Medication Administration

Pharmacokinetics

Pharmacokinetics

the study of the absorption, distribution, metabolism, and excretion (ADME) of medications in the human body

Absorption

the movement of a medication from where it was administered (enters the body) to the circulatory system. Affects speed and intensity of medicine

What must take place before absorbsorbtion can occur?

Medicine must be dissolved in a solution

Ionization

affects the degree of absorption and the rate at which the medication permeates the membranes, which ultimately impacts its distribution within the body. (non ionized absorbs faster!)

Lipid solubility affect on absorbtion

if a medication is highly lipid soluble, it is absorbed more rapidly than a medication that has low lipid solubility.

Why are many oral medications designed to be absorbed in the small intestine?

because the small intestine has a larger surface area than the stomach.

oral or enteral route of medication administration

• provides for a much slower rate of absorption.

• medications must pass through GI membranes to reach the circulatory system, which delays medication movement

Subcutaneous and intramuscular route of med administration

• have variable rates of absorption that reflects the blood flow to the site of injection.

• intramuscular injections often have a faster absorption rate than subcutaneous injections

• both have faster rate of absorption than either the oral or enteral route.

intravenous route of administration

• most rapid rate of absorption

• medications are not affected by the same factors that affect absorption of medications administered through the other routes.

Topical medications

applied directly to the area being treated (e.g., skin, eye, ear, nose) medication is absorbed through the mucous membranes or skin in the area of application and moves into the blood through the capillaries in that area.

What factors contribute to the decision whether to repeat the dose of medication after a client vomits

• the time between administration and the vomiting episode

• presence of the medication in the vomitus

• the type of medication (e.g., extended release, short-acting)

• the risks of undertreatment versus toxic effects

• the individual client.

First thing to do when a client vomits after taking oral medications

inspect vomit for presence of medication

Distribution

process of medication delivery to the target organ or tissues following absorption into the circulatory system. Distribution is affected by the client’s circulatory status or blood flow, and the medication’s solubility and protein-binding ability

Highly vascular areas of body

heart, brain, liver, and kidneys receive the greatest blood supply

Lower vascular areas of body

bones, skin, and adipose tissue receiving a lesser amount

Metabolism/biotransformation

the chemical process of converting a medication’s structure. Metabolism can result in amplified medication activity, inactivation of the medication, or increased excretion via the kidneys, and it can toxicity levels of medications.

Most meds are metabolized in the ______ by which enzymes

liver ; cytochrome p450

Prodrugs

inactive chemicals that are activated through metabolism to exert their therapeutic effects.

First pass effect

can result in a lower concentration (bioavailability) of the medication reaching the systemic circulation, if a majority of the medication has already been metabolized into an inactive form before it enters the bloodstream.

Excretion

process by which a medication is removed from the body. Mainly done by kidneys

Medication toxicity

develops when the body is unable to metabolize and excrete a medication. The remaining medication may reach toxic levels and cause deleterious and sometimes irreversible damage to organs.

Therapeutic drug monitoring (TDM)

used to monitor medication concentrations in a client’s blood. TDM is used for those medications that have a narrow therapeutic window, as a means of providing adequate and safe medication administration without causing an adverse medication reaction

Peak blood level

Highest level of a drug in the bloodstream without being at a toxic level. occur when absorption is complete

Trough blood level

Lowest concentration of a medication in the systemic circulation. It is measured before administering the next scheduled dose.

Half life

time it takes for the medication to fall to half its strength through excretion. Medications with longer half-lives may be administered only once daily to maintain a therapeutic level.

Onset of action

is the time the medication takes to produce a therapeutic effect after its administration.

The peak effect

occurs when absorption is complete, the medication is distributed throughout the body, and the medication is at its highest concentration.

Duration of action

comprises the period of time for which the medication maintains its therapeutic effects

serious adverse drug event (ADE)

life-threatening medication reaction that requires medical intervention to prevent death, permanent disability, or congenital anomaly, or that causes hospitalization or prolongs a hospitalization. Must be reported to FDA

iatrogenic.

An unforeseeable or unintended physical condition, injury, or disorder caused by a treatment or procedure

Allergic reaction

develops when the body perceives a medication as a foreign substance (allergen), which then stimulates an immune response. This reaction produces inflammatory substances, such as histamines and cytokines

The initial treatment for a client experiencing an allergic reaction is

to discontinue the medication immediately.

anaphylaxis

An acute allergic reaction to an antigen that may result in life-threatening shock, producing vasodilation, bronchospasm, and laryngeal edema.

teratogenic

known to cause fetal defects, pregnancy loss, developmental disabilities, or prematurity.

Pediatric cliients may need…

may need medication administered more frequently or in larger doses because of their faster metabolism

What is essential in med administration in younger clients?

Weight dosing. Accurate weights in kilograms for infants and children are essential

10 rights of medication administration

• Right client:

• Right medication:

• Right dose:

• Right route:

• Right time

• Right assessment:

• Right documentation:

• Right to refuse:

• Right education:

• Right evaluation:

Time-critical medications

when administered either 30 minutes before or after the scheduled administration time, can cause harm to the client or result in a substandard pharmacologic effect.

