Mosby's 2014 Nursing Drug Reference (272 page)

BOOK: Mosby's 2014 Nursing Drug Reference
13.45Mb size Format: txt, pdf, ePub
minoxidil (Rx,
OTC
)

(mi-nox′i-dill)

Loniten, Rogaine (topical)

Func. class.:
Antihypertensive

Chem. class.:
Vasodilator, peripheral

Do not confuse:
minoxidil
/Monopril
Loniten
/Lipitor

ACTION:

Directly relaxes arteriolar smooth muscle, causing vasodilation; reduces peripheral vascular resistance, decreases B/P

USES:

Severe hypertension unresponsive to other therapy (use with diuretic and β-blocker); topically to treat alopecia

Unlabeled uses:
Scleroderma renal crisis (SRC) to control hypertension

CONTRAINDICATIONS:

Dissecting aortic aneurysm, hypersensitivity, pheochromocytoma

 

Black Box Warning:

Acute MI

Precautions:
Pregnancy (C), breastfeeding, children, geriatric patients, renal disease, CVD

 

Black Box Warning:

CAD, CHF, cardiac disease, cardiac tamponade, edema, hypotension, orthostatic hypotension, pericardial effusion

DOSAGE AND ROUTES
Calculator
Severe hypertension

• Adult:
PO
2.5-5 mg/day in 1-2 divided doses; max 100 mg/day; usual range 10-40 mg/day in single dose

• Geriatric:
PO
2.5 mg/day, may be increased gradually

• Child <12 yr:
PO
(initial) 0.1-0.2 mg/kg/day; (effective range) 0.25-1 mg/kg/day; (max) 50 mg/day

Alopecia

• Adult:
TOP
1 ml bid, rub into scalp daily, max 2 ml/day

Scleroderma renal crisis (unlabeled)

• Adult:
PO
5 mg/day in 1-2 divided doses, increase after 3 days by 10-20 mg/day to reach desired B/P, max 100 mg/day

Available forms:
Tabs 2.5, 10 mg; topical 2%, 5% sol; topical foam 5%

Administer:
PO route

• 
With meals for better absorption, to decrease GI symptoms

• 
With β-blocker and/or diuretic for hypertension

Topical route

• 
1 ml no matter how much balding has occurred; increasing dosage does not speed growth

SIDE EFFECTS
Systemic

CNS:
Headache, fatigue

CV:
Severe rebound hypertension on withdrawal in children
, tachycardia, angina, increased T wave,
CHF, pulmonary edema, pericardial effusion,
edema, sodium, water retention, hypotension

GI:
Nausea, vomiting

GU:
Breast tenderness

HEMA:
Hct, Hgb; erythrocyte count may decrease initially

INTEG:
Pruritus,
Stevens-Johnson syndrome,
rash, hirsutism

PHARMACOKINETICS

PO:
Onset 30 min, peak 2-3 hr, duration 48-120 hr; half-life 4.2 hr; metabolized in liver; metabolites excreted in urine, feces; protein binding minimal

INTERACTIONS

Increase:
hypotension—antihypertensives, MAOIs

Decrease:
antihypertensive effect—NSAIDs, salicylates, estrogens

Drug/Herb

Increase:
antihypertensive effect—hawthorn

Drug/Lab Test

Increase:
renal studies

Decrease:
Hgb/Hct/RBC

NURSING CONSIDERATIONS
Assess:

 
Monitor closely; usually given with β-blocker to prevent tachycardia and increased myocardial workload; usually given with diuretic to prevent serious fluid accumulation; patient should be hospitalized during beginning treatment

• 
Nausea, edema in feet, legs daily

• 
Skin turgor, dryness of mucous membranes for hydration status

• 
Crackles, dyspnea, orthopnea

• 
Electrolytes: potassium, sodium, chloride, CO
2

• 
Renal studies: catecholamines, BUN, creatinine

• 
Hepatic studies: AST, ALT, alk phos

• 
B/P, pulse

• 
Weight daily, I&O

Perform/provide:

• 
Storage protected from light and heat

Evaluate:

• 
Therapeutic response: decreased B/P, increased hair growth

Teach patient/family:

• 
That body hair will increase but is reversible after discontinuing treatment

• 
Not to discontinue product abruptly

• 
To report pitting edema, dizziness, weight gain >5 lb, SOB, bruising or bleeding, heart rate >20 beats/min over normal, severe indigestion, dizziness, lightheadedness, panting, new or aggravated symptoms of angina

• 
To take product exactly as prescribed because serious side effects may occur

Topical

• 
That for topical use, treatment must continue for the long term, or new hair will be lost

• 
Not to use except on scalp

TREATMENT OF OVERDOSE:

Administer normal saline IV, vasopressors

Canada only   Side effects:
italics
= common;
bold
= life-threatening   
Nurse Alert

mirtazapine (Rx)

(mer-ta′za-peen)

Remeron, Remeron Soltab

Func. class.:
Antidepressant

Chem. class.:
Tetracyclic

ACTION:

Blocks reuptake of norepinephrine and serotonin into nerve endings, thereby increasing action of norepinephrine and serotonin in nerve cells; antagonist of central α
2
-receptors; blocks histamine receptors

USES:

Depression; dysthymic disorder; bipolar disorder: depressed, agitated depression

Unlabeled uses:
Resting tremor, benign familial tremor, levodopa-induced dyskinesias, pruritus

CONTRAINDICATIONS:

