Calculating drug doses

Re: Calculating drug doses

Rebecca Bailey — Sun, 17 Feb 2013 11:45:15 GMT

I am so glad you mentioned that book! I too am having trouble with the calculations (2nd year student), and I just pulled my 'bible' off the shelf and boom there it is! Although I think I'm good with the fluid therapy ones as we spent all day in pharmacology learning it!

:D xx

Re: Calculating drug doses

Jenny Cook RVN — Tue, 14 Jun 2011 09:30:48 GMT

Im not keen on calculating drug doses either, but was taught at college to use a triangle to work out what i needed.

Shame i cant draw a triangle on here, but ill try describe it.

At the top divide by 100

Middle weight (g) x 100

Bottom (split in half) Volume (mls) x % solution.

NB: Only use the top part (divide by 100) when trying to work out the weight of a drug to be used.

So to find the volume (mls) of a drug, you need to do

wt (g) x 100 / % solution = volume (mls)

Sorry ive prob made no sense whatsoever, but it works for me

Re: Calculating drug doses

Juliet Drummond DAVN (med) RVN D32/33 — Fri, 10 Jun 2011 23:41:53 GMT

[quote user="KellySVN2"]

Please help me before my head nurse screams at me again. Thank you. KellySNV2

[/quote]

OMG i'm a head nurse, you will not teach anything by screaming!

come back here as previous poster says, we will help. it takes time to learn calculations, and i always prefer my svn's to ask rather than worry about it. shockin attitude from you HVN

Re: Calculating drug doses

Phrin Vernon RVN — Fri, 10 Jun 2011 23:10:06 GMT

[quote user="Laura James"]

[quote user="greengirl101"]

How would you work the dose out if the dose rate was x ml/kg (instead of x mg/kg) and the drug was x mg/ml? So for example if Rimadyl was 50mg/ml with a dose rate of 5ml/kg?

Thanks in advance!

[/quote]

I'm a little confused (admittedly it doen't take much!!) about when and why you would work out a drug dose this way? I've worked in practice permanently for 2 years now and I've never seen/heard it done this way

Many thanks

Laura x

[/quote]

Poss needed for portfolio?

Re: Calculating drug doses

Laura James — Fri, 10 Jun 2011 22:59:38 GMT

[quote user="greengirl101"]

How would you work the dose out if the dose rate was x ml/kg (instead of x mg/kg) and the drug was x mg/ml? So for example if Rimadyl was 50mg/ml with a dose rate of 5ml/kg?

Thanks in advance!

[/quote]

Many thanks

Laura x

Re: Calculating drug doses

Steph Worsley — Thu, 09 Jun 2011 19:48:15 GMT

agree with the above posters however if you then want to find total mg just muliply the total ml by the mg/ml ...... so if you have 10ml of a 2mg/ml solution total mg = 20mg

Re: Calculating drug doses

Honeybadger — Thu, 09 Jun 2011 13:44:50 GMT

[quote user="greengirl101"]

Hi guys,

I was just reading this post and it is sooo helpful! Thank you so much! Even after a year! I have a question which im currently pulling my hair out over (trying to revise for June Practicals) so hope some lovely person can explain it to me as simply as above.

How would you work the dose out if the dose rate was x ml/kg (instead of x mg/kg) and the drug was x mg/ml? So for example if Rimadyl was 50mg/ml with a dose rate of 5ml/kg?

Thanks in advance!

[/quote]

If the dose is given as mls/kg then it is very simple.

For example: Give a 10kg dog 2mls per kg.

10kg x 2mls = 20mls.

(Just ignore the mg/ml part it is not needed)

Hope this makes sense

Re: Calculating drug doses

Sophie Bedford RVN CertVNECC — Wed, 08 Jun 2011 17:33:06 GMT

Surely in training practices they all now have a clinical coach that is there to ask questions too? I don't understand why these people aren't more approachable for the likes of Kelly to ask questions. If you aren't able to put the time into training someone properly then why be a training practice??

And in answer to greengirl - if you have a dose rate that is x ml/kg then literally just multiply by the weight of the animal. For example - if dose is 1ml/kg and you have a 10kg dog then the dose is 1mlx10kg = 10ml.

Hope this helps!

Re: Calculating drug doses

greengirl101 — Wed, 08 Jun 2011 16:06:08 GMT

Hi guys,

How would you work the dose out if the dose rate was x ml/kg (instead of x mg/kg) and the drug was x mg/ml? So for example if Rimadyl was 50mg/ml with a dose rate of 5ml/kg?

Thanks in advance!

Re: Calculating drug doses

StephSVN — Tue, 03 Aug 2010 17:07:38 GMT

PS - meant to say, this forum is amazing and there is always someone around to help!

Re: Calculating drug doses

StephSVN — Tue, 03 Aug 2010 17:06:49 GMT

[quote user="KellySVN2"]It very scary when im at work and I cant ask for help for fear of being shouted at[/quote]

Ditto Elvira above. I would hate to be in a position where I couldn't ask for help - I find it makes me doubt myself even more. Also, I find it quite scary that places like this still exisit - if people are not allowed to ask about things they are unsure of it makes the chances of mistakes happening even higher, no doubt with huge amounts of blame on the student if things go wrong, making them even less likely to ask next time. Everyone in our practice, right down to the work experience, is told right from day 1 to ask anything no matter how silly they may think it is - always better to ask the same thing 20 times than to guess wrong once.

All credit to you Kelly for having the sense to find help from somewhere else. Is there any other qualified nurses in your practice you could ask for guidance from if you can't go to the head nurse? I know when I first started I was rather intimidated by our head nurse so used to ask the other nurses everything!

