Basic medicines knowledge.
This is the 4th in the series of posts about first-aid and medical problems at sea and the second part of the 3 planned pain management posts. I chose to divide the pain post into 3 separate ones so that i covered basic practical pain assessment in the first and then begin with an introduction to medicines in this one. The third post will go into the more difficult area of severe pain and the use of opiates. My aim with this post is to give you some practical advice about dealing with ‘simple pain problems with over-the-counter (OTC) drugs and leading into carrying and using prescription-only medicines (POM’s). It is fairly normal practice for sailors going long distance and going cruising long term in distant locations to carry prescription medicines even for those who aren’t medically qualified. In 3 organised events that i have sailed in we have carried an extensive pharmacy including controlled drugs which i will mention at the end because they do have an essential place in pain management.
To begin lets keep medicines really simple and just talk about a group of drugs which we can buy over the counter in any chemist and most supermarkets. Although ‘simple’ medicines 2 groups of these still form the mainstay of pain management even in advanced pain problems. I am going to start off by talking about the use of a single well known medicine : paracetamol and a group of drugs known as the ‘NSAID’s (non steroidal anti-inflammatory drugs). The most common non-steroidals are Ibuprofen and Diclofenac and can generally be taken with paracetamol. Both are commonly used in hospital pain management and usefully for this post both have side effect problems which i will use to introduce the unwanted side effects of any medicines. Before i do that though i want to talk a little about my background and knowledge of medicines, especially analgesics.
I am of course a registered nurse and that is where i got all my basic teaching in medicines use/misuse and the various bits of legislation which we have to work to. As a student nurse we were expected to know our basic drugs ‘off by heart’ and we spent hour upon hour learning and testing each other up to the point where we did a medicines ’round’ assessment on a busy hospital ward. In that assessment we had to safely administer any medicines by the route prescribed (and to the right patient), know the correct dosage and normal timing of administration, know the side effects, cautions and likely treatment of overdose and side effects. Much later in my clinical career i had to act for the hospitals clinical nurse specialist in pain and be the bleep-holder (first-responder) for any and all specialist pain problems in the entire hospital. To say that i was under qualified for that role is an understatement but that i compensated by studying the subject conscientiously and working closely with a pain specialist consultant. Right at the end of my career as a nurse that was some of the best work i ever did.
The basis of knowledge about any medicine can be summed up as : what does the drug do, how much should we give and how often, how or where to administer it, how long will it be effective, what are it’s side effects, when should we not use that drug and how much is a dangerous dose. There are some additional details for example if the medicine should be taken before or with food and sometimes whether the use of one drug should be supported with the use of another which might make the first one more effective or reduce it’s harmful side effects.
I will jump-in here right away with a good clinical example from my recent experience. As some visitors know i live with a lot of long term back pain which is periodic rather than constant and can manage the pain episodes with either 2 OTC medicines together but sometimes with one POM which i find personally more effective…however recently a consultant in a different specialty asked me why i wasn’t also taking a gut ‘protective’ medicine (omeprazole) as an adjunct. The medicines i am talking about here are 4 fairly simple ones : paracetamol, ibuprofen, diclofenac and omeprazole and i can use each one here to answer the basic questions of how much, how often, where and how, what side effects and so on. Note here that omeprazole isn’t an analgesic but sometimes used to counter the side effects of the NSAID’s.
1.Action/effect. All medicines are intended to be used for their primary and/or sometimes secondary effect, be that an analgesic for pain relief, an antibiotic to fight infection and so on through all of the hundreds of available drugs currently to be found in the BNF (British National Formulary)….our pocket-bible of medicines. Analgesics as an example although intended to reduce pain do so through different bio-chemical pathways, paracetamol for example works differently to an opiate such as morphine. I won’t go any further into medicines along that route as it’s not valuable here. What is useful to know with analgesics is that each one is better or worse at treating different kinds and levels of pain. Here for example both paracetamol and ibuprofen are very effective for treating toothache which has an inflammatory nature because both work on the right pain mechanism. In fact with pain at almost any level of severity i would always make sure that either or both of those had been given in an advanced pain problem as long as there wasn’t a contra-indication to doing so.
