Pituitary-related drugs - Ch. 62 Flashcards
What are the uses of pituitary-related drugs?
Replacement therapy in hormone deficiency
Therapy to produce a specific response when a hormone excess is present
What are some anterior pituitary agents?
Somatropin (GH)
Octreotide
What are some posterior pituitary agents?
Vasopressin/desmopressin
How does GH (growth hormone) deficiency present?
paediatric short stature
adult muscle mass loss
What is somatropin (GH)?
Recombinant GH
-peptide
What does somatropin do in pediatric patients?
Stimulate skeletal growth
What does somatropin do in adult patients?
Increase lean muscle mass
Decrease adipose mass
How is somatropin administered?
SC
What happens if someone has GH excess during childhood?
Gigantism
-7-9 feet tall
-Body proportions are normal
What can cause gigantism?
Pituitary tumour
-surgical removal
What is associated with gigantism?
Headache
Profuse sweating
soft tissue swelling
cardiomegaly
hypertension
arthralgias
diabetes
What happens if someone has GH excess during adulthood?
Acromegaly
What happens to someone with acromegaly?
Course facial feautres
Large hands and feet
Head ache
profuse sweating
soft tissue sweating
cardiomegaly
hypertension
arthalgias
diabetes
What are the treatment options for acromegaly?
Surgery
radiation
drugs - when surgery/radiation is not wholly successful
What drugs are used to treat GH excess?
Octreotide
lancretide
pasireotide
What do Octreotide, lanreotide, pasireotide mimic?
Somatostatin
What do Octreotide, lanreotide, pasireotide do?
Inhibits GH release
How is Octreotide, lanreotide, pasireotide administered?
SC or IM
-daily or dept
What is an example of a GH receptor antagonist?
pegvisomant
What is diabetes insipidus caused by?
Most caused by deficiency of vasopressin (antidiuretic hormone) that leads to a production of large volumes of dilute urine
What does vasopressin do?
Increases water reabsorption from kidney collecting ducts
What happens when vasopressin is reduced?
Less water reabsorbed into the body so it is excreted in urine
up to 25L/day
What is central diabetes insipidus?
Common causes: Brain surgery and head trauma
-Severity depends on how much vasopressin is released
Mostly transient, some persistent
What is used in the treatment of diabetes insipidus?
Posterior pituitary drugs:
Vasopressin
Desmopressin
What do posterior pituitary drugs reduce in pts with diabetes insipidus?
Reduce urinary output
Reduce severe thirst
What is PO desmopressin used for?
Nocturnal enuresis
(bedwetting)
What is the preferred drug for long-term central DI?
PO or intranasal Desmopressin
-Has longer duration of action and better adverse effect profile
-No vasoconstrictor activity
What can vasopressin/desmopressin potentially lead to?
Water intoxication
Symptoms of water intoxication?
Drowsiness
headache
light-headedness
Shortness of breath
Hyponatremia
What else is desmopressin useful for?
Clotting disorders
-Hemophilia A
-von Willebrand’s disease (increased clotting factor VIII)
Describe the vasoconstrictor effect of Vasopressin?
Enhances CPR during cardiac arrest
Useful for treatment of various types of bleeding, especially GI bleeding
