M

macitentan

BLACK BOX ALERT Do not administer during pregnancy. May cause fetal harm. Exclude pregnancy before, during, and at least 1 mo after treatment. Treatment of female pts only available through restricted program called OPSUMIT Risk Evaluation and Mitigation Strategy (REMS).

Availability (Rx)

Tablets: 10 mg.

Administration/handling

PO

• Give without regard to meals. • Swallow whole; do not split, crush, or break.

Indications/routes/dosage

Pulmonary arterial hypertension

PO: ADULTS/ELDERLY: 10 mg once daily.

Side effects

Frequent (20%): Nasopharyngitis, pharyngitis. Occasional (14%–6%): Headache, anemia, bronchitis, urinary tract infection.

Adverse effects/toxic reactions

Hepatotoxicity, hepatic failure reported in 3% of pts. Decreased Hgb level below 10 g/dL occurred in 9% of pts. May decrease sperm count in males. May increase risk of influenza infection.

Nursing considerations

Baseline assessment

Obtain baseline CBC, hepatic function test. Confirm negative pregnancy status before initiating treatment. Receive full medication history.

Intervention/evaluation

Monitor hepatic/renal function test, Hgb, Hct, renal panel routinely. Monitor pregnancy status every mo during treatment and for 1 mo after discontinuation. Notify physician to obtain CXR if difficulty in breathing occurs and screen for veno-occlusive disease or pulmonary embolism. Monitor for jaundice, right upper abdominal pain, amber-colored urine, bruising.

Patient/family teaching

• May cause fetal harm. Immediately report suspected pregnancy. • Do not breastfeed. • Do not have unprotected sexual intercourse if taking only oral hormonal birth control. Consult with gynecologist for appropriate birth control methods. • Report any yellowing of skin or eyes, abdominal pain, bruising, black/tarry stools, dark urine, decreased urine output. • Swallow tablets whole; do not crush or chew.

magnesium

mag-nee-zee-um

magnesium chloride

(Mag-Delay, Slow-Mag)

magnesium citrate

(Citroma, Citro-Mag )

magnesium hydroxide

(Phillips Milk of Magnesia)

magnesium oxide

(Mag-Ox 400, Uro-Mag)

magnesium protein complex

(Mg-PLUS)

magnesium sulfate

(Epsom salt, magnesium sulfate injection)

Do not confuse magnesium sulfate with morphine sulfate.

Fixed-combination(s)

With aluminum, an antacid (Aludrox, Delcid, Gaviscon, Maalox); with aluminum and simethicone, an antiflatulent (Di-Gel, Gelusil, Maalox Plus, Mylanta); with aluminum and calcium, an antacid (Camalox); with mineral oil, a lubricant laxative (Haley’s MO); with magnesium oxide and aluminum oxide, an antacid (Riopan).

classification

CLINICAL: Antacid, anticonvulsant, electrolyte, laxative (see pp. 13C, 125C).

Action

Antacid: Acts in stomach to neutralize gastric acid. Therapeutic Effect: Increases pH. Laxative: Osmotic effect primarily in small intestine, draws water into intestinal lumen. Therapeutic Effect: Promotes peristalsis, bowel evacuation. Systemic (dietary supplement replacement): Found primarily in intracellular fluids. Therapeutic Effect: Essential for enzyme activity, nerve conduction, muscle contraction. Maintains and restores magnesium levels. Anticonvulsant: Blocks neuromuscular transmission, amount of acetylcholine released at motor end plate. Therapeutic Effect: Produces seizure control.

Pharmacokinetics

Antacid, laxative: Minimal absorption through intestine. Absorbed dose primarily excreted in urine. Systemic: Widely distributed. Primarily excreted in urine.

Uses

Magnesium chloride: Dietary supplement. Magnesium citrate: Evacuation of bowel before surgical, diagnostic procedures. Magnesium hydroxide: Short-term treatment of constipation, symptoms of hyperacidity. Magnesium oxide: Magnesium replacement. Magnesium sulfate: Treatment/prevention of hypomagnesemia; prevention and treatment of seizures in eclampsia; treatment of seizures associated with acute nephritis; torsade de pointes (atypical ventricular tachycardia); treatment of arrhythmias due to hypomagnesemia (ventricular tachycardia/ventricular fibrillation). OFF-LABEL: Magnesium sulfate: Premature labor, acute asthma, MI, tocolysis.

Precautions

Contraindications: Antacid: Appendicitis, symptoms of appendicitis, ileostomy, intestinal obstruction, severe renal impairment. Laxative: Appendicitis, HF, colostomy, hypersensitivity, ileostomy, intestinal obstruction, undiagnosed rectal bleeding. Systemic: Heart block, myocardial damage, renal failure. Cautions: Safety in children younger than 6 yrs not known. Antacids: Undiagnosed GI/rectal bleeding, ulcerative colitis, colostomy, diverticulitis, chronic diarrhea. Laxative: Diabetes mellitus, pts on low-salt diet (some products contain sugar, sodium). Systemic: Severe renal impairment.

