NURS 133 Levothyroxine and Phenytoin

jasmine's version from 2016-04-30 22:26


Question Answer
Levothyroxine Hormones; Thyroid supplementation in hypothyroidism; treatment or suppression of euthyroid goiters; Adjunctive treatment for thyrotropin-dependent thyroid cancer
Levothyroxine actions Replacement of or supplementation to endogenous thyroid hormones; 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
Levothyroxine therapeutic uses Replacement in hypothyroidism to restore normal hormonal balance; Suppression of thyroid cancer
Elimination/Excretion of Levothyroxine Metabolized by the liver and other tissues to active T3; Thyroid hormone undergoes enterohepatic recirculation and is excreted in the feces via the bile
Adverse/Side Effects of Levothyroxine Usually only seen when excessive doses cause iatrogenic hyperthyroidism (headache, angina pectoris, abdominal cramps, sweating, hyperthyroidism, heat intolerance accelerated one maturation in children to name a few not often adverse/side effects)
Contraindications of Levothyroxine Hypersensitivity; Recent MI; Hyperthyroidism
Drug/Food interactions of Levothyroxine Bile acid sequestrants (food additive) and orlistat decrease absorption of orally administered thyroid preparations; may increase the effects of warfarin; May increase requirements of insulin or oral hypoglycemic agents in diabetics; Concurrent estrogen therapy may increase thyroid replacement requirements; Increase cardiovascular effects with adrenergics (sympathomimetics); Foods or supplements containing calcium, iron, magnesium, or zinc may bind levothyroxine and prevent complete absorption
Medication administration of Levothyroxine PO; IM; IV
Nursing interventions of Levothyroxine Assess apical pulse and BP prior to and periodically during therapy; Assess for tachyarrhythmias and chest pain; Children: monitor height, weight, and psychomotor development; Lab test considerations: monitor thyroid function studies prior to and during therapy; monitor thyroid-stimulating hormone serum levels in adults 8-12 weeks after changing from one brand to another; Monitor blood and urine glucose in diabetic patients; Insulin or oral hypoglycemic dose may need to be increased; Pedi: Monitor neonates and infants for cardiac overload, arrhythmias, and aspiration during first 2 weeks of therapy; Geri: Extremely sensitive to thyroid hormones-initial dose should be decreased; Overdose is manifested as hyperthyroidism (tachycardia, chest pain, nervousness, insomnia, diaphoresis, tremors, weight loss);
Client education of Levothyroxine Instruct patient to take medication as directed at the same time each day; Explain to patient that medication does not cure hypothyroidism, and therapy is lifelong; Advise patient to notify health care professional if headache, nervousness, diarrhea, excessive sweating, heat intolerance, chest pain, increased pulse rate, palpitations, weight loss greater than 2 lbs per week, or any unusual symptoms occur; Caution patient to avoid taking other medications concurrently with thyroid preparations unless instructed by health care professional; Emphasize the importance of follow up exams to monitor effectiveness of therapy; Pedi: Discuss with parents the need for routine follow up studies to ensure correct development; Inform patient that partial hair loss may be experienced by children on thyroid therapy, and that it is temporary
Evaluation/Desired outcomes of Levothyroxine Resolution of symptoms of hypothyroidism and normalization of hormone levels
Potential nursing diagnoses of Levothyroxine Deficient knowledge, related to medication regimen (patient/family teaching)