2.Dosage. If you happened to have just seen your GP and she has decided to start you on a given medicine then what she will do is write out a prescription which you then give to the pharmacist. If you have a decent pharmacist he will then dispense an amount of that drug, stick a clear label on the pack telling you how many to take and how often and if he is really good then he will also tell you that. With most medicines prescribed to the general public you aren’t expected to do drug calculations such that you can work out how many pills to take….that should be stated as simply as possible on the bottle….and it might often say ‘with food’ as an example. For our new knowledge today we go up a level and begin to think about actual drug dosage in the amount of drug actually given and today that will always be in metric units, in common medicines that will be in grams or fractions of a gram for example milligrams or micrograms. Simple example here is that paracetamol comes as standard as a 500mg (milligram) tablet thus 2 of them make a gram !. Ok so now go and do a bit of simple maths and work out what 2 (paracetamol) tablets taken 4 times a day is in real terms. The reason i ask you to do that at this stage is that it becomes important later on if you are going to manage (POM’s) aboard the boat when you might have to refer to something like the BNF for dosage guidance and it then becomes really important to know for example what Amoxycillin 250 mg actually means.
3.Route of administration. Most people are familiar with at least the first 2 medicines which i am talking about today : paracetamol and ibuprofen. Both of those are normally taken orally (swallowed) as tablets or capsules/caplets. That’s a pretty normal route of administration which i am used to seeing as PO on hospital medicines charts…it means give the patient the tablet/s to swallow…..but there are several different routes of administration and i fact i commonly use a different one for another of the drugs i mentioned at the start : diclofenac or voltarol. To be blunt guys i stick it up my bottom ! (not the tablets though) in suppository form and the route of administration is then called ‘PR’ or per-rectum. It’s less common in the UK and much more common on the continent to give (or take) medicines by this route especially when there is upset higher up in the GI tract and quite frequently with young children. Personally i find that a full dose of diclofenac taken PR just before i go to bed when i have really severe back pain will almost guarantee that i will come out of spasm, be pain free and not have any of the side effects that the drug can cause. While i am in this section i should also mention other routes of administration : SL or sublingual (under the tongue), SC subcutaneous injection just under the skin, IM…intramuscular injection,which is less common now, IV …intravenous injection, inject directly into a vein. Hopefully you won’t ever have to deal with most of them but its useful to know. I can’t remember the reason now but one time i had to teach a crewmember to give IM (intramuscular injection) and i taught her to inject and orange and showed her the best sites to use. The one out of all of the routes that you might need to know one day is the subcutaneous route when administering a local anaesthetic before suturing a wound.
Time for a video clip methinks…..’sub-cut’ injection of lignocaine (lidocaine)
4. Side effects and contraindications. In a perfect world medicines would only have the effect that we want, in the real world however nearly all medicines have unwanted side effects. Add to that that many people become allergic to some medicines and that with many drugs there are also instances when they MUST not be used and we have a whole new world of knowledge to get to grips with. Even the basic medicines that i have mentioned so far, and that you can buy over the counter, have serious side effects : paracetamol can be lethal for example if too much is taken. So, here is a little exercise for you : go and find out what the contraindications and side effects are for paracetamol and ibuprofen. As a handy hint that information can easily be found on the internet but lets pretend that we are sea and don’t have access to it, rather try and find the same information in the packaging of those medicines or other written material that you can carry aboard the boat.
5.Combining medicines and combination medicines. It’s a common misconception that 2 different pain relieving medicines shouldn’t be given at the same time, this is wrong (most of the time) in fact it’s quite common practice to give the 2 most common painkillers which we have mentioned so far together : paracetamol and ibuprofen together make a very effective combination and as an example are what i would start with when treating the pain from a ‘hot’ tooth. A valuable medicine to talk about in this section is the pre-combined drug ‘co-codamol’ as it is a mixture of 2 different drugs and it also changes from an OTC medicine to a POM depending on the mixture. The mixture here includes a low-order opiate called codeine which is a controlled medicine on its own. Cocodamol is available over the counter (at a phamacy) when the mixture contains 8mg of codeine but when either the 15mg or 30 mg combination is prescribed it immediately becomes ‘prescription only’. Codeine itself is one of the next medicines that we should take a look at as it is a weak opiate but has much more problematical side effects and a highly variable effect which is genetically determined. I think we should leave that aside for now and until we deal with controlled drugs in a separate post.
6.Medicines adjuncts. At the end of this post i am going to leave you with some homework to do. The first thing i would like you to do is research the side effects paracetamol and the NSAID’s generally which is the group containing ibuprofen and diclofenac. The second thing i would like you to do is try and work out why one of the consultants i work with now asked me why i wasn’t taking the drug ‘Omeprazole’ with my regular use of NSAID’s.
The last post in this series will cover the use of high level painkillers, notably the opiates, after that i there will be a post about my own quite different approach to dealing with first aid and medical problems. After that we’ll have to go and do some boat jobs.
Note…please remember that this is only the beginning of the most basic level of medicines knowledge. If you are going to do long voyages as a self-reliant sailor or ‘medic’ to your crew then you really need to do know medicines at a higher level than this or have access to expert advice.