Lifespan considerations

Pregnancy/Lactation: Antacid: Unknown if distributed in breast milk. Parenteral: Readily crosses placenta. Distributed in breast milk for 24 hrs after magnesium therapy is discontinued. Continuous IV infusion increases risk of magnesium toxicity in neonate. IV administration should not be used 2 hrs preceding delivery. Pregnancy Category B. Children: No age-related precautions noted. Elderly: Increased risk of developing magnesium deficiency (e.g., poor diet, decreased absorption, medications).

Interactions

DRUG: May decrease absorption of quinolones, tetracycline, bisphosphonates. May increase effects of antihypertensives. HERBAL: None significant. FOOD: None known. LAB VALUES: Antacid: May increase gastrin production, pH. Laxative: May decrease serum potassium. Systemic: None significant.

Availability

MAGNESIUM CHLORIDE

Tablets (Mag Delay, Slow-Mag): 64 mg.

MAGNESIUM CITRATE

Oral Solution (Citroma): 290 mg/5 ml.

MAGNESIUM HYDROXIDE

Oral Liquid (Phillips Milk of Magnesia): 400 mg/5 ml, 800 mg/5 ml.

Tablets (Chewable [Phillips Milk of Magnesia]): 311 mg.

MAGNESIUM OXIDE

Capsules (Uro-Mag): 140 mg. Tablets (Mag-Ox 400): 400 mg.

MAGNESIUM SULFATE

Infusion Solution: 10 mg/ml, 20 mg/ml, 40 mg/ml, 80 mg/ml. Injection Solution: 125 mg/ml, 500 mg/ml.

Administration/handling

IV

Reconstitution • Must dilute to maximum concentration of 20%.

Rate of Administration • For IV infusion, maximum rate of infusion is 2 g/hr.

Storage • Store at room temperature.

IM

• For adults, elderly, use 250 mg/ml (25%) or 500 mg/ml (50%) magnesium sulfate concentration. • For infants, children, do not exceed 200 mg/ml (20%).

PO (antacid)

• Shake suspension well before use. • Chewable tablets should be chewed thoroughly before swallowing, followed by full glass of water.

PO (laxative)

• Drink full glass of liquid (8 oz) with each dose (prevents dehydration). • Flavor may be improved by following with fruit juice, citrus carbonated beverage. • Refrigerate citrate of magnesia (retains potency, palatability).

IV incompatibilities

Amphotericin B complex (Abelcet, AmBisome, Amphotec), cefepime (Maxipime), lansoprazole (Prevacid), pantoprazole (Protonix).

IV compatibilities

Amikacin (Amikin), cefazolin (Ancef), ciprofloxacin (Cipro), dexmedetomidine (Precedex), dobutamine (Dobutrex), enalapril (Vasotec), gentamicin, heparin, hydromorphone (Dilaudid), insulin, linezolid (Zyvox), metoclopramide (Reglan), milrinone (Primacor), morphine, piperacillin/tazobactam (Zosyn), potassium chloride, propofol (Diprivan), tobramycin (Nebcin), vancomycin (Vancocin).

Indications/routes/dosage

Hypomagnesemia

Magnesium sulfate

Mild deficiency

IM: ADULTS, ELDERLY: 1 g q6h for 4 doses.

Severe deficiency

IM: ADULTS, ELDERLY: Up to 250 mg/kg over 4 hrs.

IV: ADULTS, ELDERLY: 1–2 g/hr for 3–6 hrs, then 0.5–1 g/hr as needed to correct deficiency. CHILDREN: 25–50 mg/kg/dose q4–6h for 3–4 doses.

Symptomatic deficiency

IV: ADULTS, ELDERLY: 1–2 g over 5–60 min.

Usual dose for children

IM/IV: 25–50 mg/kg/dose q4–6h for 3–4 doses. Maximum single dose: 2 g.

Usual dose for neonates

IM/IV: 25–50 mg/kg/dose q8–12h for 2–3 doses.

Eclampsia

IV: ADULTS: 4–5 g infusion, then 1–2 g/hr continuous infusion. Maximum: 40 g/24 hrs.

Hypertension, seizures

IV, IM (Magnesium Sulfate): ADULTS, ELDERLY: 1 g q6h for 4 doses as needed. CHILDREN: 20–100 mg/kg/dose q4–6h as needed.

Arrhythmias, torsade de pointes

IV (Magnesium Sulfate): ADULTS, ELDERLY: Initially, 1–2 g over 15 min. CHILDREN: 25–50 mg/kg/dose.

Bronchodilation

IV (Magnesium Sulfate): ADULTS, ELDERLY: 2 g as a single dose. CHILDREN: 25–75 mg/kg/dose as a single dose.

Constipation

PO (Magnesium Hydroxide): ADULTS, ELDERLY, CHILDREN 12 YRS AND OLDER: 6–8 tablets or 30–60 ml/day (400 mg/5 ml). CHILDREN 6–11 YRS: 3–4 tablets or 15–30 ml/day (400 mg/5 ml). CHILDREN 2–5 YRS: 1–2 tablets or 5–15 ml/day (400 mg/5 ml).

