Phenobarbital, the world's oldest epilepsy drug, has fallen out of favour in the last decade or so. In the UK doctors have been forbidden to prescribe it because of its toxic effects, so now it's just given to our dogs - and to the people in the developing world. These poor people must have a completely different bio-chemical makeup to us, judging by the number of discredited drugs that are still freely available there.
Not that concerns about toxic effects have ever been a legitimate reason for a drug company to stop pushing a drug. In the case of phenobarbital, there's just not enough money in it, and they have plenty of newer drugs not yet out of patent that are making serious contributions to the bottom line.
Despite these seemingly impassable barriers, there's pressure within medicine to get the drug re-established into the front line of epilepsy care. Doctors say the drug has been unfairly damned, and that it has 'many favourable features'. It's good for a wide range of seizure types, it has a low starting dose, it's as effective as modern drugs, and low levels of the drug can stay in the body for long periods. And it's cheap.
Of course it's the last point that will ensure it won't be making a reappearance at an out-patient unit near you. Never mind that the side effects read like a horror show that prompted even the UK's sleepy drug watchdogs to act. Drowsiness, depression and vomiting are very common side effects, but you're also likely to get nightmares, constipation and joint pains, and if you're unlucky you might also get seizures, unusual bleeding, fever and severe skin rash. Oh yes, and if you drink alcohol, there's a good chance you will die. The drug is 'poorly tolerated' among young people, which is drug-speak for saying that they shouldn't come within five miles of it, and coming off the drug is the real problem.
Not that any of the approved epilepsy drugs is a day at the beach, and we have records of a number of deaths of people while taking one of the more recent anti-epileptics.
And here's the real mystery. Why is the World Health Organization actively promoting a drug to the developing world that the UK authorities have banned?
All in all, perhaps we should let sleeping dogs lie - which reminds us that it might be a good idea to stop prescribing the wretched thing to our dogs as well.
(Source: British Medical Journal, 2004; 329: 1199-1200).