Download sodium phenylacetate/sodium benzoate

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02/17/2014 10:18AM
sodium phenylacetate/sodium benzoate
proic acid may contribute to hyperammonemia and negate beneficial effects.
(soe-dee-um fen-il-as-e-tate/soe-dee-um ben-zo-ate)
Route/Dosage
Ammonul
Classification
Therapeutic: antidotes
Pharmacologic: none assigned
Indications
Adjunctive therapy of acute hyperammonemia associated with urea cycle disorders;
when lack of specific enzymes results in an inability to breakdown and eliminate
waste nitrogens.
Action
Provides an alternative pathway for nitrogen elimination in patients without a fully
functioning urea cycle. Therapeutic Effects: Decreased sequelae of hyperammonemia including encephalopathy and death.
Pharmacokinetics
Absorption: IV administration results in complete bioavailability.
Distribution: Unknown.
Metabolism and Excretion: Metabolized in the liver as part of the alternative
pathway in the urea cycle; also metabolized in the kidney.
Half-life: Unknown.
TIME/ACTION PROFILE (blood levels)
ONSET
rapid
PEAK
1–3 hr
pg 1 # 1
Interactions
Drug-Drug: Penicillin and probenecid may compete for renal secretion. Val-
1
ROUTE
IV
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DURATION
14–26 hr
Concurrent IV arginine is required.
IV (Children 0– 20 kg): Loading dose over 90– 120 min— 2.5 mL/kg (provides
250 mg/kg of sodium phenylacetate and 250 mg/kg sodium benzoate) followed by
maintenance infusion— 2.5 mL/kg (provides 250 mg/kg of sodium phenylacetate
and 250 mg/kg sodium benzoate) over 24 hr, continued until oral therapy is initiated.
IV (Children ⬎20 kg): Loading dose over 90– 120 min— 2.5 mL/kg (provides
250 mg/kg of sodium phenylacetate and 250 mg/kg sodium benzoate) followed by
maintenance infusion— 55 mL/m2(provides 5.5 g/m2 of sodium phenylacetate
and 5.5 g/m2 sodium benzoate) over 24 hr, continued until oral therapy is initiated.
NURSING IMPLICATIONS
Assessment
● Assess neurologic status frequently during therapy.
● Assess infusion site frequently during therapy. Extravasation into peripheral tis-
sues may lead to skin necrosis. If extravasation is suspected, discontinue infusion
and resume at a different site. Treatment of extravasation may include aspiration
of residual drug from catheter, limb elevation, and intermittent cooling using cold
packs.
● Lab Test Considerations: Monitor plasma ammonia levels frequently during
therapy.
● Monitor CBC and serum electrolytes frequently during therapy; maintain normal
levels. May cause hyperglycemia, hypocalcemia, hypokalemia, and anemia.
● Monitor blood chemistry, pH, and pCO2 frequently during therapy. May cause
metabolic acidosis and hyperammonemia.
Contraindications/Precautions
Contraindicated in: Hypersensitivity.
Use Cautiously in: Hepatic/renal impairment; OB: Use only if clearly needed;
Potential Nursing Diagnoses
Lactation: Safety not established.
● Must be diluted and administered through a central line; administration through
Adverse Reactions/Side Effects
CNS: SEIZURES, mental impairment. GI: vomiting. Endo: hyperglycemia. F and E:
hypokalemia.
⫽ Canadian drug name.
⫽ Genetic Implication.
Risk for injury (Indications)
Implementation
peripheral lines may cause burns.
● May cause nausea and vomiting; administer an antiemetic prior to infusion.
● Do not repeat loading dose; phenylacetate plasma levels are prolonged.
CAPITALS indicate life-threatening, underlines indicate most frequent.
Strikethrough ⫽ Discontinued.
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Name /bks_53161_deglins_md_disk/sodiumphenylacetatebenzo
02/17/2014 10:18AM
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● Begin infusion as soon as the diagnosis of hyperammonemia is made.
● Caloric supplementation and restriction of dietary protein are required during
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therapy. Caloric intake of ⬎80 cal/kg/day should be attempted. Non-protein calories should be supplied as glucose (8– 10 mg/kg/min) with Intralipid added.
● Once elevated ammonia levels have been reduced to normal range, oral therapy,
such as sodium phenylbutyrate, dietary management and protein restrictions
should be started or reinitiated.
IV Administration
● Intermittent Infusion: Diluent: Dilute with D10W at ⱖ25 mL/kg before ad-
ministration. Use a Millex Durapore GV 33 mm Sterile Syringe Filter (0.22 ␮m)
during the admixture process when injecting Ammonul into the 10% Dextrose IV
bag, regardless of whether particulate matter is seen in the vial; particulate matter
may not be seen on visual inspection. Solution is stable for 24 hr at room temperature. Do not administer solutions that are discolored or contain particulate matter. Rate: Administer loading dose over 90– 120 min.
● Continuous Infusion: Diluent: Maintenance infusions use same dilution as
loading dose and may be continued until elevated plasma ammonia levels have
been normalized or patient can tolerate oral nutrition and medications. Rate:
Administer maintenance infusion over 24 hr.
● Additive Compatibility: arginine 10%.
● Additive Incompatibility: Do not mix or infusion other solutions or medications with sodium phenylacetate and sodium benzoate.
Patient/Family Teaching
● Explain purpose of medication to parents/caregivers.
Evaluation/Desired Outcomes
● Decreased sequelae of hyperammonemia including encephalopathy and death.
Why was this drug prescribed for your patient?
䉷 2015 F.A. Davis Company