Section 2

Question Answer
Phenytoin (Dilantin) Anti-epileptic/Anti-convulsant; Treatment/prevention of tonic-clonic (grand mal) seizures and complex partial seizures; Used to control seizures, however does not treat all types of seizures
Phenytoin actions Limits seizure propagation by altering ion transport. May also decrease synaptic transmission. Anti-arrhythmic properties as a result of shortening the action potential and decreasing automaticity; In other words, it works by slowing down impulses in the brain that causes seizures
Phenytoin therapeutic uses Diminished seizure activity; termination of ventricular arrhythmias; Used to control seizures
Elimination/Excretion of Phenytoin Mostly metabolized by the liver; minimal amounts excreted in the urine
Adverse/Side Effects of Phenytoin Most listed are for chronic use of phenytoin: Suicidal thoughts; Ataxia; Diplopia, nystagmus; Hypotension (increase with IV phenytoin); Gingival hyperplasia, nausea; Stevens-Johnson syndrome, toxic epidermal necrolysis, hypertrichosis, rash; Agranulocytosis, aplastic anemia
Contraindications of Phenytoin Hypersensitivity; hypersensitivity to propylene glycol (phenytoin injection only); Alcohol intolerance (phenytoin injection and liquid only); sinus bradycardia, sinoatrial block, 2nd or 3rd degree heart block, or strokes-adams syndrome (phenytoin injection only); concurrent use of delavirdine
Drug/Food interactions of Phenytoin May decrease the effects of delavirdine, resulting in loss of virologic response and potential resistant (concurrent use contraindicated); Acute ingestion of alcohol, amiodarone, benzodiazepines, capecitabine, chloramphenicol, cimetidine, disulfiram estrogens, ethosuximide, felbamate, fluconazole, fluorouracil, fluoxetine, fluvastatin, fluvoxamine, gabapentin, halothane, isoniazid, oxcarbazepine, omeprazole, phenothiazines, salicylates, sertraline, succinamides, sulfonamides, ticlopidine, tolbutamide, topiramate, trazodone, voriconazole, and warfarin may increase levels; Chronic ingestion of alcohol, barbiturates, carbamazepine, fosamprenavir, nelfinavir, reserpine, ritonavir, and vigabatrin may decrease levels; May decrease the effects of amiodarone, atorvastatin, benzodiazepines, carbamazepine, corticosteroids, cyclosporine, digoxin, doxycycline, efavirenz, estrogens, fluvastatin, indinavir, lopinavir/ritonavir, methadone, mexiletine, nelfinavir, nisoldipine, oral contraceptives, paroxetine, quinidine, rifampin, ritonavir, saquinavir, simvastatin, tacrolimus, theophylline, topiramate, and warfarin; IV phenytoin and dopamine may cause additive hypotension; Additive CNS depression with other CNS depressants, including alcohol, anti-histamines, anti-depressants, opioids, and sedative/hypnotics; Antacids may decrease absorption of orally administered phenytoin; Increase systemic clearance of anti-leukemic drugs teniposide and methotrexate, which has been associated with a worse event free survival, phenytoin use is not recommended in children undergoing chemotherapy for acute lymphocytic leukemia; calcium and sucralfate decrease phenytoin absorption; St. John’s Wort may decrease levels; Phenytoin may decrease absorption of folic acid; Concurrent administration of enteral tube feedings may decrease phenytoin absorption; Folic acid may decrease levels
Medication administration of Phenytoin IM administration is not recommended due to erratic absorption and pain on injection; Oral route should be used whenever possible; PO, IV
Nursing interventions of Phenytoin Monitor closely for notable changes in behavior that could indicate the emergence or worsening of suicidal thoughts or behavior or depression; Assess oral hygiene; Assess patient for phenytoin hypersensitivity syndrome (fever, skin rash, lymphadenopathy). Rash usually occurs within the first 2 weeks of therapy. Hypersensitivity syndrome usually occurs at 3-8 weeks, yet may occur up to 12 weeks after initiation of therapy. May lead to renal failure, rhabdomyolysis, or hepatic necrosis-may be fatal; Observe patient for development of rash. Discontinue phenytoin at the first sign of skin reactions. Serious adverse reactions such as exfoliative, purpuric, or bullous rashes or the development of lupus erythematosus, Stevens-Johnson syndrome, or toxic epidermal necrolysis preclude further use of phenytoin or fosphenytoin; Genetic implication Stevens-Johnson syndrome and toxic epidermal necrolysis are significantly more common in patients with a particular human leukocyte antigen allele; Assess mental status (orientation, mood, behavior) before and periodically during therapy. Monitor closely for notable changes in behavior that could indicate the emergence or worsening of suicidal thoughts or behavior or depression; Seizures: Assess location, duration, frequency, and characteristics of seizure activity; Monitor BP, ECG, and respiratory function continuously during administration of IV phenytoin and throughout period when peak serum phenytoin levels occur (15-30 after administration); Arrhythmias: Monitor ECG continuously during treatment of arrhythmias; Lab test considerations: monitor CBC, serum calcium, albumin, and hepatic function tests prior to and monthly for the first several months, then periodically during therapy; Monitor serum folate concentrations periodically during prolonged therapy; Monitor serum phenytoin level routinely; Progressive signs and symptoms of phenytoin toxicity include nystagmus, ataxia, confusion, nausea, slurred speech, and dizziness
Client education of Phenytoin Instruct patient to take as directed, at the same time each day; Caution patient to avoid driving or other activities requiring alertness until response to medication is known; Caution patient to avoid alcohol and CNS depressants; Instruct patient on importance of maintaining good dental hygiene and seeing dentist frequently for teeth cleaning to prevent tenderness, bleeding, and gingival hyperplasia; Advise patient that brands of phenytoin may not be equivalent, and to check with health care professional if brand or dose form is changed; Advise diabetic patients to monitor blood glucose carefully; Advise patient not to take phenytoin within 2-3 hours of antacids; Advise patient to carry identification describing disease process and medication regimen at all times; Instruct patient that behavioral changes, skin rash, fever, sore throat, mouth ulcers, easy bruising, petechiae, unusual bleeding, abdominal pain, chills, pale stools, dark urine, jaundice, severe nausea or vomiting, drowsiness, slurred speech, unsteady gait, swollen glands, or persistent headache should be reported to health care professional. Advise patient and family to notify health care professional if thoughts about suicide or dying, attempts to commit suicide; new or worse depression; new or worse anxiety; feeling very agitated or restless; panic attacks; trouble sleeping; new or worse irritability; acting on dangerous impulses; an extreme increase in activity and talking, other unusual changes in behavior or mood occur. Advise female patients to use an additional non-hormonal method of contraception during therapy and until next menstrual period. Instruct patient to notify health care professional if pregnancy is planned or suspected. Encourage patients, who become pregnant, to enroll in the North American Anti-epileptic Drug (NAAED) Pregnancy Registry by calling 1-888-233-2334 or on the web at; Emphasize the importance of routine exams to monitor progress
Evaluation/Desired outcomes of Phenytoin Decrease or cessation of seizures without excessive sedation; Suppression of arrhythmias; Relief of neuropathic pain
Potential nursing diagnoses of Phenytoin Risk for injury (indications); Impaired oral mucous membranes (side effects)