Hyperacidity

PO (Magnesium Hydroxide): ADULTS, ELDERLY, CHILDREN 12 YRS AND OLDER: 2–4 tablets or 5–15 ml as needed up to 4 times a day.

Magnesium deficiency

PO (Magnesium Oxide): ADULTS, ELDERLY: 1–2 tablets 2–3 times a day.

Dietary supplement

PO (Magnesium Chloride): ADULTS, ELDERLY: 2 tablets daily.

Cathartic

PO (Magnesium Citrate): ADULTS, ELDERLY, CHILDREN 12 YRS AND OLDER: 120–300 ml. CHILDREN 6–11 YRS: 100–150 ml. CHILDREN YOUNGER THAN 6 YRS: 0.5 ml/kg up to maximum of 200 ml.

Side effects

Frequent: Antacid: Chalky taste, diarrhea, laxative effect. Occasional: Antacid: Nausea, vomiting, stomach cramps. Antacid, laxative: Prolonged use or large doses in renal impairment may cause hypermagnesemia (dizziness, palpitations, altered mental status, fatigue, weakness). Laxative: Cramping, diarrhea, increased thirst, flatulence. Systemic (dietary supplement, electrolyte replacement): Reduced respiratory rate, decreased reflexes, flushing, hypotension, decreased heart rate.

Adverse effects/toxic reactions

Magnesium as antacid, laxative has no known adverse reactions. Systemic use may produce prolonged PR interval, widening of QRS interval. Magnesium toxicity may cause loss of deep tendon reflexes, heart block, respiratory paralysis, cardiac arrest. Antidote: 10–20 ml 10% calcium gluconate (5–10 mEq of calcium).

Nursing considerations

Baseline assessment

Assess sensitivity to magnesium. Antacid: Assess GI pain (duration, location, quality, time of occurrence, relief with food, causative/exacerbative factors). Laxative: Assess for weight loss, nausea, vomiting, history of recent abdominal surgery. Systemic: Assess renal function, serum magnesium.

Intervention/evaluation

Antacid: Assess for relief of gastric distress. Monitor renal function (esp. if dosing is long term or frequent). Laxative: Monitor daily pattern of bowel activity, stool consistency. Maintain adequate fluid intake. Systemic: Monitor renal function, magnesium levels, EKG for cardiac function. Test patellar reflexes (knee jerk reflexes) before giving repeat parenteral doses (used as indication of CNS depression; suppressed reflexes may be sign of impending respiratory arrest). Patellar reflex must be present, respiratory rate should be 16/min or over before each parenteral dose. Initiate seizure precautions.

Patient/family teaching

• Antacid: Take at least 2 hrs apart from other medication. • Do not take longer than 2 wks unless directed by physician. • For peptic ulcer, take 1 and 3 hrs after meals and at bedtime for 4–6 wks. • Chew tablets thoroughly, followed by 8 oz of water; shake suspensions well. • Repeat dosing or large doses may have laxative effect. • Laxative: Drink full glass (8 oz) liquid to aid stool softening. • Use only for short term. Do not use if abdominal pain, nausea, vomiting is present. • Systemic: Inform physician of any signs of hypermagnesemia (dizziness, palpitations, altered mental status, fatigue, weakness).

mannitol

man-it-ol

(Aridol, Osmitrol)

Do not confuse Osmitrol with esmolol.

BLACK BOX ALERT May result in severe bronchospasm. Not recommended in pts with asthma.

classification

PHARMACOTHERAPEUTIC: Polyol (sugar alcohol). CLINICAL: Osmotic diuretic, antiglaucoma, antihemolytic.

Action

Elevates osmotic pressure of glomerular filtrate, inhibiting tubular reabsorption of water and electrolytes, resulting in increased flow of water into interstitial fluid/plasma. Therapeutic Effect: Produces diuresis; reduces intraocular pressure (IOP), intracranial pressure (ICP), cerebral edema.

Pharmacokinetics

Route	Onset	Peak	Duration
IV (diuresis)	1–3 hrs	N/A	—
IV (reduced ICP)	15–30 min	N/A	1.5–6 hrs

Remains in extracellular fluid. Primarily excreted unchanged in urine. Removed by hemodialysis. Half-life: 4.7 hrs.

Uses

Prevention, treatment of oliguric phase of acute renal failure (before evidence of permanent renal failure). Reduces increased ICP due to cerebral edema, IOP due to acute glaucoma. Promotes urinary excretion of toxic substances. OFF-LABEL: Improve renal transplant function.

Precautions

Contraindications: Dehydration, intracranial bleeding, severe pulmonary edema, congestion, severe renal disease (anuria), progressive HF. Cautions: Concurrent nephrotoxic agents, conditions increasing sensitivity to bronchoconstriction.

Lifespan considerations

Pregnancy/Lactation: Unknown if drug crosses placenta or is distributed in breast milk. Pregnancy Category C. Children: Safety and efficacy not established in those younger than 12 yrs. Elderly: Age-related renal impairment may require dosage adjustment.

