fee-noe-BAR-bi-tal
Therapeutic Classification: anticonvulsants, sedative/hypnotics
Pharmacologic Classification: barbiturates
BEERS REMS
Absorption: Absorption is slow but relatively complete (70–90%).
Distribution: Unknown.
Half-Life: Neonates: 1.8–8.3 days; Infants: 0.8–5.5 days; Children: 1.5–3 days; Adults: 2–6 days.
| ROUTE | ONSET | PEAK | DURATION |
|---|---|---|---|
| PO | 30–60 min | unknown | >6 hr |
| IM, SUBQ | 10–30 min | unknown | 4–6 hr |
| IV | 5 min | 30 min | 4–6 hr |
‡Full anticonvulsant effects occur after 2–3 wk of chronic dosing unless a loading dose has been used.
Contraindicated in:
Use Cautiously in:
CV: IVhypotension
Derm: DRUG REACTION WITH EOSINOPHILIA AND SYSTEMIC SYMPTOMS (DRESS), photosensitivity, rash, STEVENS-JOHNSON SYNDROME (SJS), TOXIC EPIDERMAL NECROLYSIS (TEN), urticaria
GI: constipation, diarrhea, nausea, vomiting
Local: phlebitis
MS: arthralgia, myalgia
Neuro: hangover, delirium, depression, drowsiness, excitation, lethargy, neuralgia, vertigo
Resp: respiratory depression, IVLARYNGOSPASM, bronchospasm
Misc: HYPERSENSITIVITY REACTIONS (INCLUDING ANGIOEDEMA AND SERUM SICKNESS), physical dependence, psychological dependence
Drug-drug:
Drug-Natural Products:
Maintenance Anticonvulsant
Sedation
Hypnotic
Hyperbilirubinemia
Lab Test Considerations:
Toxicity and Overdose:
IV Administration:
IV phenobarbital is a vesicant. Administer into a large vein. If extravasation occurs, immediately stop infusion. Leave needle/cannula in place temporarily but do not flush the line. Gently aspirate extravasated solution; then remove needle/cannula. Elevate patient's extremity and apply dry warm compresses. Initiate hyaluronidase antidote for refractory cases in addition to supportive management. For hyaluronidase, inject a total of 1 mL (15 units/mL) intradermally or SUBQ as five separate 0.2-mL injections (using a tuberculin syringe) around the site of extravasation; if IV catheter remains in place, administer IV through the infiltrated catheter; may repeat in 30–60 min if no resolution.
NDC Code