Patient leaflet - Phenobarbital 60 mg tablets
1. WHAT PHENOBARBITAL TABLETS ARE AND WHAT THEY ARE USED FOR
Phenobarbital belongs to a group of medicines called barbiturates.
These medicines reduce brain activity which would otherwise cause fits or seizures in epilepsy, except absence seizures (daydreaming or lapses in attention).
2. WHAT YOU NEED TO KNOW BEFORE YOU TAKE PHENOBARBITAL TABLETS
Do NOT take Phenobarbital tablets and tell your doctor if you have:
- An allergy (hypersensitivity to phenobarbital, other barbiturates or any of the other ingredients (see section 6)
- Porphyria (a genetic or inherited disorder of the red blood pigment haemoglobin)
- Severe kidney or liver disease
- Severe breathing difficulties
If you develop a rash or the following skin symptoms, seek immediate advice from a doctor and tell them that you are taking this medicine:
- Potentially life-threatening skin rashes (Stevens-Johnson syndrome, toxic epidermal necrolysis) have been reported with the use of Phenobarbital Tablets appearing initially as reddish target-like spots or circular patches often with central blisters on the trunk. Additional signs to look for include ulcers in the mouth, throat, nose, genitals and conjunctivitis (red and swollen eyes). These potentially life-threatening skin rashes are often accompanied by flulike symptoms. The rash may progress to widespread blistering or peeling of the skin. The highest risk for occurrence of serious skin reactions is within the first weeks of treatment.
- If you have developed Stevens-Johnson syndrome or toxic epidermal necrolysis with the use of Phenobarbital tablets you must not be re-started on Phenobarbital Tablets at any time.
Check with your doctor or pharmacist before taking Phenobarbital Tablets if you:
or the person taking these tablets are young, run down, senile or have a history of drug abuse or alcoholism
- Have kidney or liver problems
- Have breathing difficulties
- Have severe or long-term pain
A small number of people being treated with anti-epileptics such as Phenobarbital Tablets have had thoughts of harming or killing themselves. If at any time you have these thoughts, immediately contact your doctor.
Taking other medicines
Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines, including medicines obtained without a prescription. Especially:
- Disopyramide and quinidine (to treat irregular heartbeats)
- Chloramphenicol, Doxycycline, Griseofluvin, Metronidazole, Rifampicin, Telithromycin, Itraconazole, posaconazole, voriconazole, abacavir, amprenavir, Iopinavir, indinavir, darunavir, nelfinavir and saquinavir (to treat infections)
- Medicines used to thin the blood such as warfarin
- Mianserin, paroxetine, MAOI or tricyclic antidepressants or St John’s Wort (Hypericum perforatum) an herbal remedy (to treat depression)
- Oxcarbazepine, primidone, phenytoin, sodium valproate, carbamazepine, lamotrigine, tiagabine, zonisamide, ethosuxamide and vigabatrin (to treat epilepsy)
- Chlorpromazine, thioidazine, haloperidol, aripiprazole and clonazepam (to treat mental illness)
- Felodipine, verapamil, diltiazem, nimodipine, nifedipine, metoprolol, timolol and propranolol (to treat high blood pressure)
- Digitoxin or eplerenone (to treat certain heart conditions)
- Steroids such as hydrocortisone or prednisolone
- Ciclosporin or tacrolimus (to prevent organ transplant rejection)
- Folic acid or vitamin D (supplements)
- Toremifene, gestrinone, irinotecan or etoposide (to treat some cancers)
- Methadone (used in severe pain or drug addiction)
- Oral contraceptives (talk to your doctor about the best method of contraception for you) or tibolone (female hormone)
- Levothyroxine (thyroid hormone)
- Montelukast or theophylline (to treat asthma)
- Tropisetron and aprepitant (to treat nausea and vomiting)
- Memantine (to treat dementia)
- Methylphenidate (to treat attention deficit disorder)
- Sodium oxybate (to treat narcolepsy).
Pregnancy and breast-feeding
If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine. Your doctor should discuss the possible effects of Phenobarbital tablets on the unborn child and the risks and benefits of treatment should be considered carefully. Check with your doctor before taking folic acid supplements as they interact with Phenobarbital Tablets, your doctor may need to adjust your dose.
If you are taking Phenobarbital Tablets, do not breastfeed, as the medicine will pass into the breast milk and may harm the baby.
Driving and using machines
Phenobarbital tablets may make you feel less alert than normal. Make sure you are not affected before driving or operating machinery.
Phenobarbital Tablets contain Lactose
Phenobarbital Tablets contain lactose monohydrate. If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicinal product.
Phenobarbital 60mg Tablets also contain the colour sunset yellow (E110). This may cause allergic-type reactions including asthma. Allergy is more common in those people who are allergic to aspirin.
