คืนก่อน มีเด็กมาที่แผนกฉุกเฉิน มีอาการไข้สูง และชักมา แพทย์เด็กสั่งยา gardenal sodium injection แต่แผนกห้องยาไม่มียา เพราะเพิ่งหมดอายุ นำไปเปลี่ยนที่คลังยา ของใหม่ยังไม่มีมา ต้องติดต่อหายืมมาให้
พอวันรุ่งขึ้นเพิ่งจะรู้ว่า ของใหม่มาแล้วแต่คลังยากับห้องยาไม่ประสานงานกันเลย ทำให้ยาขาด แพทย์เด็กสั่งให้เขียน incident report ด้วย
Gardenal Sodium มีอีกชื่อว่า PHENOBARBITAL SODIUM
Indications and dosages
Tonic-clonic (grand mal) and partial seizures; febrile seizures in children
Adults: 60 to 100 mg/day P.O. as a single dose or in two or three divided doses; or initially, 100 to 320 mg I.V. p.r.n. (a total of 600 mg I.V. in a 24-hour period).
Infants and children: Loading dose of 15 to 20 mg/kg P.O. (produces drug blood level of 20 mcg/ml shortly after dosing). To achieve therapeutic blood level (10 to 25 mcg/ml), children usually need higher dosage/kg than adults. Follow loading dose with 3 to 6 mg/kg/day P.O. Alternatively, 4 to 6 mg/kg/day I.M. or I.V. for 7 to 10 days to achieve blood level of 10 to 15 mcg/ml.
Status epilepticus
Adults: 200 to 320 mg I.M. or I.V., repeated q 6 hours p.r.n.
Children: 15 to 20 mg/kg I.V. given over 10 to 15 minute
Sedation or hypnotic effect
Adults: For sedation, 30 to 120 mg/day P.O. or 30 to 120 mg/day I.M. or I.V. in two or three divided doses. As a hypnotic, 100 to 200 mg P.O. or 100 to 320 mg I.M. or I.V. at bedtime. Don't exceed 400 mg in a 24-hour period.
➣ Preoperative sedation
Adults: 100 to 200 mg I.M. 60 to 90 minutes before surgery
Children: 1 to 3 mg/kg I.M. or I.V., as prescribed.
Dosage adjustment
• Impaired hepatic or renal function
• Elderly or debilitated patients
Off-label uses
• Prevention and treatment of hyperbilirubinemia
Contraindications
• Hypersensitivity to drug or other barbiturates
• Manifest or latent porphyria
• Nephritis (with large doses)
• Severe respiratory disease with dyspnea or obstruction
• History of sedative-hypnotic abuse
• Subcutaneous or intra-arterial administration
Precautions
Use cautiously in:
• hepatic dysfunction, renal impairment, seizure disorder, fever, hyperthyroidism, diabetes mellitus, severe anemia, pulmonary or cardiac disease
• history of suicide attempt or drug abuse
• chronic phenobarbital use
• elderly or debilitated patients
• pregnant or breastfeeding patients
• children younger than age 6.
Administration
• Inject I.M. deep into large muscle mass; limit volume to 5 ml.
☞ Give I.V. no faster than 60 mg/minute. Keep resuscitation equipment at hand.
• Stop injection immediately if patient complains of pain or if circulation at injection site diminishes (indicating inadvertent intra-arterial injection).
☞ Don't give by subcutaneous route; severe reactions (such as pain and tissue necrosis) may occur.
☞ Know that when given I.V. for status epilepticus, drug may take 15 minutes to attain peak blood level in brain. If injected continuously until seizures stop, drug brain level would keep rising and could exceed that required to control seizures. To avoid barbiturate-induced depression, use minimal amount required and wait for anticonvulsant effect to occur before giving second dose.
• Use parenteral route only when patient can't receive drug P.O.
• Know that drug is intended only for short-term use, losing efficacy after about 2 weeks.
Route Onset Peak Duration
P.O. 30-60 min Unknown 10-16 hr
I.V. 5 min 30 min 10-16 hr
I.M. 10-30 min Unknown 10-16 hr
Adverse reactions
CNS: headache, dizziness, anxiety, depression, drowsiness, excitation, delirium, lethargy, agitation, confusion, hyperkinesia, ataxia, vertigo, nightmares, nervousness, paradoxical stimulation, abnormal thinking, hallucinations, insomnia, CNS depression
CV: hypotension, syncope, bradycardia (with I.V. use)
GI: nausea, vomiting, constipation
Hematologic: megaloblastic anemia
Hepatic: hepatic damage
Musculoskeletal: joint pain, myalgia
Respiratory: hypoventilation, laryngospasm, bronchospasm, apnea (with I.V. use); respiratory depression
Skin: rash, urticaria, exfoliative dermatitis, Stevens-Johnson syndrome
Other: phlebitis at I.V. site, drug dependence, hypersensitivity reactions including angioedema
Interactions
Drug-drug. Acetaminophen: increased risk of hepatotoxicity
Activated charcoal: decreased phenobarbital absorption
Anticoagulants, beta-adrenergic blockers (except timolol), carbamazepine, clonazepam, corticosteroids, digoxin, doxorubicin, doxycycline, felodipine, fenoprofen, griseofulvin, hormonal contraceptives, metronidazole, quinidine, theophylline, verapamil: decreased efficacy of these drugs
Chloramphenicol, hydantoins, narcotics: increased or decreased effects of either drug
Cyclophosphamide: increased risk of hematologic toxicity
Divalproex, MAO inhibitors, valproic acid: decreased phenobarbital metabolism, increased sedative effect
Other CNS depressants (including first-generation antihistamines, opioids, other sedative-hypnotics): additive CNS depression
Rifampin: increased phenobarbital metabolism and decreased effects
Drug-diagnostic tests. Bilirubin: decreased level in neonates and patients with seizure disorders or congenital nonhemolytic unconjugated hyperbilirubinemia
Drug-herbs. Chamomile, hops, kava, skullcap, valerian: increased CNS depression
St. John's wort: decreased drug effects
Drug-behaviors. Alcohol use: additive CNS effects
Patient monitoring
• Monitor vital signs; watch for bradycardia and hypotension.
☞ In patients with seizure disorders, know that drug withdrawal may cause status epilepticus.
• Assess neurologic status. Institute safety measures as needed.
☞ Closely monitor respiratory status, especially for respiratory depression and airway spasm.
• Monitor phenobarbital blood level, CBC, and kidney and liver function tests.
• Watch for signs of drug dependence.
Patient teaching
☞ Instruct patient to promptly report rash, facial and lip edema, syncope, dyspnea, or depression.
☞ Stress importance of taking exactly as prescribed, with or without food. Caution patient not to stop therapy abruptly, especially if he's taking drug for seizures.
• Tell patient that prolonged use may lead to dependence.
• Instruct patient to seek medical advice before taking other prescription or over-the-counter drugs.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects him.
• Advise patient to avoid herbs, alcohol, and other CNS depressants.
• Instruct patient taking hormonal contraceptives to use alternate birth-control method.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above
Dilution:
Sterile powder must be slowly diluted with SWI
Use a minimum of 3 mL of diluent.
Also available in sterile vials and tubexes.
Best if further diluted up to 10 mL with SWI.
Solutions from powder form must be freshly prepared.
Use only absolutely clear solution.
Discard powder or solution exposed to air for 30 minutes
ที่มา : Intravenous Medication 25th ed. 2009