Anticonvulsant / Sedative  ·  Barbiturate

Phenobarbitone (Phenobarbital)

Also known as: Luminal, Phenobarb, Gardenal

One of the oldest and most accessible anticonvulsants in the world, available from dispensary level in Kenya, and the most affordable epilepsy medicine in the country.

ATC CodeN03AA02
Kenya EML 2023Listed
Level of UseLevel 2-6
This is health education, not medical advice. Never start, stop, or change a medication without speaking to a qualified healthcare professional first.
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Controlled Medicine

Phenobarbitone is a controlled substance in Kenya under the Narcotic Drugs and Psychotropic Substances Act. It requires a prescription and is subject to strict dispensing regulations.

Which conditions is Phenobarbitone (Phenobarbital) used for?

What is Phenobarbitone (Phenobarbital)?

Phenobarbitone (also called phenobarbital) is a barbiturate anticonvulsant that has been used to treat epilepsy since 1912. Despite its age, it remains one of the most widely used anticonvulsants globally, primarily because it is highly effective, extremely affordable, and available in even the most resource-limited settings.

It is listed in Kenya's Essential Medicines List 2023 at Level 2 (dispensary level), the most accessible level in the health system. This makes it the only anticonvulsant reachable in areas with no pharmacy or clinic beyond a dispensary.

Its psychiatric use has largely been replaced by benzodiazepines, but its role in epilepsy remains important, particularly in primary care settings across Kenya.

What does it do in the brain?

Phenobarbitone enhances the effect of GABA at GABA-A receptors and also directly suppresses nerve cell excitability. Together these actions raise the threshold at which seizures begin, making abnormal electrical discharges in the brain less likely to propagate into a full seizure.

How is it available?

Tablet
15 mg, 30 mg, 60 mg, 100 mg
Taken by mouth
Widely available from Level 2 upwards
Injection
200 mg/mL
IV/IM, hospital use only
Available at hospital level

Where is it available in Africa and what is it called?

Names and availability vary by country. Always confirm with a local pharmacist or healthcare provider.
CountryCommon Brand Name(s)Notes
UgandaPhenobarbitone (generic), LuminalOn the Uganda EML from health centre level; one of the most prescribed anticonvulsants in the country.
TanzaniaPhenobarbitone (generic)On the Tanzania EML from dispensary level; backbone of epilepsy treatment in primary care.
EthiopiaPhenobarbitone (generic)Extremely widely available; key to the national epilepsy programme and used in task-shifted care.
RwandaPhenobarbitone (generic)Available from community health level; used extensively in the community mental health programme.
South AfricaPhenobarbitone (generic)Available in public sector for epilepsy; still used in specific situations.
NigeriaPhenobarb, Phenobarbitone (generic)Widely available at all government health facilities; most affordable anticonvulsant in Nigeria.
GhanaPhenobarbitone (generic)On the Ghana EML from community level; essential for epilepsy care in rural areas.
ZambiaPhenobarbitone (generic)On the Zambia EML; widely available at district hospitals and health centres.

What might you feel while taking it?

These are the most commonly reported effects. Not everyone experiences them, and many settle within the first few weeks.

  • Sedation and drowsiness, most pronounced at the start, often improves with time
  • Cognitive slowing, particularly affecting concentration and memory
  • Hyperactivity and behavioural problems in children (paradoxical effect)
  • Low mood or depressive symptoms
  • Dizziness and coordination problems at higher levels
  • Skin rash, mild rashes are common; serious rashes require immediate review
Go to a doctor or emergency room straight away if you notice any of the following.
  • Severe skin reaction (Stevens-Johnson Syndrome), any new rash must be reviewed promptly
  • Significant cognitive and behavioural effects in children, monitor school performance and behaviour closely
  • Dependence and withdrawal, abrupt stopping can cause severe seizures
  • Liver and blood disorders with long-term use

Important warnings before starting

Tell your doctor about all your medical conditions, allergies, and other medicines before starting Phenobarbitone (Phenobarbital).
  • Acute porphyria
  • Severe respiratory insufficiency
  • Known allergy to barbiturates

Situations that need extra attention

  • Never stop phenobarbitone suddenly, severe seizures or status epilepticus can result
  • Cognitive and behavioural effects in children should be monitored closely
  • Tell your doctor about all other medicines, phenobarbitone affects many other drugs including HIV medicines and the oral contraceptive pill
  • Women of reproductive age: use effective contraception as the OCP may be less effective
  • Elderly patients are particularly sensitive to sedative and cognitive effects
Pregnancy
Associated with increased risk of fetal abnormalities. High-dose folic acid is required if treatment must continue. Never stop phenobarbitone in pregnancy without medical guidance, as uncontrolled seizures carry their own serious risks.
Breastfeeding
Passes into breast milk and can cause infant sedation. Specialist guidance is needed. Not always contraindicated but requires close monitoring of the infant.

Medicines and substances that can interact with it

Always tell your doctor and pharmacist about every medicine, supplement, and herbal remedy you take, including those bought without a prescription.
  • Antiretroviral medicines for HIV: Phenobarbitone strongly induces liver enzymes and significantly reduces ARV levels, risking treatment failure. Must be reviewed carefully.
  • Oral contraceptive pill: Significantly reduced contraceptive effectiveness. Women must use alternative or additional contraception.
  • Valproate: Valproate increases phenobarbitone levels, monitor for increased sedation.
  • Alcohol and sedating medicines: Dangerous amplification of sedation. Avoid alcohol.
  • Warfarin: Phenobarbitone reduces warfarin effectiveness. Close monitoring of clotting is required if both are used.

What your doctor will monitor

  • Blood phenobarbitone levels checked when seizure control is uncertain or toxicity is suspected
  • Liver function tests annually in long-term users
  • Full blood count annually
  • Cognitive and behavioural assessment in children at every appointment
  • Bone density may decrease over many years of use, calcium and vitamin D should be discussed for long-term users

What happens if you stop taking it?

Never stop phenobarbitone abruptly. Abrupt withdrawal causes dangerous rebound seizures that can be life-threatening. Any reduction must be done very gradually over months, under close medical supervision.

What you should know about this medicine in Kenya

Phenobarbitone is the most accessible and affordable anticonvulsant in Kenya, available from dispensary level. For many Kenyans with epilepsy living far from hospitals and specialists, it is the only anticonvulsant available.

Kenya has made progress in reducing the epilepsy treatment gap, and phenobarbitone plays a central role in this. It is a component of task-shifted epilepsy care delivered by community health workers and nurses in many counties.

The interaction with antiretrovirals is an important consideration in Kenya given the high HIV prevalence. Where a person has both epilepsy and HIV, the choice of anticonvulsant should be discussed with both the treating physician and the HIV care team.

References

  1. Ministry of Health, Kenya. (2023). Kenya Essential Medicines List 2023. Nairobi: Ministry of Health.
  2. Ministry of Health, Kenya. (2023). Kenya National Medicines Formulary, 1st Edition. Nairobi: Ministry of Health.
  3. World Health Organization. (2023). Model List of Essential Medicines, 23rd Edition. Geneva: WHO.
  4. Mbuba, C. K., et al. (2008). The epilepsy treatment gap in developing countries. Epilepsia, 49(9), 1491-1503.