL, calcium (to prevent osteoporosis), potassium (for hypertension), beta-carotene (important to prevent heart attack) and many more. All in pretty high concentrations.

Brassicaceae are also rich in isothiocyanates (for example, sulforaphane), which don’t have a leading nutritional role, but show a massive importance as a defence, either in human beings and plants.

Plants developed such molecules in order to respond to environmental insults: sulforaphane is normally glucosinolated and, so, kept inactive but ready to act. Under mechanical stress (i.e. cuts), the precursor reaches particular cellular compartments where an enzyme, myrosinase, is located. As a result the isothiocyanate is released and sets to work.

The same mechanism takes places when we eat broccoli: our teeth reproduce the conditions that trigger the activation of sulforaphane and congeners in the plant, damaging the cells.

Sulforaphane is indeed a marvellous substance: it can detoxify particularly reactive cancer inducers, shunt cytotoxic and cytostatic activity of said molecules and selectively induce apoptosis of neoplastic cells (even if the gene encoding p53 has been altered).

The secret to all this mind-blowing activity has to be found in its excellent pharmacokinetics and pharmacodynamics: bound to glutathione, it yields a complex that easily diffuses through the cell membrane. Once the adduct is in the cytoplasm, sulforaphane is released and activates the mitochondrial apoptotic pathway and, where it’s possible, the nuclear as well.

As it easily enters, isothiocyanates can exit the cell via MRP’s (multi-drug resistance proteins): this, though, is not a drawback, after all, since these enzymes are saturated, so anticancer drugs remain there and can exert their function.

Isothiocyanates stimulate the synthesis of GSH too: this is consistent with Le Chatelier's Principle, since it binds to it, so the cell responds increasing the transcription of GSH.

And sulforaphane can act even in case of hypoxia, a pretty common situation in neoplastic cells.

Interestingly, while the “natural” drug isn’t associated with any side effect, sulforaphane is now studied as a “traditional” drug (so that it could be administered at higher dose to patients) but, unfortunately, adverse effects have already been reported (I was told a big pharmaceutical firm is now at phase II of the development, but you might have more recent, first-hand information): that’s likely to be a result of a radically different pharmacokinetics that you have when shifting from a natural product “extracted” directly from its original source to a tablet where one molecule, isolated, has been introduced at an arbitrary dosage.

Bioavailability is certainly different and, maybe, synergy with other components of the plant could play a key role in the effectiveness of isothiocyanates.