PHENOBARBITAL ACTIVASE 30 MG TABLETS - patient leaflet, side effects, dosage

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.

Phenobarbital Activase Tablets will be referred to as Phenobarbital Tablets throughout this leaflet.

What is in this leaflet

• 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

1. WHAT PHENOBARBITAL TABLETS ARE AND WHAT THEY ARE USED FOR

The name of your medicine is Phenobarbital Tablets. It contains the active ingredient Phenobarbital. Phenobarbital belongs to a group of medicines known as barbiturates.

This medicine reduces 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 if you:

• are allergic to the active substance, other barbiturates or any of the other ingredients of this medicine (listed in section 6)
• suffer from acute intermittent porphyria (a genetic or inherited disorder of the red blood pigment haemoglobin)
• suffer from severe difficulty breathing (respiratory depression)
• are suffering from severe liver and kidney problems.

Warnings and precautions

Talk to 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.

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.

Effects on laboratory tests

Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your body’s response to Phenobarbital Tablets.

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.

Other medicines and Phenobarbital Tablets

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines as they may interact with your Phenobarbital Tablets.

Examples of medicines that can affect Phenobarbital Tablets are:

• 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).

Phenobarbital Tablets with alcohol

Do not drink alcohol while you are taking Phenobarbital Tablets.

Pregnancy and breast-feeding

What you should know about the use of antiepileptic drugs in pregnancy

If you are pregnant, or think you may be pregnant, you must tell your doctor straight away and discuss possible risks the epilepsy medicine you are taking might pose to your unborn baby.

If you are planning to become pregnant you should discuss your epilepsy treatment with your doctor as early as possible before you become pregnant.

If you are breastfeeding or planning to breastfeed, ask your doctor or pharmacist for advice before taking this medicine

You should not stop your treatment without discussing this with your doctor. Suddenly stopping may lead to breakthrough seizures which may harm you and your unborn baby. It is important that your epilepsy is well controlled.

Taking phenobarbital during pregnancy increases the chance that the baby may have a physical birth abnormality. Studies with women treated with phenobarbital for epilepsy have shown that around 6–7 babies in every 100 will have serious physical birth abnormalities. This compares to 2–3 babies in every 100 born to women who don't have epilepsy.

The most common types of serious physical birth abnormalities (major congenital malformations) reported for phenobarbital include heart defects and, less commonly, cleft lip and palate defects.

Studies have found that the risk of physical birth abnormalities increases with increasing dose of phenobarbital. Therefore, your doctor will prescribe you the lowest effective dose. Taking more than one epilepsy medicine at the same time may also increase the risk of physical birth abnormalities. Where possible, your doctor will consider using one epilepsy medicine only to control your epilepsy.

Some studies observed that taking phenobarbital during pregnancy increases the chance that the baby may have problems affecting learning and thinking abilities.

Neurodevelopmental disorders (delays in development due to disorders in brain development) have been reported among children exposed to phenobarbital during pregnancy. Studies on the risk of neurodevelopmental disorders remain contradictory.

Babies born to mothers using phenobarbital during pregnancy may also be at increased risk of being smaller than expected.

Your doctor may advise you to take folic acid if you're planning to become pregnant and while you're pregnant. Your doctor may adjust your phenobarbital dose when you take folic acid. This is because folic acid supplements may affect your blood levels of phenobarbital.

Phenobarbital should not be used during pregnancy unless nothing else works for you.

If you have taken phenobarbital during the last third of the pregnancy, appropriate monitoring should be conducted to detect potential disorders in the newborn, such as seizures, excessive crying, muscle weakness, sucking disorders.

Woman of child-bearing potential/Con­traception

If you are a woman of childbearing age you should use effective contraception during treatment with phenobarbital and for two months after treatment. Phenobarbital may affect how hormonal contraceptives, such as the contraceptive pill, work and make them less effective at preventing pregnancy. Talk to your doctor, who will discuss with you the most suitable type of contraception to use while you are taking phenobarbital.

If you are a woman of childbearing age and are planning a pregnancy, talk to your doctor before you stop contraception and before you become pregnant about switching to other suitable treatments in order to avoid exposing the unborn baby to phenobarbital.

Breast-feeding

As phenobarbital is released into breast milk this may make your baby sleepy and therefore breast feeding is not advisable.

Driving and using machines

Phenobarbital Tablets may make you drowsy or affect your concentration. Do not drive or use any tools or machines if you are affected in this way and do not drink alcohol, as this will make these effects worse.

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.

3. how to take phenobarbital tablets

Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure.

The number of tablets you will take will depend on what you are taking the tablets for. Your doctor will probably start you on a low dose of Phenobarbital Tablets and gradually increase your dose. You should swallow the tablets whole with a glass of water. You are advised not to drink alcohol , check with your doctor if you have any questions.

The recommended dose is:

Adults: The usual dose is 60 to 180 mg daily, taken at night.

Children: If this medicine is prescribed for a child make sure that the tablets are taken as stated on the pharmacist’s label. The usual dose is 5 to 8 mg per kg of bodyweight per day.

Elderly: Your doctor may prescribe a lower dose.

If you take more Phenobarbital Tablets than you should

You should contact your doctor or nearest hospital emergency department immediately. Take the pack and remaining tablets with you. 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 Phenobarbital Tablets

If you forget to take a dose, take it as soon as you remember unless it is almost time for your next dose. Do not take a double dose to make up for a forgotten dose.

If you stop taking Phenobarbital Tablets

Do not stop taking Phenobarbital Tablets without talking to your doctor. It may take a few weeks or longer before you feel the full benefit of Phenobarbital Tablets. Continue to take Phenobarbital Tablets even if you feel well. 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, this medicine can cause side effects, although not everybody gets them.

Very serious side effects - If any of the following happens, stop taking Phenobarbital Tablets and tell your doctor immediately or go to the nearest hospital emergency department:

• Rare allergic reactions with symptoms such as difficulty breathing, swelling of your face, throat or tongue, skin rash, itching, hives, blisters, or a scaly skin.
• 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.
• Inflammation of the liver (hepatitis), damaged bile system (cholestasis). Seen as yellowing of skin and whites of eyes.
• 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).

If you experience any of the following side effects, please tell your doctor or pharmacist.

• 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.
• 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.

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 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

Keep this medicine out of the sight and reach of children.

Do not use this medicine after the expiry date which is stated on the pack. The expiry date refers to the last day of that month.

Do not store above 25°C. Store in the original container. Keep the container tightly closed.

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 is phenobarbital. Each tablet contains 30 mg phenobarbital.

The other ingredients are Maize Starch, Lactose Monohydrate, Sodium Lauryl Sulfate, Sodium Starch Glycolate (Type A), Magnesium Stearate and Stearic Acid.

What Phenobarbital Tablets look like and contents of the pack

Phenobarbital Tablets are white, circular tablets.

They are available in packs of 28 and 1000 tablets. Not all pack sizes may be marketed.

Marketing Authorisation Holder

Activase Pharmaceuticals Limited, 11 Boumpoulinas, 3rd Floor, P.C. 1060 Nicosia, Cy­prus

Manufacturer

LPC Medical (UK) Limited, 30 Chaul End Lane, Luton, Bedfordshire, LU4 8EZ, U.K.

This leaflet was last revised in 08/2021.