Blood and urine tests
If you are having blood or urine tests tell the doctor or nurse that you are taking Phenobarbital Tablets as Phenobarbital Tablets may interfere with the results.
3. HOW TO TAKE PHENOBARBITAL TABLETS
Swallow the tablets with water at the same time each day.
Always take Phenobarbital Tablets exactly as your doctor has told you. If you are not sure, check with your doctor or pharmacist. You are advised not to drink alcohol, check with your doctor if you have any questions.
Doses:
Adults: The usual dose is 60mg-180mg daily, taken at night.
Children: The usual dose is 5mg-8mg per kg of bodyweight per day.
Elderly: Your doctor may prescribe a lower dose.
If you take more Phenobarbital than you should
If you (or someone else) swallow a lot of the tablets at the same time, or you think a child may have swallowed any, contact your nearest hospital casualty department or tell your doctor immediately. Signs of an overdose include drowsiness, speech problems, jerky movements, jerky eye movements, loss of inhibition, reduced reflex response, low body temperature, low blood pressure and breathing problems.
If you forget to take the tablets
If you forget to take a dose, take it as soon as you remember it and then take the next dose at the right me. Do not take a double dose to make up for a forgotten dose. If you have any further questions on the use of this medicine, ask your doctor or pharmacist.
If you stop taking the tablets
If you stop taking the tablets you may develop withdrawal effects such as sleeplessness, anxiety, tremor, dizziness, feeling sick, fits and delirium.
4. POSSIBLE SIDE EFFECTS
Like all medicines, Phenobarbital Tablets can cause side effects, although not everybody gets them.
Tell your doctor if you notice any of the following side effects or notice any other effects not listed:
- Allergic reaction: fever, swelling of the face, lips, tongue or throat, difficulty breathing or swallowing, skin rashes.
- Blood: altered numbers and types of blood cells, if you notice increased bruising, nosebleeds, sore throats or infections, you should tell your doctor who may want to perform a blood test.
Muscle, bone and connective tissue: Problems with inflammation of tendons
(e.g. Dupuytren’s contracture of the hand, frozen shoulder), joint pain (arthralgia), bone softening and bone disease. There have been reports of bone disorders including osteopenia and osteoporosis (thinning of the bone) and fractures. Check with your doctor or pharmacist if you are on long-term antiepileptic medication, have a history of osteoporosis, or take steroids.
- Reproductive system: scar tissue formation in the penis that can cause various penis problems (Peyronie’s disease of the penis).
- Mental health: Restlessness and confusion in the elderly, unusual excitement, depression, memory impairment, hallucinations.
- Nervous system: hyperactivity, behavioural disturbances in children, jerky movements, jerky eye movements, drowsiness, lethargy.
- Heart: low blood pressure.
- Lungs: difficulty in breathing.
Liver: inflammation of the liver (hepatitis), damaged bile system (cholestasis).
Seen as yellowing of skin and whites of eyes.
- Kidneys: changes in the amount or need to pass water.
- Skin: rashes, erythema multiforme (circular, irregular red patches), lumps in the armpits or groin area. Potentially life-threatening skin rashes (Stevens Johnson syndrome-severe skin rash with flushing, fever, blisters or ulcers and toxic epidermal necrolysis-severe rash involving reddening, peeling and swelling of the skin that resembles severe burns) have been reported very rarely (See section 2).
Reporting side effects
If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App store. By reporting side effects you can help provide more information on the safety of this medicine.
5. HOW TO STORE PHENOBARBITAL TABLETS
Do not use Phenobarbital Tablets after the expiry date stated on the pack. The expiry date refers to the last day of that month.
KEEP THIS MEDICINE OUT OF THE SIGHT AND REACH OF CHILDREN.
Do not store above 25°C. Keep the container tightly closed. Store in the original container. Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.
6. CONTENTS OF THE PACK AND OTHER INFORMATION
What Phenobarbital Tablets contain
The active substance (the ingredient that makes the tablet work) is 30 mg or 60mg phenobarbital.
The other ingredients are maize starch, lactose monohydrate, sodium lauryl sulphate, sodium starch glycolate, magnesium stearate and stearic acid. The 60mg tablets also contain the colour sunset yellow E110.
What Phenobarbital Tablets looks like and the contents of the pack
Phenobarbital 30mg Tablets are white, circular tablets. Each tablet contains 30mg of phenobarbital, the active ingredient.
Phenobarbital 60mg Tablets are pale, orange, circular tablets.
Each tablet contains 60mg of phenobarbital, the active ingredient.
The tablets are available in packs of 28 and 1,000 tablets.
Not all pack sizes may be marketed.
Marketing Authorisation Holder and Manufacturer:
Relonchem Limited,
Cheshire House, Gorsey Lane,
Widnes, WA8 0RP, UK.
PL 20395/0112 and PL 20395/0113.
This leaflet was last revised in October 2019.