Drugs - Morphine reaction not related to CMT
Q: Gwen Thrower asks: I was wondering if anyone has been on MS-contin (morphine) for pain. I tried taking one 15mg pill last night and was up all night with headaches and extreme thirst. I was told that it would make me extremely tired but it had the opposite effect on me. When I got up in the morning my voice was raspy and I had trouble breathing. I immediately stopped and didn't take the morning one prescribed.
Dr. Gareth Parry answers: This paradoxical reaction occasionally occurs. Interestingly, cats predictably respond to morphine in this way. The reaction experienced is nothing to do with the CMT.

Drugs - Cancer and drugs
Question from Greta Lindsey: I have a support group located in Fort Worth, Texas. One of my members has been diagnosed with breast cancer and has had a mastectomy. She will see an oncologist soon and inquired about the list of medications that are not to be used because we have CMT. Do you know of any chemo drugs that we can take with our CMT and feel relatively safe with? Also what do the chemo drugs listed do to our CMT if used?
Dr. Parry answers: There are several chemotherapeutic agents on the list that are neurotoxic, including vincristine (and vinblastine), taxol and suramin, that should be avoided if possible. Adriomycin is neurotoxic in animals but does not seem to affect human nerves, although I usually suggest avoiding it if possible. The one that we have most experience with is vincristine that causes a marked deterioration. I am not aware of any CMT patient experiencing deterioration with the other drugs – it is mainly a theoretical risk. Of course this has to be balanced against the risk of not giving adequate chemotherapy. It does her no good if they sacrifice her life to save her nerves. However, it is usually possible to give a chemotherapeutic cocktail that is effective and yet does not include the neurotoxic agents.

Drugs - Phenytoin and seizures
Question from David Cairns: My wife has CMT Type 1, diagnosed via DNA analysis. My stepdaughter has been diagnosed by the same method. My wife recently had a grand-mal seizure, as a result of which she was diagnosed by CAT and MRI with a brain lesion. On removal by surgery last week, the lesion was found not to be a tumor or malignant, but scar tissue, possibly formed around an old infarct. We await further information.
My wife has been prescribed phenytoin to reduce the risk of a further seizure. There is information in the most recent CMT Newsletter we have received that phenytoin is contra-indicated for a person with CMT. Can you give me some more information on the phenytoin tieup? The CMT has been controllable and bearable up till now, with care and thought. If would be unfortunate if the phenytoin aggravated it.
Dr. Parry answers: The risk of phenytoin is largely theoretical. Patients who have been on phenytoin for a lifetime tend to show very mild features of neuropathy such as absent ankle reflexes and some subtle reduction of sensation in the feet. Because of this, it is generally recommended that CMT patients avoid it if possible. I am not aware of any documented evidence that CMT patients have ever deteriorated when started on phenytoin. Nonetheless, because of the theoretical risk and because there are equally effective alternative anti-epileptic drugs such as valproate and carbamazepine, I would generally avoid phenytoin in my CMT patients.