Interactions

DRUG: None significant. HERBAL: Yohimbe may decrease effects. FOOD: None known. LAB VALUES: May decrease serum phosphate, potassium, sodium.

Availability (Rx)

Injection Solution (Osmitrol): 20%, 25%.

Administration/handling

◀ ALERT ▶ Assess IV site for patency before each dose. Pain, thrombosis noted with extravasation. In-line filter (less than 5 microns) used for concentrations over 20%.

IV

Rate of Administration • Administer test dose for pts with oliguria. • Give IV push over 3–5 min; over 20–30 min for cerebral edema, elevated ICP. Maximum concentration: 25%. • Do not add KCl or NaCl to mannitol 20% or greater. Do not add to whole blood for transfusion.

Storage • Store at room temperature. • If crystals are noted in solution, warm bottle in hot water, shake vigorously at intervals. Cool to body temperature before administration. Do not use if crystals remain after warming procedure.

IV incompatibilities

Cefepime (Maxipime), filgrastim (Neupogen), imipenem-cilastatin (Primaxin).

IV compatibilities

Cisplatin (Platinol), furosemide (Lasix), linezolid (Zyvox), ondansetron (Zofran), propofol (Diprivan).

Indications/routes/dosage

Usual dosage elevated intracranial pressure

IV: ADULTS, ELDERLY: 0.25–1 g/kg/dose. May repeat q6–8h as needed. CHILDREN: 0.25–1 g/kg/dose; repeat to maintain serum osmolality <300–320 mOsm/kg.

Side effects

Frequent: Dry mouth, thirst. Occasional: Blurred vision, increased urinary frequency/volume, headache, arm pain, backache, nausea, vomiting, urticaria, dizziness, hypotension, hypertension, tachycardia, fever, angina-like chest pain.

Adverse effects/toxic reactions

Fluid, electrolyte imbalance may occur due to rapid administration of large doses or inadequate urine output resulting in overexpansion of extracellular fluid. Circulatory overload may produce pulmonary edema, HF. Excessive diuresis may produce hypokalemia, hyponatremia. Fluid loss in excess of electrolyte excretion may produce hypernatremia, hyperkalemia.

Nursing considerations

Baseline assessment

Obtain baseline B/P, pulse. Assess skin turgor, mucous membranes, mental status, muscle strength. Obtain baseline weight, chemistry studies. Assess I&O.

Intervention/evaluation

Monitor urinary output to ascertain therapeutic response. Monitor serum electrolytes, serum osmolarity, ICP, renal/hepatic function tests. Assess vital signs, skin turgor, mucous membranes. Weigh daily. Signs of hyponatremia include confusion, drowsiness, thirst, dry mouth, cold/clammy skin. Signs of hypokalemia include changes in muscle strength, tremors, muscle cramps, altered mental status, cardiac arrhythmias. Signs of hyperkalemia include colic, diarrhea, muscle twitching followed by weakness, paralysis, arrhythmias.

Patient/family teaching

• Expect increased urinary frequency/volume. • May cause dry mouth.

maraviroc

ma-ra-veer-ock

(Celsentri , Selzentry)

BLACK BOX ALERT Possible drug-induced hepatotoxicity with allergic-type features reported.

classification

PHARMACOTHERAPEUTIC: Chemokine receptor 5 (CCR5) co-receptor antagonist. CLINICAL: Antiretroviral (see pp. 70C, 121C).

Action

Binds to human chemokine receptor (CCR5), present on CD-4 and T-cell membranes, preventing interaction of HIV-1 and CCR5, necessary for HIV-1 to enter cells. Therapeutic Effect: Decreased invasion of HIV-1 virus into cells.

Pharmacokinetics

Variably absorbed following PO administration. Protein binding: 76%. Metabolized in liver. Eliminated in feces (76%), urine (20%). Half-life: 14–18 hrs.

Uses

Treatment of HIV infection in pts infected only with detectable chemokine receptor 5 (CCR5)-tropic HIV-1, with evidence of viral replication; HIV-1 strains resistant to multiple antiretroviral agents. Used in combination with at least two other antiretroviral agents.

Precautions

Contraindications: Severe renal impairment or ESRD (CrCl less than 30 ml/min) who are taking potent CYP3A4 inhibitors or inducers. Cautions: Mild to moderate hepatic/renal impairment, history of orthostatic hypotension, hepatitis B or C, concurrent medication known to lower B/P, pts at increased risk for cardiovascular events.

Lifespan considerations

Pregnancy/Lactation: Unknown if drug crosses placenta or is distributed in breast milk. Breastfeeding not recommended. Pregnancy Category B. Children: Safety and efficacy not established in those younger than 16 yrs. Elderly: Age-related hepatic/renal impairment requires close monitoring.

