Mosby's 2014 Nursing Drug Reference (339 page)

BOOK: Mosby's 2014 Nursing Drug Reference
9.83Mb size Format: txt, pdf, ePub
pyridoxine (vit B
6
) (Rx,
OTC
)

(peer-i-dox′een)

Equaline Vitamin B6, Neuro-K, Walgreens Finest B-6, Walgreens Gold Seal Vitamin B6

Func. class.:
Vit B
6
, water soluble

ACTION:

Needed for fat, protein, carbohydrate metabolism; enhances glycogen release from liver and muscle tissue; needed as coenzyme for metabolic transformations of a variety of amino acids

USES:

Vit B
6
deficiency of inborn errors of metabolism, seizures, isoniazid therapy, oral contraceptives, alcoholic polyneuritis

Unlabeled uses:
Palmar-plantar erythrodysesthesia syndrome

CONTRAINDICATIONS:

Hypersensitivity

Precautions:
Pregnancy (A), breastfeeding, children, Parkinson’s disease; patients taking levodopa should avoid supplemental vitamins with >5 mg pyridoxine

DOSAGE AND ROUTES
Calculator
RDA

• Adult:
PO
(male) 1.7-2 mg; (female) 1.4-1.6 mg

• Child 9-13 yr:
PO
1 mg/day

• Child 4-8 yr:
PO
0.6 mg/day

• Child 1-3 yr:
PO
0.5 mg/day

• Infant 7-12 mo:
PO
0.3 mg/day

Vit B
6
deficiency

• Adult:
PO
5-25 mg/day × 3 wk

• Child:
PO
10 mg until desired response

Pyridoxine deficiency neuritis/seizure (not drug induced)

• Adult:
PO
without neuritis
2.5-10 mg/day after corrected 2-5 mg/day;
with neuritis
100-200 mg/day × 3wk then 2-5 mg/day

• Child:
PO
without neuritis
5-25 mg/day × 3wk then 1.5-2.5 mg/day in a multivitamin;
with neuritis:
10-50 mg/day × 3wk then 1-2 mg/day

• Neonate with seizures:
IM/IV
50-100 mg as single dose

Deficiency caused by isoniazid, cycloserine, hydralazine, penicillamine

• Adult:
PO
100-300 mg/day

• Child:
PO
10-50 mg/day

Prevention of deficiency caused by isoniazid, cycloserine, hydralazine, penicillamine

• Adult:
PO
25-100 mg/day

• Child:
PO
1-2 mg/kg/day

Palmar-plantar erythrodysesthesia syndrome (unlabeled)

• Adult:
PO
50-150 mg/day

Available forms:
Tabs 10, 25, 50, 100 mg; ext rel tabs 100 mg; inj 100 mg/ml; ext rel caps 150 mg

Administer:
PO route

• 
Do not break, crush, or chew ext rel tabs/caps

IM route

• 
Rotate sites; burning or stinging at site may occur

• 
Z
-track to minimize pain

IV route

• 
Undiluted or added to most IV sol; give ≤50 mg/1 min if undiluted

Syringe compatibilities:
Doxapram

SIDE EFFECTS

CNS:
Paresthesia, flushing, warmth, lethargy (rare with normal renal function)

INTEG:
Pain at inj site

PHARMACOKINETICS

PO/INJ:
Half-life 2-3 wk, metabolized in liver, excreted in urine

INTERACTIONS

Decrease:
effects of levodopa

Decrease:
effects of pyridoxine—oral contraceptives, isoniazid, cycloSERINE, hydrALAZINE, penicillamine, chloramphenicol, immunosuppressants

NURSING CONSIDERATIONS
Assess:

• 
Pyridoxine deficiency:
seizures, irritability, cheilitis, conjunctivitis, anemia, confusion, red tongue, weakness, fatigue prior to and during treatment; monitor pyridoxine levels

• 
Nutritional status: yeast, liver, legumes, bananas, green vegetables, whole grains

• 
Blood studies: Hct, Hgb

Perform/provide:

• 
Storage in tight, light-resistant container

Evaluate:

• 
Therapeutic response: absence of nausea, vomiting, anorexia, skin lesions, glossitis, stomatitis, edema, seizures, restlessness, paresthesia

Teach patient/family:

• 
To avoid vitamin supplements unless directed by prescriber

• 
To increase meat, bananas, potatoes, lima beans, whole grain cereals in diet

• 
To take as directed; to continue with follow-up exams, blood work

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

pyrimethamine (Rx)

(peer-i-meth′a-meen)

Daraprim

Func. class.:
Antimalarial, antiprotozoal

Chem. class.:
Folic acid antagonist

ACTION:

Inhibits folic acid metabolism in parasite, prevents transmission by stopping growth of fertilized gametes

USES:

Malaria prophylaxis,
Plasmodium vivax, Pneumocystis jiroveci

Unlabeled uses:
Isosporiasis, pneumocystis pneumonia prophylaxis, toxoplasmic encephalitis prophylaxis

CONTRAINDICATIONS:

Hypersensitivity, chloroquine-resistant malaria, megaloblastic anemia caused by folate deficiency

Precautions:
Pregnancy (C), breastfeeding, geriatric patients, blood dyscrasias, seizure disorder, G6PD disease, renal/hepatic disease

DOSAGE AND ROUTES
Calculator
Prophylaxis of malaria

Begin 2 wk before entering endemic area, continue for 6-10 wk after return

• Adult/child
>
10 yr:
PO
25 mg/wk

• Child 4-10 yr:
PO
12.5 mg/wk

• Child
<
4 yr:
PO
6.25 mg/wk

Malaria treatment

• Adult/adolescent/child
>
10 yr:
PO
25 mg q day × 2 days with a sulfonamide

• Child 4-10 yr:
PO
25 mg/day × 2 days

Toxoplasmosis

• Adult:
PO
50-75 mg, then reduce by about 50% for 4-5 wk with 1-4 g sulfadoxine × 1-3 wk, then reduce by 50% for 4-5 wk

• Child:
PO
1 mg/kg/day in 2 divided doses or 2 mg/kg/day × 3 days then 1 mg/kg/day or divided twice daily × 4 wk, max 25 mg/day

Toxoplasmosis in AIDS patients

• Adult:
PO
100-200 mg/day × 1-2 days, then 50-100 mg/day × 3-6 wk, then 25-50 mg/day for life (given with clindamycin or sulfADIAZINE)

Isosporiasis (unlabeled)

• Adult:
PO
75 mg/day with leucovorin 10 mg/day × 14 days

Available forms:
Tabs 25 mg; combo tabs 500 mg sulfadoxine/25 mg pyrimethamine

Administer:
PO route

• 
Leucovorin IM 3-9 mg/day × 3 days if folic acid deficiency occurs

• 
Before or after meals at same time each day to maintain product level, decrease GI symptoms

• 
Extemporaneous susp:
tabs may be crushed and mixed with 25 ml distilled water, sucrose-containing solution (1 mg/ml); shake well, stable for 5-7 days at room temperature if mixed with sucrose-containing solutions

SIDE EFFECTS

CNS:
Stimulation, irritability,
seizures,
tremors, ataxia, fatigue, fever

CV:
Dysrhythmias

GI:
Nausea, vomiting, cramps, anorexia
, diarrhea, atrophic glossitis, gastritis

HEMA:
Thrombocytopenia, leukopenia, pancytopenia, megaloblastic anemia,
decreased folic acid,
agranulocytosis

INTEG:
Skin eruptions, photosensitivity,
Stevens-Johnson syndrome

RESP:
Respiratory failure

PHARMACOKINETICS

PO:
Peak 2 hr, half-life 96 hr, half-life accelerated to 23 hr in AIDS patients, metabolized in liver, highly protein bound, excreted in urine (metabolites)

INTERACTIONS

• 
Synergistic action: folic acid

Increase:
Megaloblastic anemia risk, agranulocytosis, thrombocytopenia—zidovudine

Increase:
bone marrow suppression—bone marrow depressants, folate antagonists, radiation therapy

NURSING CONSIDERATIONS
Assess:

• 
Folic acid level; megaloblastic anemia occurs

 
Blood dyscrasias:
blood studies, CBC, platelets; 2×/wk if dosage is increased

 
Toxicity:
vomiting, anorexia, seizure, blood dyscrasia, glossitis; product should be discontinued immediately

• 
Serious skin disorders:
Stevens-Johnson syndrome (swelling of face, lips, throat, fever)

Perform/provide:

• 
Storage in tight, light-resistant container

Evaluate:

• 
Therapeutic response: decreased symptoms of malaria, toxoplasmosis

Teach patient/family:

• 
To report visual problems, fever, fatigue, bruising, bleeding, sore throat; may indicate
blood dyscrasias

TREATMENT OF OVERDOSE:

Gastric lavage, short-acting barbiturate, leucovorin, respiratory support if needed

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

Other books

Daisy's Perfect Word by Sandra V. Feder, Susan Mitchell
A Family For Christmas by Linda Finlay
La noche de la encrucijada by Georges Simenon
Deficiency by Andrew Neiderman
The Clown by Heinrich Boll
Dismissed by Kirsty McManus
My Ruthless Prince by Gaelen Foley