Re: Calculating drug doses

Elvira — Sun, 01 Aug 2010 16:23:13 GMT

[quote user="KellySVN2"] My practice does not encourage questions to be asked more than once and this has been explained to me once but im too afraid to ask again and I dont understand.[/quote]

Does anyone else find this situation rather sad? I would never have got through my training without asking some questions more than once and getting them explained more than once. Some people take longer than others to get things straight in their head. The training practice should be training you and if that means repeating stuff if necessary then so be it.

Re: Calculating drug doses

Rachel Jayne — Sat, 31 Jul 2010 22:57:56 GMT

If you ever get stuck on percentgae solutions, I remember being taught how to calculate them by drawing a little triangle, with volume, % and (arg I've forgottent the other part- did anyone else get taught this way who can but in & help?!)

Anyhoo, it would look better drawn out, and basically, you look at it & cover the part of the calculation you need & follow what's left & it gets you to your answer.

Sorry if I haven't made much sense, I'll look it up, and try & put a picture on here somehow.

Re: Calculating drug doses

Sally Seddon — Thu, 29 Jul 2010 22:59:53 GMT

[quote user="Catherine Raymond"]

[quote user="Phrin SVN"]

Oooooh! Dont get me started on books!

My fave 'bible' is Anaesthesia for Veterinary Nurses, and I love love love the BSAVA Jones' book! Still have my old Jones' in 2 editions too! Green for first year, blue for 2nd year! LOL

[/quote]

I still have my green and blue books too! Even have the question books. From many moons ago!!

[/quote]

I brought these off ebay last year, as sad as this sounds i quite often sit and read them hehe..............im still a baby in this nursing world

Re: Calculating drug doses

Catherine Raymond — Thu, 29 Jul 2010 22:29:30 GMT

[quote user="Phrin SVN"]

Oooooh! Dont get me started on books!

My fave 'bible' is Anaesthesia for Veterinary Nurses, and I love love love the BSAVA Jones' book! Still have my old Jones' in 2 editions too! Green for first year, blue for 2nd year! LOL

[/quote]

I still have my green and blue books too! Even have the question books. From many moons ago!!

Re: Calculating drug doses

Phrin Vernon RVN — Thu, 29 Jul 2010 22:21:07 GMT

Oooooh! Dont get me started on books!

My fave 'bible' is Anaesthesia for Veterinary Nurses, and I love love love the BSAVA Jones' book! Still have my old Jones' in 2 editions too! Green for first year, blue for 2nd year! LOL

Re: Calculating drug doses

BengalcatRVN — Thu, 29 Jul 2010 22:15:19 GMT

[quote user="Phrin SVN"]

Although now I have passed my pracs, I will probably allow myself to start gradually forgetting things..... haha!

[/quote]

I can't, I have to train everyone to be mini-me's lol! Although I'm never scared to get the nursing bibles out....jones' and my guide to nursing with all the layman instructions in it. Great books they are too.

Re: Calculating drug doses

Phrin Vernon RVN — Thu, 29 Jul 2010 22:10:17 GMT

we use buprenorphine daily too, but dosages are off a wall chart

i haven't used rimadyl for ages either, but used it so much for so long that the dose rates are ingrained in my brain!

Although now I have passed my pracs, I will probably allow myself to start gradually forgetting things..... haha!

Re: Calculating drug doses

BengalcatRVN — Thu, 29 Jul 2010 22:08:34 GMT

Don't use rimadyl due to wastage (my vet is metacam all the way) but I can remember it after 6yrs of using only rimadyl, I thought that was the easiest to remember. 50mg per ml, 4mg per kg

Kinda rhymes ;)

Re: Calculating drug doses

KellySVN2 — Thu, 29 Jul 2010 22:07:24 GMT

It is brilliant, thank you so much for you help everyone. It very scary when im at work and I cant ask for help for fear of being shouted at, thought I left all that behind when I left school!!!..............wish I worked with you guys. Your all so helpful. x x x x x

Re: Calculating drug doses

Steph Worsley — Thu, 29 Jul 2010 22:03:47 GMT

[quote user="Phrin SVN"]

I thought of buprenorphine too Steph, but couldn't remember the actual mgs/kg dose!

[/quote]

its one of the drugs I calculate on a daily basis so I know it off the top of my head, prob bit like you with rimadyl (cant remember the last time i used injectable rimadyl LOL

Re: Calculating drug doses

Phrin Vernon RVN — Thu, 29 Jul 2010 22:02:50 GMT

Hope you keep coming back here for help Kelly - this forum is bloody brilliant!

Re: Calculating drug doses

Phrin Vernon RVN — Thu, 29 Jul 2010 22:01:58 GMT

I thought of buprenorphine too Steph, but couldn't remember the actual mgs/kg dose!

Re: Calculating drug doses

Steph Worsley — Thu, 29 Jul 2010 21:55:03 GMT

hmmmm I am just wondering if the original example is possibly for vetergesic, whose dose rate can be 10-20 micrograms pr kg not 1-2 milligrams(mg) per kg

remember 20 micrograms is 0.02mg

in this case taking your 20kg dog phrin

0.02 x 20 = 0.4mg

0.4mg / 0.3mg = 1.33ml

Re: Calculating drug doses

KellySVN2 — Thu, 29 Jul 2010 21:54:51 GMT

Wow, I get it. Thank you sooooooo much. I cant believe that I understand it. Thank you thank you thank you. x x x x