Interactions

DRUG: CYP3A4 inhibitors (e.g., atazanavir, atazanavir/ritonavir, ketoconazole, lopinavir, ritonavir, saquinavir/ritonavir) may increase concentration. CYP3A4 inducers (e.g., efavirenz, rifampin) may decrease concentration. HERBAL: St. John’s wort may lead to loss of virologic response, potential resistance to maraviroc. FOOD: Grapefruit products may increase orthostatic hypotension. LAB VALUES: May increase serum AST, ALT, bilirubin, amylase, lipase. May decrease lymphocytes/neutrophil count.

Availability (Rx)

Tablets: 150 mg, 300 mg.

Administration/handling

PO

• Give without regard to food. • Do not break, crush, dissolve, or divide film-coated tablets.

Indications/routes/dosage

HIV infection

PO: ADULTS, ELDERLY, CHILDREN OVER 16 YRS WITH CONCURRENT ANTIRETROVIRAL AGENTS: 300 mg twice a day. With CYP3A4 inhibitors: (e.g., clarithromycin, delavirdine, itraconazole, ketoconazole): 150 mg twice a day. With CYP3A4 inducers: (e.g., carbamazepine, efavirenz, phenobarbital, phenytoin, rifampin): 600 mg twice a day.

Dosage in renal impairment

Creatinine clearance 30 ml/min or greater
CYP3A4 inhibitors	150 mg twice daily
CYP3A4 inducers	600 mg twice daily
Creatinine clearance less than 30 ml/min: 150 mg twice daily
CYP3A4 inhibitors	Not recommended
Postural hypotension	150 mg twice daily

Side effects

Common (20%): Upper respiratory tract infection. Frequent (13%–7%): Cough, fever, rash, musculoskeletal pain, abdominal pain, dizziness, appetite change, herpes simplex infection, sleep disturbances. Occasional (6%–4%): Sinusitis, joint pain, bronchitis, constipation, bladder infection, paresthesia, sensory abnormalities. Rare (3% or less): Sleep disturbances, pruritus, peripheral neuropathy, dermatitis, dyspepsia.

Adverse effects/toxic reactions

Cardiovascular events (MI, ischemia, unstable angina, coronary artery occlusion/disease), CVA, hepatic failure/cirrhosis, neoplasms were reported.

Nursing considerations

Baseline assessment

Obtain baseline laboratory testing, esp. hepatic function tests, before beginning therapy and at periodic intervals during therapy. Offer emotional support. Obtain medication history.

Intervention/evaluation

Closely monitor for evidence of GI discomfort. Monitor daily pattern of bowel activity, stool consistency. Assess skin for evidence of rash. Monitor serum chemistry tests for marked laboratory abnormalities, particularly hepatic profile. Assess for opportunistic infections: onset of fever, cough, or other respiratory symptoms.

Patient/family teaching

• Report fever, abdominal pain, jaundice, dark urine. • Avoid tasks that require alertness, motor skills until response to drug is established. • Maraviroc is not a cure for HIV infection, nor does it reduce risk of transmission to others. • May continue to experience illnesses, including opportunistic infections.

meclizine

mek-li-zeen

(Antivert, Bonine, Dramamine Less Drowsy Formula)

Do not confuse Antivert with Alavert or Axert.

classification

PHARMACOTHERAPEUTIC: Anticholinergic. CLINICAL: Antiemetic, antivertigo.

Action

Reduces labyrinthine excitability, diminishes vestibular stimulation of labyrinth, affecting chemoreceptor trigger zone. Therapeutic Effect: Reduces nausea, vomiting, vertigo.

Pharmacokinetics

Route	Onset	Peak	Duration
PO	30–60 min	N/A	8–24 hrs

Well absorbed from GI tract. Widely distributed. Metabolized in liver. Primarily excreted in urine. Half-life: 6 hrs.

Uses

Prevention/treatment of nausea, vomiting, vertigo due to motion sickness. Treatment of vertigo associated with diseases affecting vestibular system.

Precautions

Contraindications: None known. Cautions: Narrow-angle glaucoma, obstructive diseases of GI/GU tract, asthma, prostatic hyperplasia, CNS disorders where CNS depression is present.

Lifespan considerations

Pregnancy/Lactation: Unknown if drug crosses placenta or is distributed in breast milk (may produce irritability in nursing infants). Pregnancy Category B. Children/Elderly: May be more sensitive to anticholinergic effects (e.g., dry mouth).

Interactions

DRUG: Alcohol, CNS depressants may increase CNS depressant effect. HERBAL: None significant. FOOD: None known. LAB VALUES: May produce false-negative results in antigen skin testing unless meclizine is discontinued 4 days before testing.

Availability (Rx)

Tablets (Antivert): 12.5 mg, 25 mg, 50 mg. (Dramamine Less Drowsy Formula): 25 mg. Tablets (Chewable): 25 mg.

Administration/handling

PO

• Give without regard to meals. • Scored tablets may be crushed.

Indications/routes/dosage

Motion sickness

PO: ADULTS, ELDERLY, CHILDREN 12 YRS AND OLDER: 25–50 mg 1 hr before travel. May repeat q12–24h.

