Compositions of opioid antagonists and methods for treating conditions caused by the varicella-zoster virus therewith

1. A method for treating a vesicular eruption caused by the varicella-zoster virus, the method comprising topically administering to a subject in need thereof an effective amount of naltrexone or a pharmaceutically-acceptable salt thereof, wherein the naltrexone or the pharmaceutically-acceptable salt thereof is administered in the form of a pharmaceutical composition comprising:

a) the naltrexone or the pharmaceutically-acceptable salt thereof in an amount of about 0.1% to about 5% by weight of the pharmaceutical composition;

b) an emulsifying agent in an amount of about 2% to about 5% by weight of the pharmaceutical composition;

c) a stiffening agent in an amount of about 1% to about 45% by weight of the pharmaceutical composition;

d) a surfactant in an amount of about 0.5% to about 2.5% by weight of the pharmaceutical composition;

e) a preservative in an amount of about 0.01% to about 0.6% by weight of the pharmaceutical composition;

f) a humectant in an amount of about 1% to about 15% by weight of the pharmaceutical composition;

g) alkalizing or buffering agent in an amount of about 0.01% to about 3% by weight of the pharmaceutical composition;

h) an emollient in an amount of about 1% to about 50% by weight of the pharmaceutical composition; and

i) a solvent,

wherein the vesicular eruption regresses within 5 days of administration of the pharmaceutical composition.

2. The method of claim 1 , wherein the naltrexone or the pharmaceutically-acceptable salt thereof has less than about 10% by weight of other stereoisomers.

3. The method of claim 1 , wherein the naltrexone or the pharmaceutically-acceptable salt thereof has less than about 5% by weight of other stereoisomers.

4. The method of claim 1 , wherein the naltrexone or the pharmaceutically-acceptable salt thereof is present in an amount of about 0.5% to about 2% by weight of the pharmaceutical composition.

5. The method of claim 1 , wherein the naltrexone or the pharmaceutically-acceptable salt thereof is present in an amount of about 1% by weight of the pharmaceutical composition.

6. The method of claim 1 , wherein the pharmaceutical composition is in the form of a gel, cream, ointment, liquid, suspension, solution, emulsion, foam, or aerosol.

7. The method of claim 1 , wherein the pharmaceutical composition is administered to the subject by spreading or spraying the composition onto the affected area.

8. The method of claim 1 , wherein the naltrexone or the pharmaceutically-acceptable salt thereof is administered in a total daily dose of up to about 150 mg/cm 2 of skin.

9. The method of claim 1 , wherein the naltrexone or the pharmaceutically-acceptable salt thereof is administered in a total daily dose of about 10 mg/cm 2 to about 100 mg/cm 2 of skin.

10. The method of claim 1 , wherein the naltrexone or the pharmaceutically-acceptable salt thereof is administered in a total daily dose of about 50 mg/cm 2 of skin.

11. The method of claim 1 , wherein the pharmaceutical composition is administered 1, 2, 3, 4, or 5 times daily.

12. The method of claim 1 , further comprising administering to the subject one or more additional agents effective to treat the vesicular eruption.

13. The method of claim 12 , wherein the additional agent is acyclovir, valacyclovir, or famciclovir.

14. The method of claim 1 , wherein the administration blocks an opioid receptor in the subject.

15. The method of claim 14 , wherein the opioid receptor that is blocked is a mu (μ) opioid receptor.

16. The method of claim 14 , wherein the opioid receptor that is blocked is a delta (δ) opioid receptor.

17. The method of claim 14 , wherein the opioid receptor that is blocked is a kappa (κ) opioid receptor.

18. The method of claim 1 , wherein the method further comprises treating post-herpetic neuralgia caused by varicella-zoster virus in the subject.

19. The method of claim 1 , wherein a pain of the subject associated with the varicella-zoster virus regresses within 3 days of administration.

20. The method of claim 1 , wherein an itching of the subject associated with the varicella-zoster virus regresses within 3 days of administration.

21. The method of claim 1 , wherein a hyperesthesis of the subject associated with the varicella-zoster virus regresses within 3 days of administration.

22. The method of claim 1 , wherein an itching, pain, and hyperesthesis of the subject associated with the varicella-zoster virus regresses within 3 days of administration.

23. The method of claim 1 , wherein no additional treatment is required to treat the vesicular eruption.

24. The method of claim 1 , wherein the administration produces no side-effect in the subject.

25. The method of claim 1 , wherein the administration occurs daily.

26. The method of claim 1 , wherein the administration occurs three times daily.

27. The method of claim 1 , wherein the naltrexone or the pharmaceutically-acceptable salt thereof is administered in a total daily amount of about 1 g.

28. The method of claim 1 , wherein the pharmaceutical composition comprises:

a) the naltrexone or the pharmaceutically-acceptable salt thereof in an amount of about 0.5% to about 2% by weight of the pharmaceutical composition;

b) the emulsifying agent in an amount of about 2% to about 5% by weight of the pharmaceutical composition;

c) the stiffening agent in an amount of about 2% to about 5% by weight of the pharmaceutical composition;

d) the surfactant in an amount of about 0.5% to about 1.5% by weight of the pharmaceutical composition;

e) the preservative in an amount of about 0.01% to about 0.6% by weight of the pharmaceutical composition;

f) the humectant in an amount of about 2% to about 10% by weight of the pharmaceutical composition;

g) the alkalizing or buffering agent in an amount of about 0.01% to about 3% by weight of the pharmaceutical composition;

h) the emollient in an amount of about 15% to about 30% by weight of the pharmaceutical composition; and

i) the solvent.

29. The method of claim 1 , wherein the pharmaceutical composition comprises:

a) the naltrexone or the pharmaceutically-acceptable salt thereof in an amount of about 1% by weight of the pharmaceutical composition;

b) the emulsifying agent, wherein the emulsifying agent is cetyl alcohol in an amount of about 3.6% by weight of the pharmaceutical composition, and carboxypolymethylene in an amount of about 0.2% by weight of the pharmaceutical composition;

c) the stiffening agent in an amount of about 3.6% by weight of the pharmaceutical composition, wherein the stiffening agent is stearyl alcohol;

d) the surfactant in an amount of about 0.8% by weight of the pharmaceutical composition, wherein the surfactant is sodium lauryl sulfate;

e) the preservative, wherein the preservative is nipagin in an amount of about 0.1% by weight of the pharmaceutical composition, and nipasol in an amount of about 0.05% by weight of the pharmaceutical composition;

f) the humectant in an amount of about 5% by weight of the pharmaceutical composition, wherein the humectant is propylene glycol;

g) the alkalizing or buffering agent in an amount of about 0.03% by weight of the pharmaceutical composition, wherein the alkalizing or buffering agent is sodium hydroxide;

h) the emollient, wherein the emollient is white vaseline in an amount of about 13.5% by weight of the pharmaceutical composition, and liquid vaseline in an amount of about 5.4% by weight of the pharmaceutical composition; and

i) the solvent, wherein the solvent is water.