Non-time-critical medications

medications that can be administered between 1 to 2 hours early or late without causing harm or resulting in substandard pharmacologic effects to the client.

The nurse is preparing to administer medications to a client. The pharmacy has delivered the correctly prescribed medications, but they are labeled with another client’s name and medical record number. What action should the nurse take?

collaborate with pharmacist

When should the nurse verify the rights of administration?

When the medication is obtained by the nurse from the client’s medication drawer or from an automated medication dispensing machine

During preparation of the medication

At the client’s bedside immediately prior to administration

A complete medication prescription should contain…

client’s name, date/time that the prescription was written, medication name (generic), dosage, route of administration, frequency, indication for use, and provider’s signature.

medication administration record (MAR)

A record of the medications prescribed for the client by the provider. The MAR is used by the nurse to record and confirm medication administration per the prescription.

When is medication reconcillation performed?

• upon admission

• whenever the client transitions from one level of care to another, both within the facility (e.g., from the intensive care unit [ICU] to the general medical–surgical unit) or from one health care facility to another (e.g., a client transferred from the hospital to a rehabilitation facility)

• when the client is discharged home from a facility

Process of medication reconcilliation

1. Create list (name, dose, route, frequency, and purpose) of home medications upon admission.

2. Compare the list of home medications to newly prescribed medications during hospitalization and reconcile any discrepancies.

3. Update the medication list and repeat the comparison and reconciliation process at any transition of care during the client’s hospitalization, as well as at discharge.

4. Communicate the reconciled medication list to the next care provider.

5. Educate the client and caregivers upon discharge and provide the client with written information about their medication.

The nurse should never…

leave medications at the bedside for a client to self-administer, as this practice fails to follow the rights of medication administration and may lead to a medication error or a serious ADE.

When to use aseptic technique

parenteral medications

Protocol for unit dose medications

Prepare all unit dose medications at the bedside.

Open unit dose medications after scanning and immediately prior to administration

never prepare medications for future administration.

When to assess client for adverse effects

after 30 minutes

Do capsules act slower or faster than tablets

Faster (also less likely to have bad taste!)

Position to reduce aspiration

elevating the head of the bed to semi-Fowler’s or high-Fowler’s position

When pouring medication from a bottle, make sure to hold what part of the bottle?

Hold the lable in the palm of your hand to prevent medication from dripping and obscuring the lable

Remain with client until…

all medication is swallowed (NEVER leave meds at clients bedside table)

Things to remember when giving meds through an enteral feeding tube (EFT)

• administer medications in liquid form whenever possible to avoid clogging the tube with crushed pills (or dissolve pill in water beforehand)

• flush the tubing with 30 to 60 mL of water prior to and after administration of medications and to flush with 15 to 30 mL in between medication

• ensure the medication is compatible with this route of administration

• nurses must follow the tubing from the client to the point of origin (feeding pump or IV bag) before connecting or reconnecting any device or infusion

• do not mix medication with feeding infusion

What type of meds should never be crushed

Enteric-coated, capsules, sustained-release, and immediate-release medications

Transdermal patches

allow for the medication to be absorbed slowly, providing prolonged medication release lasting for several days. Transdermal patches are generally applied to the upper torso, chest, upper arms, or back, or behind the ears.

How to apply transdermal patches

Nonsterile gloves should be used during the removal and application of the patch to prevent the nurse from absorbing the medication. The new application should be rotated to different sites to avoid irritation. Do not place patch on nonintact or irritated skin

Ophthalmic medications

are applied to the mucous membranes of the eyes or conjunctiva

How to administer ophthalamic medications

• Perform punctal occlusion (nurse places an index finger at the inner corner of the client’s eye, maintaining gentle pressure there for 30 to 60 seconds)

• Strict aseptic technique must be maintained

• Do not instill medication directly on the cornea

Otic medications

used for the treatment of local infections and inflammation; they are instilled into the outer ear

How to administer otic medications

• Never administer cold solutions into the ear canal

• pull the pinna up and back gently (down and back for kids)

• Position the client in a side-lying recumbent position with the affected ear facing up

When using rectal medications

instruct client not to pass stool for 20 minutes

Difference between insulin and TB syringes

• The units of measurement are different

• length of the needle is shorter on the TB syringe

• The TB syringe needle is shorter because it is used to administer medications intradermally (between the layers of the skin)

• insulin needle is slightly longer to administer the insulin subcutaneously (below the skin).

Things to consider when selecting appropriate needle size

The location of the injection, the type of injection, the size and age of the client, and the amount and viscosity of the medications

When selecting a site for intradermal injection, it is important to avoid

areas of the skin that are inflamed, have scars or lesion, or are covered by hair.

Subcutaneous maximum amount of dose

No more than 1.5 mL

Subcutaneous needle length and gauge

Length:⅜ to ⅝ inch length

Gauge: 25 to 27G

Subcutaneous injection special considerations

For insulin, use a 28 to 31G insulin syringe.

Pinch the skin and insert at a 45° to 90° angle.

Use a 90° angle for clients who are obese.

Rotate sites.