Vertigo

PO: ADULTS, ELDERLY, CHILDREN 12 YRS AND OLDER: 25–100 mg/day in divided doses, as needed.

Side effects

Frequent: Drowsiness. Occasional: Blurred vision, dry mouth, nose, throat.

Adverse effects/toxic reactions

Hypersensitivity reaction (eczema, pruritus, rash, cardiac disturbances, photosensitivity) may occur. Overdose may vary from CNS depression (sedation, apnea, cardiovascular collapse, death) to severe paradoxical reaction (hallucinations, tremor, seizures). Children may experience paradoxical reaction (restlessness, insomnia, euphoria, anxiety, tremors). Overdose in children may result in hallucinations, seizures, death.

Nursing considerations

Baseline assessment

Assess degree of nausea/vomiting, degree of vertigo.

Intervention/evaluation

Monitor B/P, esp. in elderly (increased risk of hypotension). Monitor children closely for paradoxical reaction. Monitor serum electrolytes in pts with severe vomiting. Assess skin turgor, mucous membranes to evaluate hydration status.

Patient/family teaching

• Tolerance to sedative effect may occur. • Avoid tasks that require alertness, motor skills until response to drug is established. • Dry mouth, drowsiness, dizziness may be an expected response to drug. • Avoid alcohol. • Sugarless gum, sips of water may relieve dry mouth. • Coffee, tea may help reduce drowsiness.

*medroxyPROGESTERone

me-drox-e-proe-jes-te-rone

(Apo-Medroxy , Depo-Provera, Depo-Provera Contraceptive, Depo-SubQ Provera 104, Novo-Medrone , Provera)

BLACK BOX ALERT Prolonged use (over 2 yrs) of contraceptive injection form may result in loss of bone mineral density. May increase risk of dementia in postmenopausal women. Increased risk of invasive breast cancer in postmenopausal women in combination with conjugated estrogens.

Do not confuse medroxyprogesterone with hydroxyprogesterone, methylprednisolone, or methyltestosterone, or Provera with Covera, Femara, Parlodel, or Premarin.

classification

PHARMACOTHERAPEUTIC: Hormone. CLINICAL: Progestin, antineoplastic.

Action

Transforms endometrium from proliferative to secretory (in estrogen-primed endometrium). Inhibits secretion of pituitary gonadotropins. Therapeutic Effect: Prevents follicular maturation, ovulation. Stimulates growth of mammary alveolar tissue; relaxes uterine smooth muscle. Corrects hormonal imbalance.

Pharmacokinetics

Well absorbed after PO administration. Slowly absorbed after IM administration. Protein binding: 90%. Metabolized in liver. Primarily excreted in urine. Half-life: PO: 12–17 hrs. IM: 40–50 days.

Uses

PO: Reduction of endometrial hyperplasia in nonhysterectomized postmenopausal women (concurrently given with estrogen to women with intact uterus), treatment of secondary amenorrhea, abnormal uterine bleeding due to hormonal imbalance. IM: Adjunctive therapy, palliative treatment of inoperable, recurrent, metastatic endometrial carcinoma; prevention of pregnancy; endometriosis-associated pain. OFF-LABEL: Treatment of endometrial, stromal carcinoma.

Precautions

Contraindications: Carcinoma of breast, estrogen-dependent neoplasm, history of or active thrombotic disorders (cerebral apoplexy, thrombophlebitis, thromboembolic disorders), known or suspected pregnancy, missed abortion, severe hepatic dysfunction, undiagnosed abnormal vaginal bleeding, cerebrolvascular disease, use as pregnancy test. Cautions: Those with conditions aggravated by fluid retention (asthma, seizures, migraine, cardiac/renal dysfunction), diabetes, history of mental depression, preexisting hypertriglyceremia.

Lifespan considerations

Pregnancy/Lactation: Avoid use during pregnancy, esp. first 4 mos (congenital heart, limb reduction defects may occur). Distributed in breast milk. Pregnancy Category X. Children: Safety and efficacy not established. Elderly: No age-related precautions noted.

Interactions

DRUG: CYP3A inducers (e.g., carbamazepine, phenytoin, rifampin) may decrease effect. HERBAL: St. John’s wort may decrease effect of progestin contraceptive. FOOD: None known. LAB VALUES: May alter serum thyroid, hepatic function tests, PT, metapyrone test, HDL, total cholesterol, triglycerides. May increase LDL.

Availability (Rx)

Injection Suspension: 104 mg/0.65 ml prefilled syringe (Depo-SubQ Provera 104), 150 mg/ml (Depo-Provera Contraceptive), 400 mg/ml (Depo-Provera). Tablets (Provera): 2.5 mg, 5 mg, 10 mg.

Administration/handling

IM

• Shake vial immediately before administering (ensures complete suspension). • Administer deep IM into gluteal or deltoid muscle.

Subcutaneous

• Shake vigorously prior to administration. • Inject in upper thigh or abdomen (avoid bony areas and umbilicus). • Give over 5–7 sec; do not rub injection area.

PO

• Give with food.

