drug administeration and calculations Flashcards
name the types of oral medicines that are avaliable
- tablet (orodispersible, effervescent, dispersible)
- capsules
- elixirs & syrups
- emulsions
- linctus
name two oral routed other than swallowing
- sublingual
- buccal
what are the pros to using tablets?
- convient
- accurate dose
- formulation can be adjusted (enteric-coating / sustained release)
what are the cautions associated with tablets?
- must not be bitten / chewed
- must not be broken to divide dose
- ensure patient takes dose
- fluid drug taken with (eg.milk)
what are capsules? and what are they useful for?
- oval-shaped and coated with hard gelatin coat
- useful for bitter drugs (eg.antibiotics)
what are the drawbacks and cautions assicated with capsules?
- can be large as powder not compacted
- same cautons as tablets
what is meant by the sublingual route and why would this route be used?
- drug absorbed through mucosa under tongue → rapid absorption
- aviods 1st pass metabolism
what forms can sublingual medication take?
- sprays
- tablets
what is meant by the buccal route and why would this route be used?
- usually tablet placed between lip & gum or cheek & gum
- rapidly absorbed
when would the buccal route be useful, give an example and what are the drawbacks?
- useful for antiemetics (eg. prochlorperazine and long lasting GTN)
- increases dental cavities
what is a compound medicine and how would this be indicated?
- 2 or more medicines in the same tablet
- indicated by ‘co’
how would compound drugs be calculated?
- no alternative calculation just give number of tablets prescribed
what are elixirs and syrups?
liquid medications which are flavoured and sweetened (caution with diabetic patients / alcohol dependent patient - elixir has alcohol base)
what is an emulsion?
a liquid medication which is a mxture of 2 liquids - one dispersed throughout the other
what cautions are associated with emulsions?
- must be shaken weel before use - danger of liquids seperating
- potential inaccuracy
give an example of an emulsion
- oral nutritional supplements
what is a linctus?
liquid medication - sweet syrupy preparations
what might be given as a linctus and what are the cautions?
- cough medicine
- bottle gets sticky - dosage difficult to measure
what are the general points which should be considered when administering liquid medication?
- shake / agitate before dispensing
- pour liquid away from label
- measure at eye level
- dose <5ml use syringe
- always use syringe for infants / children
what information about the drug should be found on the label?
- clear, legible, comprehensive & in English
- name of product
- formulation (tablet/capsule/suppository)
- strength (eg. 5mg/150ml)
- quantity (eg. 48 tablets)
- info about excipients
- storage info
- method & route of admin
- expiry date
- batch ref number
- special warnings
- instructions for self use
- special precautions for disposal
- marketing authorisation
how should drugs be stored?
- original packaging
- locked cupboard / trolley / patient bedside
- locked refridgerator (2-8°c)
- room temp away from direct sunlight
explain the general principles of drug administration regarding documentation
- prescribing & recording sheet: patient bedside or document trolley
explain the general principles of the nurse/patient interaction regarding drug administration
- identification of patient
- explaination given to patient
- try to avoid interuptions
explain the general principles regarding the technique of drug administration
- wash hands
- patient in upright position (ideally)
- patient takes meds themselves (if poss.)
- witness med’s being taken
- record on fluid balance sheet (if nec.)
- retain any rejected med’s
explain the hazards associated with giving medication
- med’s to wrong patient
- interupptions leading to errors
- med’s given earlier/leter than appropiate
- missappropriation of drugs from unattended trolley
- route - irritation of GI tract / aspiration
what is the formula for calculating tablet dosages?
what you need = number of tablets required
what you have
what is the general rule of complex drug calculations?
must convert the dosage to the same SI unit before doing calculation
list tablet dosages from large to small and explain how you would convert from small to large and vice versa
- kilograms
- grams
- milligrams
- micrograms
- nanograms
* to get from smaller to larger ÷ by 1000
* to get from larger to smaller x by 1000
what is the formaula for calculating liquid dosages?
What you need x strength available = volume of liquid
What you have
how are some drugs prescribed - especially for children?
dose per weight basis or body surface area (m2)
to how many decimal places would you round when calculating dosages for injection which are more than 1ml?
- if drug calculation is more than 1ml ‘round up or ‘round down’ to one decimal place
- eg. answer 1.63ml - round down to 1.6ml
- answer 1.87 - round up to 1.9ml
if a drug calculation for injection was less than 1ml to how many decimal places would you round?
less than 1ml you would ‘round up’ answer to two decimal places - a 1ml syringe should be used
- eg. answer 0.66666ml - round up to 0.67ml
what should match the number of decimal places of the dosage calculation for injection?
the graduations on the syringe
list different types of syringes and the graduations they are subdivided into
- 1ml syringe = 0.1ml (subdivided 0.01ml)
- 2ml syringe = 0.5ml (0.1ml gradulations)
- 5ml syringe = 1ml (0.2ml graduations)
- 10ml syringe = 1ml (0.5ml gradulations
what can be expressed as a %?
- weight / volume (w/v) - eg. 15mg / 1ml
0. 9% saline (0.9g NaCl/ 100ml) - weight / weight (w/w) - 0.5% hydrocortisone (0.5g hydrocortisone / 100g cream)
- volume / volume (v/v) - rare
what do you need to know when calculating strength expressed weight/weight?
- solution: always part of 100
- weight is always in grams per 100g
- eg 0.5% hydrocortisone (0.5g hydrocortisone / 100g cream
what do you need to know when calculating strength volume / volume?
- solution: always part of 100
- volume always in ml to volume 100ml
- eg. 2% v/v hydrogen peroxide = 2ml hydrogen peroxide in 10ml of finished solution
what do you need to know when calculating strengths weight / volume?
- solution: always part of 100
- weight is always in grams / volume per 100ml
- eg. 15mg/1ml = 0.9% saline (0.9g NaCl / 100ml
what are units of activity?
some medicine obtained from natural sources are expressed in units of activty
give 3 examples of antibiotics which are expressed as units of activity
- bleomycin
- colistin
- nystatin
give 5 examples of hormones which are expressed as units of activity
- calcitonin
- gonadatropins
- insulin
- oxytocin
- vasopressin
give 3 examples of immunological products which are expressed as units of activity
- immunoglobuilns
- interferons
- antisera
give 2 examples of vitamins which are expressed as units of activity
- vitamin A
- vitamin D
give 3 examples of other drugs which are expressed as units of activity
- domase alfa
- epoetin alfa
- heparin
