Neuralgia drugs
Maree's condition
Maree hasn't been back to hospital again since her last spell in mid-May, and during all of this time she has been in much improved condition. She is not back to her normal self and able to do everything, but the pain has been kept to a dramatically better level since she started on the new drug regime.
In July and August she had two visits to a pain management clinic, and the specialists are in agreement with the neuralgia diagnosis from the neurologist (who Maree has been seeing regularly since February). The general consensus seems to be that Maree has a variant of trigeminal neuralgia. The best classification of facial pain at the moment was published by Oregon Health & Science University in 2004, and Maree has either "Trigeminal Neuralgia, Type 2" (TN2) or "Trigeminal neuropathic pain" (TNP).
The drugs that make a difference
Maree has now been taking Gabapentin (Neurontin) since her hospital spell in late February, and it has been quite effective at managing her nerve-based (neuropathic) pain during the day. The other key drug is Carbamazepine (Tegretol), which has been extremely effective at dealing with the pain overnight. Both of these are anti-convulsant drugs, and are primarily used to treat either epilepsy or neuropathic pain. Tegretol has been around for decades and is a subsidised medicine in Australia, however Gabapentin is much newer and is only subsidised for epilepsy. Maree is currently on quite high doses of Gabapentin which makes for an expensive drug habit, even though there are now generic versions of Gabapentin on the market.
The Wikipedia article on Gabapentin discusses some of the controversy that has surrounded this drug in the US, where the drug company has paid a huge fine - and there are still ongoing law suits. Gabapentin has only been approved for use in a small number of conditions, however it was apparently being heavily promoted for several other purposes as well - and marketing of unapproved (off-label) uses is illegal.
As of yesterday (12 Aug) Maree has been started on a new drug in place of Gabapentin, which is called Pregabalin (Lyrica). Once again there is no subsidy except for epilepsy, however it seems that it can often be as effective as Gabapentin in much lower doses. It works in much the same way as Gabapentin and is from the same drug company (Pfizer). In Australia, Pregabalin was approved for the treatment of neuropathic pain in February 2005.
Commercially this new drug looks like a very good thing for Pfizer, since they might be able to switch most of the sales from their Gabapentin blockbuster to Pregabalin instead of losing them all to generics. On the other hand, their ability to pull a new improved drug out of the hat at just the right time does seem overly convenient. They've also been playing the patent game aggressively; the main Gabapentin patents expired in 1998 and 2001 but in about 2000 they registered a patent on the production process so that generics couldn't be produced until 2014.
During the course of this illness Maree has also consistently been taking some anti-inflammatory drugs, primarily some of the current non-steroidal types (NSAIDs). Since February she has been taking Meloxicam (Mobic), which is a COX-2 inhibitor NSAID. This isn't at all effective on the main neuropathic pain, however it's still an important part of the drug regime. Maree stopped taking it for about 5 days in July, and it was very clear that there is another strong facial pain that is only blocked well by the Meloxicam.
Maree also had short spells with a range of other anti-inflammatory drugs, with the most interesting being Etoricoxib (Arcoxia). Maree was given a high dosage of Etoricoxib during some of the first few weeks of her illness; it was provided by a GP in New Zealand as a drug company sample. Etoricoxib is not approved in US or Australia yet; I gather that it's extremely similar chemically to Rofecoxib - the infamous Vioxx.
Maree hasn't been back to hospital again since her last spell in mid-May, and during all of this time she has been in much improved condition. She is not back to her normal self and able to do everything, but the pain has been kept to a dramatically better level since she started on the new drug regime.
In July and August she had two visits to a pain management clinic, and the specialists are in agreement with the neuralgia diagnosis from the neurologist (who Maree has been seeing regularly since February). The general consensus seems to be that Maree has a variant of trigeminal neuralgia. The best classification of facial pain at the moment was published by Oregon Health & Science University in 2004, and Maree has either "Trigeminal Neuralgia, Type 2" (TN2) or "Trigeminal neuropathic pain" (TNP).
The drugs that make a difference
Maree has now been taking Gabapentin (Neurontin) since her hospital spell in late February, and it has been quite effective at managing her nerve-based (neuropathic) pain during the day. The other key drug is Carbamazepine (Tegretol), which has been extremely effective at dealing with the pain overnight. Both of these are anti-convulsant drugs, and are primarily used to treat either epilepsy or neuropathic pain. Tegretol has been around for decades and is a subsidised medicine in Australia, however Gabapentin is much newer and is only subsidised for epilepsy. Maree is currently on quite high doses of Gabapentin which makes for an expensive drug habit, even though there are now generic versions of Gabapentin on the market.
The Wikipedia article on Gabapentin discusses some of the controversy that has surrounded this drug in the US, where the drug company has paid a huge fine - and there are still ongoing law suits. Gabapentin has only been approved for use in a small number of conditions, however it was apparently being heavily promoted for several other purposes as well - and marketing of unapproved (off-label) uses is illegal.
As of yesterday (12 Aug) Maree has been started on a new drug in place of Gabapentin, which is called Pregabalin (Lyrica). Once again there is no subsidy except for epilepsy, however it seems that it can often be as effective as Gabapentin in much lower doses. It works in much the same way as Gabapentin and is from the same drug company (Pfizer). In Australia, Pregabalin was approved for the treatment of neuropathic pain in February 2005.
Commercially this new drug looks like a very good thing for Pfizer, since they might be able to switch most of the sales from their Gabapentin blockbuster to Pregabalin instead of losing them all to generics. On the other hand, their ability to pull a new improved drug out of the hat at just the right time does seem overly convenient. They've also been playing the patent game aggressively; the main Gabapentin patents expired in 1998 and 2001 but in about 2000 they registered a patent on the production process so that generics couldn't be produced until 2014.
During the course of this illness Maree has also consistently been taking some anti-inflammatory drugs, primarily some of the current non-steroidal types (NSAIDs). Since February she has been taking Meloxicam (Mobic), which is a COX-2 inhibitor NSAID. This isn't at all effective on the main neuropathic pain, however it's still an important part of the drug regime. Maree stopped taking it for about 5 days in July, and it was very clear that there is another strong facial pain that is only blocked well by the Meloxicam.
Maree also had short spells with a range of other anti-inflammatory drugs, with the most interesting being Etoricoxib (Arcoxia). Maree was given a high dosage of Etoricoxib during some of the first few weeks of her illness; it was provided by a GP in New Zealand as a drug company sample. Etoricoxib is not approved in US or Australia yet; I gather that it's extremely similar chemically to Rofecoxib - the infamous Vioxx.
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