Indications/routes/dosage

Endometrial hyperplasia

PO: ADULTS: 2.5–10 mg/day for 12–14 consecutive days each month starting on day 1 or 16 of cycle.

Secondary amenorrhea

PO: ADULTS: 5–10 mg/day for 5–10 days, beginning at any time during menstrual cycle.

Abnormal uterine bleeding

PO: ADULTS: 5–10 mg/day for 5–10 days, beginning on calculated day 16 or day 21 of menstrual cycle.

Endometrial carcinoma

IM: ADULTS, ELDERLY: Initially, 400–1,000 mg; repeat at 1-wk intervals. If improvement occurs and disease is stabilized, begin maintenance with as little as 400 mg/mo.

Pregnancy prevention

IM (Depo-Provera Contraceptive): ADULTS: 150 mg q3mos.

Subcutaneous (Depo-Subq Provera 104): ADULTS: 104 mg q3mos (q12–14wks).

Endometriosis-associated pain

Subcutaneous (Depo-Subq Provera 104): ADULTS: 104 mg q3mos (q12–14 wks) for up to 2 yrs.

Side effects

Frequent: Transient menstrual abnormalities (spotting, change in menstrual flow/cervical secretions, amenorrhea) at initiation of therapy. Occasional: Edema, weight change, breast tenderness, anxiety, insomnia, fatigue, dizziness. Rare: Alopecia, depression, dermatologic changes, headache, fever, nausea.

Adverse effects/toxic reactions

Thrombophlebitis, pulmonary/cerebral embolism, retinal thrombosis occur rarely.

Nursing considerations

Baseline assessment

Obtain usual menstrual history. Question for hypersensitivity to progestins, possibility of pregnancy before initiating therapy (Pregnancy Category X). Obtain baseline weight, serum glucose, B/P.

Intervention/evaluation

Check weight daily; report weekly gain of 5 lb or more. Assess B/P periodically. Assess skin for rash, urticaria. Report development of chest pain, sudden shortness of breath, sudden decrease in vision, migraine headache, pain (esp. with swelling, warmth, redness) in calves, numbness of arm/leg (thrombotic disorders) immediately.

Patient/family teaching

• Inform physician of sudden loss of vision, severe headache, chest pain, coughing up of blood (hemoptysis), numbness in arm/leg, severe pain/swelling in calf, unusual heavy vaginal bleeding, severe abdominal pain/tenderness. • Depo-Provera Contraceptive injection should be used as long-term birth control method (e.g., longer than 2 yrs) only if other birth control methods are inadequate.

megestrol

meh-jes-trol

(Apo-Megestrol , Megace, Megace ES, Megace OS )

Do not confuse megestrol with mesalamine.

classification

PHARMACOTHERAPEUTIC: Synthetic hormone. CLINICAL: Antineoplastic (see p. 88C).

Action

Suppresses release of luteinizing hormone (LH) from anterior pituitary gland by inhibiting pituitary function. Therapeutic Effect: Reduces tumor size. Increases appetite.

Pharmacokinetics

Well absorbed from GI tract. Metabolized in liver. Excreted in urine. Half-life: 13–105 hrs (mean 34 hrs).

Uses

Palliative management of recurrent, inoperable, metastatic endometrial or breast carcinoma; treatment of anorexia, cachexia, unexplained significant weight loss in pts with AIDS.

Precautions

Contraindications: Suspension: Known or suspected pregnancy, concomitant use with doftilide. Cautions: History of thrombophlebitis, diabetes.

Lifespan considerations

Pregnancy/Lactation: If possible, avoid use during pregnancy, esp. first 4 mos. Breastfeeding not recommended. Pregnancy Category D (tablets), X (suspension). Children: Safety and efficacy not established. Elderly: No age-related precautions noted.

Interactions

DRUG: None significant. HERBAL: Avoid black cohosh, dong quai in estrogen-dependent tumors. Avoid herbs with progestogenic properties (e.g., chasteberry); may increase adverse effects. FOOD: None known. LAB VALUES: May alter serum thyroid, hepatic function tests, PT, HDL, total cholesterol, triglycerides. May increase LDL.

Availability (Rx)

Oral Suspension: 40 mg/ml (Megace), 125 mg/ml (Megace ES). Tablets (Megace): 20 mg, 40 mg.

Administration/handling

PO

• Store tablets, oral suspension at room temperature. • Shake suspension well before use. • Oral suspension compatible with water, orange juice, apple juice. • Administer without regard to food.

Indications/routes/dosage

Palliative treatment of advanced breast cancer

PO: ADULTS, ELDERLY: 160 mg/day in 4 equally divided doses.

Palliative treatment of advanced endometrial carcinoma

PO: ADULTS, ELDERLY: 40–320 mg/day in divided doses. Maximum: 800 mg/day in divided doses.

Anorexia, cachexia, weight loss

PO (Megace): ADULTS, ELDERLY: 800 mg (20 ml)/day.

PO (Megace ES): ADULTS, ELDERLY: 625 mg/day.

