Method of alleviating pruritis

An improved method of relieving severe itching associated with conditions such as Hodgkin's Disease, mycosis fungoides, intractable pruritis and the like comprising administering an effective dosage of naloxone to a patient suffering from such itching.

BACKGROUND OF THE INVENTION 
Itching or pruritis is a common dermatologic symptom. The causes of 
pruritis are complex and poorly understood. The best understood mechanism 
of itching is the release of histamine in the skin leading to urticarial 
wheals and intense itching. Such itching has traditionally been relieved 
by antihistamines. While antihistamine therapy is often effective, the 
sedation and drowsiness produced by antihistaminic agents limits their 
effectiveness. 
Many kinds of itching are not however easily relieved by antihistamines. 
For example, conditions such as Hodgkin's Disease, mycosis fungoides and 
severe jaundice produce intense itching unrelieved by antihistamines. 
Therefore, there is a need for improved treatment to relieve severe 
itching which can be not only an alternative to antihistaminic treatment 
of itching which responds to such treatment, but which further provides 
relief in intractable cases of pruritis which heretofore have been 
virtually impossible to treat. The present invention provides such a 
method. 
Naloxone is a narcotic antagonist which is not known to cause physical or 
psychological dependence and which exhibits essentially no pharmacological 
activity in non-addicts. Naloxone is normally given by injection to 
addicts to assist them in narcotic withdrawal and sometimes is 
administered to post operative patients for partial reversal of narcotic 
depression following the use of narcotics during surgery. 
It has been found surprisingly that naloxone is useful in alleviating 
severe itching in various conditions. 
SUMMARY 
The present invention provides an improved method of treating severe 
itching comprising administering a therapeutically effective amount of 
naloxone or a pharmaceutically acceptable salt thereof to a mammalian 
patient in need of such treatment. 
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
Naloxone hydrochloride is commercially available from Endo Laboratories, 
Inc., a subsidiary of the DuPont Company, 1000 Stewart Avenue, Garden 
City, New York 11530. The preparation of naloxone is disclosed in U.S. 
Pat. No. 3,254,088. 
In the practice of this invention, naloxone is administered to patients 
suffering from severe itching in dosages of from 0.4 to 1000 milligrams, 
2-8 times a day. It has been found that subcutaneous administration to 
patients having intractable pruritis have an onset of action of 5 to 10 
minutes with a duration of action of from 2 to 3 hours. Oral 
administration of naloxone to patients with severe itching provides a 
delayed onset of action of about 20 minutes, but a more prolonged duration 
of action of roughly 5 hours. The following examples further illustrate 
the present invention.

EXAMPLE 1 
0.4 milligrams of naloxone hydrocholoride, obtained from the Endo 
Pharmaceutical Company, was administered to a 120 pound, 49 year old black 
patient suffering from intractable pruritis secondary to biliary 
cirrhosis. This patient received 2 injections of 0.4 mg. of naloxone, 3 
hours apart. The injections relieved the itching with an onset of action 
of 5 minutes and a duration of action of 120-180 minutes. 
EXAMPLE 2 
0.4 milligrams of naloxone hydrochloride, obtained from the Endo 
Pharmaceutical Company, was administered to a 150 pound, 55 year old white 
patient suffering from intractable pruritis secondary to uremia. The 
patient received 2 injections of 0.8 mg of naxolone, 3 hours apart. The 
injections relieved the itching with an onset of action of 5 minutes and a 
duration of action of 180 minutes. 
EXAMPLE 3 
400 milligrams of naloxone hydrochloride, obtained from the Endo 
Pharmaceutical Company, was administered subcutaneously to a 25 year old 
black patient weighing 180 pounds and suffering from a giant urticartia. 
The injection relieved itching 8 minutes and relief was obtained for 150 
minutes. 
EXAMPLE 4 
1 gram of naloxone, obtained from the Endo Pharmaceutical Co., was 
administered orally to a 70 year old white patient weighing 125 pounds 
suffering from severe itching. Relief from itching was obtained after 20 
minutes and relief from a single oral dose of 1 gram was provided for 300 
minutes. 
While naloxone is generally administered parenterally when used as a 
narcotic antagonist and is generally available commercially in parenteral 
dosage forms, it may be more desirable to treat the symptoms of pruritis 
by oral routes of administration, and the present invention also provides 
oral compositions suitable for treating the symptoms of pruritis. 
This the present invention includes within the scope thereof, 
pharmaceutical compositions suitable for oral administration comprising, 
as the active ingredient thereof, naloxone or a pharmaceutically 
acceptable salt thereof and a pharmaceutically acceptable carrier or 
diluent. 
Solid dosage forms for oral administration include capsules, tablets, 
pills, powders, and granules. In such solid dosage forms, the active 
compound is admixed with at least one inert diluent such as sucrose, 
lactose or starch. Such dosage forms can also comprise, as is normal 
practice, additional substances other than inert diluents, e.g. 
lubricating agents such as magnesium stearate. In the case of capsules, 
granules tablets and pills, the dosage forms may also comprise buffering 
agents. Tablets and pills can additionally be prepared with enteric 
coatings, if desired. 
Liquid dosage forms for oral administration include pharmaceutically 
acceptable emulsions, solutions, suspensions, syrups and elixirs 
containing inert diluents commonly used in the art, such as water. Besides 
such inert diluents, compositions can also include adjuvants such as 
wetting agents, emulsifying agents and suspending agents and sweetening, 
flavoring and performing agents. 
The following example further illustrates the present invention to 
exemplifying a pharmaceutical composition suitable for oral 
administration. 
EXAMPLE 5 
Tablets weighing one gram and having the following composition are 
formulated: 
______________________________________ 
Ingredient Mg. 
______________________________________ 
Naloxone Hydrochloride 
500 
Starch 450 
Colloidal Silica 47 
Magnesium Stearate 3 
______________________________________ 
The term pharmaceutically acceptable salts, as used herein, refers to the 
physiologically acceptable acid addition salts of naloxone such as the 
hydrochloride, hydrobromide, hydroiodide, acetate, valerate, oleate, etc. 
It will be apparent to those skilled in the art that only the preferred 
embodiments have been described by way of exemplification and that there 
are various modifications which fall within the scope of this invention.