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P A R T 6
Drugs acting on the endocrine system
is also given by subcutaneous injection once daily and
independent of meals. It has a duration of action of
24 hours.
Sitagliptin is a DPP-4 inhibitor. It slows the break-
down of GLP-1 in the body, prolonging the effects of
increased insulin secretion, decreased glucagon secretion
and slowed GI emptying. It is an oral drug, taken once a
day, often in combination with other agents. It is rapidly
absorbed, with peak effects in 1 to 4 hours. It has a
half-life of 12.4 hours and is excreted unchanged in the
urine. Few adverse effects have been reported with this
drug, and it also must be used in combination with an
appropriate diet and exercise program.
Canagliflozin and dapagliflozin are among the
newest oral hypoglycaemic agents on the market. These
drugs lower glucose reabsorption by lowering the renal
threshold for glucose. Hence, more glucose can be elim-
inated in the urine. Both drugs are rapidly absorbed and
extensively metabolised.
Prototype summary: Metformin
Indications:
Adjunct to diet and exercise for the
treatment of type 2 diabetics for people older than
10 years of age; extended release form for people
older than 17 years of age; adjunct treatment with
polycystic ovary syndrome.
Actions:
May increase the peripheral use of glucose,
increase production of insulin, decrease hepatic
glucose production and alter intestinal absorption
of glucose.
Pharmacokinetics:
Route Onset
Peak
Duration
Oral
Slow
2–2.5 hours 10–16 hours
T
1/2
:
6.2 and then 17 hours; metabolised in the liver
and excreted in the urine.
Adverse effects:
Hypoglycaemia, lactic acidosis,
GI upset, nausea, anorexia, diarrhoea, heartburn,
allergic skin reaction.
Care considerations for people taking
other oral hypoglycaemic agents
Assessment: History and examination
■
■
Assess for contraindications or cautions:
history of allergy to any of these agents
to
avoid hypersensitivity reactions
;
severe renal or
hepatic dysfunction,
which could interfere with
metabolism and excretion of the drugs
; and
status of pregnancy or breastfeeding
, which are
contraindications to the use of these agents.
■
■
Perform a complete physical assessment to establish
baseline status
before beginning therapy and to
evaluate effectiveness and any potential adverse
effects during therapy.
■
■
Assess for the presence of any skin lesions
for
indication of possible infection and to establish
appropriate sites for subcutaneous administration
as appropriate
; orientation and reflexes; baseline
pulse and blood pressure; adventitious breath
sounds; abdominal sounds and function,
to
monitor effects of altered glucose levels.
■
■
Assess body systems
for changes suggesting
possible complications associated with poor blood
glucose control.
■
■
Investigate nutritional intake, noting any problems
with intake and adherence to prescribed diet.
■
■
Assess activity level, including amount and degree
of exercise.
■
■
Monitor blood glucose levels as ordered.
■
■
Monitor results of laboratory tests, including
urinalysis, for evidence of glycosuria, and renal
and liver function tests, especially with use of the
thiazolidinediones, which can cause liver failure,
to determine the need for possible dose adjustment
and evaluate for signs of toxicity.
Implementation with rationale
■
■
Administer the drug as prescribed in the
appropriate relationship to meals
to ensure
therapeutic effectiveness.
■
■
Ensure that the individual is following diet and
exercise modifications
to improve effectiveness of
the drug and decrease adverse effects.
■
■
Monitor nutritional status
to provide nutritional
consultation as needed.
■
■
Monitor response carefully; blood glucose
monitoring is the most effective way
to evaluate
dose
. Obtain blood glucose levels as ordered.
■
■
Monitor liver enzymes of people receiving
pioglitazone very carefully
to avoid liver toxicity
;
arrange to discontinue the drug
to avert serious
liver damage if liver toxicity develops.
■
■
Monitor individuals during times of trauma,
pregnancy or severe stress,
and arrange to switch
to insulin coverage as needed.
■
■
Provide thorough teaching, including drug
name, dosage and schedule for administration;
administration technique if appropriate; need for
food intake within specified time period; signs
and symptoms of hypo- and hyperglycaemia; skin
assessment, including daily inspection of feet; signs
and symptoms to report immediately; measures
to use when ill or unable to eat; proper diet and
exercise program; hygiene measures; recommended