Side effects

Frequent: Weight gain secondary to increased appetite. Occasional: Nausea, breakthrough menstrual bleeding, backache, headache, breast tenderness, carpal tunnel syndrome. Rare: Feeling of coldness.

Adverse effects/toxic reactions

Thrombophlebitis, pulmonary embolism occur rarely.

Nursing considerations

Baseline assessment

Question for possibility of pregnancy (Pregnancy Category D [tablets]; X [suspension]). Provide support to pt, family, recognizing this drug is palliative, not curative.

Intervention/evaluation

Monitor for tumor response. Monitor pt weight, caloric intake (appetite stimulant).

Patient/family teaching

• Contraception is imperative. • Report lower leg (calf) pain, difficulty breathing, vaginal bleeding. • May cause headache, nausea, vomiting, breast tenderness, backache.

meloxicam

mel-ox-i-kam

(Apo-Meloxicam , Mobic, Novo-Meloxicam )

BLACK BOX ALERT Increased risk of serious cardiovascular thrombotic events, including myocardial infarction, CVA. Increased risk of severe GI reactions, including ulceration, bleeding, GI perforation.

classification

PHARMACOTHERAPEUTIC: NSAID. CLINICAL: Anti-inflammatory, analgesic (see p. 130C).

Action

Produces analgesic, anti-inflammatory effects by inhibiting prostaglandin synthesis. Therapeutic Effect: Reduces inflammatory response, intensity of pain.

Pharmacokinetics

Route	Onset	Peak	Duration
PO (analgesic)	30 min	4–5 hrs	N/A

Well absorbed after PO administration. Protein binding: 99%. Metabolized in liver. Eliminated in urine, feces. Not removed by hemodialysis. Half-life: 15–20 hrs.

Uses

Relief of signs/symptoms of osteoarthritis, rheumatoid arthritis (RA). Treatment of juvenile rheumatoid arthritis (JRA).

Precautions

Contraindications: History of asthma, urticaria with NSAIDs, perioperative pain in setting of CABG surgery. Cautions: Renal/hepatic impairment, asthma, coagulation disorders, hypertension, history of GI disease. Concurrent use of anticoagulants.

Lifespan considerations

Pregnancy/Lactation: Distributed in breast milk. Pregnancy Category C (D if used in third trimester or near delivery). Children: Safety and efficacy not established. Elderly: Age-related renal impairment may require dosage adjustment. More susceptible to GI toxicity; lower dosage recommended.

Interactions

DRUG: May decrease antihypertensive effects of ACE inhibitors. May increase risk of nephrotoxicity with cyclosporine. Aspirin may increase risk of epigastric distress (heartburn, indigestion). Warfarin, aspirin may increase risk of bleeding. May increase concentration, risk of toxicity of lithium. HERBAL: Cat’s claw, dong quai, evening primrose, feverfew, garlic, ginger, ginkgo, green tea, red clover, SAMe may increase antiplatelet activity, risk of bleeding. FOOD: None known. LAB VALUES: May increase serum creatinine, AST, ALT.

Availability (Rx)

Oral Suspension: 7.5 mg/5 ml. Tablets: 7.5 mg, 15 mg.

Administration/handling

PO

• Give with food or milk to minimize GI irritation. Shake oral suspension gently before administering.

Indications/routes/dosage

Osteoarthritis, rheumatoid arthritis (RA)

PO: ADULTS, ELDERLY: Initially, 7.5 mg/day. Maximum: 15 mg/day (7.5 mg for pts on dialysis).

Juvenile rheumatoid arthritis (JRA)

PO: CHILDREN, 2 YRS AND OLDER: 0.125 mg/kg once daily. Maximum: 7.5 mg.

Side effects

Frequent (9%–7%): Dyspepsia, headache, diarrhea, nausea. Occasional (4%–3%): Dizziness, insomnia, rash, pruritus, flatulence, constipation, vomiting. Rare (less than 2%): Drowsiness, urticaria, photosensitivity, tinnitus.

Adverse effects/toxic reactions

In pts treated chronically, peptic ulcer, GI bleeding, gastritis, severe hepatic reaction (jaundice), nephrotoxicity (hematuria, dysuria, proteinuria), severe hypersensitivity reaction (bronchospasm, angioedema) occur rarely.

Nursing considerations

Baseline assessment

Assess onset, type, location, duration of pain/inflammation. Inspect appearance of affected joints for immobility, deformities, skin condition.

Intervention/evaluation

Monitor CBC, hepatic/renal function tests. Assess skin for petechiae. Assess for therapeutic response: relief of pain, stiffness, swelling; increased joint mobility; reduced joint tenderness; improved grip strength.

Patient/family teaching

• Take with food, milk to reduce GI upset. • Report tinnitus, persistent abdominal pain/cramping, severe nausea, vomiting, difficulty breathing, unusual bruising or bleeding, rash, peripheral edema, chest pain, palpitations.

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Tags: Saunders Nursing Drug Handbook 2015

Mar 8, 2017 | Posted by admin in NURSING | Comments Off

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