Mosby's 2014 Nursing Drug Reference (257 page)

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

mercaptopurine (6-MP) (Rx)

(mer-kap-toe-pyoor′een)

Purinethol

Func. class.:
Antineoplastic-antimetabolite

Chem. class.:
Purine analog

ACTION:

Inhibits purine metabolism at multiple sites, which inhibits DNA and RNA synthesis; specific for S phase of cell cycle

USES:

Acute lymphocytic leukemia

Unlabeled uses:
Ulcerative colitis, Crohn’s disease

CONTRAINDICATIONS:

Pregnancy (D), breastfeeding, patients with prior product resistance, hypersensitivity, requires an experienced clinician, secondary malignancy, infection, hypocalcemia, hyperuricemia, hyperphosphatemia, hyperkalemia

Precautions:
Renal/hepatic disease, tumor lysis syndrome, dental disease, herpes, radiation therapy, leukopenia, thrombocytopenia, anemia

DOSAGE AND ROUTES
Calculator
Acute lymphocytic leukemia

• Adult:
PO
2.5-5 mg/kg/day or 80-100 mg/m
2
/day, maintenance 1.5-2.5 mg/kg/day

• Child:
PO
2.5-5 mg/kg/day, maintenance 1.5-2.5 mg/kg/day or 70-100 mg/m
2
/day

Crohn’s disease/ulcerative colitis (unlabeled)

• Adult:
PO
1.5-2 mg/kg/day

Available forms:
Tabs 50 mg

Administer:

• 
Give product after evening meal, before bedtime, on an empty stomach

• 
Sodium bicarbonate to maintain uric acid levels, alkalinization of urine

SIDE EFFECTS

CNS:
Weakness

GI:
Nausea, vomiting, anorexia, diarrhea, stomatitis
,
hepatotoxicity
(high doses), jaundice, gastritis,
pancreatitis

GU:
Renal failure,
hyperuricemia,
oliguria,
crystalluria,
hematuria

HEMA:
Thrombocytopenia, leukopenia, myelosuppression, anemia

INTEG:
Rash
, dry skin, urticaria, alopecia

PHARMACOKINETICS

Incompletely absorbed when taken orally, metabolized in liver, excreted in urine, peak 1-2 hr, terminal half-life 1-1.5 hr

INTERACTIONS

Increase:
effects of mercaptopurine—allopurinol, avoid use of decrease dose

Increase:
effects—radiation or other antineoplastics, immunosuppressants

Increase:
bone marrow depression—azaTHIOprine, sulfamethoxazole-trimethoprim, avoid concurrent use

Increase:
anticoagulant action—anticoagulants, NSAIDs, thrombolytics, platelet inhibitors, salicylates

Decrease:
antibodies—live virus vaccines

Decrease:
TPMT, rapid bone marrow suppression—balzalazide, olsalazine, mesalamine, sulfaSALAzine, use cautiously

NURSING CONSIDERATIONS
Assess:

 
Bone marrow suppression:
CBC, differential, platelet count weekly; withhold product at first sign of abnormally large decrease in blood counts, unless bone marrow aplasia is the goal

• 
Thiopurine methyltransferase (TPMT) deficiency:
individuals are prone to rapid bone marrow suppression, dosage reduction may be required in homozygous-TPMT-deficient persons

• 
Tumor lysis syndrome:
monitor for increased potassium, uric acid, phosphate, decreased urine output, calcium

• 
Renal studies: BUN, serum uric acid, urine CCr, electrolytes before, during therapy

• 
I&O ratio; report fall in urine output to <30 ml/hr

• 
Monitor temp; fever may indicate beginning infection; no rectal temp

• 
Hepatotoxicity:
Hepatic studies before, during therapy: bilirubin, alk phos, AST, ALT, weekly during beginning therapy, hepatic encephalopathy, toxic hepatitis, ascites can be fatal

• 
Bleeding:
hematuria, guaiac, bruising, petechiae, mucosa or orifices, avoid IM inj if platelets are low; blood transfusions may be needed

• 
Stomatitis:
buccal cavity for dryness, sores, ulceration, white patches, oral pain, bleeding, dysphagia

Perform/provide:

• 
Increase fluid intake to 2-3 L/day to prevent urate deposits, calculi formation, unless contraindicated

• 
Rinsing of mouth tid-qid with water, club soda; brushing of teeth bid-tid with soft brush or cotton-tipped applicators for stomatitis; use unwaxed dental floss

• 
Storage in tightly closed container in cool environment

Evaluate:

• 
Therapeutic response: decreased size of tumor, spread of malignancy

Teach patient/family:

• 
To avoid foods with citric acid, hot or rough texture for stomatitis; to report stomatitis: any bleeding, white spots, ulcerations in mouth; to examine mouth daily, report symptoms

• 
Pregnancy:
That contraceptive measures recommended during therapy (D); to avoid breastfeeding

• 
To drink 10-12 8-oz glasses of fluid/day

• 
To notify prescriber of fever, chills, sore throat, nausea, vomiting, anorexia, diarrhea, bleeding, bruising, which may indicate blood dyscrasias/infection

• 
To report signs of infection: fever, sore throat, flulike symptoms

• 
To report signs of anemia: fatigue, headache, faintness, SOB, irritability

• 
To report bleeding; to avoid use of razors, commercial mouthwash

• 
To avoid use of aspirin products, NSAIDs

• 
To take entire dose at one time

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

meropenem (Rx)

(mer-oh-pen′em)

Merrem

Func. class.:
Antiinfective—miscellaneous

Chem. class.:
Carbapenem

ACTION:

Bactericidal; interferes with cell-wall replication of susceptible organisms; osmotically unstable cell wall swells, bursts from osmotic pressure

USES:

Serious infections caused by gram-positive bacteria:
Streptococcus pneumoniae
, group A β-hemolytic streptococci, enterococcus; gram-negative:
Klebsiella, Proteus, Escherichia coli, Pseudomonas aeruginosa;
appendicitis, peritonitis caused by
viridans
group streptococci;
Bacteroides fragilis, Bacteroides thetaiotaomicron
, bacterial meningitis (≥3 mo)

Unlabeled uses:
Febrile, neutropenic, community-acquired pneumonia

CONTRAINDICATIONS:

Hypersensitivity to this product, carbapenems, cephalosporins, penicillins

Precautions:
Pregnancy (B), breastfeeding, geriatric patients, renal disease, seizure disorder

DOSAGE AND ROUTES
Calculator
Intraabdominal infections (complicated appendicitis, peritonitis)

• Adult/child/adolescent >50 kg:
IV
1 g q8hr

• Infant ≥3 mo/child/adolescent ≤50 kg:
IV
20 mg/kg q8hr

Complicated skin and skin structure infections

• Adult/adolescents/child >50 kg:
IV
500 mg q8hr

• Infants ≥3 mo/children/adolescents ≤50 kg:
IV
10 mg/kg q8hr

Bacterial meningitis

• Adult:
IV
2 g q8hr

• Infant/child/adolescent ≤50 kg:
IV
40 mg/kg q8hr

Renal disease

• Adult:
IV
CCr 26-50 ml/min, give dose q12hr; CCr 10-25 ml/min, give 1/2 dose q12hr; CCr <10 ml/min, give 1/2 dose q24hr

Febrile neutropenia (unlabeled)

• Adult:
IV
1 g q8hr

Community-acquired pneumonia (CAP) (unlabeled)

• Adult:
IV
1 g q8hr with ciprofloxacin or with aminoglycoside plus fluoroquinolone

Available forms:
Powder for inj 500 mg, 1 g

Administer:

• 
After C&S is taken

Direct IV route

• 
Reconstitute 500-mg or 1-g vials with 10, 20 ml of sterile water for inj, respectively; shake to dissolve, let stand until clear (average conc 50 mg/ml); reconstituted sol may be stored for 2 hr at room temp or for 12 hr refrigerated; inject up to 1 g in 5-20 ml over 3-5 min

Intermittent IV INF route

• 
Vials may be directly reconstituted with compatible inf fluid (NS, D
5
W) to 2.5-50 mg/ml; vials with NS can be stored 2 hr at room temp or for ≤18 hr refrigerated, (D
5
W solutions) may be stored for up to 1 hr at room temp or ≤8 hr refrigerated; infuse over 15-30 min

Y-site compatibilities:
Aminophylline, atenolol, atropine, cimetidine, dexamethasone, digoxin, diphenhydrAMINE, enalaprilat, fluconazole, furosemide, gentamicin, heparin, insulin (regular), metoclopramide, morphine, norepinephrine, PHENobarbital, vancomycin

SIDE EFFECTS

CNS:
Seizures,
dizziness, weakness,
headache

CV:
Hypotension, palpitations, tachycardia

GI:
Diarrhea, nausea, vomiting,
pseudomembranous colitis, hepatitis,
glossitis

INTEG:
Rash
, urticaria,
pruritus
, pain at inj site, phlebitis, erythema at inj site

RESP:
Dyspnea, hyperventilation

SYST:
Anaphylaxis, Stevens-Johnson syndrome, angioedema

PHARMACOKINETICS

IV:
Onset immediate, peak dose dependent, half-life 1 hr, excreted unchanged in urine (70%)

INTERACTIONS

Increase:
meropenem plasma levels—probenecid

Decrease:
effect of valproic acid

Drug/Lab Test

Increase:
AST, ALT, LDH, BUN, alk phos, bilirubin, creatinine

False positive:
direct Coombs’ test

NURSING CONSIDERATIONS
Assess:

• 
Sensitivity to carbapenem antibiotics, penicillins

• 
Renal disease: lower dose may be required; monitor serum creatinine/BUN before, during therapy

• 
Pseudomembranous colitis:
bowel pattern daily; if severe diarrhea, fever, abdominal pain, fatigue occurs, product should be discontinued

• 
Infection:
temp, sputum, characteristics of wound before, during, and after treatment

 
Allergic reactions, anaphylaxis:
rash, laryngeal edema, wheezing, urticaria, pruritus; may occur immediately or several days after therapy begins, identify if there has been hypersensitivity to penicillins, cephalosporins, beta-lactams, cross-sensitivity may occur

• 
Seizures:
may occur in those with brain lesions, seizure disorder, bacterial meningitis, or renal disease; stop product, notify prescriber if seizures occur

• 
Overgrowth of infection: perineal itching, fever, malaise, redness, pain, swelling, drainage, rash, diarrhea, change in cough, sputum

Evaluate:

• 
Therapeutic response: negative C&S; absence of symptoms and signs of infection

Teach patient/family:

• 
Pseudomembranous colitis:
to report severe diarrhea

• 
To report sore throat, bruising, bleeding, joint pain; may indicate blood dyscrasias (rare)

• 
To report overgrowth of infection: black, furry tongue; vaginal itching; foul-smelling stools

• 
To avoid breastfeeding; product is excreted in breast milk

TREATMENT OF ANAPHYLAXIS:

EPINEPHrine, antihistamines; resuscitate if necessary

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