Phenobarbitone

Tranquilizer, Sedative/Hypnotic · Barbiturate

Indications

As sedative, anticonvulsant. See under dosage.

Dosage

Adults: Daytime Sedation: 30-120 mg/day orally given in 2-3 doses, or IM/IV given in 2-9 doses. Epilepsy (all forms except absence seizures): 60-180 mg orally at night. Children: Pre-op sedation: 1-3 mg/kg IM/IV. Epilepsy (all forms except absence seizures): 5-8 mg/kg/day orally at night.

Administration

Avoid rapid IV administration >50 mg/min; Avoid intra-arterial injection.

Adverse Effects

Drowsiness, ataxia, allergic skin reactions, paradoxical excitement, irritability, hyperactivity and confusion, megaloblastic anaemia. Restlessness and confusion in the elderly. Hyperkinesia in children. Tolerance and dependence. Lethargy, nystagmus, respiratory depression, hallucinations, memory and cognitive impairment, behavioural disturbances, depression, agranulocytosis, thrombocytopenia, hepatitis, cholestasis, osteomalacia, hypotension.

Risk Factor (Pregnancy/Lactation)

Pregnancy: Contraindicated in pregnancy. Lactation: Contraindicated or not recommended. Contraindications: Severe respiratory depression. Porphyria. Severe renal or hepatic impairment. Precautions: Elderly, debilitated, children. Renal and hepatic impairment, pulmonary insufficiency (contraindicated if severe). Maintain adequate intake of vit D. Monitor for and advise patients to report mood changes or suicidal thoughts. History of alcoholism or drug abuse. Risk of serious skin reactions. Withdraw gradually.

Interactions

Coumarin anticoagulants, alcohol and other CNS depressants, oral contraceptives, griseofulvin, rifampicin, phenytoin, metronidazole, doxycycline, chloramphenicol, telithromycin, antidepressants, St. John's Wort, antipsychotics, nucleoside reverse transcriptase inhibitors, protease inhibitors, eplerenone, voriconazole, other anticonvulsants, NRTIs, digoxin, antiarrhythmics, montelukast, phenylbutazone, calcium channel blockers, B blockers, corticosteroids, cyclosporin, tacrolimus, theophylline, memantine, toremifene, tibolone, folic acid, thyroid, hormones, methylphenidate.

Advice to Patient

Take oral form with or without meals. Take elixir undiluted or mix it with water, milk, or fruit juice. Use a calibrated device to measure doses. If you have difficulty in swallowing tablets, crush and sprinkle on food or fluid. If you are self-administering the injection, follow directions for administration and syringe disposal. Do not take any new medication, OTC preparations (especially pain medications, sedatives, antihistamines, hypnotics) without consulting prescriber. Contact prescriber if there is difficulty in breathing, difficulty in swallowing, tightness feeling in throat, headache, increased sleepiness, confusion, depression, lack of sleep, nightmares, excitation, skin rash, skin irritation, change in urinary pattern, change in menstrual pattern, muscle weakness or tremors. Avoid alcohol during therapy. Take sufficient amount of fluids (2-3 litres per day) to maintain…

Pharmacokinetics

Onset of action: Oral: = 60minutes; IV: 5 minutes; Peak effect: IV: CNS depression: =15 minutes. Duration: Oral: 10 to 12 hours; IV: >6 hours. Absorption: Oral: Rapid. Metabolism: Hepatic. Bioavailability: Oral: Adults: 95% to 100%. Half-life elimination: Neonates (<48 hours old), Infants, and Children: Approx. 110 hours (60 to 180 hours); Adults: Approx. 79 hours (range: 53 to 118 hours). Time to peak, serum: Oral: 1.4 hours (0.5 to 4 hours). Excretion: Urine (25% to 50% as unchanged drug); feces (minimal).

Brands with this active ingredient

Compiled by Healify Pharmacy from published drug references. How we compile it →

Always consult a pharmacist or doctor.