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Active substance(s): PHENOBARBITAL

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PHENOBARBITAL 30mg and 60mg Tablets
Read all of this leaflet carefully before you start taking this medicine because it contains
important information for you.
 Keep this leaflet. You may need to read it again.
 If you have any further questions, ask your doctor or pharmacist.
 This medicine has been prescribed for you only. Do not pass it on to others. It may

harm them, even if their signs of illness are the same as yours.
If you get any side effects, talk to your doctor or pharmacist. This includes any
possible side effects not listed in this leaflet. See section 4.

1. What Phenobarbital tablets are and what they are used for
2. What you need to know before you take Phenobarbital Tablets
3. How to take Phenobarbital Tablets
4. Possible side effects
5. How to store Phenobarbital Tablets
6. Contents of the pack and other information
Phenobarbital belongs to a group of medicines called barbiturates.
These medicines reduce brain activity which would otherwise cause fits or seizures in
epilepsy, except nascence seizures (day dreaming).
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
 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,
Itraconazole, posaconazole, voriconazole, abacavir,
amprenavir, Iopinavir, indinavir, darunavir, nelfinavir and saquinavir (to treat
Medicines used to thin the blood such as warfarin
Mianserin, paroxetine, MAOI or tricyclic antidepressants or St John’s Wort
(Hypericum perforatum) a herbal remedy (to treat depression)
Oxcarbazepine, primidone, phenytoin, sodium valproate, carbamazepine,
lamotrigine, tiagabine, zonisamide, ethosuxamide and vigabatrin (to treat
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
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 contains Lactose
Phenobarbital Tablets contains 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.

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.
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 time. Do not take a double dose to make up for a forgotten
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.
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.
 Metabolism and nutrition: 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.

Mental health: Restlessness and confusion in the elderly, unusual
excitement, depression, memory impairment, hallucinations.
Nervous system: hyperactivity, behavioural disturbances in children, jerky
movements, drowsiness, lethargy.
Heart: low blood pressure.
Lungs: difficulty 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 (StevensJohnson 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 By reporting side
effects you can help provide more information on the safety of this medicine.
Do not use Phenobarbital Tablets after the expiry date stated on the pack. The expiry
date refers to the last day of that month.
Do not store above 25°C. Keep the container tightly closed. Store in the original
container. Medicines should not be disposed of via wastewater or household waste.
Ask your pharmacist how to dispose of medicines no longer required. These
measures will help to protect the environment.
What Phenobarbital tablets contains
The active substance (the ingredient that makes the tablet work) is 30 mg or 60mg
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
Marketing Authorisation Holder
Relonchem Limited, Cheshire House, Gorsey Lane, Widnes, WA8 0RP, UK.
PL 20395/0112 and PL 20395/0113
This leaflet was last revised in April 2017.

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