Intramuscular Sites for Injection and Maximum Amount of Medication/Dose

Ventrogluteal: 3 mL

Deltoid: 2 mL

Vastus lateralis: 1 to 3 mL

Intramuscular needle length and gauge

Length: 1½ inch length

Gauge: 18 to 25G

Intramuscular special considerations

The ventrogluteal site is a relatively safe site because of the lack of major nerves.

The deltoid site is used frequently for immunizations in adults due to its easy access.

Injections should be given at a 90° angle.

The length of the needle may need to be adjusted depending on the client’s weight/size.

Intradermal Sites for Injection and Maximum Amount of Medication/Dose

Ventral aspect of forearm: 0.1 mL

Intradermal needle length and gauge

Length: ¼ to ⅝ inch length

Gauge: 25 to 27G

Intradermal special considerations

Use a 1-mL TB syringe.

Insert at a 5° to 15° angle.

Insert the needle with the bevel up.

A small bleb should appear.

The ventrogluteal site is located

between the anterior superior iliac spine and the iliac crest. The needle is placed in between the “V” formed between the index and middle fingers.

The vastus lateralis site is located

in the middle of the of the thigh, on the anterior (outer) portion of the thigh.

The deltoid injection site is in

the middle of the deltoid muscle, about 2.5 to 5 cm (1 to 2 inches) below the acromion process.

Piggyback IV fluids

diluted in a large volume of IV fluid (50 to 200 mL) and infused over a period of time determined by the medication manufacturer’s directions. allows for slow infusion of medications that otherwise could be harmful to the client if delivered rapidly or undiluted.

Things to consider before IV push

• if medicine is safe for IV push

• if medicine needs to be diluted first

Central venous access devices (CVADs)

catheters inserted into a large centrally located vein for the purpose of administering blood products, medications, fluids, and other therapies. Medications are delivered directly into the client’s central blood circulation. They are absorbed quickly, so effects may be seen quickly. These devices may be recommended for clients who require frequent and/or long-term IV therapy, such as long-term IV medication therapy.

Monitor client with venous access devices for

• Phlebitis: inflammation of the vein, as evidenced by localized redness, pain, heat, and swelling.

• Infiltration: when an infusing intravenous fluid or medication is inadvertently administered to surrounding tissue, as evidenced by pain, swelling, redness, cool skin temperature around the insertion site, taut skin around the IV site, oozing of IV fluid at the insertion site, and repeated alarming of the IV infusion or medication syringe pump.

• Infection at the site of insertion

• redness and purulent drainage at the site; chills, fever, general malaise, and in the worst-case scenario, septic shock.

• Occlusion of the catheter

To prevent infiltration of the medication the nurse should

check for a venous blood return from the venous access device, before administering a medication through the device. If blood return is seen in the catheter, syringe, or tubing, that confirms the catheter is in a vein and the nurse can continue by gently flushing the blood back through the catheter.

The nurse can attempt to gently flush the catheter; if resistance is met (catheter occlusion), the medication should not be administered. If no blood return is seen when accessing a CVC, the nurse should not infuse any fluid or medication and notify the provider and possibly order x ray

To prevent the development of phlebitis

properly secure the IV catheter to avoid movement of the catheter that could cause mechanical irritation to the vein. Some medications can also be irritants to the vein and need to be diluted.

What should nurse do when signs of infiltration are present?

nurse should first stop the infusion of IV fluids, then remove the IV catheter to prevent additional IV fluid from infusing into the tissue surrounding the IV site.

When administering oral medications to kids

• The child should be held in a semi-reclining position to prevent aspiration.

• When using a syringe administer the liquid in a direction toward the inside of the child’s cheek.

• not recommended to mix medication in infant formula or expressed breast milk

• talk to provider if child spits or vomits our medicat

How to inject infants

preferred site is the vastus lateralis muscle. Only small amounts of medication (0.5 to 1 mL) can be injected into this muscle due to its size. Use the smallest-gauge (25 to 30G) needle to reduce the pain. The length of the needle should be only 1 inch for infants from 1 month to 1 year of age and should be inserted into the vastus lateralis at a 90° angle.

Intramuscular injections age considerations

• can be administered in the vastus lateralis.

• deltoid muscle can also be used after 18 months of age

• maximum amount of medication to be injected in the deltoid remains at 0.5 to 1 mL.

• amount for each injection is a maximum of 2 mL in vastus lateralis

• ventrogluteal site can be used in preschoolers, school-age children, and adolescents.

• Adolescents often receive the same doses, routes of administration, and forms of medication as adults, depending on the medication and its purpose.

Topical medication in infants

Infants are at high risk of medication toxicity from topical medications. apply topical medications only in small amounts to small areas as prescribed by the provider.

What level should information be provided in

sixth grade level

Preschoolers can

Take capsules and be injected in the deltoid muscle

First step before administering insulin

have a second nurse confirm the insulin dose to reduce the risk for a medication error. All forms of insulin are considered high alert medications that require a second nurse to confirm the dosage prior to medication administration.

STAT administration

should be given immediately and usually one time. STAT prescriptions should be administered within 30 min of the health care provider prescribing the medication.