Chapter 30: Pituitary Drugs Flashcards
Hypothalamus
Consists of the anterior pituitary gland (adenohypophysis) and posterior pituitary gland (neurohypophysis)
Endocrine system
Can be considered similarly to the CNS for signaling; each operates in a stimulus-and-response manner. Together, they function to maintain the physiologic stability of the endocrine system
These are stored in the posterior pituitary gland and is secreted by the hypothalamus
The hormones vasopressin and oxytocin
The hypothalamus secretes several
Hormone releasing factors that stimulate the anterior pituitary gland to secrete a variety of hormones that control many bodily functions
Water soluble hormones
Protein based substances such as the catecholamines norepinephrine and epinephrine
Lipid soluble hormones
Consist of the steroid and thyroid hormones
Anterior pituitary gland (adenohypophysis) hormones
Adrenocorticotropic hormone (ACTH) Follicle-stimulating hormone (FSH) Growth hormone (GH) Luteinizing hormone (LH) Prolactin (PH) Thyroid-stimulating hormone (TSH)
Drugs include: cosyntropin, somatropin, and octreotide
Posterior pituitary gland (neurohypophysis)
Antidiuretic hormone (ADH) Oxytocin
Drugs include: vasopressin, desmopressin
Negative feedback loop
A system where the production of one hormone is controlled by the levels of a second hormone that reduces the output of the first hormone.
Ex: when gland X releases hormone X, this stimulates target cells to release hormone Y. When there is an excess of hormone Y, gland X senses this excess and decreases its release of hormone X.
Pituitary drugs
Used as replacement therapy for hormone deficiency or as a diagnostic aid to determine the status of the patients hormonal functions.
Exogenous corticotropin
IV is no longer manufactured
IV was replaced by cosyntropin
IM or SubQ injections are available
H.P. Actuary Gel is also available
Cosyntropin MOA
Travels to the adrenal cortex (located just above the kidney) and stimulates the secretion of cortisol which has many anti inflammatory effects (e.g., reduce leukocyte inflammatory functions and scar tissue formation) and promotes renal retention of sodium, which can result in edema and hypertension
Drugs that mimic the GH (MOA)
Somatropin and Somatrem promote growth by stimulating various anabolic (tissue building) processes, liver glycogenolysis (to raise blood sugar), lipid mobilization from body fat stores, and retention of sodium, potassium, and phosphorus. Promoting growth in children lacking endogenous hormone
Drug that antagonizes the effects natural GH by inhibiting GH release (MOA)
Octreotide is similar to GH release-inhibiting factor (somatostatin) and reduces conc.s of vasoactive intestinal polypeptide (VIP)- a protein secreted by a type of tumor known as VIPoma causing profuse watery diarrhea
Vasopressin mimics the ADH (posterior pituitary effector) (MOA)
Concentrated urine, reduces water by up to 90%; potent vasoconstrictor used in certain hypotension emergencies (e.g., vasodilator/septic shock), ACLS of pulseless cardiac arrest, and stop bleeding of esophageal varies
Desmopressin mimics the ADH (posterior pituitary effector) (MOA)
Concentrated the urine, reducing water excretion by up to 90%; causes a dose-dependent increase in plasma levels of factor VIII (antihemophilic), von Willebrand factor, and tissue plasminogen activator making it useful in treating certain blood disorders; also is used to manage nocturnal enuresis
Oxytocin (MOA)
Mimics the endogenous hormone, promoting uterine contractions
Cosyntropin indication
Used in the diagnosis of adrenocortical insufficiency
Drug treatment involves replacement therapy using forms of the deficient corticosteroid hormones
Somatropin and somatrem indication
Effective in stimulating skeletal growth in patients with an inadequate secretion of normal endogenous GH, such as those with hypo pituitary dwarfism, and are also used for wasting associated with HIV infection
Octreotide indication
Alleviating certain symptoms of carcinoid tumors stemming from VIP secretion, including severe diarrhea, flushing, and potentially life-threatening hypotension associated with carcinoid crisis; also used to treat esophageal varices
Vasopressin and Desmopressin indications
Prevent or control polydipsia (thirst), polyuria, and dehydration in patients with diabetes insipidus caused by a deficiency of endogenous ADH.
