Thyroxin
Trade names: Eltroxin
Class: Thyroid hormones Pregnancy: (Category A) Action:
§
Principal effect is
increasing metabolic rate of body tissues:
§
Promote gluconeogenesis
§
Increase utilization and
mobilization of glycogen stores
§
Stimulate protein synthesis
§
Promote cell growth and
differentiation
§ Aid in the development of the brain and CNS § Contain
T3 (triiodothyronine) and T4 (thyroxin) activity.
§
Therapeutic Effects:
§
Replacement in deficiency
states with restoration of normal hormonal balance § Suppression of
thyrotropin-dependent thyroid cancers.
Uses:
§
Replacement or substitution
therapy in diminished or absent thyroid function of many causes
§
Treatment of some types of
thyroid cancer.
Dose:
ADULT, initially
50–100 micrograms (50 micrograms for those over 50 years) daily, preferably
before breakfast, adjusted in steps of 50 micrograms every 3–4 weeks until
normal metabolism maintained (usually 100–200 micrograms daily); where there is
cardiac disease, initially 25 micrograms daily or 50 micrograms on alternate
days, adjusted in steps of
25 micrograms every 4 weeks
Congenital hypothyroidism and
juvenile myxoedema, CHILD up to 1 month initially 5– 10 micrograms/kg daily, over
1 month initially 5 micrograms/kg daily adjusted in steps of 25 micrograms
every 2–4 weeks until mild toxic symptoms appear then reduce dose slightly Contraindications:
§ Hypersensitivity
§ Recent MI
§ Thyrotoxicosis
§ Known alcohol intolerance (liothyronine injection only) § Hypersensitivity
to beef (Thyrar product).
Side effects:
§ CNS: insomnia, irritability,
nervousness, headache.
§ CV: CARDIOVASCULAR
COLLAPSE, arrhythmias, tachycardia, angina pectoris, hypotension, increased
blood pressure, increased cardiac output.
§ GI: cramps, diarrhea, vomiting.
§ Derm: hair loss (in children),
increased sweating.
§ Endo: hyperthyroidism, menstrual
irregularities.
§ Metab: weight loss, heat intolerance.
§ MS: accelerated bone maturation
in children.
Nursing
considerations:
§ The treatment is initiated slowly (with small doses) &
gradually increased.
§ Store medications in cool dark place.
§ Take complete nursing history .
§ Note if the client is taking antidiabetics drugs & document
.
§ Take baseline ECG. then at regular intervals.
§ Monitor thyroid function closely.
§ Observe client for side effects.
§ Monitor PT & PTT closely
since the drug increases hypoprothrombinemia.
§ Monitor HR & B.P. closely for cardiac patients.
§ Instruct the client to
report side effects e.g. weight loss & nervousness to physician.
§ Have dietitian counsel clients regarding diet according to
the energy demands.
§ Female client should record menstrual irregularities . § Encourage the client to keep follow-up visits.
