Medication Administration and Calculations
The right medication – always verify the medication you’re dispensing. Check the label against the medication form 3 times
(before removing from the drawer, when removing from container, before returning container to storage).
The right dose – the unit-dose system minimizes errors, however, when you have to calculate or convert a medication dosage,
another nurse should verify it has been done correctly.
The right client – check the medication administration record against the client’s identification bracelet and then double check
that their name corresponds with their bracelet.
The right route – check with the prescriber if the order does not designate a route of administration (ie. Oral) and take extra
precaution when administering injections.
The right time – “Nurses must know why a medication is ordered for certain time of the day, and whether the time schedule can
be altered.” If a medication if to be dispensed “STAT” then it is to be administered immediately.
The right documentation – Correct documentation is essential to ensure safe medication administration. Appropriate
documentation includes the client’s name, the name of ordered medication, the time medication was administered, dose, route,
The right reason – As a nurse, it is our professional responsibility to understand the rationale for prescribed meds. Research the
medication by using drug manuals, or online drug information databases.
- Pharmacokinetics – study of how medications enter, affect, and exit the body.
- Drug names – a medication may have as many as 3 different names.
o Chemical name: provides an exact description of the medication’s composition and
o Generic (or nonpropietary) name: becomes the name used under which the medication is
listed in official publications like the Compendium of Pharmaceuticals and Specialties
(CPS). Example is acetaminophen.
o Drug identification number (DIN): 8 digit number unique to every drug.
o Trade (brand or proprietary) name: the name given by a manufacturer who markets a
medication. It will be followed by a TM (trademark) symbol. Example is Tylenol. - Classification – depends on the effect the medication has on the body system, symptoms the
medications produce, or the medication’s desired effect. Some meds belong to more than one
category. Example is aspirin which is an analgesic, an anti-pyretic, and an anti-inflammatory
- Medication forms – composition of a medication is designed to enhance its absorption and
metabolism. Ie. Tablets, capsules, suppositories, inhalers, patches, liquids.
- Controlled Drugs and SubstancesAct– federal government legislation that regulates the
manufacture, distribution, and sale of narcotics. This act is carried out by the health protection
branch (HPB) of the federal government. Application for approval of drugs must be made to the
- Canadian Formulary (CF) – sets standards for drug strength, quality, purity (concentrations),
potentcy, bioavailability (ability to be dissolved, absorbed, and transported by the body to the
drug’s site of action), efficacy (effectiveness), packaging, safety (effects of the drug), labelling,
and dosage form. Ensures that pure drugs are taken in safe and effective dosages.
- Oral forms of medication:
Tablet: powdered medication compressed into a hard disc or cylinder. Contains
binders (adhesives so that powder sticks together), disintegrators (promotes tablet
Enteric-coated tablet: won’t dissolve in the stomach, coatings dissolve in the
intestines where medication will be absorbed.
Elixir: clear fluid med with either water or alcohol, often sweetened.
Tincture: medicinal alcoholic extract from a plant or vegetable.
- Controlled substances – affect the mind or behaviour and can only be dispensed with a
prescription. Nurses are responsible to follow legal provisions when administering controlled
substances. Violations of the Narcotic Control Act are punishable.
- Intravenous injection (IV) produces the most rapid absorption because this route provides
immediate access to systemic circulation.
- After a medication is absorbed by the body, it is distributed to tissues and organs, wherever the
specific site of action is. Distribution is dependent on circulation, membrane permeability, and
- After reaching the site of action the medication metabolizes into a less active or inactive form that
is more easily excreted. Biotransformation occurs when enzymes detoxify, break down, and
remove biologically active chemicals. - After medications are metabolized they are excreted and exit the body through the kidneys, liver,
bowel, lungs, or exocrine glands. Chemical make-up determines the organ of excretion. Kidneys
are the main organ for excretion and meds exit in the urine. If renal function declines, client is at
risk for medication toxicity.
- Effects of medication:
o Therapeutic effects – physiological responses. Some meds have more than 1 therapeutic
effect (ie. Aspirin).
o Side effects – unintended, secondary effects
o Adverse effects