Barbit Elixir

Indications

Phenobarbital (also called phenobarbitone) is an older medicine used to control many types of epileptic seizures, including generalised tonic-clonic and focal seizures, and to stop prolonged seizures (status epilepticus) and seizures in newborn babies. It is sometimes used to manage alcohol or sedative withdrawal under specialist care. It is now rarely used just for anxiety or sleep.

How It Works

Phenobarbital belongs to the barbiturate group. It boosts the action of GABA, the brain's main calming chemical, and reduces excitatory signals. This lowers excess electrical activity in the brain, which helps prevent seizures, but it also causes drowsiness.

Dosage and Administration

Take exactly as prescribed. The dose is set by your doctor according to age, body weight, seizure type and blood levels, and is usually taken once a day, often at bedtime. Tablets and elixir are taken by mouth; measure liquid with the measuring device provided. The injection is given by a doctor or nurse. Do not stop suddenly, as this can cause withdrawal and dangerous seizures; any change must be made slowly under medical advice.

Interactions

Phenobarbital speeds up the breakdown of many medicines and can make them less effective, including oral contraceptives, Warfarin, corticosteroids, Doxycycline, Griseofulvin, some HIV and heart medicines, Lamotrigine, Carbamazepine and other antiepileptics. Valproate can raise phenobarbital levels. Alcohol, opioids, benzodiazepines, sleeping tablets, antihistamines and other sedatives increase drowsiness and the risk of slowed breathing. Women using hormonal contraception need a reliable alternative method.

Contraindications

Do not use if you are allergic to barbiturates, have acute porphyria, severe breathing problems, or severe liver or kidney failure.

Side Effects

Common effects are drowsiness, tiredness, dizziness, unsteadiness and slowed thinking. Children and older people may become restless, irritable or overactive. Long-term use can cause low folate, softening of the bones, mood changes, depression and dependence. Skin rash may occur.

Get urgent medical help for a severe skin reaction (blistering, peeling or mouth sores), yellowing of the skin or eyes, very slow or shallow breathing, extreme drowsiness, thoughts of self-harm, or seizures that become worse or more frequent.

Pregnancy and Lactation

Phenobarbital may increase the risk of birth defects and can cause drowsiness and withdrawal in the newborn, but uncontrolled seizures are also dangerous. Do not stop it on your own: speak to your doctor before or as soon as you become pregnant. Folic acid is usually advised, and vitamin K may be given near delivery. It passes into breast milk and can make the baby sleepy; breastfeed only with your doctor's advice and watch the baby for drowsiness and poor feeding.

Precautions and Warnings

• Do not drive or use machines until you know how it affects you.
• Avoid alcohol.
• Take care in older people, depression, liver or kidney disease, lung disease and history of drug misuse.
• Blood level checks may be needed.
• It can be habit-forming; use only as prescribed.

Overdose

Overdose is dangerous and can cause deep sleep, confusion, slurred speech, low body temperature, slow or stopped breathing, low blood pressure and coma. Call emergency services immediately. Treatment is in hospital with breathing support and other measures.

Therapeutic Class

Barbiturate anticonvulsant (antiepileptic) and sedative

Storage

Store below 30°C in a dry place, away from light and out of the reach of children. Keep securely, as it can be misused.