Mosby's 2014 Nursing Drug Reference (391 page)

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

thiamine (vit B
1
) (
PO
-
OTC
;
IV
,
IM
-Rx)

Vitamin B-1

Func. class.:
Vit B
1

Chem. class.:
Water soluble

Do not confuse:
thiamine
/Tenormin

ACTION:

Needed for pyruvate metabolism, carbohydrate metabolism

USES:

Vit B
1
deficiency or polyneuritis, cheilosis adjunct with thiamine beriberi, Wernicke-Korsakoff syndrome, pellagra, metabolic disorders, alcoholism

CONTRAINDICATIONS:

Hypersensitivity

Precautions:
Pregnancy (A)

DOSAGE AND ROUTES
Calculator
RDA

• Adult:
PO
(Males) 1.2-1.5 mg; (females) 1.1 mg; (pregnancy) 1.4 mg; (breastfeeding) 1.4 mg

• Child 9-13 yr:
PO
0.9 mg

• Child 4-8 yr:
PO
0.6 mg

• Child 1-3 yr:
PO
0.5 mg

• Infant 7 mo-1 yr:
PO
0.3 mg

• Neonate and infant ≤6 mo:
PO
0.2 mg

Beriberi

• Adult:
PO
5-30 mg daily or in 3 divided doses × 1 mo;
IM/IV
5-30 mg daily or in 3 divided doses then convert to
PO

• Infant/child:
PO
10-50 mg daily × 2 wk then 5-10 mg daily × 1 mo;
IV/IM
10-25 mg/day × 2 wk then 5-10 mg daily × 1 mo

Available forms:
Tabs 50, 100, 250, 500 mg; inj 100 mg/ml; enteric-coated tabs 20 mg

Administer:
IM route

• 
By IM inj; rotate sites if pain and inflammation occur; do not mix with alkaline sol;
Z
-track to minimize pain

Direct IV route

• 
Undiluted at 100 mg/ml over 5 min

Continuous IV INF route

• 
Diluted in compatible IV sol

Y-site compatibilities:
Famotidine

SIDE EFFECTS

CNS:
Weakness, restlessness

CV:
Collapse, pulmonary edema,
hypotension

EENT:
Tightness of throat

GI:
Hemorrhage,
nausea, diarrhea

INTEG:
Angioneurotic edema,
cyanosis, sweating, warmth

SYST:
Anaphylaxis

PHARMACOKINETICS

PO/INJ:
Unused amounts excreted in urine (unchanged)

NURSING CONSIDERATIONS
Assess:

• 
Anaphylaxis (IV only):
swelling of face, eyes, lips, throat, wheezing

• 
Thiamine deficiency:
anorexia, weakness/pain, depression, confusion, blurred vision, tachycardia

• 
Nutritional status: yeast, beef, liver, whole or enriched grains, legumes

Perform/provide:

• 
Storage in tight, light-resistant container

• 
Application of cold to help decrease pain

Evaluate:

• 
Therapeutic response: absence of nausea, vomiting, anorexia, insomnia, tachycardia, paresthesias, depression, muscle weakness

Teach patient/family:

• 
About the necessary foods to be included in diet: yeast, beef, liver, legumes, whole grains

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

thioridazine (Rx)

(thye-or-rid′a-zeen)

Func. class.:
Antipsychotic (typical)

Chem. class.:
Phenothiazine piperidine

Do not confuse:
thioridazine
/thiothixene/Thorazine

ACTION:

Depresses cerebral cortex, hypothalamus, limbic system, which control activity, aggression; blocks neurotransmission produced by dopamine at synapse; exhibits strong α-adrenergic and anticholinergic blocking action; mechanism for antipsychotic effects is unclear

USES:

Psychotic disorders, schizophrenia, behavioral problems in children, anxiety, major depressive disorders, organic brain syndrome

Unlabeled uses:
Behavioral symptoms associated with dementia in geriatric patients

CONTRAINDICATIONS:

Children <2 yr, hypersensitivity, coma, CNS depression

 

Black Box Warning:

QT prolongation, cardiac dysrhythmias

Precautions:
Pregnancy (C), breastfeeding, seizure disorders, hypertension, hepatic/pulmonary disease, renal failure, BPH, glaucoma, phenothiazine hypersensitivity, suicidal ideation, smoking, Reye’s syndrome, Parkinson’s disease

 

Black Box Warning:

Cardiac disease, dementia, AV block, bundle branch block, torsades de pointes

DOSAGE AND ROUTES
Calculator
Psychosis

• Adult:
PO
25-100 mg tid, max 800 mg/day; dose gradually increased to desired response then reduced to minimum maintenance

Depression/behavioral problems/organic brain syndrome

• Adult:
PO
25 mg tid, range from 10 mg bid-qid to 50 mg tid-qid, max 800 mg/day for short period

• Geriatric:
PO
10-25 mg daily-bid, increase 4-7 days by 10-25 mg to desired dose, max 300 mg/day for short period

• Child 2-12 yr:
PO
0.5-3 mg/kg/day in divided doses, max 3 mg/kg/day

Available forms:
Tabs 10, 25, 50, 100 mg

Administer:

• 
Antiparkinsonian agent on order from prescriber for EPS

• 
Avoid use with CNS depressants

• 
Antacids separated by 2 hr or more

SIDE EFFECTS

CNS:
EPS: pseudoparkinsonism, akathisia, dystonia, tardive dyskinesia
,
seizures,
headache
, confusion,
neuroleptic malignant syndrome,
dizziness, drowsiness

CV:
Orthostatic hypotension,
cardiac arrest,
ECG changes,
tachycardia, QT prolongation, torsades de pointes

EENT:
Blurred vision, glaucoma, dry eyes

GI:
Dry mouth, nausea, vomiting, anorexia, constipation
, diarrhea, jaundice, weight gain

GU:
Urinary retention, urinary frequency, enuresis, impotence, amenorrhea, gynecomastia, ejaculation dysfunction, priapism

HEMA:
Anemia,
leukopenia, leukocytosis, agranulocytosis

INTEG:
Rash
, photosensitivity, dermatitis

RESP:
Laryngospasm,
dyspnea,
respiratory depression

PHARMACOKINETICS

PO:
Onset erratic; peak 2-4 hr; metabolized by liver; excreted in urine, breast milk; crosses placenta; half-life 26-36 hr; 91%-99% protein binding

INTERACTIONS

 
Increase:
QT prolongation—class IA/III antidysrhythmics, some phenothiazines, β agonists, local anesthetics, tricyclics, haloperidol, chloroquine, droperidol, pentamidine; CYP3A4 inhibitors (amiodarone, clarithromycin, erythromycin, telithromycin, troleandomycin), arsenic trioxide, levomethadyl; CYP3A4 substrates (methadone, pimozide, QUEtiapine, quiNIDine, risperiDONE, ziprasidone), CYP2D6 inhibitors

• 
Oversedation: other CNS depressants, alcohol, barbiturate anesthetics

Increase:
anticholinergic effects—anticholinergics

Decrease:
antiparkinson’s agent effects

Decrease:
thioridazine effect—lithium, barbiturates

Decrease:
antihypertensive effect—centrally acting antihypertensives

Decrease:
absorption—aluminum hydroxide, magnesium hydroxide antacids

Drug/Lab Test

Increase:
LFTs, prolactin, bilirubin, alk phos

Decrease:
Hct/Hgb, platelets, granulocytes, leukocytes, neutrocytes, eosinophils

NURSING CONSIDERATIONS
Assess:

• 
Mental status before 1st dose

• 
I&O ratio; palpate bladder if low urinary output occurs, urinary retention may be the cause

• 
Bilirubin, CBC, LFTs monthly

• 
Urinalysis recommended before and during prolonged therapy

• 
Affect, orientation, LOC, reflexes, gait, coordination, sleep pattern disturbances

• 
B/P standing, lying; include pulse and respirations q4hr during initial treatment; establish baseline before starting treatment; report drops of 30 mm Hg

• 
Dizziness, faintness, palpitations, tachycardia on rising

• 
EPS
including akathisia (inability to sit still, no pattern to movements), tardive dyskinesia (bizarre movements of jaw, mouth, tongue, extremities), pseudoparkinsonism (rigidity, tremors, pill rolling, shuffling gait)

 
Neuroleptic malignancy syndrome:
altered mental status, muscle rigidity, increased CPK, hyperthermia, dyspnea, fatigue

 
QT prolongation:
ECG, ejection fraction; assess for chest pain, palpitations, dyspnea

• 
Constipation, urinary retention daily; increase bulk, water in diet

Perform/provide:

• 
Supervised ambulation if needed until stabilized on medication; do not involve patient in strenuous exercise program because fainting is possible; patient should not stand still for long periods

• 
Sips of water, candy, gum for dry mouth

• 
Storage in tight, light-resistant container; avoid contact with skin

Evaluate:

• 
Therapeutic response: decrease in emotional excitement, hallucinations, delusions, paranoia; reorganization of patterns of thought, speech

Teach patient/family:

• 
That orthostatic hypotension occurs frequently; to rise from sitting or lying position gradually; to avoid hazardous activities until stabilized on medication

• 
To avoid hot tubs, hot showers, tub baths because hypotension may occur

• 
To avoid abrupt withdrawal of thioridazine because EPS may result; that product should be withdrawn slowly

• 
To avoid OTC preparations (cough, hay fever, cold) unless approved by prescriber; that serious product interactions may occur; to avoid use with alcohol because increased drowsiness may occur

• 
To use sunscreen to prevent burns

• 
About compliance with product regimen

• 
About the necessity for meticulous oral hygiene because oral candidiasis may occur

• 
To report sore throat, malaise, fever, bleeding, mouth sores; if these occur, CBC should be drawn and product discontinued; that product may cause vision impairment, should be reported to prescriber

• 
That in hot weather, heat stroke may occur; to take extra precautions to stay cool

• 
That product may cause discoloration of urine

TREATMENT OF OVERDOSE:

Lavage if orally ingested, provide an airway; do not induce vomiting; CV monitoring, continuous ECG

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