Hypersensitivity to tricyclics, recovery phase of MI, agranulocytosis, jaundice

Precautions:
Pregnancy (C), geriatric patients, suicidal patients, severe depression, increased intraocular pressure, closed-angle glaucoma, urinary retention, cardiac/renal/hepatic disease, hypo/hyperthyroidism, electroshock therapy, elective surgery, seizure disorder, bone marrow suppression, thrombocytopenia

 

Black Box Warning:

Suicidal ideation, children

DOSAGE AND ROUTES
Calculator

• Adult:
PO
15 mg/day at bedtime, maintenance to continue for 6 mo, titrate up to 45 mg/day;
ORALLY DISINTEGRATING
tabs: open blister pack, place tab on tongue, allow to disintegrate, swallow

• Geriatric:
PO
7.5 mg at bedtime, increase by 7.5 mg q1-2wk to desired dose, max 45 mg/day

Resting tremor/benign familial tremor/levodopa-induced dyskinesias (unlabeled)

• Adult:
PO
titrate up to 30 mg at bedtime

Pruritus (unlabeled)

• Adult:
PO
15-30 mg/day

Available forms:
Tabs 7.5, 15, 30, 45 mg; orally disintegrating tab (Soltab) 15, 30, 45 mg

Administer:

• 
Increased fluids, bulk in diet for constipation, especially for geriatric patients

• 
With food, milk for GI symptoms

• 
Dosage at bedtime if oversedation occurs during day; may take entire dose at bedtime; geriatric patients may not tolerate once daily dosing

• 
Gum, hard candy, or frequent sips of water for dry mouth

• 
Orally disintegrating tab:
no water needed; allow to dissolve on tongue, do not split

SIDE EFFECTS

CNS:
Dizziness, drowsiness
, confusion, headache, anxiety, tremors, stimulation, weakness, nightmares, EPS (geriatric patients), increased psychiatric symptoms,
seizures

CV:
Orthostatic hypotension, ECG changes, tachycardia
,
hypertension,
palpitations

EENT:
Blurred vision
, tinnitus, mydriasis

GI:
Diarrhea, dry mouth
, nausea, vomiting,
paralytic ileus,
increased appetite, cramps, epigastric distress, constipation,
jaundice, hepatitis,
stomatitis, weight gain

GU:
Urinary retention
,
acute renal failure

HEMA:
Agranulocytosis, thrombocytopenia, eosinophilia, leukopenia

INTEG:
Rash, urticaria, sweating, pruritus, photosensitivity

SYST:
Flulike symptoms, increased cholesterol levels

PHARMACOKINETICS

PO:
Peak 2 hr, metabolized by CYP1A2, 2D6, 3A4 in liver; excreted in urine, feces; crosses placenta; half-life 20-40 hr, protein binding 85%

INTERACTIONS

 
Increase: hyperpyretic crisis, seizures, hypertensive episode—MAOIs

Increase:
CNS depression—alcohol, barbiturates, benzodiazepines, other CNS depressants

Increase:
serotonin syndrome—SSRIs, SNRIs, serotonin-receptor agonists, fenfluramine, dexfenfluramine, sibutramine, nefazodone

Decrease:
effects of cloNIDine, indirect-acting sympathomimetics (ePHEDrine)

Drug/Herb

• 
Serotonin syndrome: St. John’s wort

Increase:
CNS depression—kava

Drug/Lab Test

Increase:
serum bilirubin, blood glucose, alk phos

Decrease:
VMA, 5-HIAA

False increase:
urinary catecholamines

NURSING CONSIDERATIONS
Assess:

• 
B/P (lying, standing), pulse q4hr; if systolic B/P drops 20 mm Hg, hold prod
uct, notify prescriber; vital signs q4hr in patients with CV disease

• 
Blood studies: CBC, leukocytes, differential, cardiac enzymes, lipid profile, blood glucose if patient is receiving long-term therapy

• 
Hepatic studies: AST, ALT, bilirubin, creatinine

• 
Weight weekly; appetite may increase with product

• 
ECG for flattening of T wave, bundle branch block, AV block, dysrhythmias in cardiac patients

 

Black Box Warning:

Mental status: mood, sensorium, affect, suicidal tendencies (especially among adolescents, young adults), increase in psychiatric symptoms: depression, panic; EPS primarily in geriatric patients: rigidity, dystonia, akathisia

 
Serotonin syndrome:
hyperthermia, hypertension, myoclonus, rigidity, delirium, coma; if using other serotonergic products

• 
Alcohol consumption; if alcohol consumed, hold dose until morning

Perform/provide:

• 
Storage in tight container at room temp; do not freeze

• 
Assistance with ambulation during beginning therapy, since drowsiness, dizziness occurs

Evaluate:

• 
Therapeutic response: decreased depression

Teach patient/family:

• 
That therapeutic effects may take 2-3 wk; to take at bedtime; that there is decreased sedation with increased doses

• 
To use caution when driving, performing other activities requiring alertness because of drowsiness, dizziness, blurred vision

• 
To avoid alcohol, other CNS depressants

• 
About how to take orally disintegrating tabs; dissolve on tongue, swallow

• 
Not to use within 14 days of MAOIs

 

Black Box Warning:

To notify prescriber of suicidal thoughts, behavior

TREATMENT OF OVERDOSE:

ECG monitoring, lavage, activated charcoal; administer anticonvulsant, IV fluids

Other books

The Reaches by David Drake
Jake's Wake by Cody Goodfellow, John Skipp
The Seventh Trumpet by Peter Tremayne
True Beginnings by Willow Madison
Closer Still by Jo Bannister
The Rose of Provence by Susanna Lehner
The Return of Black Douglas by Elaine Coffman
The road by Cormac McCarthy