Due to vasoconstrictive properties, are used to treat bleeding esp in particular GI hemorrhage
Desmopressin is useful in the treatment of hemophilia A and type I von Willebrand Disease because of its effects on various blood clotting factors
Pituitary “contraindications”
Simply special caution in patients with acute or chronic illnesses such as migraine headaches, epilepsy, and asthma
Octreotide adverse effects
Fatigue, malaise, HA Increase or decrease in glucose Diarrhea, N/V Dyspnea Arthralgia Conduction abnormalities
Desmopressin and vasopressin adverse effects
Increased blood pressure Fever, vertigo, HA N, heartburn, cramps Uterine cramping Nasal irritation & congestion, tremor, sweating
Growth hormone analogues adverse effects
HA
Hyperglycemia, hypothyroidism
Hypercalciuria
Rash, urticaria, development of antibodies to GH, inflammation at injection site, flulike syndrome
Desmopressin interactions
Carbamazepine, result in enhanced desmopressin effects; lithium, alcohol, demeclocycline result in reduced desmopressin effects
Octreotide interactions
Cyclosporine- Care report of transplant rejection; thioridazine and ciprofloxacin prolong QT interval
Somatropin interaction
Glucocorticoids reduce growth effects
Vasopressin interactions
Carbamazepine and fludrocortisone enhance the antidiuretic effect
Demeclocycline, norepinephrine, and lithium reduce the antidiuretic effect
Octreotide drug profile
Contraindicated in allergy; caution in patients with renal impairment (may impair gallbladder function)
May affect glucose: can cause severe hypoglycemia in patients with type 1 diabetes and hyperglycemia in patients with type 2 diabetes or patients without diabetes
May enhance toxic effects of drugs that prolong the QT interval- like Ciprofloxacin
Can be given IV, IM, or SubQ
Pregnancy category B
Somatropin drug profile
Indicated to treat growth failure due to inadequate GH secretion. Used for patients with HIV infection with wasting or cachexia in conjunction with antiviral therapy.
Pregnancy category B or C (manufacturer-dependent)
Contraindicated in allergy, in children with closed growth plates, patients with tumors, and patients with acute illnesses.
ADRs: HA, injection site reactions, muscle pain, hypoglycemia, or hyperglycemia
DO NOT SHAKE
Usually given SubQ; some products are given IM
Vasopressin drug profile
Used to control various types of bleeding (in particular GI hemorrhage) and in pulseless arrest and vasodilatory shock (continuous IV)
Contraindicated in allergy, pregnancy (category C), caution in patients with seizure disorder, asthma, CV disease, renal disease
Watch IV for infiltration (May lead to severe vasoconstriction and localized tissue necrosis) and use a central venous line access device when possible
Nasal spray- a topical applied to the nasal membranes and must NOT be inhaled, IM, or IV use
Desmopressin drug profile
Used to treat hemophilia A and Type I von Willebrand desease because of its effects in various blood clotting factors.
Available as DDAVP Rhinal Tube and has an antidiuretic effect that is about one tenth that of an equivalent dose given IV.
Octreotide acetate assessment
Prescriber May order an electrocardiogram because of possible conduction abnormalities
Baseline glucose, liver and kidney functions completed as prescribed
Desmopressin assessment
Assess VS, Hx of seizures, asthma, or CV disease which require cautious use with neurological status, VS, breath sounds, and heart sounds
Vasopressin assessment
If being treated for shock:
Close monitoring with ECG, VS, and invasive monitoring methods like arterial lines, central venous pressure lines, and/or arterial blood gas
GH assessment
Obtain baseline thyroid, glucose, and calcium levels (as prescribed) due to the potential side effects of hyperglycemia, hypothyroidism, and hypercalciuria
Somatropin assessment
Monitor growth, motor skills, height, and weight of the pediatric patient
Octreotide implementations
Take care not to confuse the injection form with the injectable depot suspension dosage form
Only clear solutions; check for complications
Report abd. distress, diarrhea, N/V that’s unimaginable
Stress the importance of follow ups for lab tests
Desmopressin implementations
Per prescribers orders because dose and route vary with indication
Can be given oral, IV, intranasal, and SubQ
Rotate SubQ/ IM injections (somatropin)
Mix injectable solutions by swirling the liquid; ONLY CLEAR SOLS.
Intranasal can lead to changes in nasal mucosa with unpredictable drug absorption
For patients with diabetes insipidus, fluid intake may be adjusted according to the predicted risk for water intoxication and sodium deficit.
Vasopressin implementations
Available as a nasal spray, IM, or IV
Check clarity of sols. Before administration; discard if there are any visible particles or fluid discoloration
Notify I’d ADRs of elevated blood pressure, fever, nausea, or abd. Cramping worsen
Given topically when given nasally- NOT TO BE INHALED
Octreotide evaluation
Therapeutic effects include improved S/S related to carcinoid tumors, VIPoma, or esophageal varies
Vasopressin evaluation
Improvement in diabetes insipidus, esophageal varices, or vasodilatory shock
Somatropin evaluation
Increased growth is expected for whom it is indicated
Evaluate for ADRs: HA, muscle pain, and altered blood glucose levels
Desmopressin and vasopressin evaluation
ADRS: increased blood pressure, fever, HA, abd. Cramps, and nausea
GH evaluation
May lead to HA, hyperglycemia hypothyroidism, hypercalciuria, and flu-like syndrome
Intranasal dosages
Nasal passages must be cleared before admin
Prime drug by pressing down 4 times
Pump will stay primed for 1 week then reprime
Store nasal spray at room temp
Store DDAVP Rhinal Tube in Fridge
Children with endocrine disorders
May have increased risk for bone problems
If limping= need to be evaluated by prescribers
