Posted by ed_uk on November 22, 2004, at 10:38:24
In reply to Re: Best choice SP med in the UK? MAOIs?, posted by jclint on November 22, 2004, at 10:05:34
To John,
I wouldn't worry too much about the restrictions that an MAOI may bring. They're unlikely to be as bad as the restrictions that SP brings! As far as the sexual side effects go, if you did get them on Nardil you could always try Parnate instead. I don't think that you should let this get in the way of trying a potentially effective treatment.
Info..........
Nardil=phenelzine
Parnate=tranylcypromine
Manerix=moclobemide
Hypotension=low blood pressure
Hypertension=high BP
Syncope=fainting (you probably know all this anyway but I decided to mention it anyway just in case you didn't, please don't be offended!!!)Monoamine oxidase inhibitors (MAOIs) + Tyramine-rich drinks
Patients taking the older MAOI (tranylcypromine, phenelzine, nialamide, pargyline, etc.) can suffer a serious hypertensive reaction if they drink some tyramine-rich drinks (some beers, lagers or wines), but no serious interaction is likely with the newer reversible and selective MAOIs (moclobemide, etc.). The hypotensive side-effects of the MAOIs may be exaggerated in a few patients by alcohol and they may experience dizziness and faintness after drinking relatively modest amounts.
Clinical evidence, mechanism, importance and management
(a) Hypertensive reactions
A severe and potentially life-threatening hypertensive reaction can occur in patients on MAOIs if they take alcoholic drinks containing significant amounts of tyramine. A dose of 10–25 mg tyramine is believed to be required before a serious rise in blood pressure takes place.Remember: All alcoholic drinks are the end-product of a biological fermentation process and no two batches are ever absolutely identical. For example there may be a 50-fold difference even between wines from the same grape stock. There is no way of knowing for certain the tyramine-content of a particular drink without a detailed analysis.
(i) Ales, Beers and Lagers
Some ales, beers and lagers in ‘social’ amounts contain enough tyramine to reach the 10–25 mg threshold dosage, for example a litre (a little under two pints) of some samples of Canadian ale or beer. A man on phenelzine developed a typical hypertensive reaction after drinking only 15 oz. (a little less than 0.5 L) of Upper Canada lager beer on tap (containing about 45 mg tyramine/l). Alcohol-free beer and lager may have a tyramine-content which is equal to ordinary beer and lager. One patient on tranylcypromine suffered an acute cerebral haemorrhage after drinking a de-alcoholised Irish beer, and hypertensive reactions occurred in four other patients after drinking no more than 375 ml (⅔ pint) of alcohol-free beer or lager. A very extensive study of 79 different brands of beer (from Canada, England, France, Holland, Ireland, Scotland, USA) found that the tyramine content of the bottled and canned beers examined was generally too low to matter (<10 mg/l), but four beers (all identified as being on tap) contained more than enough tyramine (26–112 mg/l) to cause a hypertensive reaction. It was concluded in this report that the consumption of canned or bottled beer, including de-alcoholised beer, in moderation (fewer than four bottles, 1.5 L in a four-hour period) was safe, but ales, beers and lagers on tap should be avoided. However the safety of all de-alcoholised beers is clearly still uncertain.(ii) Spirits
Gin, whiskey, vodka and other spirits do not contain significant amounts of tyramine because they are distilled and the volumes drunk are relatively small. There seem to be no reports of hypertensive reactions in patients taking MAOIs after drinking spirits and none would be expected.(iii) Wines
In the context of adverse interactions with MAOIs, Chianti has developed a sinister reputation because 400 ml of one early sample of Italian Chianti wine contained enough tyramine to reach the 10–25 mg threshold dosage. However, it is claimed by the Chianti producers and others that the newer methods which have replaced the ancient ‘governo alla toscana’ process result in negligible amounts of tyramine in today’s Chianti. This seems to be borne out by the results of recent analyses two of which failed to find any tyramine at all in some samples. In conclusion, small or moderate amounts (1–2 glasses) are unlikely to be hazardous.(b) Hypotensive reactions
Some degree of hypotension can occur in patients on MAOIs (therapeutically exploited in the case of pargyline) and this may be exaggerated by the vasodilation and reduced cardiac output caused by alcohol. Patients should therefore be warned of the possibility of orthostatic hypotension and syncope if they drink. They should be advised not to stand up too quickly, and to remain sitting or lying if they feel faint or begin to ‘black out’.(c) Other reactions
In addition to the hypertensive and hypotensive reactions described in (a) and (b), the possibility that the alcohol-induced deterioration in psychomotor skills (i.e. those associated with safe driving) might be increased by the MAOIs has also been studied. Moclobemide appears to have only a minor and clinically unimportant effect and brofaromine and befloxatone do not interact with alcohol.Regards,
Ed
poster:ed_uk
thread:418891
URL: http://www.dr-bob.org/babble/20041118/msgs/418935.html