1. Use of phanquinone for the manufacture of a pharmaceutical composition for the treatment or prevention of Alzheimer's disease. 2. Use of phanquinone and a compound, or a mixture of compounds, selected from the group comprising antioxidants, acetylcholine enhancers, trace metals, prosthetic groups and clioquinol, for the manufacture of a pharmaceutical composition for the treatment or prevention of Alzheimer's disease. 3. Use according to Claim 2, wherein the antioxidant is vitamin C, vitamin E, Q10, or a combination thereof. 4. Use according to Claim 2 or 3, wherein the acetylcholine enhancer is donepezil or tacrine. 5. Use according to Claim 2, 3, or 4, wherein prosthetic group is vitamin B12. 6. Use according to any of Claims 2-5, wherein phanquinone is used for the manufacture of a pharmaceutical composition in combination with clioquinol. 7. Use according to any of Claims 2-6, wherein phanquinone is used for the manufacture of a pharmaceutical composition in combination with clioquinol and. vitamin B12. 8. Use according to any of Claims 1-7 for the manufacture of a pharmaceutical composition formulated for oral, parenteral or intradermal administration. 9. Use according to any of Claims 1-7 for the manufacture of a pharmaceutical composition formulated as a single pharmaceutical entity. 10. Use according to any of Claims 2-7 for the manufacture of a pharmaceutical composition formulated as two or more separate pharmaceutical entities for sequential or substantially simultaneous administration. 11. A pharmaceutical composition comprising (a) an amount of phanquinone effective to treat or prevent Alzheimer's disease, and (b) an amount of a compound or a mixture of compounds selected from the group comprising antioxidants, acetylcholine enhancers, trace metals, prosthetic groups and clioquinol, with proviso that when clioquinol is selected then at least vitamin B12.is also selected from the group. 12. A pharmaceutical composition according to Claims 11, wherein the antioxidant is selected from the group comprising vitamin C, vitamin E, coenzyme Q10, or combinations thereof. 13. A pharmaceutical composition according to Claim 11, wherein the acetylcholine enhancer is donepezil or tacrine. 14. A pharmaceutical composition according to Claim 11, wherein prosthetic group is vitamin B12. 15. A pharmaceutical composition comprising (a) an amount of phanquinone effective to treat or prevent Alzheimer's disease, and (b) mixture of clioquinol and vitamin B12. 16. A pharmaceutical composition according to any of the Claims 11 or 15, which further comprises a pharmaceutical acceptable carrier. 17. A pharmaceutical composition according to any of the Claims 11, 15 or 16, wherein the amount of phanquinone is 5 to 250 mg, preferably, 10 mg to 50 mg per single entity. 18. A pharmaceutical composition according to any of the Claims 11, 15 or 16, wherein the amount of clioquinol is 5 to 250 mg, preferably, 10 mg to 50 mg per single entity. 19. A pharmaceutical composition according to any of the Claims 15 or 16, wherein the amount of vitamin B12 is 5 μg to 2 mg, preferably, 0.5 mg to 1 mg per single entity. 20. A pharmaceutical composition according to any of Claims 11, 15 or 16 formulated for oral administration, parenteral administration or intradermal administration. 21. A pharmaceutical composition according to Claim 11, 15 or 16, wherein the composition is formulated as a tablet. 22. A pharmaceutical composition according to Claim 11, 15 or 16, wherein clioquinol and vitamin B12 are formulated separately, phanquinone being prepared together with clioquinol, vitamin B12 or separately. 23. A kit comprising in one or more containers an amount of phanquinone and clioquinol effective to treat or prevent Alzheimer's disease, and an amount of vitamin B12 effective to inhibit a detrimental side effect of clioquinol administration.